Cold rolling equipment for low-bending forming of seamless steel pipe

Abstract

The invention discloses cold rolling equipment for low-curvature forming of seamless steel tubes, relates to the technical field of cold rolling of seamless steel tubes, and aims to solve the technical problems that a single roller body is adopted in the cold rolling equipment to bear excessive functions, stress is concentrated for a long time, and the finished product curvature over-standard rate is high. In the combined cold rolling assembly, the wear rate of the roller surface of a rolling roller is reduced through a surfacing high-chromium-nickel alloy layer, a tungsten carbide alloy layer cladded on the surface of a rough trimming roller and a molybdenum disulfide coating sprayed on a fine trimming roller are used for carrying out rough trimming on the steel pipe, and the wear rate of the surface of the steel pipe is reduced while the microstress of the surface of the steel pipe is homogenized. And the friction loss between the roller body and the steel pipe is greatly reduced. The combined cold rolling assembly is arranged, corresponding surface layer structures are arranged for the cold rolling assembly of each part, the stress during machining is reduced, the service life of the roller body is prolonged, and therefore the bending degree of steel pipe machining is stably controlled to a low degree.

Description

Technical Field

[0001] The present invention relates to the technical field of seamless steel pipe cold rolling, and more specifically, to a cold rolling device for low-bending forming of seamless steel pipes. Background Art

[0002] Cold rolling of steel pipes is a metal processing technology that cold-works hot-rolled steel pipes at room temperature to improve the dimensional accuracy, surface quality, and mechanical properties of the steel pipes. Compared with the hot rolling process, the metal material does not go through the heating process during cold rolling, so it has higher dimensional accuracy and surface finish, and at the same time can improve the strength and hardness of the material through work hardening.

[0003] However, in the existing seamless steel pipe cold rolling technology, a single roll is often used to undertake the functions of feeding, rolling, and straightening at the same time, resulting in long-term stress concentration in a local area of the roll surface. This not only makes it difficult to accurately control the bending degree of the steel pipe, and the over-standard rate of the finished product bending degree is relatively high, but also aggravates the wear of the roll. The roll needs to be replaced every time a certain amount of steel pipes are produced on average, and the maintenance cost is high. This further aggravates the bidding rate of the bending degree and is difficult to meet the production requirements of high-precision low-bending seamless steel pipes. In view of this, we propose a cold rolling device for low-bending forming of seamless steel pipes. Summary of the Invention

[0004] The purpose of the present invention is to overcome the deficiencies of the prior art, adapt to the actual needs, and provide a cold rolling device for low-bending forming of seamless steel pipes to solve the technical problem that in the current cold rolling device, a single roll undertakes too many functions and stress is concentrated for a long time, resulting in a relatively high over-standard rate of the finished product bending degree.

[0005] To solve the above technical problems, the present invention provides the following technical solution: A cold rolling device for low-bending forming of seamless steel pipes, including a cold rolling device main body, on which a cold rolling assembly is provided, and the cold rolling assembly is composed of a rolling structure, a rough repair structure, and a fine repair structure; The rolling structure includes two symmetrical rolling rolls, the surface of the rolling roll is provided with a high-toughness impact-resistant layer, and both ends of the rolling roll are respectively set as a feeding part and a rolling part. The diameter of the arc surface of the feeding part is larger than that of the arc surface of the rolling part, and it smoothly transitions from the feeding part to the rolling part; The rough repair structure includes two symmetrical rough repair rolls, and the surface of the rough repair roll is provided with a high-hardness wear-resistant layer; The fine repair structure includes a number of fine repair rolls arranged in an equidistant annular manner, and the surface of the fine repair roll is provided with a high-hardness low-friction layer; The rolling structure is used to guide the steel pipe blank to enter smoothly through the gradually changing diameter design of the arc surface of the feeding part, use the high-toughness impact-resistant layer to buffer the impact stress when the blank contacts, and at the same time apply a stable radial compressive stress through the arc surface of the rolling part to uniformly reduce the wall thickness of the steel pipe; The rough repair structure is used to apply directional correction stress through the high-hardness wear-resistant layer of the symmetric rough repair roller, and perform high-pressure rolling on the areas of the steel pipe with ovality or uneven wall thickness; The fine repair structure is used to apply uniform radial compressive stress through several equally spaced annularly arranged fine repair rollers, and at the same time reduce the frictional stress to avoid additional torque by using the high-hardness and low-friction layer.

[0006] Preferably, the cold rolling assembly includes a cold rolling chamber, and the rolling structure, the rough repair structure, and the fine repair structure are all provided with rolling drive structures; The rolling drive structure includes a track, a track drive, a mounting frame, a rack, a gear, a roller frame, and a fixing frame; The track drive is slidably connected to the track, the mounting frame and the fixing frame are respectively installed on different track drives, the rolling roller and the rough repair roller are respectively rotatably connected inside the mounting frame, a first gear is installed on one side of the rolling roller, a second gear is installed on one side of the rough repair roller, the first gear and the second gear are respectively meshed with different racks, the racks are installed in the cold rolling chamber, the roller frame is rotatably connected to the fine repair roller, and the roller frame is installed on the fixing frame.

[0007] Preferably, a lubrication structure and a spraying device are provided at the rolling structure, a cooling structure and a cleaning structure are provided at the rough repair structure, and the cleaning structure includes a support plate and a cleaning ring; The support plate is installed on the mounting frame, and the cleaning ring is installed at the edge of the through hole of the support plate.

[0008] Preferably, the lubrication structure includes a lubricating liquid tank, a lubricating liquid pipe, and an application structure. The lubricating liquid tank is connected to the mounting frame, the lubricating liquid pipe is connected to the lubricating liquid tank, and the lubricating liquid pipe communicates with the application structure.

[0009] Preferably, the application structure includes an arc plate, a connecting block, and a connecting cable; the arc plate deforms along the arc surface direction, three connecting blocks are provided between the two arc plates, the two arc plates and the three connecting blocks are connected to each other through the connecting cable, and the connecting cable is installed on the lubricating liquid tank.

[0010] Preferably, the lubrication structure further includes an adaptive drive structure, and the adaptive drive structure includes a mounting plate, a telescopic rod, an elastic pushing member, a bracket, and a pushing wheel; The mounting plate is installed on the lubricating liquid tank, the telescopic rod is installed on the mounting plate, the elastic pushing member is sleeved on the telescopic rod, the bracket is installed on the telescopic rod, and the elastic pushing member is connected between the mounting plate and the bracket. The two pushing wheels are respectively rotatably connected to the two side arms of the bracket, and the pushing wheels are attached to the inner wall of the arc plate.

[0011] Preferably, the lubricating structure further includes a connecting block separating structure, which includes a fixed frame, a self-resetting ejector rod, a pushing block, a curved rod, a slider, a pushing groove, a pushing arm, and a fixed arm; The fixed frame is installed on the connecting rod extended from the mounting plate. The self-resetting ejector rod is slidably connected to the fixed frame. The pushing block is installed at the end of the self-resetting ejector rod. One ends of two curved rods are rotatably connected to both sides of the pushing block. The middle parts of the two curved rods are rotatably connected inside the fixed frame. The two sliders are slidably connected to both sides of the lower part of the fixed frame. The pushing groove is formed at the top end of the slider, and the other end of the curved rod is located in the pushing groove. The pushing arm is installed at the bottom end of the slider, and the fixed arm is installed at the bottom end of the fixed frame. The two pushing arms are respectively connected to the connecting blocks on both sides, and the fixed arm is connected to the connecting block in the middle.

[0012] Preferably, the adaptive driving structure expands when it is located at the feeding part, and the lubricating part formed by the arc plate and the connecting block being away from each other fits the arc surface of the feeding part. The adaptive driving structure contracts when it is located at the rolling part, and the lubricating part formed by the arc plate and the connecting block being in contact with each other fits the arc surface of the rolling part.

[0013] Preferably, the lubricating liquid pipe is communicated with the end of the arc plate. The lubricating liquid pipe is communicated with the connecting channel, and a connecting end is installed in the connecting channel at the communicating part. The connecting channel is formed inside the connecting block. A soft seal is installed at the lubricating liquid pipe at the end of the arc plate. The connecting end is provided with convex rods distributed in an equidistant annular shape, and the soft seal is composed of a plurality of radial structures adapted to the convex rods.

[0014] Preferably, the cooling structure includes a cooler and a cooling block; the cooler is connected with a mounting frame, the cooling channel in the cooling block is communicated with the cooler, and the cooling channel is attached to the roughing roll.

[0015] Compared with the prior art, the beneficial effects of the present invention are: 1. In the combined cold rolling components of the present invention, in traditional cold rolling equipment, a single roll body needs to undertake the functions of feeding, rolling, and straightening simultaneously, resulting in stress concentration in local areas of the roll surface. This not only makes it difficult to control the bending degree of the steel pipe but also exacerbates the wear of the roll body, requiring frequent replacement of the roll body and incurring high maintenance costs. However, in the rolling roll of the present invention, through the design of a gradually changing arc surface in the feeding part, the impact stress during the contact of the blank is dispersed over the entire roll surface. Combined with the surfacing of a high-chromium nickel alloy layer, it can absorb instantaneous impact force, reducing the wear rate of the roll surface. The tungsten carbide alloy layer clad on the surface of the roughing roll forms a stress balance field through symmetric arrangement during the roundness correction of the steel pipe, avoiding excessive stress on one side. Compared with the traditional single-sided correction method, the wear amount of the roll body is reduced. The molybdenum disulfide coating sprayed on the finishing roll reduces the friction coefficient, homogenizes the microscopic stress on the surface of the steel pipe, and significantly reduces the friction loss between the roll body and the steel pipe, extending the service life of the finishing roll. By setting up combined cold rolling components and corresponding surface structures for each part of the cold rolling components, the present invention reduces the stress during processing, improves the service life of the roll body, and thus stably controls the bending degree of the steel pipe processing at a relatively low level.

[0016] 2. By specifically setting auxiliary structures with different functions at key parts of the cold rolling components, in the rolling structure, the coordinated operation of the lubrication structure and the spraying equipment greatly reduces the frictional resistance between the rolling roll and the steel pipe blank. Combined with the spraying of water by the spraying equipment to cool the steel pipe, it avoids metal fatigue caused by excessive temperature. The cooling structure and the cleaning structure at the roughing part further address the problems of high heat and metal debris generated by high-pressure rolling. The cleaning ring in the cleaning structure is made of high-elastic wear-resistant rubber material, with fine silicon carbide fiber filaments embedded inside, and closely adheres to the surface of the roughing roll under the support of the support plate. When the roughing roll rotates, the cleaning ring can efficiently remove the attached metal debris and residual lubricant, preventing impurities from entering the roughing area and affecting the surface quality of the steel pipe. Through the design of the auxiliary structure, the present invention significantly improves the operation reliability of each part of the cold rolling components and further reduces the risk of steel pipe bending caused by external factors during the processing.

[0017] 3. By setting up an adaptive drive structure, the telescopic rod and the elastic pushing member in the adaptive drive structure form a flexible linkage mechanism. When the rolling roll rotates and undergoes arc surface curvature changes when passing through the feeding part and the rolling part, the elastic pushing member automatically compensates for the gap through compression or stretching, ensuring that the driving wheel always fits the inner wall of the arc plate with a constant pressure. The double-arm structure of the bracket ensures that the two driving wheels symmetrically support the arc plate. Combined with the tension adjustment of the connecting cable, the arc plate can adapt to the rapid replacement requirements of rolling rolls of different specifications. By setting up an adaptive drive structure and a variable coating structure, the present invention effectively solves the problem of uneven lubricant coating caused by roll surface deformation in traditional rigid coating devices and optimizes the lubricant coating effect on the rolling roll.

[0018] 4. The present invention realizes the automatic separation of the connecting blocks through the linkage mechanism of the connecting block separation structure and the adaptive driving structure. The fixed frame is rigidly connected to the mounting plate through a connecting rod. The self-resetting ejector rod slides axially along the fixed frame under driving, driving the pushing block to squeeze the two side curved rods. The curved rods rotate with the middle part of the fixed frame as the fulcrum and convert the linear motion of the self-resetting ejector rod into the lateral sliding of the slider through the pushing groove. The bottom pushing arm of the slider is fixedly connected to the two side connecting blocks, and the middle connecting block is positioned through a fixed arm. When the adaptive driving structure is located at the feeding part, the self-resetting ejector rod moves downward to push the curved rods to expand the slider, causing the two side connecting blocks to expand outward. The arc plate and the connecting blocks form an unfolded state that fits the arc surface of the feeding part, enabling the connecting blocks to move away from each other, so as to evenly discharge the lubricating fluid in the connecting blocks. When located at the rolling part, the self-resetting ejector rod retracts, driving the slider to move inward, causing the two side connecting blocks to approach each other. The arc plate and the connecting blocks fit together to form a contracted state that fits the arc surface of the rolling part. The present invention controls the equidistant separation of the connecting blocks through the connecting block separation structure, so that the lubricating fluid can be evenly discharged from the connecting blocks when at the feeding part, optimizing the lubrication effect.

[0019] 5. Through the cooperation of the soft sealing member and the connecting end head in the present invention, the soft sealing member provided at the connection is composed of twelve radially elastic flap pieces. Each flap piece corresponds to the convex rod on the connecting end head. When the arc plate and the connecting blocks contract with the adaptive driving structure and the connecting block separation structure, the connecting end head pushes open the flap pieces through the convex rods, enabling the lubricating fluid pipe to communicate with the connecting channel, and the lubricant enters the connecting blocks. When separated, the flap pieces automatically reset to block the lubricating fluid pipe, and the lubricant in the connecting blocks automatically flows out. Through the soft sealing member and the connecting end head in the present invention, the discharge amount of the lubricant can be automatically controlled during the movement of the arc plate and the connecting blocks, avoiding excessive lubricant resulting in high costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic structural diagram of the present invention.

[0021] Figure 2 It is a schematic structural diagram of the cold rolling assembly of the present invention.

[0022] Figure 3 It is a schematic structural diagram of the rolling structure of the present invention.

[0023] Figure 4 It is a schematic structural diagram of the rough repair structure of the present invention.

[0024] Figure 5 It is a schematic structural diagram of the fine repair structure of the present invention.

[0025] Figure 6 It is a schematic structural diagram of the rolling roll of the present invention.

[0026] Figure 7 It is a schematic structural diagram of the rough repair roll of the present invention.

[0027] Figure 8This is a schematic structural diagram of the finishing roll of the present invention.

[0028] Figure 9 This is a schematic structural diagram of the lubrication structure of the present invention.

[0029] Figure 10 This is a schematic sectional view of the lubrication structure of the present invention.

[0030] Figure 11 This is a schematic structural diagram of the coating structure of the present invention when it is located at the feeding part.

[0031] Figure 12 This is the present invention Figure 11 The enlarged schematic structural diagram at position A in the present invention.

[0032] Figure 13 This is the present invention Figure 11 The enlarged schematic structural diagram at position B in the present invention.

[0033] Figure 14 This is a schematic structural diagram of the cleaning structure of the present invention.

[0034] Explanation of the reference numerals in the figure: 1. Cold rolling equipment main body; 2. Cold rolling assembly; 3. Rolling structure; 4. Rough finishing structure; 5. Finishing structure; 6. Rolling drive structure; 7. Lubrication structure; 8. Spraying equipment; 9. Cooling structure; 201. Cold rolling chamber; 301. Rolling roll; 302. High toughness and impact resistant layer; 303. Feeding part; 304. Rolling part; 401. Rough finishing roll; 402. High hardness wear resistant layer; 403. Cleaning structure; 4031. Support plate; 4032. Cleaning ring; 501. Finishing roll; 502. High hardness and low friction layer; 601. Track; 602. Track drive; 603. Mounting frame; 604. Rack; 605. Gear; 606. Roll stand; 607. Fixed frame; 701. Lubricating liquid tank; 702. Lubricating liquid pipe; 703. Coating structure; 704. Adaptive drive structure; 705. Connecting block separation structure; 7031. Arc plate; 7032. Connecting block; 7033. Connecting cable; 7034. Connecting channel; 7035. Soft seal; 7036. Connecting end; 7041. Mounting plate; 7042. Telescopic rod; 7043. Elastic pushing member; 7044. Support; 7045. Pushing wheel; 7051, Fixed frame; 7052, Self - resetting ejector rod; 7053, Pushing block; 7054, Curved rod; 7055, Slide block; 7056, Pushing groove; 7057, Pushing arm; 7058, Fixed arm; 901, Cooling machine; 902, Cooling block. Specific implementation method

[0035] As Figures 1 to 8 As shown in the figure, a cold - rolling device for seamless steel pipe low - bend forming according to the present invention includes a cold - rolling device main body 1. A cold - rolling assembly 2 is provided on the cold - rolling device main body 1. The cold - rolling assembly 2 is composed of a rolling structure 3, a rough - repair structure 4 and a fine - repair structure 5; The rolling structure 3 includes two symmetrical rolling rolls 301. A high - toughness impact - resistant layer 302 is provided on the surface of the rolling roll 301. The two ends of the rolling roll 301 are respectively set as a feeding part 303 and a rolling part 304. The diameter of the arc surface of the feeding part 303 is larger than that of the arc surface of the rolling part 304, and it smoothly transitions from the feeding part 303 to the rolling part 304; The rough - repair structure 4 includes two symmetrical rough - repair rolls 401. A high - hardness wear - resistant layer 402 is provided on the surface of the rough - repair roll 401; The fine - repair structure 5 includes six equally - spaced and annularly - arranged fine - repair rolls 501. A high - hardness low - friction layer 502 is provided on the surface of the fine - repair roll 501; The rolling structure 3 is used to guide the steel pipe blank to enter smoothly through the gradually - changing diameter design of the arc surface of the feeding part 303. The high - toughness impact - resistant layer 302 is used to buffer the impact stress when the blank contacts, convert the concentrated stress into a uniformly - distributed stress along the roll surface, and at the same time apply a stable radial compressive stress through the arc surface of the rolling part 304, so that the wall thickness of the steel pipe is uniformly thinned, and the bending moment caused by stress mutation is inhibited; The rough - repair structure 4 is used to apply a directional correction stress through the high - hardness wear - resistant layer 402 of the symmetrical rough - repair rolls 401, perform high - pressure rolling on the area with uneven roundness or wall thickness of the steel pipe, forcibly adjust the material distribution to offset the bending internal stress, release the residual stress accumulated during the rolling process, and form a stress balance field through the symmetrical arrangement to prevent a new bending trend caused by excessive unilateral stress; The fine - repair structure 5 is used to apply a uniform radial compressive stress through the six equally - spaced and annularly - arranged fine - repair rolls 501, equalize the peak value of the microscopic stress on the surface of the steel pipe, and at the same time reduce the frictional stress to avoid additional torque, form a 360° full - circumference stress - wrapping field to dynamically compensate for small bending deviations, and finally achieve the uniform distribution of the circumferential and axial stresses of the steel pipe to ensure low bend degree.

[0036] The rolling roll 301, the rough - repair roll 401 and the fine - repair roll 501 are all made of 42CrMo alloy steel; The surface of the rolling roll 301 forms a high-toughness impact-resistant layer 302 by surfacing with a high-chromium nickel alloy. This alloy contains Cr and Ni, which can effectively buffer the impact of the billet and reduce the peak stress; The surface of the roughing roll 401 is clad with a tungsten carbide alloy containing WC particles. After cladding, the hardness is increased. With its high-hardness characteristics, it strongly corrects the steel pipe, and its wear resistance is improved compared to ordinary roll bodies.

[0037] The surface of the finishing roll 501 is sprayed with a molybdenum disulfide ( ) coating, which can, while equalizing the stress, avoid additional deformation caused by friction and ensure effective control of the final camber of the steel pipe.

[0038] In the present invention, by adopting the combined cold-rolling assembly 2, in the traditional cold-rolling equipment, a single roll body needs to undertake the functions of feeding, rolling, and correcting simultaneously, resulting in stress concentration in a local area of the roll surface. This not only makes it difficult to control the camber of the steel pipe but also exacerbates the wear of the roll body, requiring frequent replacement of the roll body and incurring high maintenance costs. However, in the rolling roll 301 of the present invention, through the gradually changing arc surface design of the feeding part 303, the impact stress during the contact of the billet is dispersed to the entire roll surface. Combined with the surfacing high-chromium nickel alloy layer, it can absorb the instantaneous impact force and reduce the wear rate of the roll surface. The tungsten carbide alloy layer clad on the surface of the roughing roll 401 forms a stress balance field through symmetric arrangement when correcting the ovality of the steel pipe, avoiding excessive stress on one side. Compared with the traditional single-sided correction method, the wear amount of the roll body is reduced. The molybdenum disulfide coating sprayed on the finishing roll 501 reduces the friction coefficient. While equalizing the microscopic stress on the surface of the steel pipe, it greatly reduces the friction loss between the roll body and the steel pipe, extending the service life of the finishing roll 501. The present invention sets the combined cold-rolling assembly 2 and sets corresponding surface structures for each part of the cold-rolling assembly 2, reducing the stress during processing, increasing the service life of the roll body, and thus stably controlling the camber of the steel pipe processing at a relatively low level.

[0039] Specifically, such as Figures 2 to 5As shown in the figure, the cold rolling assembly 2 involved in the present invention includes a cold rolling chamber 201, and rolling drive structures 6 are provided on the rolling structure 3, rough repair structure 4, and fine repair structure 5; the rolling drive structure 6 includes a track 601, a track drive 602, a mounting frame 603, a rack 604, a gear 605, a roller frame 606, and a fixing frame 607; the track drive 602 is slidably connected to the track 601, the mounting frame 603 and the fixing frame 607 are respectively mounted on different track drives 602, the rolling roller 301 and the rough repair roller 401 are respectively rotatably connected within the mounting frame 603, a first gear 605 is mounted on one side of the rolling roller 301, a second gear 605 is mounted on one side of the rough repair roller 401, the first gear 605 and the second gear 605 are respectively meshed with different racks 604, the racks 604 are mounted within the cold rolling chamber 201, the roller frame 606 is rotatably connected to the fine repair roller 501, and the roller frame 606 is mounted on the fixing frame 607.

[0040] In the present invention, by setting the rolling drive structure 6 to drive the movement of the equipment, during the process of the track drive 602 moving on the track 601, the gear 605 rotates on the rack 604, causing the rolling roller 301 and the rough repair roller 401 to rotate for rolling and rough repair, and the fixing frame 607 drives the roller frame 606 to move, and the roller frame 606 drives the fine repair roller 501 to move. When the fine repair roller 501 moves along the steel pipe, it rotates for fine repair.

[0041] It is worth noting that, as Figures 2 to 5 shown in the figure, a lubrication structure 7 and a spraying device 8 are provided at the rolling structure 3 involved in the present invention, a cooling structure 9 and a cleaning structure 403 are provided at the rough repair structure 4, and the cleaning structure 403 includes a support plate 4031 and a cleaning ring 4032; the support plate 4031 is mounted on the mounting frame 603, and the cleaning ring 4032 is mounted at the edge of the through hole of the support plate 4031.

[0042] The cooling structure 9 includes a cooler 901 and a cooling block 902; the cooler 901 is connected to the mounting frame 603, the cooling channels within the cooling block 902 are communicated with the cooler 901, and the cooling channels are in contact with the rough repair roller 401.

[0043] In the present invention, by specifically arranging auxiliary structures with different functions at key parts of the cold rolling assembly 2, in the rolling structure 3, the coordinated operation of the lubrication structure 7 and the spraying device 8 greatly reduces the frictional resistance between the rolling roller 301 and the steel pipe blank. The spraying device 8 sprays water flow to cool the steel pipe, avoiding metal fatigue caused by excessive temperature. The cooling structure 9 and the cleaning structure 403 at the rough repair structure 4 further address the problems of high heat and metal debris generated by high-pressure rolling. The cleaning ring 4032 in the cleaning structure 403 is made of high-elastic wear-resistant rubber material, with fine silicon carbide fiber filaments embedded inside, and tightly fits the surface of the rough repair roller 401 under the support of the support plate 4031. When the rough repair roller 401 rotates, the cleaning ring 4032 can efficiently remove the attached metal debris and residual lubricant, preventing impurities from entering the rough repair area and affecting the surface quality of the steel pipe. Through the design of the auxiliary structure, the present invention significantly improves the operation reliability of each part of the cold rolling assembly 2 and further reduces the risk of steel pipe bending caused by external factors during the processing process.

[0044] Further, as Figures 3 to 9 shown, the lubrication structure 7 involved in the present invention includes a lubricating liquid tank 701, a lubricating liquid pipe 702, and an application structure 703. The lubricating liquid tank 701 is connected with a mounting bracket 603. The lubricating liquid pipe 702 is connected to the lubricating liquid tank 701, and the lubricating liquid pipe 702 communicates with the application structure 703.

[0045] The application structure 703 includes an arc plate 7031, a connecting block 7032, and a connecting cable 7033. The arc plate 7031 deforms along the arc surface direction. There are three connecting blocks 7032 between the two arc plates 7031. The two arc plates 7031 and the three connecting blocks 7032 are connected to each other through the connecting cable 7033, and the connecting cable 7033 is installed on the lubricating liquid tank 701.

[0046] The lubrication structure 7 further includes an adaptive driving structure 704. The adaptive driving structure 704 includes a mounting plate 7041, a telescopic rod 7042, an elastic pushing member 7043, a bracket 7044, and a driving wheel 7045. The mounting plate 7041 is installed on the lubricating liquid tank 701. The telescopic rod 7042 is installed on the mounting plate 7041. The elastic pushing member 7043 is sleeved on the telescopic rod 7042. The bracket 7044 is installed on the telescopic rod 7042, and the elastic pushing member 7043 is connected between the mounting plate 7041 and the bracket 7044. The two driving wheels 7045 are respectively rotatably connected to the two side arms of the bracket 7044, and the driving wheels 7045 are attached to the inner wall of the arc plate 7031.

[0047] In the present invention, an adaptive driving structure 704 is provided. The telescopic rod 7042 and the elastic pushing member 7043 in the adaptive driving structure 704 form a flexible linkage mechanism. When the rolling roll 301 rotates and the arc surface curvature changes during passing through the feeding part 303 and the rolling part 304, the elastic pushing member 7043 automatically compensates for the gap through compression or extension, so that the pushing wheel 7045 always fits against the inner wall of the arc plate 7031 with a constant pressure. The double-arm structure of the bracket 7044 ensures that the two pushing wheels 7045 symmetrically support the arc plate 7031. With the tension adjustment of the connecting cable 7033, the arc plate 7031 can adapt to the rapid replacement requirements of rolling rolls 301 of different specifications. By providing the adaptive driving structure 704 and the variable coating structure 703, the present invention effectively solves the problem of uneven lubricant coating caused by the deformation of the roll surface in the traditional rigid coating device, and optimizes the lubricant coating effect on the rolling roll 301.

[0048] Furthermore, as Figures 9 to 10 shown, the lubrication structure 7 involved in the present invention further includes a connecting block separation structure 705. The connecting block separation structure 705 includes a fixed frame 7051, a self-resetting ejector rod 7052, a pushing block 7053, a curved rod 7054, a slider 7055, a pushing groove 7056, a pushing arm 7057, and a fixed arm 7058. The fixed frame 7051 is installed on the connecting rod extending from the mounting plate 7041. The self-resetting ejector rod 7052 is slidably connected to the fixed frame 7051. The pushing block 7053 is installed at the end of the self-resetting ejector rod 7052. One ends of the two curved rods 7054 are rotatably connected to both sides of the pushing block 7053. The middle parts of the two curved rods 7054 are rotatably connected inside the fixed frame 7051. The two sliders 7055 are slidably connected to both lower sides of the fixed frame 7051. The pushing groove 7056 is opened at the top end of the slider 7055, and the other end of the curved rod 7054 is located in the pushing groove 7056. The pushing arm 7057 is installed at the bottom end of the slider 7055. The fixed arm 7058 is installed at the bottom end of the fixed frame 7051. The two pushing arms 7057 are respectively connected to the connecting blocks 7032 on both sides, and the fixed arm 7058 is connected to the connecting block 7032 in the middle.

[0049] When the adaptive driving structure 704 is located at the feeding part 303, it expands, and the lubrication part formed by the separation of the arc plate 7031 and the connecting block 7032 adapts to the arc surface of the feeding part 303. When the adaptive driving structure 704 is located at the rolling part 304, it contracts, and the lubrication part formed by the fitting of the arc plate 7031 and the connecting block 7032 adapts to the arc surface of the rolling part 304.

[0050] The automatic separation of the connecting block 7032 is realized by the linkage mechanism of the connecting block separation structure 705 and the adaptive driving structure 704. The fixed frame 7051 is rigidly connected to the mounting plate 7041 through a connecting rod. The self-resetting ejector rod 7052 slides axially along the fixed frame 7051 under driving, driving the pushing block 7053 to squeeze the two side curved rods 7054. The curved rods 7054 rotate with the middle part of the fixed frame 7051 as the fulcrum and convert the linear motion of the self-resetting ejector rod 7052 into the lateral sliding of the slider 7055 through the pushing groove 7056. The bottom pushing arm 7057 of the slider 7055 is fixedly connected to the two side connecting blocks 7032, and the middle connecting block 7032 is positioned by the fixing arm 7058. When the adaptive driving structure 704 is located at the feeding part 303, the self-resetting ejector rod 7052 moves downward to push the curved rod 7054 to expand the slider 7055, so that the two side connecting blocks 7032 expand outward, and the arc plate 7031 and the connecting block 7032 form an unfolded state adapting to the arc surface of the feeding part 303, enabling the connecting blocks 7032 to move away from each other, thereby uniformly discharging the lubricating fluid in the connecting blocks 7032. When located at the rolling part 304, the self-resetting ejector rod 7052 retracts to drive the slider 7055 to move inward, causing the two side connecting blocks 7032 to approach each other, and the arc plate 7031 and the connecting block 7032 fit to form a contracted state adapting to the arc surface of the rolling part 304. The present invention controls the equidistant separation of the connecting blocks 7032 through the connecting block separation structure 705, so that the lubricating fluid can be uniformly discharged from the connecting blocks 7032 at the feeding part 303, optimizing the lubrication effect.

[0051] Furthermore, as Figures 10 to 14 shown, the lubricating fluid pipe 702 related to the present invention is communicated with the end of the arc plate 7031. The lubricating fluid pipe 702 is communicated with the connecting channel 7034, and a connecting end head 7036 is installed in the connecting channel 7034 at the communicating part. The connecting channel 7034 is opened inside the connecting block 7032. A soft seal 7035 is installed at the lubricating fluid pipe 702 at the end of the arc plate 7031. The connecting end head 7036 is provided with convex rods distributed in an equidistant annular shape, and the soft seal 7035 is composed of twelve radial structures adapted to the convex rods.

[0052] Through the cooperation of the soft seal 7035 and the connecting end 7036, the soft seal 7035 provided at the connection is composed of twelve radially elastic flaps. Each flap corresponds to a convex rod on the connecting end 7036. When the arc plate 7031 and the connecting block 7032 contract with the adaptive driving structure 704 and the connecting block separating structure 705, the connecting end 7036 pushes open the flaps through the convex rods, enabling the lubricating fluid pipe 702 to communicate with the connecting channel 7034. The lubricant enters the connecting block 7032. When separated, the flaps automatically reset to block the lubricating fluid pipe 702, and the lubricant in the connecting block 7032 automatically flows out. Through the soft seal 7035 and the connecting end 7036, the present invention can automatically control the discharge amount of the lubricant during the movement of the arc plate 7031 and the connecting block 7032, avoiding excessive lubricant and resulting in high costs.

[0053] As Figures 1 to 14 shown, a method for using a cold rolling device for seamless steel pipe low-bending forming according to the present invention includes the following steps: S1. Loading and rolling preparation: Hoist the steel pipe blank to the loading area of the cold rolling chamber 201, and send it into the rolling structure 3 through the conveying roller path. The rolling roller 301 in the rolling structure 3 is in the initial position. The feeding part 303 causes a change in the adaptive driving structure 704, the telescopic rod 7042 extends, and the elastic pushing member 7043 pushes the bracket 7044 and the pushing wheel 7045, so that the arc plate 7031 and the connecting block 7032 of the coating structure 703 unfold to form a shape adapted to the arc surface of the feeding part 303 of the rolling roller 301. S3. Rolling process: Under the push of the conveying device, the steel pipe blank and the rolling roller 301 rotate continuously. The feeding part 303 of the rolling roller 301 enters the rolling part 304 through the gradually changing arc surface. During this process, the high-toughness impact-resistant layer 302 on the surface of the rolling roller 301 effectively buffers the impact stress when the blank contacts. The gradually changing diameter design of the arc surface of the feeding part 303 disperses the concentrated stress to the entire roller surface. At the same time, the arc surface of the rolling part 304 applies a stable radial compressive stress, causing the wall thickness of the steel pipe to be uniformly thinned. The spraying device 8 is started synchronously to spray coolant on the surface of the steel pipe to reduce the high temperature generated by rolling and avoid metal fatigue. At the same time, when rotating to the rolling part 304, the connecting block 7032 contacts the arc plate 7031, and the soft seal 7035 cooperates with the connecting end 7036. The convex rod on the connecting end 7036 pushes open the radial flaps of the soft seal 7035, the lubricating fluid pipe 702 communicates with the connecting channel 7034 inside the connecting block 7032, and the lubricant in the lubricating fluid tank 701 flows into the connecting block 7032 through the lubricating fluid pipe 702 and is evenly applied to the surface of the feeding part 303 of the rolling roller 301 through the micro holes on the connecting block 7032, and the lubricant is discharged through the connecting block 7032 when rotating to the feeding part 303.

[0054] S4. Rough repair process: The steel pipe that has completed the preliminary rolling enters the rough repair structure 4 area through the cleaning structure 403. The cleaning ring 4032 closely adheres to the surface of the rough repair roll 401 under the support of the support plate 4031. As the rough repair roll 401 rotates, the silicon carbide fiber filaments inside the cleaning ring 4032 efficiently remove the attached metal debris and residual lubricant. The symmetrically arranged rough repair rolls 401 perform high-pressure rolling on the areas with ovality or uneven wall thickness of the steel pipe through the high-hardness wear-resistant layer 402 on the surface. During the rough repair process, the cooler 901 circulates and cools the rough repair roll 401 through the cooling channels in the cooling block 902, controlling the surface temperature of the rough repair roll 401 within a reasonable range to prevent the performance of the roll body from decreasing due to overheating.

[0055] S5. Fine repair process: The steel pipe that has undergone rough repair continues to enter the fine repair structure 5 area. The fixing frame 607 drives the roll frame 606 to move, enabling the six equally spaced and annularly arranged fine repair rolls 501 to be in place around the steel pipe. The high-hardness and low-friction layer 502 on the surface of the fine repair roll 501 begins to apply uniform radial compressive stress to the steel pipe, equalizing the peak value of the microscopic stress on the steel pipe surface. At the same time, the frictional stress is reduced to avoid additional torque. The fine repair roll 501 moves along the axial direction of the steel pipe and rotates under the drive of the roll frame 606, forming a 360° full-circumference stress wrapping field to dynamically compensate for small bending deviations and ensure that the steel pipe finally meets the low bending degree requirements.

[0056] The embodiments disclosed in the present invention are preferred embodiments, but are not limited thereto. Those of ordinary skill in the art can easily understand the spirit of the present invention based on the above embodiments and make different extensions and changes. However, as long as they do not depart from the spirit of the present invention, they are within the protection scope of the present invention.

Claims

1. A cold rolling device for seamless steel pipe low-bending forming, characterized in that, It includes the main body of the cold rolling equipment, on which a cold rolling assembly is provided, and the cold rolling assembly is composed of a rolling structure, a rough repair structure and a fine repair structure; The rolling structure includes two symmetrical rolling rolls, the surface of the rolling roll is provided with a high-toughness impact-resistant layer, both ends of the rolling roll are respectively set as a feeding part and a rolling part, the diameter of the arc surface of the feeding part is larger than that of the arc surface of the rolling part, and it smoothly transitions from the feeding part to the rolling part; The rough repair structure includes two symmetrical rough repair rolls, and the surface of the rough repair roll is provided with a high-hardness wear-resistant layer; The fine repair structure includes several equally spaced and annularly arranged fine repair rolls, and the surface of the fine repair roll is provided with a high-hardness low-friction layer; The rolling structure is used to guide the steel pipe blank to enter smoothly through the gradually changing diameter design of the arc surface of the feeding part, use the high-toughness impact-resistant layer to buffer the impact stress when the blank contacts, and at the same time apply a stable radial compressive stress through the arc surface of the rolling part to uniformly reduce the wall thickness of the steel pipe; The rough repair structure is used to apply a directional correction stress through the high-hardness wear-resistant layer of the symmetrical rough repair rolls, and perform high-pressure rolling on the areas with out-of-roundness or uneven wall thickness of the steel pipe; The fine repair structure is used to apply a uniform radial compressive stress through several equally spaced and annularly arranged fine repair rolls, and at the same time reduce the frictional stress to avoid additional torque.

2. The cold rolling equipment for seamless steel pipe low bending degree forming according to claim 1, characterized in that, The cold rolling assembly includes a cold rolling chamber, and the rolling structure, the rough repair structure and the fine repair structure are all provided with rolling drive structures; The rolling drive structure includes a track, a track drive, a mounting frame, a rack, a gear, a roll frame, and a fixing frame; The track drive is slidably connected to the track, the mounting frame and the fixing frame are respectively installed on different track drives, the mounting frame is respectively rotatably connected to the rolling roll and the rough repair roll, a first gear is installed on one side of the rolling roll, a second gear is installed on one side of the rough repair roll, the first gear and the second gear are respectively meshed and connected to different racks, the racks are installed in the cold rolling chamber, the roll frame is rotatably connected to the fine repair roll, and the roll frame is installed on the fixing frame.

3. A cold rolling device for seamless steel pipe low bending degree forming according to claim 2, characterized in that, A lubrication structure and a spraying device are provided at the rolling structure, a cooling structure and a cleaning structure are provided at the rough repair structure, and the cleaning structure includes a support plate and a cleaning ring; The support plate is installed on the mounting frame, and the cleaning ring is installed at the edge of the through hole of the support plate.

4. A cold rolling device for seamless steel pipe low bend forming according to claim 3, characterized in that, The lubrication structure includes a lubricating liquid tank, a lubricating liquid pipe and an application structure, the lubricating liquid tank is connected to the mounting frame, the lubricating liquid pipe is connected to the lubricating liquid tank, and the lubricating liquid pipe communicates with the application structure.

5. A cold rolling device for seamless steel pipe low bending degree forming according to claim 4, characterized in that, The application structure includes an arc plate, a connecting block, and a connecting cable; the arc plate deforms along the arc surface direction, three connecting blocks are arranged between the two arc plates, the two arc plates and the three connecting blocks are connected to each other through the connecting cable, and the connecting cable is installed on the lubricating liquid tank.

6. A cold rolling device for seamless steel pipe low bending degree forming according to claim 5, characterized in that, The lubrication structure further includes an adaptive drive structure, and the adaptive drive structure includes a mounting plate, a telescopic rod, an elastic pushing member, a bracket, and a pushing wheel; The mounting plate is mounted on the lubricating fluid tank, the telescopic rod is mounted on the mounting plate, the elastic pusher is sleeved on the telescopic rod, the bracket is mounted on the telescopic rod, and the elastic pusher is connected between the mounting plate and the bracket. The two pushing wheels are respectively rotatably connected to the two side arms of the bracket, and the pushing wheels are attached to the inner wall of the arc plate.

7. A cold rolling device for seamless steel pipe low-bending forming according to claim 6, characterized in that, The lubricating structure further includes a block separating structure, and the block separating structure includes a fixed frame, a self-resetting ejector rod, a pushing block, a curved rod, a slider, a pushing groove, a pushing arm, and a fixed arm; The fixed frame is mounted on the connecting rod extended from the mounting plate, the self-resetting ejector rod is slidably connected to the fixed frame, the pushing block is mounted at the end of the self-resetting ejector rod, one ends of the two curved rods are rotatably connected to both sides of the pushing block, the middle parts of the two curved rods are rotatably connected inside the fixed frame, the two sliders are slidably connected to both sides of the lower part of the fixed frame, the pushing groove is formed at the top end of the slider, and the other ends of the curved rods are located in the pushing groove. The pushing arm is mounted at the bottom end of the slider, the fixed arm is mounted at the bottom end of the fixed frame, the two pushing arms are respectively connected to the blocks on both sides, and the fixed arm is connected to the block in the middle.

8. A cold rolling device for seamless steel pipe low-bending forming according to claim 6, characterized in that, The adaptive driving structure expands when it is located at the feeding part, and the lubricating part formed by the arc plate and the block being away from each other is adapted to the arc surface of the feeding part. The adaptive driving structure contracts when it is located at the rolling part, and the lubricating part formed by the arc plate and the block being in contact with each other is adapted to the arc surface of the rolling part.

9. A cold rolling device for seamless steel pipe low-bending forming according to claim 4, characterized in that, The lubricating fluid pipe communicates with the end of the arc plate, the lubricating fluid pipe communicates with the connecting channel, and a connecting end head is installed in the connecting channel at the communicating place. The connecting channel is formed inside the block. A soft seal is installed at the lubricating fluid pipe at the end of the arc plate. The connecting end head is provided with convex rods distributed in an equidistant annular shape, and the soft seal is composed of a number of radial structures adapted to the convex rods.

10. A cold rolling device for seamless steel pipe low-bending forming according to claim 3, characterized in that, The cooling structure includes a cooler and a cooling block; the cooler is connected with a mounting frame, the cooling channels in the cooling block communicate with the cooler, and the cooling channels are attached to the roughing roll.

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