CN114535495A

CN114535495A - Manufacturing process of mining round-link chain

Info

Publication number: CN114535495A
Application number: CN202210175631.1A
Authority: CN
Inventors: 王瑞丰
Original assignee: Individual
Current assignee: Individual
Priority date: 2022-02-25
Filing date: 2022-02-25
Publication date: 2022-05-27

Abstract

The invention relates to the field of round-link chains, and particularly discloses a manufacturing process of a mining round-link chain, which comprises the following steps of prefabricating a bar stock, manufacturing two ends of the bar stock into overlapping parts, arranging a locking groove on each overlapping part, prefabricating a locking pin, bending the bar stock into a special-shaped ring body formed by two U-shaped parts, connecting the special-shaped ring body with a chain ring, driving the two U-shaped parts to relatively twist around a central shaft of the middle section of the bar stock, deforming the special-shaped ring body into the chain ring, butting the locking grooves to form a locking hole, installing and fixing the locking pin in the locking hole, and finally sequentially carrying out surface treatment, heat treatment and round-link chain molding post-treatment. In the process, the chain link joint is fixedly connected in a locking piece mode, the structure is stable and reliable, the defect that the welding position of the joint is easy to break in the past is overcome, longitudinal upsetting is not needed in the chain link processing process, the size and shape standards of the chain links woven into the same circular chain are guaranteed, the stress of the chain links is balanced in the working process, the abrasion speed is reduced, and the transmission efficiency is improved.

Description

Manufacturing process of mining round-link chain

Technical Field

The invention relates to the technical field of round-link chains, in particular to a manufacturing process of a round-link chain for a mine.

Technical Field

The round-link chain is widely applied to mining mechanical equipment, is often used as a traction part in important mining equipment such as a coal planer, a scraper conveyor, a reversed loader and the like, and once the chain is broken in the working process, the whole working surface is stopped, even safety accidents are caused, so that the round-link chain has extremely high requirements on safety. At present, the manufacturing process of the mining round-link chain is mostly consistent, bar materials are usually manufactured by blanking high-strength alloy steel, a chain knitting machine is utilized to bend the long round-link chain consisting of two straight arms and two arc-shaped ends and to knit the long round-link chain into the chain, and finally, joints are welded to manufacture the mining round-link chain. The existing statistical data show that in the condition of chain breakage of the mining round-link chain, the chain ring breakage position is mostly in a welding area, but the reason is that although the joint can obtain higher strength compared with the joint adopting welding in other connection modes, shallow cracks on the surface are easy to be generated at the welding joint due to the influence of factors such as material difference of welding materials and parent metal, existence of welding defects, retention of residual stress and the like, and the shallow cracks are difficult to be found in time in daily maintenance, become the largest potential safety hazard in working operation and are the main inducement of breakage at the welding joint, and particularly when a motor is overloaded and blocked and the working load is increased sharply, the welding joint with cracks is easier to break compared with other parts of the chain ring.

The link of the existing mining round-link chain is usually formed by bending a bar stock and is of a single-joint structure, the joint is welded in a flash butt welding mode, the link is subjected to upsetting force in the flash butt welding process to be longitudinally shortened integrally, certain material loss exists in the two joints due to the fact that a melting substance on a joint surface is extruded out, the other straight arm of the two joints is not correspondingly shortened in a shaping deformation mode, and the material loss does not exist, so that the sizes and the shapes of the two straight arms of the link are unequal; meanwhile, the balance of plastic deformation generated by a straight arm without a joint in the upsetting process is difficult to pre-control, and even obvious uneven deformation such as local bending, local coarseness and the like can occur; in addition, the two arc-shaped ends are pressed during the upsetting process, so that certain deformation is generated and the deformation state is difficult to control; due to the above factors, the chain ring shape of the round-link chain produced and manufactured by the existing process is not standard and uniform, the stress distribution of the chain rings is unbalanced in the working process, and unfavorable phenomena such as chain jumping, tooth punching, tooth disengaging difficulty and the like easily occur due to poor matching among the chain rings and between the chain rings and the chain teeth, so that the abrasion rate of the mining round-link chain is increased, and the phenomenon is one of important reasons for the short service life of the existing round-link chain due to the fact that the chain is easy to break.

Disclosure of Invention

In order to overcome the defects of the existing mining round-link chain, the invention provides a brand-new manufacturing process of the mining round-link chain.

In order to achieve the technical purpose, the invention adopts the following technical scheme:

a manufacturing process of a mining round-link chain comprises the following steps:

a. prefabricating and pretreating bar stock

Blanking an alloy steel raw material to obtain a bar stock, straightening the bar stock to enable the bar stock to be close to a standard cylinder, cutting two end parts of the bar stock to respectively prepare semi-cylindrical lap joint parts, arranging a locking groove on the lap joint parts, chamfering two end openings of the locking groove, removing residual excess materials on the bar stock and ensuring that no burrs exist at the cutting part of the lap joint part;

b. prefabricated locking pin

Manufacturing a locking pin by using alloy steel which is made of the same material as the bar stock, wherein the locking pin is columnar, has a length larger than the outer diameter of the bar stock and has a 8-shaped cross section;

c. chaining

c1, fixing the middle section of the bar stock, and respectively bending the parts at the two sides of the middle section by 180 degrees in the plane where the plane side wall of the corresponding lapping part is located, so that the bar stock is forced to be plastically deformed to form two integrally connected U-shaped parts, and the bar stock is prefabricated into a non-closed special-shaped ring body; in the special-shaped ring body, the two U-shaped parts have the same size parameters and are respectively the same as the relative position relations of the corresponding lapping parts, the lapping parts are regarded as semi-cylinders, one lapping part and a locking groove thereof are in plane symmetry with the other lapping part and a locking groove thereof, the central shaft of the middle section of the bar is positioned on the symmetrical plane of the two lapping parts, and a gap is arranged between the two lapping parts for buckling and connecting with the adjacent chain links;

c2, taking a special-shaped ring body, buckling and connecting the special-shaped ring body with a chain ring to be connected by virtue of a gap between two overlapping parts, respectively clamping arc ends of the two U-shaped parts, driving the two U-shaped parts to relatively twist around a central shaft of the middle section of the bar material, enabling the two overlapping parts to be spliced and butted to form a cylindrical structure, enabling the two U-shaped parts to be positioned in the same plane to form a closed chain ring with two straight arms and two arc ends, enabling locking grooves on the two overlapping parts to be butted and communicated to form a locking hole with a cross section being 8-shaped and capable of containing a locking pin, and enabling chamfers at ports of the locking grooves to be butted with each other to enable two ends of the locking hole to form a groove;

c3, inserting the locking pin into the locking hole, extruding the two ends of the locking pin by using pressure equipment, so that the two ends of the locking pin are subjected to plastic deformation and accumulated in grooves at the two ends of the locking hole, and removing the parts of the two ends of the locking pin, which protrude out of the outer side wall of the overlapping part, so as to ensure that the outer wall at the joint of the chain link is smooth and neat;

d. surface treatment and heat treatment

Carrying out surface treatment on the newly knitted chain ring along with the progress of chain knitting to remove impurities and burrs on the surface of the chain ring, and carrying out heat treatment to improve the physical performance;

e. post-processing of round link chain

The round-link chain is woven to the preset length by adopting the mode, the formed round-link chain is subjected to tensile correction, and the round-link chain can be subjected to paint dipping and warehousing after inspection and pairing.

Compared with the prior art, the manufacturing process of the mining round-link chain disclosed by the invention has the following technical effects:

the joint of the chain ring is fixedly connected in a locking piece mode, so that the structure is stable and reliable, compared with the traditional welding mode, the existence of obvious adverse factors such as welding defects, different expansion coefficients of welding materials and base materials, a heat affected zone and the like is eliminated, cracks are not easy to generate at the joint, the main inducement that the joint of the traditional circular chain is easy to break is overcome, and the defect that the joint of the traditional circular chain is easy to break is overcome; based on the specific forming mode of the chain ring in the process, longitudinal upsetting is not needed in the chain ring processing process, two straight arms of the chain ring formed in a closed mode are straight and tend to be the same in shape, the whole chain ring is hardly accidentally deformed in the manufacturing process, the size and shape of the chain ring which is woven into the same circular chain are standard and uniform, the stress distribution of the chain ring is more balanced in the working process, and high-speed abrasion caused by the fact that the size and the shape of the chain ring are not matched is reduced; in conclusion, the mining round-link chain produced and manufactured by the manufacturing process is not easy to break, low in abrasion rate, more stable in performance, remarkably improved in safety and service life, and meanwhile, the transmission efficiency of the round-link chain is improved to a certain extent due to the fact that the shape and size standards of the chain links are the same.

Drawings

FIG. 1 is a schematic view of the initial configuration of a bar.

FIG. 2 is a schematic view of the structure of the bar stock after the lap joints are formed at the two ends of the bar stock.

FIG. 3 is a schematic view of the relative positions of the laps at the ends of the billet.

Fig. 4 is a schematic structural view of the lap joint part after a locking groove is formed.

FIG. 5 is a schematic view of the configuration of the end of the bar.

Fig. 6 is a schematic structural view of the locking pin.

FIG. 7 is a schematic view of a forming process of bending a bar into a shaped ring body.

Fig. 8 is a schematic structural diagram of the shaped ring after molding.

Fig. 9 is a schematic diagram of the relative positions of two overlapping parts in the special-shaped ring body.

FIG. 10 is a schematic view of the process of twisting the profiled rings into a chain ring.

FIG. 11 is a schematic view of the chain link after forming.

FIG. 12 is a schematic view showing the engagement of the overlapping portions after the formation of the chain link.

Fig. 13 is a schematic structural view after the locking pin is inserted into the locking hole.

Fig. 14 is a schematic structural view of the two overlapping portions and the locking pin after they are firmly connected.

Fig. 15 is a schematic structural view of a plurality of sets of locking pins and locking holes on two overlapping parts.

In the figure, 1, a bar stock 101, a lap joint part 102, a locking groove 103, a middle section 2, a locking pin 3, a special-shaped ring body 301, a U-shaped part 4, a chain ring 401, an arc-shaped end 402, a straight arm 5, a locking hole 501 and a groove.

Detailed Description

The following describes the manufacturing process of the mining round-link chain disclosed by the invention in detail with reference to the embodiment.

The 23MnNiMoCr54 alloy steel is a relatively common mining chain steel, the mining round-link chain manufactured by the alloy steel has the characteristics of good grinding performance, high fatigue times, high strength, strong impact resistance, large bearing load and the like, and the bar 1 and the locking pin 2 are both made of 23MnNiMoCr54 alloy steel in the application.

a. Prefabricating and pretreating bar stock

As shown in fig. 1, according to the requirement of the model of the round-link chain to be produced for the mine, alloy steel round steel or wire rods with corresponding specifications are selected for straightening, blanking is carried out by using a precise bar shearing machine to prepare a bar 1 with a preset length, the bar 1 is straightened by using a straightening machine, the shape of the bar 1 tends to a standard cylinder, inspection and screening can be carried out in a test station mode, and secondary straightening is carried out on the bar 1 with unqualified degree; as shown in fig. 2 and 3, the straightened bar 1 is clamped and fixed by a clamp, and two ends of the bar 1 are respectively cut by a precision cutter, so that two ends of the bar 1 respectively form semi-cylindrical lapping parts 101, and the included angle of the planes of the plane side walls of the two lapping parts 101 is ^ alpha; as shown in fig. 4 and 5, a locking groove 102 is formed in the overlapping part 101, and two ports of the locking groove 102 are chamfered, wherein the cross section of the locking groove 102 is C-shaped, and the side opening is located on the planar side wall of the overlapping part 101, and the extending direction of the locking groove 102 is parallel to the end plane of the overlapping part 101 where the locking groove 102 is located; after the pretreatment is finished, removing residual materials on the bar stock 1, and ensuring that no burrs exist at the part of the lap joint part 101 for cutting and grooving;

b. prefabricated locking pin

As shown in fig. 6, a locking pin 2 is made of alloy steel 23MnNiMoCr54 which is the same as the bar material, the locking pin 2 is columnar, the length of the locking pin is greater than the outer diameter of the bar material, and the cross section of the locking pin 2 is 8-shaped;

c. chaining

c1, as shown in fig. 7-9, taking a preprocessed bar stock 1, fixing the middle section 103 of the bar stock 1 by using a clamp, respectively performing bending processing on parts at two sides of the middle section 103 in a plane where the plane side walls of the corresponding overlapping parts 101 are located, wherein the bending angle is 180 degrees, so that the bar stock 1 is forced to be plastically deformed to form two U-shaped parts 301, and the two U-shaped parts 301 are connected into an integral structure through the middle section 103 of the bar stock 1, thereby prefabricating the bar stock 1 into a non-closed special-shaped ring body 3, wherein a gap is formed between the two overlapping parts 101 and can be used for buckling and connecting the special-shaped ring body 3 with an adjacent chain ring 4; in the special-shaped ring body 3 prepared in the above way, the two U-shaped parts 301 have the same size parameters and the same relative position relationship with the corresponding lapping part 101, if the lapping part 101 is regarded as an independent semi-cylinder, one lapping part 101 and the locking groove 102 thereof are in plane symmetry with the other lapping part 101 and the locking groove 102 thereof by a plane β, and the central axis of the middle section 103 of the bar material is just positioned on the plane β;

2, referring to fig. 10, 11, 12 and 13, a special-shaped ring body 3 is taken, and is buckled with a chain ring 4 to be connected by a gap between two overlapping parts 101, namely, the special-shaped ring body is connected into a woven circular chain, two rotatable clamps are used for clamping and fixing the arc ends of the two U-shaped parts 301 respectively, the two U-shaped parts 301 are driven to relatively twist around the central axis of the middle section 103 of the bar 1, so that the plane side wall of one overlapping part 101 gradually approaches against the plane side wall of the other overlapping part 101, based on the shape characteristics of the special-shaped ring body 3, finally the plane side walls of the two overlapping parts 101 are butted and overlapped, namely, the two overlapping parts 101 are spliced to form a cylindrical structure, at the moment, the two U-shaped parts 301 are positioned in the same plane to form a closed long circular chain ring 4, the chain ring 4 is provided with two straight arms 402 and two arc ends 401, the locking grooves 102 on the two overlapping parts 101 are butted and communicated to form a locking hole 5, the section of the locking hole 5 is in an 8 shape and is just suitable for the locking pin 2 to pass through, and chamfers at the ports of the locking grooves 102 are mutually butted to form a bell-mouth-shaped groove 501 at two ends of the locking hole 5;

c3, referring to fig. 13 and 14, inserting the locking pin 2 into the locking hole 5, and simultaneously pressurizing from two ends of the locking pin 2 by using pressure equipment, wherein the part of the locking pin 2 located in the locking hole 5 is limited by space and cannot be deformed, and two ends located outside the locking hole 5 are subjected to plastic deformation and accumulated in the grooves 501 at two ends of the locking hole 5, so that the two overlapping parts 101 and the locking pin 2 are stably connected; the parts of the two ends of the locking pin 2 protruding out of the outer side wall of the overlapping part 101 are removed by using a cutter or a grinding tool so as to ensure that the outer wall of the joint of the chain ring 4 is smooth and tidy;

d. surface treatment and heat treatment

With the progress of chain knitting, the newly knitted chain ring 4 is sequentially subjected to surface treatment and heat treatment, wherein the surface treatment is used for removing impurities and burrs on the surface of the chain ring 4, and the heat treatment is used for improving the physical performance of the ring chain;

e. post-processing of round link chain

After the round-link chain is woven to the preset required length in the mode, a full-automatic stretching correction machine is adopted to perform stretching correction on the formed round-link chain, and the stretching load is 85% of the breaking load, so that the performance of the round-link chain is optimized; and then, inspecting items such as surface quality, size, breakage and the like of the round-link chain, pairing the round-link chain after the round-link chain is qualified, and finally, dipping paint and warehousing.

Referring to fig. 1, 10 and 11, in the manufacturing process of the mining round-link chain, the chain link 4 is not directly bent into a long circle in the same plane by the bar stock 1, but first prefabricates the bar stock 1 into a special-shaped ring body 3 consisting of two integrally connected U-shaped parts 301, then the special-shaped ring body 3 is deformed into the long round chain ring 4 by a twisting mode, based on the process characteristics, on one hand, the two lapping parts 101 can be in tighter butt joint fit, the joint tends to be seamless by processing in a high-precision mode in the prior art, so that the stability of the joint is improved, and on the other hand, in the process of twisting the two U-shaped portions 301, the middle section 103 of the bar 1 is subjected to plastic torsional deformation, so that the physical properties of the middle section 103 of the bar 1 can be improved to a certain extent, and the whole strength of the chain ring 4 is increased to a certain extent.

Referring to fig. 14, in the mining round-link chain produced by the process, as the joints of the chain links 4 are connected in a locking piece mode, the structure is more stable and reliable, compared with the traditional welding mode, the influence of obvious adverse factors such as welding defects, different expansion coefficients of welding materials and base materials, a heat affected zone and the like is avoided, cracks are not easy to generate at the joints, the main inducement that the joints of the chain links 4 are easy to break in the prior art is eliminated, and the defect that the joints of the round-link chain are easy to break in the prior art is overcome.

Referring to fig. 14, the stress state of the mining round-link chain during operation is relatively complex, but the mining round-link chain generally mainly takes longitudinal tension as a main part, the mining round-link chain is intensively acted on the inner sides of two arc ends and then is transmitted to the whole chain link 4, and the maximum load borne by the joint formed by the two overlapping parts 101 of the chain link 4 and the straight arm 402 where the joint is located are both in the longitudinal direction; in the mining round-link chain produced by the process, the cross section of the overlapping part 101 is semicircular, so that the joint formed by abutting the overlapping part 101 is lower in tensile strength compared with the conventional welded joint, but the straight arm 402 where the joint is located does not bear force independently when the longitudinal load is handled, and shares the joint with the other straight arm 402 together, and based on the stress characteristic of the chain ring 4, the overlapping part 101 and the joint formed by abutting the overlapping part 101 have enough capacity to handle the maximum load borne by the chain ring, but not the weak part which is most prone to fracture in the chain ring 4; meanwhile, due to the fact that a plurality of adverse factors existing in the welding process are avoided through the connection mode in the process, the connection mode is more stable and reliable, cracks are not prone to being generated at the joint, and the shape of the chain ring 4 is standard, stress is balanced in the working process, and the joint is not prone to being broken compared with the existing welding mode; in addition, because the middle section 103 of the bar stock 1 is twisted to generate plastic deformation in the manufacturing process, the mechanical performance of the corresponding straight arm 402 is improved to a certain extent, more loads can be shared in the working process of the chain link 4, the risk that the lap joint 101 and the joint formed by butt joint of the lap joint 101 are broken is reduced, and the overall tensile performance of the chain link 4 is improved.

Referring to fig. 3 and 7, in the manufacturing process of the mining circular link, after two ends of a bar material 1 are respectively cut to form overlapping parts 101, the included angle of the planes of the plane side walls of the two overlapping parts 101 is ≤ α, and the process has two requirements on the value of ≤ α; on one hand, after the bar 1 is bent into the special-shaped ring body 3, the size of the gap between the two overlapping parts 101 is directly determined by the angle alpha, and the numerical value of the angle alpha is required to ensure that the gap can be used for buckling the special-shaped ring into the adjacent chain ring 4 so as to carry out subsequent chain knitting operation; on the other hand, in the chain knitting link, the two U-shaped parts 301 are twisted to ensure that the twisting angle when the two U-shaped parts form the closed long circular chain ring 4 is directly determined by the angle alpha, and the value of the angle alpha is required to ensure that the twisting angle is in a reasonable range, so that the middle section 103 of the bar stock 1 can obtain remarkable improvement of physical performance through torsional deformation; therefore, an optimal numerical range can be obtained by debugging, detecting and comparing based on the two requirements.

Referring to fig. 14, in the manufacturing process of the round-link chain for the mine, based on the specific forming mode and the joint connecting mode of the round-link chain, the flash butt welding link does not exist in the processing process of the chain ring 4, and further the upsetting in the length direction is not needed, that is, in the process after the chain ring 4 is formed, it is not deformed by being forced in the longitudinal direction, so that the two straight arms 402 of the chain link 4 are straight and have the same size, the shapes of the two arc ends 401 are consistent, the size and the shape of all the chain links 4 woven into the same circular chain are standard and uniform, the stress distribution of each chain ring 4 is more equal and balanced in the working process, and the high-speed abrasion between the chain rings 4 and the chain wheel, which is caused by the non-standard mismatch of the sizes and the shapes of the chain rings 4, is reduced, so that the performance of the round-link chain is more stable, and the safety and the service life are obviously improved; meanwhile, as the shape and size standards of the chain ring 4 are the same, the chain ring has good matching with the chain wheel in the working process, and the transmission efficiency of the round-link chain is improved to a certain extent.

Referring to fig. 14 and 15, in the manufacturing process of the round-link chain for mining, two overlapping parts 101 mainly depend on the matching of the locking pin 2 and the locking hole 5 to realize the corresponding locking and fixing effect, in order to avoid the joint of the two overlapping parts 101 being a weak point affecting the overall strength of the chain ring 4, the locking pins 2 and the locking holes 5 can be arranged in a plurality of groups according to the practical conditions of the size specification, the strength requirement and the like of the round-link chain, specifically, each lapping part 101 is provided with a plurality of locking grooves 102 which are distributed in parallel, the number of the locking grooves 102 on the two lapping parts 101 is the same, when the plane side walls of the two overlapping parts 101 are abutted and overlapped, the locking grooves 102 on the two overlapping parts 101 are correspondingly butted and communicated one by one to form a plurality of locking holes 5, each locking hole 5 is provided with a locking pin 2, whereby the plurality of locking holes 5 cooperate with the locking pin 2 to secure a sufficient strength at the junction of the two overlapping portions 101.

Referring to fig. 2, in the manufacturing process of the mining round-link chain, the overlapping part 101 is formed by cutting the end of the bar stock 1, if the length of the overlapping part 101 is too long, more material needs to be cut, the material cost and the process cost of the chain link 4 are increased, if the length of the overlapping part 101 is too short, a stable connection effect cannot be achieved, the factors are combined for debugging and comparison analysis, the optimal length of the overlapping part 101 is 1.5-2 times of the diameter of the bar stock 1, the manufacturing material cost of the chain link 4 is lower under the size, the manufacturing is easier, and the overlapping part 101 has enough space for arranging one or more locking grooves 102, so as to meet the strength requirement of the chain link 4 on the connection position of the two overlapping parts 101.

Referring to fig. 4 and 11, in the manufacturing process of the mining round-link chain, before the bar stock 1 is bent into the special-shaped ring body 3, a cutting surface generated in the manufacturing process of the overlapping part 101 and an end plane of the overlapping part 101 are ground by using a grinding tool, so that the dimensional accuracy of the overlapping part 101 is improved, the joint of the two overlapping parts 101 is tighter after the chain link 4 is formed, and the connection stability of the joint of the chain link 4 is ensured.

In the manufacturing process of the mining round-link chain, the bar stock 1 is bent into the special-shaped ring body 3 in a hot bending mode, before bending, the bar stock 1 is heated by using heating equipment, so that the temperature of the part to be bent is 800 plus 850 ℃, and the part to be bent has good plasticity at the temperature, thereby reducing the processing difficulty and improving the processing precision, and simultaneously avoiding the generation of cracks.

In the manufacturing process of the mining round-link chain, before the two U-shaped parts 301 are twisted relatively, the bar stock 1 is heated by using heating equipment, so that the temperature of the middle section 103 is 700-750 ℃, and the special-shaped ring body 3 is deformed into the closed long round-link chain 4 in a thermoforming manner; at the temperature, the middle section 103 of the bar 1 has good plasticity, so that the processing difficulty can be reduced, the closing precision of a joint can be improved, and meanwhile, the middle section 103 of the bar 1 can be prevented from generating cracks.

In the manufacturing process of the mining round-link chain, the locking pin 2 and the locking hole 5 are in interference fit, so that the connection stability of the locking pin and the locking hole is ensured.

Further, in the manufacturing process of the mining round link chain disclosed above, the process links of bending the bar stock 1 into the special-shaped ring body 3, relatively twisting the two U-shaped parts 301 and assembling the locking pin 2 in an interference manner are performed in sequence, and the corresponding temperature maintained by the bar stock 1 is decreased progressively, in view of this characteristic, in the process step of chaining, the whole bar stock 1 is heated to 800-850 ℃ in advance, the parts on the two sides of the middle section 103 are subjected to bending treatment, the bar stock 1 is bent into a special-shaped ring body 3, then the special-shaped ring body 3 is cooled in an air cooling mode, when the temperature of the middle section 103 is at 700-750 ℃, the two U-shaped parts 301 are twisted relatively, the special-shaped ring body 3 is deformed into the chain ring 4, and finally the chain ring 4 is cooled further in an air cooling mode, so that the locking pin 2 can be assembled in the locking hole 5 in an interference fit mode. Therefore, the process steps can be completed in sequence by utilizing the waste heat of the workpiece after the bar stock 1 is heated once, the processing efficiency can be obviously improved, and the process cost can be reduced.

In the manufacturing process of the mining round-link chain, in the heat treatment link, firstly, the pre-heat treatment is carried out through a normalizing process, the normalizing temperature is 820-; then quenching is carried out, the quenching temperature is 920-; through comparative analysis, after the circular chain is subjected to heat treatment by adopting the process parameters, the structure of the circular chain is more uniformly refined, and the tensile strength and the comprehensive mechanical property are improved to a certain extent.

Claims

1. The manufacturing process of the mining round-link chain is characterized by comprising the following steps:

a. prefabricating and pretreating bar stock

b. prefabricated locking pin

c. chaining

c2, taking a special-shaped ring body, connecting the special-shaped ring body with a chain ring to be connected in a buckled manner by virtue of a gap between two lap joint parts, respectively clamping the arc ends of the two U-shaped parts, driving the two U-shaped parts to relatively twist around the central shaft of the middle section of the bar material, splicing and butting the two lap joint parts to form a cylindrical structure, wherein the two U-shaped parts are positioned in the same plane to form a closed chain ring with two straight arms and two arc ends, the locking grooves on the two lap joint parts are butted and communicated to form a locking hole with a cross section in a shape of a Chinese character '8' and can contain a locking pin, and the chamfers at the ports of the locking grooves are butted with each other to form grooves at two ends of the locking hole;

d. surface treatment and heat treatment

e. post-processing of round link chain

2. The manufacturing process of the mining round-link chain according to claim 1, characterized in that: the bar stock and the locking pin are both made of 23MnNiMoCr54 alloy steel.

3. The manufacturing process of the mining round-link chain according to claim 1, characterized in that: all be provided with a plurality of parallel distribution's locking groove on every overlap joint portion, the locking groove quantity in two overlap joint portions is the same, and when the plane lateral wall of two overlap joint portions supported the top and overlaps, a plurality of locking groove one-to-one on two overlap joint portions butt joint intercommunication and form a plurality of locking holes, all installed the locking round pin on every locking hole.

4. The manufacturing process of the mining round-link chain according to claim 1, characterized in that: the length of the lap joint part is 1.5-2 times of the diameter of the bar stock.

5. The manufacturing process of the mining round-link chain according to claim 1, characterized in that: before the bar is bent into the special-shaped ring body, a cutting surface generated in the process of manufacturing the lapping part and an end plane of the lapping part are polished by a grinding tool, so that the size precision of the lapping part is improved.

6. The manufacturing process of the mining round-link chain according to claim 1, characterized in that: the method comprises the following steps of bending a bar into a special-shaped ring body in a hot bending mode, and heating the bar by utilizing heating equipment before bending so that the temperature of a part to be bent is 800-850 ℃.

7. The manufacturing process of the mining round-link chain according to claim 1, characterized in that: before the two U-shaped parts are twisted relatively, the bar stock is heated by utilizing heating equipment, so that the temperature of the middle section is 700-750 ℃, and the special-shaped ring body is deformed into a closed long-circle-shaped chain ring in a thermoforming mode.

8. The manufacturing process of the mining round-link chain according to claim 1, characterized in that: the locking pin and the locking hole are in interference fit.