Manufacturing method of steel wire rope for high-permeability conveying belt

Abstract

The invention belongs to the field of steel wire rope manufacturing, and provides a manufacturing method of a steel wire rope for a high-permeability conveying belt, which comprises the following steps: roughly drawing a wire rod, thermally treating, hot galvanizing, drawing a steel wire, and destressing to obtain the steel wire; the steel wire is subjected to pre-deformation treatment, and the steel wire subjected to pre-deformation treatment is obtained; the steel wires subjected to pre-deformation treatment are twisted into outer-layer strands and center strands, and the twisted outer-layer strands and center strands are subjected to straightening treatment; performing pre-deformation treatment on the outer layer strands obtained by twisting; the outer-layer strands are twisted on the periphery of the center strand, and the steel wire rope is obtained; and the steel wire rope is straightened, residual stress is eliminated, and the steel wire rope is obtained. The steel wires are pre-deformed before stranding by adopting the pre-deformer, so that gaps of the steel wires in the stranded steel strands are increased, and the deformation rate of the outer-layer strands of the steel wire rope is increased to 90-95%, so that rubber can enter the steel wire rope more easily, and the problem of rubber permeability of the conveying belt is solved.

Description

Technical Field

[0001] The present invention belongs to the field of wire rope manufacturing and relates to a manufacturing method of wire ropes for high-permeability conveyor belts. Background Art

[0002] Disclosing the information of this background art section is only intended to enhance the understanding of the overall background of the present invention, and it is not necessarily regarded as an admission or an implication in any form that this information constitutes the prior art already known to those of ordinary skill in the art.

[0003] Steel cord conveyor belts have the advantages of high strength, small elongation, large span, good grooving performance, etc. They are suitable for long-distance and high-power conveyors, are the main components of conveyors, play the role of carrying logistics, and are commonly used for single-machine large-span, high-speed, and large-capacity conveying of bulk, granular, powdery and other materials, and are suitable for conveying places such as coal mines, mines, and docks. The steel cord flame-retardant conveyor belt for coal mines is mainly applied to coal mine transportation occasions. To ensure that the steel cord does not corrode with the media in the coal mine environment, it is required that there is good rubber permeability between the rubber and the steel cord that make up the conveyor, so as to extend the service life of the conveyor belt.

[0004] The wire ropes for conveyor belts are made by twisting multiple round wires of different specifications. Therefore, there will be certain gaps between the wires. When the conveyor belt is produced, the rubber gradually penetrates into the gaps in the wire rope under the pressure of the flat vulcanizer. However, due to the poor fluidity of the rubber, it cannot completely enter the tiny gaps between the wires, resulting in no rubber contact with the wires at some positions, so that the rubber permeability of the conveyor belt fails to meet the requirements of the standard MT / T 668 - 2019 "Steel Cord Flame-Retardant Conveyor Belt for Coal Mines". Summary of the Invention

[0005] To solve the above problems, the present invention provides a manufacturing method of wire ropes for high-permeability conveyor belts. Before stranding the strands, the present invention uses a special tooling disclosed in Patent ZL 201420496135.7 "Pre-deformer for Warrington Strand" to pre-deform the wires, so as to increase the gaps between the wires in the stranded steel strands and increase the deformation rate of the outer strands of the wire rope to 90 - 95%, thereby making it easier for the rubber to enter the wire rope interior, solving the problem of rubber permeability of the conveyor belt, and at the same time not affecting the mechanical properties of the wires or the wire rope itself.

[0006] To achieve the above object, the present invention adopts the following technical solutions: In the first aspect of the present invention, there is provided a manufacturing method of wire ropes for high-permeability conveyor belts, including: Wire rod rough drawing, heat treatment, hot dip galvanizing, wire drawing, stress relief to obtain wires; Performing pre-deformation treatment on the wires to obtain pre-deformed wires; The pre-deformed steel wires are twisted into outer strands and a center strand, and the twisted outer strands and center strand are straightened; The twisted outer strands are pre-deformed; The outer strands are twisted around the center strand to obtain a wire rope; The wire rope is straightened to eliminate residual stress, thus obtaining the product.

[0007] In the second aspect of the present invention, there is provided a wire rope for a highly permeable conveyor belt prepared by the above method.

[0008] In the third aspect of the present invention, there is provided the application of the above wire rope for a highly permeable conveyor belt in the preparation of a conveyor belt.

[0009] Advantages of the present invention (1) For the wire rope for a conveyor belt produced by the present invention, the gap between the steel strands and the steel wires is significantly increased, and the overall structure of the wire rope is relatively loose. During the production process of the conveyor belt, rubber can easily penetrate into the wire rope, come into contact with the steel wires and undergo a chemical reaction, forming a good bond, greatly improving the rubber permeability of the conveyor belt and ensuring the performance requirements of the conveyor belt for coal mines.

[0010] (2) By pre-deforming before strand twisting and pre-deforming the outer strands of the wire rope, the present invention effectively improves the rubber permeability of the wire rope and maintains the mechanical properties of the wire rope. The preparation method of the present invention is simple, highly practical and easy to promote. Description of the drawings

[0011] The accompanying drawings forming a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention.

[0012] Figure 1 It is a process flow chart of the wire rope production of the present invention. Detailed embodiments

[0013] It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs.

[0014] As described in the background art, in traditional wire ropes, the steel wires do not need to be pre-deformed. The steel wires are in close contact with each other and between the wire layers, with small gaps. Rubber cannot fully enter the interior of the wire rope strands to contact each steel wire, thus reducing the rubber permeability. The main production process flow of conventional wire ropes for conveyor belts is basically: wire rod rough drawing - heat treatment + hot galvanizing - wire drawing + stress relief - strand forming and deformation - wire rope twisting - stress elimination.

[0015] Therefore, a manufacturing method of steel wire ropes for high-permeability conveyor belts according to the present invention includes: (1) Before the outer strands and the center strand are twisted, pre-deformation of the steel wires is increased, making the structure of the strands after twisting looser, the gaps between the steel wires larger, and it is more conducive to the penetration of rubber.

[0016] (2) Then, in the outer strands and the deformation stage before the steel wire ropes are twisted, the deformation rate is controlled to be 90-95%, making the structure of the steel wire ropes looser, the gaps between the outer strands larger, and it is more conducive to the penetration of rubber into the center strand.

[0017] In some embodiments, the deformation rate of the pre-deformation treatment of the steel wires is 90-110%.

[0018] In some embodiments, the stress state of the straightened outer strands is -4 to 0 turns.

[0019] In some embodiments, the stress state of the straightened center strand is -5 to 0 turns.

[0020] In some embodiments, the ratio of the outer strands to the center strand is 1.10-1.30.

[0021] In some embodiments, the deformation rate of the pre-deformation treatment of the outer strands is 90%-95%.

[0022] In some embodiments, the stress state of the steel wire ropes after stress removal is ±1 / 2 turn.

[0023] In some embodiments, the specifications of the steel wire ropes are 6×19W-WSC, D7.3mm, 6×19-WSC, D6.8mm.

[0024] The following combines specific embodiments to further elaborate on the present invention. It should be noted that the specific embodiments are explanations rather than limitations of the present invention.

[0025] Embodiment 1 Taking the steel wire rope with a nominal diameter of D7.2mm and a 6×19W-WSC structure as an example, according to the requirements in Table A.3 of the standard GB / T 12753-2020 "Steel Wire Ropes for Conveyor Belts", the minimum breaking force of the steel wire ropes of this structure at Grade IV strength is 51.2 kN. According to the requirements in 4.10 of the standard MT / T668-2019 "Flame Retardant Conveyor Belts with Steel Wire Rope Core for Coal Mines", a pressure difference of 100 kPa is applied at both ends of the test piece, and the change in the pressure difference within 60 s shall not exceed 5 kPa.

[0026] In this embodiment, the manufacturing method of the steel wire ropes for high-permeability conveyor belts is specifically implemented according to the following steps: (1) 5.5 mm high carbon steel high quality carbon wire rod is roughly drawn to 1.70-2.60 mm as rough drawn wire blank.

[0027] (2) The 1.70-2.60 mm thick drawn wire blank is subjected to heat treatment and hot-dip galvanizing processes to produce heat-treated galvanized steel wire with a nominal diameter of 1.70-2.60 mm.

[0028] (3) The 1.70-2.60 mm heat-treated galvanized steel wire is drawn into a 0.35-0.65 mm galvanized steel wire through a wire drawing machine, and the stress is fully removed through a straightener.

[0029] (4) 0.35-0.65 mm galvanized steel wires are twisted into outer strands 2 and center strands 3 in a certain arrangement. 2.30 mm outer strands 2 and 2.60 mm center strands 3 are twisted. Before twisting, special tooling is used to pre-deform the steel wires in the strands, with a deformation rate of 90-110% (the deformation rate of the steel wires at each location in the entire steel strand is controlled within this range).

[0030] (5) After twisting, the outer strands 2 and the center strands 3 are straightened to fully eliminate residual stress. The stress state of the outer strands 2 is -4 to 0 turns, and the stress state of the center strands 3 is -5 to 0 turns. The loose twist is "-" and the twist is "+". Then they are rolled up on the I-shaped wheels respectively.

[0031] (6) The 2.60 mm center strand 3 wound on the I-shaped wheel is twisted into 7 2.30 mm outer strands 2. The outer strands 2 need to be pre-deformed, and the deformation rate should be controlled to be no less than 90-95%.

[0032] (7) After the steel wire rope 1 is twisted, it must be straightened to fully eliminate the residual stress. The stress state of the steel wire rope 1 is ±1 / 2 turn.

[0033] After testing and verification, the measured breaking force of the high permeability conveyor belt steel wire rope of the present invention is 54.6kN, which meets the standard requirements. According to the method in Appendix C of MT / T 668-2019 standard, the pressure difference change is very small. The results of three measurements are 0.2 kPa, 0.08 kPa, and 0.3 kPa, respectively, which do not exceed 5kPa, meeting the standard requirements and showing excellent rubber permeability.

[0034] Example 2 Taking the wire rope with a nominal diameter of D6.80mm and a 6×19-WSC structure as an example, according to the requirements in Table A.2 of the standard GB / T 12753-2020 "Steel Wire Ropes for Conveyor Belts", the minimum breaking force of the wire rope with grade Ⅳ strength of this structure is 43.7kN. According to the requirements in 4.10 of the standard MT / T668-2019 "Flame Retardant Steel Cord Conveyor Belts for Coal Mines", a pressure difference of 100kPa is applied at both ends of the test piece, and the change in pressure difference within 60s shall not exceed 5kPa.

[0035] A manufacturing method of a wire rope for a high-permeability conveyor belt according to the present invention is specifically implemented according to the following steps: (1) Roughly draw high-quality carbon steel wire rods with a diameter of 5.5 - 6.5mm to 1.80 - 2.20mm as rough wire blanks.

[0036] (2) Subject the 1.80 - 2.20mm rough wire blanks to heat treatment and hot-dip galvanizing processes to produce heat-treated galvanized steel wires with a nominal diameter of 1.80 - 2.20mm.

[0037] (3) Draw the 1.80 - 2.20mm heat-treated galvanized steel wires to 0.40 - 0.66mm galvanized steel wires through a wire drawing machine, and fully remove the stress through a straightener.

[0038] (4) Twist the 0.40 - 0.66mm galvanized steel wires into outer strands 2 and center strand 3 in a certain arrangement. Twist the 1.35mm outer strands 5 and 2.76mm center strand 6. Before twisting, pre-deform the wires in the strands using special tooling, and the deformation rate is 90 - 110%.

[0039] (5) After twisting, straighten the outer strands 5 and center strand 6 respectively to fully eliminate the residual stress. The stress state of the outer strand 5 is -4 to 0 turns, and the stress state of the center strand 6 is -5 to 0 turns, where loose twisting is "-" and adding twisting is "+", and then wind them onto spools respectively.

[0040] (6) Twist 7 1.35mm outer strands 5 around the 2.76mm center strand 6 wound on the spool. The outer strands 5 need to be pre-deformed, and the deformation rate control should be not less than 90 - 95%.

[0041] (7) After the wire rope 4 is twisted, it must be straightened to fully eliminate the residual stress. The stress state of the wire rope 4 is ±1 / 2 turn.

[0042] Through experimental testing and verification, the measured breaking tensile force of the steel wire rope for high-permeability conveyor belts of the present invention is 46.1 kN, meeting the standard requirements. When tested according to the method in Appendix C of MT / T 668-2019 standard, the change in pressure difference is very small. The results of three measurements are 0 kPa, 0.03 kPa, and 0.01 kPa respectively, not exceeding 5 kPa, meeting the standard requirements, and the rubber permeability is excellent.

[0043] Comparative Example 1 Taking the steel wire rope with a nominal diameter of D7.2mm and a 6×19W-WSC structure as an example, the specific implementation steps are as follows: (1) Roughly draw a 5.5mm high-quality carbon steel wire rod of high-carbon steel to 1.70 - 2.60mm as the rough drawn wire blank.

[0044] (2) Subject the 1.70 - 2.60mm rough drawn wire blank to heat treatment and hot-dip galvanizing processes to produce heat-treated galvanized steel wires with a nominal diameter of 1.70 - 2.60mm.

[0045] (3) Draw the 1.70 - 2.60mm heat-treated galvanized steel wire to 0.35 - 0.65mm galvanized steel wire through a wire drawing machine, and fully remove the stress through a straightener.

[0046] (4) Twist the 0.35 - 0.65mm galvanized steel wires into the outer strands 2 and the center strand 3 in a certain arrangement. Twist the 2.30mm outer strands 2 and the 2.60mm center strand 3. The steel wires are not pre-deformed before twisting.

[0047] (5) After twisting, straightening treatments must be carried out on the outer strands 2 and the center strand 3 respectively to fully eliminate the residual stress. The stress state of the outer strand 2 is -4 to 0 turns, and the stress state of the center strand 3 is -1 to 1 turn, where loose twisting is "-" and adding twisting is "+", and then they are respectively wound onto spools.

[0048] (6) Twist 7 pieces of 2.30mm outer strands 2 around the 2.60mm center strand 3 wound on the spool. The outer strands 2 need to be pre-deformed, and the deformation rate should be controlled at 90 - 95%.

[0049] (7) After the steel wire rope 1 is twisted, it must be straightened to fully eliminate the residual stress. The stress state of the steel wire rope 1 is ±1 / 2 turn.

[0050] Through experimental testing and verification, the measured breaking tensile force of the steel wire rope for high-permeability conveyor belts of the present invention is 54.3 kN, meeting the standard requirements. When tested according to the method in Appendix C of MT / T 668-2019 standard, the change in pressure difference is very large. The results of three measurements are 19.18 kPa, 8.95 kPa, and 41.47 kPa respectively, exceeding 5 kPa, not meeting the standard requirements, and the rubber permeability is poor.

[0051] Comparative Example 2 Taking a wire rope with a nominal diameter of D6.80mm and a 6×19-WSC structure as an example, it is specifically implemented according to the following steps: (1) Roughly draw high-quality carbon steel wire rods with a height of 5.5 - 6.5mm to 1.80 - 2.20mm as rough drawn wire blanks.

[0052] (2) Subject the 1.80 - 2.20mm rough drawn wire blanks to heat treatment and hot-dip galvanizing processes to produce heat-treated galvanized steel wires with a nominal diameter of 1.80 - 2.20mm.

[0053] (3) Draw the 1.80 - 2.20mm heat-treated galvanized steel wires to 0.40 - 0.66mm galvanized steel wires through a wire drawing machine and fully remove the stress through a straightener.

[0054] (4) Twist the 0.40 - 0.66mm galvanized steel wires into outer strands 2 and center strand 3 in a certain arrangement. Twist the 1.35mm outer strand 5 and 2.76mm center strand 6. Before twisting, use special tooling to pre-deform the wires in the strands, and the deformation rate is 90 - 110%.

[0055] (5) After twisting, straighten the outer strand 5 and center strand 6 respectively to fully eliminate the residual stress. The stress state of the outer strand 5 is -4 to 0 turns, and the stress state of the center strand 6 is -5 to 0 turns, where loose twisting is "-" and adding twisting is "+", and then wind them onto spools respectively.

[0056] (6) Twist 7 1.35mm outer strands 5 around the 2.76mm center strand 6 wound on the spool. The outer strand 5 needs to be pre-deformed, and the deformation rate should be controlled at 80 - 85%.

[0057] (7) After the wire rope 4 is twisted, it must be straightened to fully eliminate the residual stress. The stress state of the wire rope 4 is ±1 / 2 turn.

[0058] Through experimental testing and verification, the measured breaking tensile force of the wire rope for high-permeability conveyor belts of the present invention is 46.4kN, meeting the standard requirements. Detected according to the method in Appendix C of MT / T 668-2019 standard, the pressure difference changes greatly, and the results of measuring 3 times are 0.05 kPa, 8.95kPa, and 0.62kPa respectively, exceeding 5kPa, not meeting the standard requirements, and the rubber permeability is poor.

[0059] From the comparison between Example 1 and Comparative Example 1, it can be seen that after the pre-deformation treatment in step (4), the measured breaking force of the steel wire rope in Example 1 meets the standard requirements, and the rubber permeability also meets the standard requirements. On the contrary, the measured breaking force of the steel wire rope in Comparative Example 1 meets the standard requirements, but the rubber permeability does not meet the standard requirements.

[0060] From the comparison between Example 2 and Comparative Example 2, it can be seen that in step (6) of Comparative Example 2, the deformation rate of the outer strands of the steel wire rope is 80-85%, which does not reach 90-95%. The measured breaking force of the steel wire rope meets the standard requirements, but the rubber permeability does not meet the standard requirements.

[0061] It can be seen therefrom that through the two pre-deformation treatments in steps (4) and (6) of the present invention, the rubber permeability of the steel wire rope is effectively improved, and the mechanical properties of the steel wire rope are maintained.

[0062] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for manufacturing a steel wire rope for a high permeability conveyor belt, characterized in that: include: Wire rod rough drawing, heat treatment, hot dip galvanizing, wire drawing, stress relief, to obtain steel wire; Performing a pre-deformation treatment on the steel wire to obtain a pre-deformed steel wire; The pre-deformed steel wire is twisted into outer strands and center strands, and the twisted outer strands and center strands are straightened; Pre-deformation treatment is performed on the outer strands obtained by twisting; The outer strands are twisted around the center strand to obtain a steel wire rope; The steel wire rope is straightened to eliminate residual stress.

2. The method for manufacturing a high permeability steel wire rope for a conveyor belt according to claim 1, characterized in that: The deformation rate of the pre-deformation treatment of the steel wire is 90~110%.

3. The method for manufacturing a high permeability steel wire rope for a conveyor belt according to claim 1, characterized in that: The stress state of the outer strands after straightening is -4~0 circles.

4. The method for manufacturing a high permeability steel wire rope for a conveyor belt according to claim 1, characterized in that: The stress state of the center strand after straightening is -5~0 circles.

5. The method for manufacturing a high permeability steel wire rope for a conveyor belt according to claim 1, characterized in that: The ratio of the outer strands to the center strands is 1.10 to 1.

30.

6. The method for manufacturing a high permeability steel wire rope for a conveyor belt according to claim 1, characterized in that: The deformation rate of the pre-deformation treatment of the outer strands is 90%-95%.

7. The method for manufacturing a high permeability steel wire rope for a conveyor belt according to claim 1, characterized in that: The stress state of the wire rope after stress relief is ±1 / 2 turn.

8. The method for manufacturing a high permeability steel wire rope for a conveyor belt according to claim 1, characterized in that: The specifications of the steel wire rope are 6×19W-WSC, D7.2mm, 6×19-WSC, D6.8mm.

9. A high permeability steel wire rope for conveyor belts prepared by the method described in any one of claims 1 to 8.

10. Use of the high permeability steel wire rope for conveyor belts according to claim 9 in the preparation of conveyor belts.

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