Compact chain of constant strength for mining and method of manufacture

Abstract

A method for manufacturing a mining-grade constant-strength compact chain includes the following steps: determining the size specifications of the compact chain; selecting the diameter of the flat rings; processing test sample flat rings of the corresponding specifications; measuring the breaking load value of the test sample flat rings; calculating the diameter of the vertical rings based on the measured breaking load value of the test sample flat rings; processing flat ring blanks of the corresponding specifications, and simultaneously processing vertical rings of the corresponding specifications according to the calculated vertical ring diameter; chaining according to chain length or number of rings requirements; welding open flat rings to form a semi-finished chain; and processing the semi-finished chain to finally form the product. This invention, without changing the original compact chain's type, structure, and strength, uses raw materials with a vertical ring diameter smaller than the flat ring diameter. The resulting mining-grade compact chain has flat rings with the same tensile strength as vertical rings. During use, not only do the flat and vertical rings exhibit consistent stress deformation, but the structure is also more rational and the ductility is superior. This invention also provides a mining-grade constant-strength compact chain.

Description

Technical Field

[0001] This invention relates to the field of compact chain technology for mining, and in particular to a compact chain of equal strength for mining and its manufacturing method. Background Technology

[0002] Mining chains are used as a transmission medium in coal mine face conveyors and are widely used in various coal mine equipment such as scraper conveyors and transfer conveyors, playing a crucial role in coal transportation.

[0003] Currently, the flat rings of the compact chains used in coal mine working faces are welded round rings (the size and type of the flat rings are consistent with those of round ring chains), while the vertical rings are composed of hot-extruded or forged rings with flattened sides and reduced outer width. According to MT / T929 "High-Strength Compact Chains for Mining," the diameter of the vertical rings of the same specification of compact chains is the same as that of the flat rings. However, due to the different manufacturing processes used for the flat and vertical rings, their strengths differ, with the vertical rings generally being stronger than the flat rings. When compact chains produced according to this standard are in use, the different tensile loads that the flat and vertical rings can withstand result in the deformation and elongation mainly concentrated in the flat rings under tensile loads. This leads to inconsistent deformation and elongation between the flat and vertical rings under tensile loads, resulting in an unreasonable distribution of the overall extensibility of the compact chain. Furthermore, since the diameter of the vertical rings in compact chains is the same as that of the flat rings, but the overall strength of the chain depends on the relatively shorter flat rings, there is a problem of raw material waste during the production of the vertical rings. Summary of the Invention

[0004] In order to solve the technical problems existing in the above-mentioned technologies, it is necessary to provide a method for manufacturing a compact chain of equal strength for mining.

[0005] A method for manufacturing a compact chain of equal strength for mining applications includes the following steps:

[0006] S1: Determine the compact chain size specifications based on production requirements;

[0007] S2: Determine the flat ring diameter based on the selected compact chain size specification;

[0008] S3: Based on the selected flat ring diameter, process the test sample flat ring of the corresponding specification;

[0009] S4: Perform a breaking load test on the test sample flat ring and record the breaking load value of the test sample flat ring;

[0010] S5: Set the breaking load value of the flat ring to be the same as that of the vertical ring, and calculate the diameter of the vertical ring based on the breaking load value of the flat ring of the test sample measured in step S4.

[0011] S6: Process flat ring blanks of corresponding specifications according to the determined flat ring diameter, and at the same time process vertical rings of corresponding specifications according to the calculated vertical ring diameter.

[0012] S7: According to the chain length or number of rings requirements, use a special compact chain weaving equipment to weave the produced flat ring blanks and vertical rings into a long chain with a specified number of rings in an alternating splicing manner;

[0013] S8: Using a flash butt welding machine, the open flat ring is welded and closed to form a semi-finished chain;

[0014] S9: The semi-finished chain undergoes heat treatment, pre-stretching, length measurement and matching, and rust prevention treatment to finally form the product.

[0015] Preferably, in step S5, when calculating the size of the vertical ring, the diameter of the vertical ring can be calculated based on the principle that tensile tension equals cross-sectional area multiplied by tensile stress, when the breaking load of the vertical ring reaches the same condition as the breaking load of the flat ring.

[0016] Preferably, in step S6, the vertical ring is manufactured by forging.

[0017] Preferably, in step S6, the vertical ring is processed in the following manner: short bars of predetermined size are sawn according to the product diameter specifications, the short bars are heated to a predetermined temperature, and then the short bars are die-forged using forging equipment and a vertical ring mold. The dimensions of the vertical ring are ensured by trimming and straightening. The forged vertical ring is then normalized to remove surface stress, and finally shot-blasted to remove oxide scale.

[0018] Preferably, in step S6, the flat ring blank is processed in the following manner: the round bar of a predetermined length is cut according to the flat ring specification dimensions, the round bar is heated to a predetermined temperature, and the heated round bar is pressed into a blank of a predetermined shape using a hydraulic press.

[0019] Preferably, when heating round bars, the temperature needs to be raised to 800℃~850℃.

[0020] Preferably, in step S7, the processed flat ring blank is first heated to a predetermined temperature, and a pre-forged vertical ring is inserted into it. Using a dedicated compact chain weaving equipment and a pre-made chain weaving mold, the flat ring blank is bent into an open flat ring of a predetermined shape, thereby forming the first chain link. After the first chain link is completed, the flat ring blank is simultaneously inserted into a forged vertical ring and the vertical ring in the first chain link, and the flat ring blank is bent into an open flat ring of a predetermined shape. Finally, according to the chain length or number of links required, a long chain with a specified number of links is woven by alternating splicing, and the long chain is subjected to rust removal treatment.

[0021] Preferably, the heating temperature of the flat ring billet is 850–900℃.

[0022] A mining-grade equal-strength compact chain is prepared using the aforementioned mining-grade equal-strength compact chain manufacturing method.

[0023] As can be seen from the above technical solution, the mining-grade compact chain manufacturing method provided by the present invention, under the condition of meeting the mechanical performance requirements of the overall chain and without changing the original compact chain's shape, structure, and strength, uses raw materials with a vertical ring diameter smaller than the horizontal ring diameter. The resulting mining-grade compact chain has a horizontal ring tensile strength that is consistent with that of the vertical ring. During use, not only do the horizontal and vertical rings tend to deform under stress in a consistent manner, resulting in a more reasonable structure and better ductility, but it also saves raw material consumption, reduces production costs, and makes rational use of resources. Attached Figure Description

[0024] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the structure of a compact chain for mining in the prior art.

[0026] Figure 2 This is a schematic diagram of the structure of the compact mining chain produced by the present invention.

[0027] Figure 3 This is a graph of the fracture test in Embodiment 1 of the present invention.

[0028] Figure 4 This is a graph of the fracture test in Embodiment 2 of the present invention.

[0029] In the diagram: Horizontal ring 01, Vertical ring 02. 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] In the description of this invention, it should be understood that the terms "upper", "middle", "outer", "inner", "lower", etc., which indicate orientation or positional relationship, are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the components or elements referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting this invention.

[0032] Example 1:

[0033] A method for manufacturing a compact chain of equal strength for mining applications includes the following steps:

[0034] S1: Select 48×152-C specification mining compact chain according to production needs;

[0035] S2: Based on the selected compact chain size specification, determine the diameter of flat ring 01 to be Φ48mm;

[0036] S3: Based on the selected diameter of the flat ring 01, use 23MnNiMoCr54 high-quality alloy steel to process the test sample flat ring 01 of the corresponding specifications.

[0037] S4: Perform a breaking load test on the test sample flat ring 01 and record the breaking load value of the test sample flat ring 01 as 3000kN;

[0038] S5: Set the breaking load value of the flat ring 01 to be the same as that of the vertical ring 02. According to the principle that tensile tension equals cross-sectional area multiplied by tensile stress, the diameter of the vertical ring 02 when the breaking load of the vertical ring 02 reaches the same condition as that of the flat ring 01 is calculated to be Φ46.5mm.

[0039] S6: According to the determined diameter of the flat ring 01, select 23MnNiMoCr54 high-quality alloy steel to process the flat ring 01 blank of the corresponding specification; cut the round bar of the predetermined length according to the specifications of the flat ring 01, heat the round bar to 800℃~850℃, and use hydraulic press equipment to press the heated round bar into a blank of the predetermined shape.

[0040] Simultaneously, based on the calculated diameter of the vertical ring 02, high-quality 23MnNiMoCr54 alloy steel was selected, and the vertical ring 02 of the corresponding specifications was processed by forging. Short bars of the predetermined size were sawn according to the product diameter specifications. After heating the short bars to the predetermined temperature, the short bars were forged using forging equipment and a vertical ring 02 mold. The dimensions of the vertical ring 02 were ensured by trimming and straightening. The forged vertical ring 02 was normalized to remove surface stress and finally shot blasted to remove oxide scale.

[0041] S7: First, heat the processed flat ring 01 blank to 850-900℃, insert a pre-forged vertical ring 02, and use a special compact chain weaving equipment and a pre-made chain weaving mold to bend the flat ring 01 blank into an open flat ring 01 of a predetermined shape, thereby forming the first chain link; after the first chain link is completed, insert the flat ring 01 blank into a forged vertical ring 02 and the vertical ring 02 in the first chain link at the same time, and then bend the flat ring 01 blank into an open flat ring 01 of a predetermined shape; finally, according to the chain length or number of links required, use an alternating splicing method to weave a long chain with a specified number of links, and perform rust removal treatment on the long chain;

[0042] S8: Using a flash butt welding machine, the open flat ring 01 is welded and closed to form a semi-finished chain;

[0043] S9: The semi-finished chain undergoes heat treatment, pre-stretching, length measurement and matching, and rust prevention treatment to finally form the product.

[0044] Three 48×152-C mining compact chains produced according to the method in Example 1 were taken, and tests were conducted on the elongation at break, breaking load, and total elongation at break for the three 48×152-C mining compact chains. The specific test results are shown in Table 1.

[0045] Table 1

[0046]

[0047] Please refer to Figure 3 , Figure 3 The graph shows the fracture test results for a 48×152-C mining compact chain. Figure 3 It can be clearly determined that the load at which the compact chain breaks far exceeds the standard value, and its performance indicators meet the requirements of MT / T929 "High-strength Compact Chain for Mining".

[0048] Example 2:

[0049] A method for manufacturing a compact chain of equal strength for mining applications includes the following steps:

[0050] S1: Select 42×146-C specification mining compact chain according to production needs;

[0051] S2: Based on the selected compact chain size specification, determine the diameter of flat ring 01 to be Φ42mm;

[0052] S3: Based on the selected diameter of the flat ring 01, use 23MnNiMoCr54 high-quality alloy steel to process the test sample flat ring 01 of the corresponding specifications.

[0053] S4: Perform a breaking load test on the test sample flat ring 01 and record the breaking load value of the test sample flat ring 01 as 2400kN;

[0054] S5: Set the breaking load value of the flat ring 01 to be the same as that of the vertical ring 02. According to the principle that tensile tension equals cross-sectional area multiplied by tensile stress, the diameter of the vertical ring 02 when the breaking load of the vertical ring 02 reaches the same condition as that of the flat ring 01 is calculated to be Φ39mm.

[0055] S6: According to the determined diameter of the flat ring 01, select 23MnNiMoCr54 high-quality alloy steel to process the flat ring 01 blank of the corresponding specification; cut the round bar of the predetermined length according to the specifications of the flat ring 01, heat the round bar to 800℃~850℃, and use hydraulic press equipment to press the heated round bar into a blank of the predetermined shape.

[0056] Simultaneously, based on the calculated diameter of the vertical ring 02, high-quality 23MnNiMoCr54 alloy steel was selected, and the vertical ring 02 of the corresponding specifications was processed by forging. Short bars of the predetermined size were sawn according to the product diameter specifications. After heating the short bars to the predetermined temperature, the short bars were forged using forging equipment and a vertical ring 02 mold. The dimensions of the vertical ring 02 were ensured by trimming and straightening. The forged vertical ring 02 was normalized to remove surface stress and finally shot blasted to remove oxide scale.

[0057] S7: First, heat the processed flat ring 01 blank to 850-900℃, insert a pre-forged vertical ring 02, and use a special compact chain weaving equipment and a pre-made chain weaving mold to bend the flat ring 01 blank into an open flat ring 01 of a predetermined shape, thereby forming the first chain link; after the first chain link is completed, insert the flat ring 01 blank into a forged vertical ring 02 and the vertical ring 02 in the first chain link at the same time, and then bend the flat ring 01 blank into an open flat ring 01 of a predetermined shape; finally, according to the chain length or number of links required, use an alternating splicing method to weave a long chain with a specified number of links, and perform rust removal treatment on the long chain;

[0058] S8: Using a flash butt welding machine, the open flat ring 01 is welded and closed to form a semi-finished chain;

[0059] S9: The semi-finished chain undergoes heat treatment, pre-stretching, length measurement and matching, and rust prevention treatment to finally form the product.

[0060] Three 42×146-C mining compact chains produced according to the method in Example 2 were taken, and tests were conducted on the elongation at break, breaking load, and total elongation at break for the three 42×146-C mining compact chains. The specific test results are shown in Table 2.

[0061] Table 2

[0062]

[0063]

[0064] Please refer to Figure 4 , Figure 4 A graph showing the fracture test results for a 42×146-C mining compact chain, from... Figure 4 It can be clearly determined that the load at which the compact chain breaks far exceeds the standard value, and its performance indicators meet the requirements of MT / T929 "High-strength Compact Chain for Mining".

[0065] The above-disclosed embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of the invention. Those skilled in the art will understand that implementing all or part of the above-described embodiments and making equivalent changes in accordance with the claims of the present invention are still within the scope of the invention.

Claims

1. A method of manufacturing a mine-duty equal strength compact chain, characterized by: It comprises the following steps, S1: determining the compact chain size specification according to production requirements; S2: determining the flat ring diameter according to the selected compact chain size specification; S3: processing the test sample flat ring of the corresponding specification according to the selected flat ring diameter; S4: detecting the breaking load of the test sample flat ring and recording the breaking load value of the test sample flat ring; S5: setting the breaking load value of the flat ring to be the same as that of the vertical ring, calculating the vertical ring diameter according to the breaking load value of the test sample flat ring determined in step S4; when calculating the vertical ring size, the tensile stress is equal to the cross-sectional area multiplied by the tensile stress, and the vertical ring diameter when the breaking load of the vertical ring reaches the same condition as the breaking load of the flat ring is calculated; S6: processing the flat ring blank of the corresponding specification according to the determined flat ring diameter, and processing the vertical ring of the corresponding specification according to the calculated vertical ring diameter; S7: according to the chain length or ring number requirement, using the special compact chain weaving equipment to weave the produced flat ring blank and vertical ring in an alternating and continuous manner to form a long chain with a specified number of rings; S8: using a flash butt welding machine to weld and close the open flat ring to form a semi-finished chain; S9: performing heat treatment process, pre-stretching process, length measurement and pairing, and rust prevention treatment on the semi-finished chain to finally form a product.

2. The method of manufacturing an iso-strength compact chain for mining as claimed in claim 1, wherein: In the step S6, the vertical ring is processed by forging.

3. The method of producing a mine-resistant compact chain of uniform strength according to claim 2, characterized in that: In the step S6, the vertical ring is processed in the following manner: short rod stock of a predetermined size is sawn according to the product diameter specification, the short rod stock is heated to a predetermined temperature, and then the short rod stock is formed by die forging using a forging equipment and a vertical ring die. After edge cutting and correction to ensure the size of the vertical ring, the forged vertical ring is normalized to remove surface stress, and finally shot blasting treatment is performed to remove the oxide scale.

4. The method of claim 1, wherein: In the step S6, the flat ring blank is processed in the following manner: round rod stock of a predetermined length is sawn according to the flat ring specification size, the round rod stock is heated to a predetermined temperature, and then the heated round rod stock is pressed into a blank of a predetermined shape using a hydraulic machine.

5. The method of claim 4, wherein: When heating the round rod stock, it needs to be heated to 800-850°C.

6. The method of claim 1, wherein: In the step S7, the processed flat ring blank is first heated to a predetermined temperature, a previously forged vertical ring is inserted, a special compact chain weaving equipment and a pre-prepared weaving die are used to bend the flat ring blank into an open flat ring of a predetermined shape, thereby forming a first chain ring. After the first chain ring is completed, the flat ring blank is inserted into a forged vertical ring and a vertical ring in the first chain ring at the same time, and then the flat ring blank is bent into an open flat ring of a predetermined shape. Finally, according to the chain length or ring number requirement, a long chain with a specified number of rings is woven in an alternating and continuous manner, and the long chain is subjected to rust removal treatment.

7. The method of producing an iso-strength compact chain for mining as claimed in claim 6, characterized in that: The heating temperature of the flat ring blank is 850-900°C.

8. A mine-duty equal strength compact chain characterized by: The mine equal-strength compact chain is prepared by the mine equal-strength compact chain manufacturing method of any one of claims 1 to 7.

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