Double-strand synchronous low-stress twisted double parallel twist crane wire rope and its manufacturing process

Abstract

This invention relates to the field of wire rope production technology, specifically to a double-parallel twist crane wire rope and its production process using a double-strand synchronous low-stress twisting method. The wire rope body has a 9-strand parallel twist structure, designated 3X40SF / 3X24F-3X7, comprising: an inner layer of 3 strands with a 3X7 structure twisted in an S-direction parallel twist; and an outer layer of 6 strands twisted in an S-direction parallel twist, with 3 strands having a 3X40SF structure and 3 strands having a 3X24F structure. The inner and outer layers are joined together using a Z-direction parallel twist. The wire rope body is prepared using a pre-tensioned tubular double-parallel twisting process. This invention, through a pre-tensioned tubular double-parallel twisting device, applies a constant and precise online pre-tension force simultaneously during the twisting process, forcing the wire to undergo lattice slip and dislocation reorganization during plastic deformation. This significantly eliminates residual stress generated during twisting and forging, solving the problems of low efficiency and uneven results associated with traditional offline pre-tensioning.

Description

Technical Field

[0001] This invention relates to the field of wire rope production technology, specifically to a double-parallel twist crane wire rope with double-strand synchronous low-stress twisting and its production process. Background Technology

[0002] Steel wire ropes, as key load-bearing components, are widely used in mining, construction, marine engineering, and oil drilling. Among them, steel wire ropes for oil drilling are considered high-end products due to their extreme working conditions and extremely high safety requirements. As global oil and gas resource extraction moves towards deeper, ultra-deeper, and more complex formations, the drilling depth capability of oil drilling rigs has generally increased from 3,000 meters in the early days to over 5,000 meters, and even reaching 12,000 meters. This increase in well depth leads to extremely harsh working conditions for drilling steel wire ropes, placing unprecedentedly stringent requirements on their performance.

[0003] In oil drilling operations, wire ropes are connected to a complex pulley system via overhead cranes and traveling blocks, and are wound in multiple layers on a drum. Their working process can be summarized as follows: while bearing enormous tensile force, they are repeatedly bent on multiple pulleys and subjected to intense compression between the layers of the drum. This combined stress state leads to the main failure modes of the wire rope being repeated bending fatigue failure, wear, and localized plastic deformation and wire breakage caused by contact stress. Specifically, existing wire ropes used in oil drilling typically face the following contradictions and technical problems: The contradiction between ultra-high strength and high toughness / long fatigue life. To increase drilling depth and hoisting efficiency, wire ropes are required to have higher breaking strength (typically reaching 1960 MPa or higher), which means using higher strength wires. However, increased wire strength is often accompanied by decreased plasticity and toughness, leading to deterioration of the wire rope's bending fatigue performance, making it unable to meet the requirements of long-duration, high-cycle operations in deep well drilling. In drilling operations, the safety factor of wire ropes is typically only 3, resulting in high tensile forces and severe fatigue failure.

[0004] Secondly, cleaning the surface of the rope after oiling or lubrication is a common process in wire rope manufacturing to remove excess oil and dirt to meet requirements for appearance, storage, feel, or subsequent processing. Existing techniques mainly include physical scraping, chemical cleaning, high-pressure media rinsing, and manual wiping; however, these methods generally suffer from incomplete cleaning, residue buildup, and difficulty in removal. Summary of the Invention

[0005] The purpose of this invention is to provide a double-strand synchronous low-stress twisted double parallel twist crane wire rope and its manufacturing process, so as to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a double-strand synchronous low-stress twisted double parallel twist crane wire rope and its manufacturing process, wherein the wire rope body has a 9-strand parallel twist structure, its structural designation is 3X40SF / 3X24F-3X7, including: An inner layer consisting of three strands twisted in parallel in the S direction, with a 3x7 structure. An outer layer is made of 6 strands of rope twisted in parallel in the S direction, of which 3 strands are 3X40SF and 3 strands are 3X24F. The inner and outer layers are twisted together in a parallel Z-direction twisting manner; The wire rope body is prepared using a pre-tensioned tubular double parallel twist process. The process includes applying an online pre-tension force to the initially assembled rope blank and performing final twisting during the rope-jointing process. The magnitude of the online pre-tension force is 35%-45% of the minimum breaking tensile strength of the wire rope. The lay length of the wire rope body is 197mm to 204mm; During the twisting process, the residual torsion angles of the 3X7 strands, 3X24F strands, and 3X40SF strands that constitute the main body of the wire rope are all controlled within the range of -90° to 0°.

[0007] Production process: S1. Raw material and steel wire preparation: 82A high carbon steel wire rod with trace amounts of Mo and Nb alloying elements is subjected to rough drawing, sorbitizing heat treatment and phosphating treatment in sequence to obtain heat-treated billet with sorbitization rate greater than 99%; then the heat-treated billet is subjected to multiple fine drawing, with the average compression rate of each pass controlled at about 12%, and pressure die technology is used to produce finished steel wire with a tensile strength of not less than 2200MPa; S2, strand twisting: The finished steel wires obtained in step S1 are twisted according to the structural designs of 3X7, 3X24F and 3X40SF respectively, and the steel wires are lubricated with oil during the twisting process. S3. Rope Assembly and Online Pre-tensioning: Using a pre-tensioning tubular double parallel twisting device, the 3-strand 3x7-strand ropes obtained in step S2 are assembled with the 6 outer layer strands. During the rope assembly process, the initially assembled rope blank is first subjected to high-frequency rotary forging and compaction. Then, under the action of the speed difference between the traction system and the tensioning system, an online pre-tensioning force of 35%-45% of the minimum breaking tensile force of the wire rope body is applied to the rope blank, and the final twisting is completed under the maintenance of this pre-tensioning force.

[0008] In step S1, the process parameters for the sorbitizing heat treatment are: DV value 63.5, austenitizing temperature range of 940℃ to 960℃, pre-lead temperature of 565℃, and post-lead temperature of 555℃. In step S1, the number of thinning passes shall not be less than 12; In step S1, the orifice diameter of the pressure die is 1.15 times the diameter of the incoming steel wire; In step S3, the magnitude of the online pre-tension force is 40% of the minimum breaking tensile force of the wire rope body.

[0009] The pre-tensioned tubular double parallel twisting equipment for production process includes a frame, closing pressure plate, traction system, cleaning system, take-up device and PLC control system. Its feature is that it also includes a tensioning system, force measuring wheel and high frequency rotary forging machine. The traction system, high-frequency rotary forging machine, cleaning system, force measuring wheel and tensioning system are arranged sequentially along the travel direction of the wire rope body; Both the traction system and the tensioning system are active drive systems used to provide traction and tension forces; The force-measuring wheel is used to measure the tension of the wire rope body in real time; The PLC control system is connected to the drive motors of the traction system, the drive motors of the tensioning system, and the force measuring wheel, and is configured to perform the following controls: The speed of the drive motor of the traction system is controlled according to the preset target pitch. Based on the difference between the actual tension value fed back by the force measuring wheel and the preset target tension force, the speed of the drive motor of the tensioning system is adjusted in real time to keep the actual tension borne by the wire rope body stable at the target tension force.

[0010] The cleaning system includes a support base fixed to the ground. One or more connecting seats are installed sequentially on the top of the support base along the conveying direction of the wire rope body. A positioning housing is fixedly connected to the top of the connecting seats. The end of the positioning housing that first contacts the wire rope body is the front end. An elastic scraping workpiece is set at the front end. A fine elastic workpiece is set at the rear end of the positioning housing.

[0011] The elastic scraping workpiece includes a circular movable cavity opened in the positioning housing. An annular groove is coaxially opened at the front end of the inner wall of the movable cavity. A connecting port is opened at the top of the positioning housing at the matching position of the annular groove. A rotating ring block is rotatably connected in the groove. Several inner baffles are coaxially and evenly fixedly connected to the inner wall of the rotating ring block. The several inner baffles enclose an movable space for the steel wire rope body to pass through.

[0012] Each inner baffle has a guide cylinder fixedly connected to the middle of its inner wall, extending towards the center line of the movable cavity. Inside the guide cylinder, a sliding rod is elastically connected via a spring. The sliding rod extends outward from the guide cylinder and is fixedly connected to a connecting plate. A cleaning head is fixedly connected to the front end of the connecting plate. The cleaning head has a "V" shaped groove in its cross-section. One side of the groove is inclined towards the center line of the positioning housing, and the other side of the groove is extended outward. A protrusion is fixedly connected to the front end of the inner wall of each movable cavity. When the protrusion is conveyed with the wire rope body, it abuts against the gap on the outer wall of the wire rope body.

[0013] An annular groove is provided in the middle of the outer wall of the rotating ring block. A gear ring is coaxially installed in the annular groove. The top of the gear ring is connected to the servo motor through the drive gear. The servo motor is fixedly installed on the top of the positioning housing.

[0014] The refined elastic workpiece includes multiple guide cylinders evenly installed on the rear outer wall of the positioning housing. The number of guide cylinders is at least 4. The inner wall of each guide cylinder extends toward the center line of the positioning housing. Each guide cylinder inner wall is connected to a movable rod in a horizontal sliding manner through a side strip. The inner end of the movable rod is rotatably connected to a blunt scraper. The movable rod is located outside the guide cylinder and is elastically connected by a spring. A positioning ring is fixedly connected to the tail end of the positioning housing. The middle part of the positioning ring is coaxial with the movable cavity and is used to receive the wire rope body that is being transported.

[0015] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention uses a pre-tensioned tubular double parallel twisting device to simultaneously apply a constant and precise online pre-tensioning force during the rope twisting process, forcing the steel wire to undergo lattice slip and dislocation reorganization while plastically deforming, thereby significantly eliminating the residual stress generated by twisting and forging, and solving the problems of low efficiency and uneven effect of traditional offline pre-tensioning.

[0016] 2. This invention, by setting up a cleaning system with elastic scraping of workpieces and fine elastic workpieces, allows the mud-removing head to adapt to the texture of the outer wall of the wire rope and actively rotate to scrape, while the blunt scraping head can elastically penetrate into the gaps for cleaning.

[0017] 3. This invention, through a state of low residual stress and an optimized 9-strand parallel twist compaction structure, reduces the driving force for fatigue crack initiation and propagation in the wire rope under external load, thereby increasing its service life and meeting the extreme working conditions required for deep and ultra-deep well drilling.

[0018] 4. This invention forms a complete high-performance wire rope manufacturing system by obtaining high-strength and tough steel wire through micro-alloyed wire rod and controlled drawing, precise control of residual torsion angle, online forging and compaction, and closed-loop pre-tensioning and twisting. Ultimately, the product achieves breakthroughs in breaking tensile strength ≥670kN, high toughness torsion value, and dimensional stability. Attached Figure Description

[0019] Figure 1 This is a schematic diagram illustrating the effect of heating time on the mechanical properties of steel wire.

[0020] Figure 2 This is a schematic diagram of the metallographic structure of Φ1.80mm 60# steel wire under different heating times.

[0021] Figure 3 This is a schematic diagram showing the relationship between the mechanical properties of steel wire and the total compression ratio.

[0022] Figure 4 This is a schematic diagram of the overall structure of the cleaning system.

[0023] Figure 5 For the present invention Figure 4 The main view structure diagram.

[0024] Figure 6 For the present invention Figure 4 Top view of the structure.

[0025] Figure 7 For the present invention Figure 6 A schematic diagram of the cross-section along the AA direction.

[0026] Figure 8 This is a schematic cross-sectional view of the cleaning system of the present invention.

[0027] Figure 9 This is a schematic cross-sectional view of the movable rod in its movable state according to the present invention.

[0028] Figure 10 This is a schematic diagram of the overall structure of the workpiece elastically scraped by the present invention.

[0029] In the diagram: 1. Support base; 11. Connecting base; 12. Wire rope body; 2. Positioning housing; 21. Movable cavity; 22. Positioning ring; 23. Rotating ring block; 24. Inner baffle; 25. Guide cylinder; 26. Slide rod; 27. Connecting plate; 28. Spring one; 29. ​​Protrusion; 210. Cleaning head; 211. Gear ring; 212. Servo motor; 213. Drive gear; 214. Guide slide cylinder; 215. Side bar; 216. Movable rod; 217. Blunt scraper head; 218. Spring two. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] Example 1: See Figures 1-3 The production process of double-strand synchronous low-stress twisted double parallel twist crane wire rope: Manufacturing process of KDSC 3x40SF / 3x24F-3x7-25.4mm steel wire rope for oil drilling: S1. Preparation of special steel wire: Synergistic optimization of materials and processes.

[0032] Wire rod composition design: The core lies in the high purification and micro-alloying of the base material. High-purity 82A steel is selected, with a carbon content of 0.80%-0.85%, and precise addition of Mo 0.02%-0.05% and Nb 0.01%-0.03%.

[0033] The carbonitrides of Mo and Nb precipitate during the austenitization process, pinning grain boundaries and refining the original austenite grains, laying the foundation for obtaining a fine lamellar sorbite structure.

[0034] Sorbiticizing heat treatment: This is key to achieving an excellent balance of strength and toughness. The effect of austeniticizing heating time (47 s to 85 s) on the microstructure and properties of steel wire was investigated.

[0035] The results showed that when heated for 70 seconds, the microstructure was uniform and fine sorbite, at which point the number of twists and bends of the steel wire reached its peak: twist > 40 times and bend > 20 times.

[0036] Therefore, this embodiment adopts a process with a heating time of 70s, a DV value of 63.5, an austenitizing temperature of 950-960℃, and a lead bath temperature of 555-565℃ to ensure a sorbitization rate of >99%.

[0037] Controlled drawing process: The core of the drawing process is to balance strength and plasticity.

[0038] like Figure 3 As shown, the effects of total compression ratio q on the tensile strength σ, yield strength ratio, torsion, and number of bends of steel wire were studied. A mathematical model was established: σ = σ0 + k·ln(1-q).

[0039] In this embodiment, a total compression ratio of approximately 90% is selected, with an average pass compression ratio of 12%. Under these conditions, the steel wire strength can reach over 2300 MPa, while the yield strength ratio is moderate and the torsion value exceeds 30 times, achieving the best combination of strength and toughness.

[0040] The entire drawing process employs a pressure die and multiple passes, with the die diameter being 1.15 times the wire inlet diameter and ≥12 passes, to ensure uniform deformation and reduce internal defects.

[0041] S2. Precision twisting of strands: pre-control of stress and structure.

[0042] Structural parameters: The yarn diameter, strand diameter, and twist pitch of the inner 3X7 strand and the outer 3X24F and 3X40SF strands are all clearly specified. For example, the 3X7 strand has a diameter of 5.75mm and a twist pitch of 46mm; the 3X40SF strand has a diameter of 10.28mm and a twist pitch of 82.2mm.

[0043] The above 3X24F indicates that the wire rope is a 3-strand type with 24 strands per strand and right-hand cross-twist; 3X40SF indicates that the wire rope is a 3-strand type with 40 strands per strand and a slub filler structure. Residual torsion angle: The twisting equipment has a residual torsion angle monitoring and feedback function. The process requires that the residual torsion angle of each strand of rope be controlled in real time within the range of -90° to 0° during the twisting process.

[0044] This parameter is a key indicator characterizing the residual torsional stress state of the wires within the strand. A negative value indicates a preset reverse torsion angle to counteract the unidirectional torsion generated during subsequent rope assembly.

[0045] At the same time, oil lubrication is used to ensure a stable coefficient of friction between the steel wires in the strand and a uniform stress distribution.

[0046] S3. Core process of rope bonding: integration of online pretensioning and forging compaction.

[0047] This step is implemented using specialized equipment, which is based on existing equipment technology, and will not be described in detail here.

[0048] Equipment composition and process: The equipment consists of the following components in sequence: a basket frame for holding nine I-beam rollers, a closing pressure plate, a traction wheel system, a high-frequency rotary forging machine, a force measuring wheel, a tensioning wheel system, and a take-up device.

[0049] The PLC control system is connected to the traction motor, tension motor, and force measuring wheel via signals.

[0050] Process: Bundling and initial forging: The nine strands of rope are drawn from the basket frame and initially bundled by the pressure plate to form a loose rope blank. The rope blank immediately enters the high-frequency rotary forging mill and is compacted by high-speed hammering. The diameter is reduced from about 28.4 mm before forging to about 26.4 mm after forging, the metal filling rate is greatly improved, and the contact between strands changes from point and line contact to surface contact.

[0051] Online pre-tensioning closed-loop control: This is the core of eliminating residual stress. The compacted rope blank enters the tension zone formed by the traction wheel and tension wheel. The PLC system sets targets such as a lay length of 197mm and a target tension force, such as 40% of the minimum breaking strength, i.e., 262kN. The traction wheel rotates at a constant linear velocity V1, while the drive motor of the tension wheel, under PLC control, maintains a linear velocity V2 slightly greater than V1, where V2 = V1·(1+δ), and δ is a small elongation setting. This velocity difference causes the rope blank to be subjected to axial tension.

[0052] The force-measuring wheel detects the actual tension F in real time and feeds it back to the PLC. The PLC dynamically adjusts the motor speed of the tensioning wheel through a PID algorithm to keep F stable within the range of 262kN±2%. Under this constant tension, the rope blank completes the final Z-axis twisting.

[0053] Principle and Effect: This process simulates the effect of "offline pre-tensioning," but it is completed synchronously, online, and dynamically during the twisting process. Applying constant tension while plastically twisting can most effectively promote lattice slip and dislocation reorganization of the steel wire, thereby significantly eliminating residual stress caused by twisting deformation.

[0054] S4. Product Performance Verification The obtained product underwent full-item testing, and the key data are as follows: Overall mechanical properties: The measured breaking tensile strength of the whole rope is 670kN, the strength of the broken strands of steel wire is 2300-2390MPa, the number of torsion cycles is generally 38-45, and the number of bending cycles is 15-26.

[0055] Dimensional stability: Thanks to online pretensioning, the structural elongation at delivery is ≤0.3% and the diameter reduction is ≤0.8%, which is significantly better than conventional products.

[0056] Metallographic structure: The typical metallographic structure of the finished steel wire is shown, which is uniform and fine sorbite, without harmful structures such as network ferrite.

[0057] Fatigue performance: Customer application feedback and laboratory simulation tests show that, under the same drilling conditions, its service life is three times that of traditional 6X19S structural steel wire ropes, meeting the long service life requirements of ultra-deep well drilling.

[0058] It should be noted that: Figure 1 In the figure, (a) represents tensile strength and yield strength ratio; (b) represents the number of torsion and bending cycles.

[0059] Figure 2 In, (a) t=47s; (b) t=55s; (c) t=62s; (d) t=70s; (e) t=77s; (f) t=85s.

[0060] Figure 3 In the figure, (a) represents tensile strength and yield strength ratio; (b) represents torsion and repeated bending number.

[0061] Example 2: Based on the above production process, the following wire rope products were manufactured: The wire rope body 12 has a 9-strand parallel lay structure, and its structure is marked as 3X40SF / 3X24F-3X7, including: An inner layer consisting of three strands twisted in parallel in the S direction, with a 3x7 structure. An outer layer is made of 6 strands of rope twisted in parallel in the S direction, of which 3 strands are 3X40SF and 3 strands are 3X24F. The inner and outer layers are twisted together in a parallel Z-direction twisting manner; The wire rope body 12 is prepared by a pre-tensioned tubular double parallel twist process. The process includes applying an online pre-tension force to the initially joined rope blank and performing final twisting during the rope joining process. The magnitude of the online pre-tension force is 35%-45% of the minimum breaking tensile force of the wire rope body 12.

[0062] The nominal diameter of the wire rope body 12 is 25.4 mm, the nominal tensile strength is 1960 MPa, and the measured breaking tensile force of the whole rope is not less than 670 kN. The twist pitch of the wire rope body 12 is 197mm to 204mm; During the twisting process, the residual torsion angles of the 3X7 strands, 3X24F strands, and 3X40SF strands that constitute the wire rope body 12 are all controlled within the range of -90° to 0°.

[0063] Example 3: A pre-tensioned tubular double parallel twisting device for production process, comprising a frame, closing pressure plate, traction system, cleaning system, take-up device and PLC control system, characterized in that it further comprises a tensioning system, a force measuring wheel and a high-frequency rotary forging machine; The traction system, high-frequency rotary forging machine, cleaning system, force measuring wheel and tensioning system are arranged sequentially along the travel direction of the wire rope body 12; Both the traction system and the tensioning system are active drive systems used to provide traction and tension forces; The force measuring wheel is used to measure the tension of the wire rope body 12 in real time; The PLC control system is connected to the drive motors of the traction system, the drive motors of the tensioning system, and the force measuring wheel, and is configured to perform the following controls: The speed of the drive motor of the traction system is controlled according to the preset target pitch. Based on the difference between the actual tension value fed back by the force measuring wheel and the preset target tension force, the speed of the drive motor of the tensioning system is adjusted in real time so that the actual tension borne by the wire rope body 12 is stabilized at the target tension force.

[0064] The cleaning system includes a support base 1 fixed to the ground. One or more connecting seats 11 are installed sequentially on the top of the support base 1 along the conveying direction of the wire rope body 12. A positioning housing 2 is fixedly connected to the top of the connecting seat 11. The end of the positioning housing 2 that first contacts the wire rope body 12 is the front end. An elastic scraping workpiece is provided at the front end. A fine elastic workpiece is provided at the rear end of the positioning housing 2.

[0065] See Figures 5-10The elastic scraper at the front end is used to adapt to the outer wall of the wire rope body 12 and can adapt to the external texture of the wire rope body 12. It can rotate at a certain tilt angle to provide active driving force for the sludge on the surface of the wire rope body 12. Relying on the rotary cutting force at the tilt angle, it can better perform the cleaning action.

[0066] The elastic scraping of the workpiece includes a circular movable cavity 21 opened at the positioning housing 2. An annular groove is coaxially opened at the front end of the inner wall of the movable cavity 21. A connecting port is opened at the top of the positioning housing 2 at the matching position of the annular groove. A rotating ring block 23 is rotatably connected inside the groove. Several inner baffles 24 are coaxially and evenly fixedly connected to the inner wall of the rotating ring block 23. The several inner baffles 24 enclose an active space for the steel wire rope body 12 to pass through.

[0067] See Figures 7-10 The movable space is used for the movement of the wire rope body 12, and the movable space is coaxially set with the movable cavity 21 to ensure that the wire rope body 12 can be straightened and wound up in conjunction with subsequent equipment when cleaning.

[0068] A bearing is provided at the sliding point between the slid groove and the rotating ring block 23 to reduce friction.

[0069] Each inner baffle 24 has a guide cylinder 25 fixedly connected to the middle of its inner wall, extending towards the center line of the movable cavity 21. Inside the guide cylinder 25, a slide rod 26 is elastically connected via a spring 28. The slide rod 26 is located outside the guide cylinder 25, extending towards the front end and fixedly connected to a connecting plate 27. A cleaning head 210 is fixedly connected to the front end of the connecting plate 27. The cleaning head 210 has a "V" shaped groove in its cross-section. One side of the groove is inclined towards the center line of the positioning housing 2, and the other side of the groove is extended outward. A protrusion 29 is fixedly connected to the front end of the inner wall of each movable cavity 21. When the protrusion 29 is conveyed with the wire rope body 12, it abuts against the gap of the outer wall of the wire rope body 12.

[0070] See Figure 10 The slide bar 26 can drive the entire connecting plate 27 and the mud cleaning head 210 to rotate inside the guide cylinder 25. Since multiple mud cleaning heads 210 are adjacent, when one tilts, the other mud cleaning heads 210 will also deflect upon contact, thereby removing and cleaning the oil sludge on the outer wall of the wire rope body 12. In addition, excess oil sludge can be detached outward under the action of the "V" shaped groove, avoiding oil sludge accumulation.

[0071] An annular groove is provided in the middle of the outer wall of the rotating ring block 23. A gear ring 211 is coaxially installed in the annular groove. The top of the gear ring 211 is connected to the servo motor 212 through the drive gear 213. The servo motor 212 is fixedly installed on the top of the positioning housing 2.

[0072] See Figure 8 The entire rotating ring block 23 is driven by a servo motor 212 in a clockwise / counterclockwise direction, which provides a rotary cutting force to the sludge cleaning head 210 on the sludge.

[0073] Specifically, firstly, under the elastic pressure of spring 28, the inclined groove wall inside the cleaning head 210 tightly adheres to the surface of the wire rope. When the servo motor 212 drives the rotating ring block 23 to rotate all the cleaning heads 210, the cutting edge of the inclined groove wall continuously shears and scrapes the sludge on the surface of the wire rope.

[0074] Secondly, the scraped sludge enters the 'V'-shaped groove due to inertia and rotational disturbance. The inclined surface inside the groove guides and collects the sludge, causing it to gather at the bottom of the groove and preventing it from flowing back.

[0075] Most importantly, under the centrifugal force generated by the high-speed rotation of the cleaning head 210, the sludge accumulated in the 'V'-shaped groove is subjected to an outward force along the radius of rotation. Because the outer wall of the 'V'-shaped groove is designed to expand, it provides a smooth outflow channel for the sludge. Centrifugal force drives the sludge to be accelerated and thrown out along this expanded wall, with its movement direction roughly along the tangential direction of rotation, thus completely removing the sludge from the cleaning area.

[0076] The refined elastic workpiece includes multiple guide cylinders 214 evenly installed on the rear outer wall of the positioning housing 2. The number of guide cylinders 214 is at least 4. The inner wall of each guide cylinder 214 extends toward the center line of the positioning housing 2. The inner wall of each guide cylinder 214 is horizontally slidably connected to a movable rod 216 through a side strip 215. The inner end of the movable rod 216 is rotatably connected to a blunt scraper head 217. The movable rod 216 is located outside the guide cylinder 214 and is elastically connected by a spring 218.

[0077] See Figure 9 Each movable rod 216 will move towards the center line of the movable cavity 21, that is, the wire rope body 12, under the elasticity of the second spring 218, and elastically abut against the gap of the outer wall of the wire rope body 12. The blunt scraper head 217 can also move, which increases the cleaning effect of the wire rope body 12. Furthermore, the elasticity of the second spring 218 can reduce the damage to the wire rope body 12 to a certain extent.

[0078] A positioning ring 22 is fixedly connected to the tail end of the positioning housing 2. The middle part of the positioning ring 22 is coaxial with the movable cavity 21 and is used to receive the wire rope body 12 that is being transported.

[0079] See Figure 8 It is used to ensure the stability of the wire rope body 12 during operation and can scrape off the oil and sludge adhering to the outer wall of the wire rope body 12 after being treated by the blunt scraper head 217.

[0080] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A double-strand synchronous low-stress twisted double-parallel twist crane wire rope, characterized in that: Includes a wire rope body, wherein the wire rope body has a 9-strand parallel twist structure, comprising: An inner layer consisting of three strands twisted in parallel in the S direction, with a 3x7 structure. An outer layer is made of 6 strands of rope twisted in parallel in the S direction, of which 3 strands are 3X40SF and 3 strands are 3X24F. The inner layer and the outer layer are twisted together in a Z-direction parallel twist manner; The wire rope body is prepared by a pre-tensioned tubular double parallel twist process. The process includes applying an online pre-tension force to the initially joined rope blank and performing final twisting during the rope joining process. The magnitude of the online pre-tension force is 35%-45% of the minimum breaking tensile force of the wire rope body.

2. The double-strand synchronous low-stress twisted double-parallel twist crane wire rope according to claim 1, characterized in that: The twist pitch of the wire rope body is 197mm to 204mm; During the twisting process, the residual torsion angles of the 3X7 strands, 3X24F strands, and 3X40SF strands that constitute the main body of the wire rope are all controlled within the range of -90° to 0°.

3. A manufacturing process for producing a double-strand synchronous low-stress twisted double-parallel twist crane wire rope as described in any one of claims 1-2, comprising the following steps performed sequentially: S1. Raw material and steel wire preparation: 82A high carbon steel wire rod with trace amounts of Mo and Nb alloying elements is subjected to rough drawing, sorbitizing heat treatment and phosphating treatment in sequence to obtain a heat-treated billet with a sorbitization rate of more than 99%; then the heat-treated billet is subjected to multiple fine drawing, with the average compression rate of each pass controlled at about 12%, and finished steel wire with a tensile strength of not less than 2200MPa is obtained using pressure die technology. S2, strand twisting: The finished steel wires obtained in step S1 are twisted according to the structural designs of 3X7, 3X24F and 3X40SF respectively, and the steel wires are lubricated with oil during the twisting process. S3. Rope Assembly and Online Pre-tensioning: Using a pre-tensioning tubular double parallel twisting device, the 3-strand 3x7-strand ropes obtained in step S2 are assembled with the 6 outer layer strands. During the rope assembly process, the initially assembled rope blank is first subjected to high-frequency rotary forging and compaction. Then, under the action of the speed difference between the traction system and the tensioning system, an online pre-tensioning force of 35%-45% of the minimum breaking tensile force of the wire rope body is applied to the rope blank, and the final twisting is completed under the maintenance of this pre-tensioning force.

4. The wire rope manufacturing process according to claim 3, characterized in that: In step S1, the process parameters for the sorbitizing heat treatment are: DV value 63.5, austenitizing temperature range of 940℃ to 960℃, pre-lead temperature of 565℃, and post-lead temperature of 555℃. In step S1, the number of fine drawing passes is no less than 12; In step S1, the aperture of the pressure mold is 1.15 times the diameter of the incoming steel wire; In step S3, the magnitude of the online pre-tension force is 40% of the minimum breaking tensile force of the wire rope body.

5. A pre-tensioned tube-type double parallel twisting device for implementing the production process as described in claim 3, comprising a frame, closing pressure plates, a traction system, a cleaning system, a take-up device, and a PLC control system, characterized in that, It also includes a tensioning system, a force measuring wheel, and a high-frequency rotary forging machine; The traction system, the high-frequency rotary forging machine, the cleaning system, the force measuring wheel, and the tensioning system are arranged sequentially along the travel direction of the wire rope body; Both the traction system and the tensioning system are active drive systems used to provide traction force and tension force; The force measuring wheel is used to measure the tension of the wire rope body in real time; The PLC control system is connected to the drive motors of the traction system, the tensioning system, and the force measuring wheel, and is configured to perform the following controls: The speed of the drive motor of the traction system is controlled according to the preset target pitch. Based on the difference between the actual tension value fed back by the force measuring wheel and the preset target tension, the speed of the drive motor of the tensioning system is adjusted in real time so that the actual tension borne by the wire rope body is stabilized at the target tension.

6. The pre-tensioned tubular double parallel twisting device according to claim 5, characterized in that: The cleaning system includes a support base fixed to the ground. One or more connecting seats are installed sequentially on the top of the support base along the conveying direction of the wire rope body. A positioning housing is fixedly connected to the top of the connecting seats. The end of the positioning housing that first contacts the wire rope body is the front end. An elastic scraping workpiece is provided at the front end. A fine elastic workpiece is provided at the rear end of the positioning housing.

7. The pre-tensioned tubular double parallel twisting device according to claim 6, characterized in that: The elastic scraping workpiece includes a circular movable cavity opened at the positioning housing. An annular groove is coaxially opened at the front end of the inner wall of the movable cavity. A connecting port is opened at the top of the positioning housing at the matching position of the annular groove. A rotating ring block is rotatably connected inside the groove. Several inner baffles are coaxially and evenly fixedly connected to the inner wall of the rotating ring block. The several inner baffles enclose a movable space for the steel wire rope body to pass through.

8. The pre-tensioned tubular double parallel twisting device according to claim 7, characterized in that: Each inner baffle has a guide cylinder fixedly connected to the middle of its inner wall, extending towards the center line of the movable cavity. A sliding rod is elastically connected inside the guide cylinder via a spring. The sliding rod extends outward from the guide cylinder and is fixedly connected to a connecting plate. A cleaning head is fixedly connected to the front end of the connecting plate. The cleaning head has a "V" shaped groove in its cross-section. One side of the groove is inclined towards the center line of the positioning housing, and the other side of the groove is extended outward. A protrusion is fixedly connected to the front end of the inner wall of each movable cavity. The protrusion abuts against the gap on the outer wall of the wire rope body when it is conveyed with the wire rope body.

9. The pre-tensioned tubular double parallel twisting device according to claim 7, characterized in that: An annular groove is formed in the middle of the outer wall of the rotating ring block. A gear ring is coaxially installed in the annular groove. The top of the gear ring is connected to a servo motor through a drive gear. The servo motor is fixedly installed on the top of the positioning housing.

10. The pre-tensioned tubular double parallel twisting device according to claim 6, characterized in that: The refined elastic workpiece includes multiple guide cylinders evenly installed on the rear outer wall of the positioning housing. The number of guide cylinders is at least 4. The inner wall of each guide cylinder extends toward the center line of the positioning housing, and the inner wall of each guide cylinder is horizontally slidably connected to a movable rod through a side strip. The inner end of the movable rod is rotatably connected to a blunt scraper. The movable rod is located outside the guide cylinder and is elastically connected by a spring. A positioning ring is fixedly connected to the tail end of the positioning housing. The middle part of the positioning ring is coaxial with the movable cavity and is used to receive the steel wire rope body that is being transported.

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