High-precision expanding cone and deep-sea pipe forming equipment

Abstract

The application provides a high-precision expanding cone and a deep-sea pipe forming equipment, wherein the outer periphery of the expanding cone is provided with a circle of V-shaped grooves in the circumferential direction, and the bottom of the expanding die set is provided with a V-shaped surface which is adapted to the V-shaped groove and is in sliding connection with the V-shaped groove. The V-shaped surface structure design can effectively increase the contact area of the cone surface, reduce the unit pressure and the heat caused by friction, avoid reducing the stress area and the strength of the cone due to the T-shaped key groove, and has the self-centering characteristic by using the V-shaped surface, thereby improving the coaxiality of the die movement, increasing the contact area, reducing the unit pressure, reducing the friction heat, increasing the bearing capacity, and improving the axial guiding precision.

Description

Technical Field

[0001] This invention relates to the field of steel pipe forming technology, specifically a high-precision expanding cone and deep-sea pipe forming equipment. Background Technology

[0002] Currently, the demand for high-strength, small-diameter, and thick-walled steel pipes is increasing in fields such as deep-sea oil and gas transportation and marine engineering. Pipe forming equipment is the core tooling in the steel pipe expansion process, and its performance directly determines the dimensional accuracy and finished product quality of the steel pipe. However, existing pipe forming equipment (such as patents CN120169904A and CN110153299A) uses a T-slot and T-key sliding mechanism between the cone and the expansion module. When producing such special-specification steel pipes, this method has the following technical defects, specifically: The use of T-slots on the contact surface results in a small effective bearing area, and the conical surface and mold are prone to scratches and wear. In addition, the T-keys and screws may experience spiral breakage. Occasionally, the mold and the cone may seize up. During diameter expansion, the off-center load leads to poor dimensional consistency. When expanding the wall of the tube, the cone bears high pressure, generates a lot of heat, and dissipates heat slowly. At high temperatures, the viscosity of the lubricating oil will decrease, leading to lubrication failure.

[0003] In summary, existing expanding head assemblies suffer from technical defects when applied to the expanding process of high-strength, small-diameter, and thick-walled steel pipes. These defects include insufficient structural rigidity, localized stress concentration, poor heat dissipation, and weak strength of key connecting components. This leads to frequent failures such as scratches, fractures, and seizing, making it difficult to meet the requirements of high-efficiency, high-precision, and low-defect-rate mass production. Therefore, there is an urgent need to develop a new type of expanding cone structure that can adapt to such demanding working conditions. Summary of the Invention

[0004] The purpose of this invention is to solve the problems of insufficient rigidity, localized stress concentration, and poor heat dissipation in existing expanded diameter cone structures, and to provide a high-precision expanded diameter cone and deep-sea pipe forming equipment.

[0005] To address the above problems, the present invention provides the following technical solution: A high-precision expanded-diameter cone includes a connecting section, a conical surface section, and a guide section arranged sequentially from front to back; The outer diameter of the conical section gradually decreases from front to back, and a ring of V-shaped grooves is distributed around the outer periphery of the conical section in a circumferential array. The V-shaped grooves slide in conjunction with the diameter expansion module on its outer side. The high-precision expanded-diameter cone has a through hole in the middle for a piston rod to pass through. The connecting section is fixedly connected to the end of the piston rod, and the guide section is used to guide it to slide along the axial direction of the guide module.

[0006] In the high-precision expanded-diameter cone described above, the length of the guide section is not less than one-third of the overall length of the cone surface section.

[0007] In the high-precision expanded-diameter cone described above, the V-groove has a slotting angle of 90° to 150°.

[0008] As described above, a high-precision expanded-diameter cone has 12 V-grooves arranged in a circumferential array along the outer periphery of the conical section.

[0009] As described above, in a high-precision expanded-diameter cone, the surface hardness of the cone section is greater than the core hardness.

[0010] As described above, in a high-precision expanded-diameter cone, the surface hardness of the cone section is HRC58-62, and the core hardness is HRC35-40.

[0011] The high-precision expanded-diameter cone described above is made of 30CrNiMo8, 42CrMo, or GCr15.

[0012] As described above, a high-precision expanded cone includes an expanded diameter module comprising multiple expanded diameter components that slide and engage with the V-groove. Each expanded diameter component comprises a module, a wedge, and a slider arranged in sequence. The side of the slider away from the wedge is a V-shaped surface that is adapted to fit and slides with the V-groove.

[0013] As described above, in a high-precision expanded diameter cone, the guide module includes a front guide ring and a rear guide ring, the expanded diameter module is disposed between the front guide ring and the rear guide ring, and the connecting section and the guide section are slidably connected to the front guide ring and the rear guide ring, respectively.

[0014] Another objective of this application is to provide a deep-sea pipe forming equipment, including a guide module, an expansion module, and a high-precision expansion cone as described above. The high-precision expansion cone is inserted through the middle of the guide module and can slide along its axial direction. The expansion module includes multiple sets of expansion components that slide in accordance with the V-groove. The multiple sets of expansion components surround the outer periphery of the conical section.

[0015] Compared with the prior art, the present invention has the following advantages: This invention provides a high-precision expanding cone and deep-sea pipe forming equipment. The expanding cone has a ring of V-grooves arranged in a circumferential array along its outer periphery. The bottom of the expanding module is provided with a V-shaped surface that is adapted to fit and slidably connected to the V-grooves. The V-shaped surface structure design of this application can effectively increase the contact area of ​​the cone surface, reduce the unit pressure and heat generation caused by friction, avoid reducing the force-bearing area and cone strength of the cone due to the opening of T-slots, and improve the coaxiality of the mold movement by using the self-centering characteristic of the V-shaped surface, increase the contact area, reduce the unit pressure, reduce frictional heat generation, increase the load-bearing capacity, and improve the axial guiding accuracy. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a partially exploded view of the pipe forming equipment in an embodiment of the present invention; Figure 2 This is a rear view of the tube forming equipment in an embodiment of the present invention; Figure 3 yes Figure 2 A schematic diagram of the cross-section along the AA direction; Figure 4 This is a side view of the tube forming equipment in an embodiment of the present invention; Figure 5 yes Figure 4 Schematic diagram of the cross section in the BB direction; Figure 6 This is a schematic diagram of the expanded diameter cone in an embodiment of the present invention; Figure 7 This is a schematic diagram of the diameter expansion component in an embodiment of the present invention; Figure 8 This is a schematic diagram of the internal structure of the diameter expansion component in an embodiment of the present invention; The corresponding numbers for the attached figures are as follows: Guide module 1, front guide ring 11, rear guide ring 12, first oil supply connector 121, second oil supply connector 122, third oil supply connector 123, first oil supply passage 124, second oil supply passage 125, third oil supply passage 126, nozzle bracket 13, lubricating oil nozzle 14, front guide structure 15, T-shaped snap-fit ​​part 151, snap pin 152, rear guide structure 16, T-shaped guide groove 161, T-shaped guide key 162, front clamping structure 17, front leaf spring 171, rear clamping structure 18, rear leaf spring 181. 2. Expanding cone, 20. Through hole, 21. Conical surface section, 210. V-groove, 22. Connecting section, 23. Guide section, 3. Expanding module, 30. Slider, 31. V-shaped surface, 310. First lubricating oil outlet, 311. Wedge, 32. First lubricating oil inlet, 321. First main oil passage, 322. First branch oil passage, 323. Second lubricating oil inlet, 324. Second lubricating oil outlet, 325. Second main oil passage, 326. Second branch oil passage, 327. Module, 33. U-shaped dustproof strip, 34. Detailed Implementation

[0018] 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 a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present invention.

[0019] Please see the appendix Figure 1-8 This application provides a pipe forming equipment, including a guide module 1, an expanding cone 2, and an expanding module 3; wherein the expanding cone 2 passes through the middle of the guide module 1 and can slide along its axial direction, the expanding module 3 includes multiple sets of expanding components 30 that are slidably engaged with the expanding cone 2, the multiple sets of expanding components 30 surround the outer periphery of the expanding cone 2, the middle of the expanding cone 2 is provided with a through hole 20 for a piston rod (not shown), the piston rod drives the expanding cone 2 to move axially on the guide module 1, and the expanding cone 2 drives the expanding module 3, which is slidably connected to it, to expand the pipe radially outward along the guide module 1.

[0020] The expanded cone 2 of this application embodiment includes a conical section 21 whose outer diameter gradually decreases from front to back. As the main improvement of this application, a ring of V-grooves 210 is distributed around the outer periphery of the conical section 21. The bottom of the expanded component 30 is provided with a V-shaped surface 310 that is adapted to fit and slidably connected to the V-grooves 210. This application uses V-grooves 210 to extend the cone, which reduces the reduction in cone strength and sliding contact area caused by the "T-shaped guide keyway" on the conical surface of the existing cone. The V-shaped surface 310 structure design of this application can effectively increase the contact area of ​​the conical surface, reduce the unit pressure and heat generation caused by friction, avoid the reduction of the cone's force-bearing area due to the T-shaped keyway, increase the load-bearing capacity, and improve the axial guiding accuracy.

[0021] The diameter expansion module 3 of this application embodiment includes multiple sets of diameter expansion components 30 that slide and engage with the V-groove 210. Specifically, the diameter expansion component 30 includes a module 33, a wedge 32, and a slider 31 stacked in sequence. The side of the slider 31 away from the wedge 32 is a V-shaped surface 310 that is adapted to fit and slides with the V-groove 210. The slider 31 on the bottom surface of the wedge 32 has an inverted V-shaped structure, which matches and contacts the V-groove 210 of the diameter expansion cone 2. This can increase the effective contact area, improve the force distribution, reduce local stress concentration, prevent the mold from seizing, and reduce frictional heat generation. Compared with the existing T-shaped guide key 162 structure, the cone surface temperature of continuously expanding 3 tubes will exceed 50°C. In practical applications, this application can achieve continuous diameter expansion of 15 tubes with a cone surface temperature ≤42°C.

[0022] Preferably, the slider 31 is a copper sliding plate embedded in the bottom of the wedge 32. The copper sliding plate can also be replaced with other self-lubricating materials (such as graphite copper sleeves). The above-mentioned structure of this application can avoid mold seizure. By using an inverted V-shaped copper sliding plate and independent lubrication, the mold and cone seizure situation in existing pipe forming equipment can be avoided.

[0023] The existing cone structure uses a T-shaped keyway, which results in a small effective load-bearing area. However, the cone structure of this application uses a V-shaped surface 310, which, due to the absence of a keyway, increases the effective load-bearing area by 30% to 40%. In a specific embodiment of this application, the slotting angle of the V-shaped groove 210 is 90° to 150°, more preferably 120°. The expanded cone 2 of this application uses a V-shaped contact surface, reducing the reduction in the cone's stress area caused by the T-shaped keyway, thus increasing the load-bearing capacity by approximately 30% to 40%. This makes it more suitable for expanding and shaping small-diameter, thick-walled steel pipes. In a specific embodiment, 12 V-shaped grooves 210 are arranged in a circumferential array along the outer periphery of the cone section 21. The increased cone load-bearing capacity, the larger contact area of ​​the V-shaped surface 310, and the reduced unit pressure by approximately 35% are all advantages. The V-shaped surface 310 has self-centering properties, improving the coaxiality of the mold movement, increasing the contact area, reducing unit pressure, and reducing frictional heat generation.

[0024] The guide module 1 of this application embodiment includes a front guide ring 11 and a rear guide ring 12 spaced apart. The diameter expansion module 3 is disposed between the front guide ring 11 and the rear guide ring 12. The diameter expansion cone 2 includes a connecting section 22, a conical section 21, and a guide section 23 arranged sequentially from front to back. The front and rear connecting sections 22 and guide sections 23 of the diameter expansion cone 2 are slidably connected to the front guide ring 11 and the rear guide ring 12, respectively. The connecting section 22 is fixedly connected to the end of the piston rod (not shown). The guide section 23 is in contact with and slides against the inner wall of the rear guide ring 12. The guide section 23 is used to guide the pipe to slide along the axial direction of the guide module 1. In this application, the length of the guide section 23 at the tail of the expanding cone 2 is extended to cooperate with the rear guide ring 12 at the rear end, so as to ensure the axial guidance of the pipe forming equipment, enhance the axial guidance accuracy of the pipe forming equipment, prevent the mold from being overloaded, and improve the consistency of the expanding diameter. The consistency error is ≤0.5mm. The expanding head form of this application with bidirectional guidance solves the key technical bottlenecks caused by the pipe shape problem, such as large local forming load, concentrated local bearing of the cone, and poor dimensional consistency, so as to achieve high efficiency, high precision and low defect rate of steel pipe expanding.

[0025] More preferably, the length of the guide section 23 is not less than one-third of the overall length of the conical section 21. The existing conical structure guides only the conical surface, while the guide section 23 of this application cooperates with the rear guide ring 12. This design further provides axial guidance, prevents the cone from being overloaded, improves the stability of the diameter expansion process, ensures dimensional consistency, can share the lateral force of the conical surface, and reduce the wear of the conical surface.

[0026] As a further preferred embodiment of this application, the cone surface adopts a gradient hardness design, with the hardness distributed in a radial gradient. The surface hardness of the cone segment 21 is greater than the core hardness. Preferably, the surface hardness of the cone segment 21 is HRC58-62, and the core hardness is HRC35-40. The high surface hardness provides good wear resistance, while the high core toughness provides strong impact resistance, extending service life and making it suitable for impact loads during the expansion of thick-walled steel pipes. More preferably, the material of the expanding cone 2 is 30CrNiMo8, 42CrMo, or GCr15.

[0027] The existing cone structure has a lubricating oil hole, which weakens its strength. However, the cone structure of this application does not have a lubricating oil hole and adopts an independent external oil supply. The cone of this application does not have a lubricating oil hole. The wedge block 32 is provided with a first lubricating oil inlet hole 321, and the V-shaped surface 310 is provided with a first lubricating oil outlet hole 311 that communicates with the first lubricating oil inlet hole 321. The lubricating oil hole provides lubrication to the contact surface between the expanded diameter cone 2 and the expanded diameter assembly 30 through the first oil supply passage 124 and the first lubricating oil outlet hole 311 built into the wedge block 32. The slider 31 at the bottom of the wedge 32 in this application adopts an inverted "V" shape structure, which cooperates with the expanded diameter cone 2 with a V-shaped contact surface, effectively increasing the contact surface of the cone. It adopts a fully independent lubrication oil circuit to ensure 100% lubrication of the cone surface, avoiding the weakening of the cone strength due to the opening of oil holes, and the lubrication failure caused by the blockage of oil holes. It can achieve forced lubrication, adapt to high temperature and high load conditions, avoid lubrication failure at high temperature, and is suitable for the production of high steel grade and large wall thickness steel pipes. It improves the lubrication effect, and provides uniform lubrication between the contact surface between the V-groove 210 and the V-shaped surface 310, reducing the scratch rate to 0.

[0028] In a preferred embodiment of this application, the first lubricating oil inlet 321 on each wedge 32 is independently supplied with oil through a corresponding first oil supply path 124. In a specific embodiment of this application, the rear end of the guide module 1 is provided with a plurality of first oil supply connectors 121 that are respectively connected to and supplied with oil through a plurality of first oil supply paths 124. Each expansion component 30 of this application adopts an independent external oil supply. Even if one of the first oil supply paths 124 is blocked or malfunctions, it will not affect its overall lubrication function, ensuring 100% lubrication of the conical surface, which is suitable for the production of high-grade steel pipes with large wall thickness.

[0029] Specifically, the V-shaped surface 310 has multiple first lubricating oil outlet holes 311 on both sides of its inclined surface; the wedge block 32 has a first main oil passage 322 that connects to the first lubricating oil inlet hole 321, and a first branch oil passage 323 is provided between the first main oil passage 322 and the multiple first lubricating oil outlet holes 311. In this application, the expanded diameter cone 2 does not have lubricating oil holes. The lubricating oil enters the first main oil passage 322 built into the wedge block 32 through an independent first oil supply passage 124, and is then transported to the first lubricating oil outlet hole 311 through the first branch oil passage 323 to fill the contact surface between the expanded diameter cone 2 and the copper slider 31, achieving 100% uniform lubrication of the cone surface, avoiding lubrication failure at high temperatures, and is suitable for the production of high-grade steel pipes with large wall thickness.

[0030] In a specific embodiment, a guide structure is provided between the expanding component 30 and the guide module 1. Multiple expanding components 30 are respectively positioned around the outer periphery of the conical section 21 via the guide structure. The guide structure guides the expanding components 30 to move radially towards the guide module 1. Furthermore, a clamping structure is provided between the expanding component 30 and the guide module 1 to elastically clamp the expanding component 30 onto the V-groove 210. This application's bidirectional guided expanding head design solves the key technical bottlenecks currently caused by pipe shape issues, such as large local forming loads, concentrated local stress on the cone, and poor dimensional consistency, achieving high efficiency, high precision, and low defect rate in steel pipe expanding.

[0031] Specifically, the guiding structure includes a front guide structure 15 disposed between the front side of the wedge 32 and the rear side of the front guide ring 11 for guiding the front side of the wedge 32 to move radially toward the front guide ring 11, and a rear guide structure 16 disposed between the rear side of the wedge 32 and the front side of the rear guide ring 12 for guiding the rear side of the wedge 32 to move radially toward the rear guide ring 12; the pressing structure includes a front pressing structure 17 disposed between the front side of the wedge 32 and the rear side of the front guide ring 11 for elastically pressing the front side of the wedge 32 onto the V-groove 210, and a rear pressing structure 18 disposed between the rear side of the wedge 32 and the front side of the rear guide ring 12 for elastically pressing the rear side of the wedge 32 onto the V-groove 210.

[0032] The rear guide structure 16 includes a T-shaped guide groove 161 radially formed on the front side of the rear guide ring 12, and a T-shaped guide key 162 slidably connected to the T-shaped guide groove 161 on the rear end of the wedge block 32. The rear clamping structure 18 includes multiple stacked rear leaf springs 181, the rear ends of which are fixed to the rear guide ring 12 by leaf spring pressure plates. The lengths of the rear leaf springs 181 decrease sequentially from bottom to top, and the front end of the lowest layer of rear leaf springs 181 is pressed against the T-shaped guide key 162. This application uses a T-shaped key and leaf spring pressure plate for guidance, which improves the guiding performance during the reciprocating motion of the mold and increases the overall anti-eccentric load capacity of the expansion head. The leaf spring pressure plate can be replaced with a disc spring or a coil spring.

[0033] Specifically, the front clamping structure 17 includes a front leaf spring 171, the front end of which is fixed to the front guide ring 11, and the rear end of which is pressed against the front end of the wedge block 32; the front guide structure 15 includes a T-shaped locking part 151 provided on the rear end of the front leaf spring 171, and two locking pins 152 provided on the front end of the wedge block 32 and respectively locked to both sides of the T-shaped locking part 151.

[0034] In a specific embodiment of this application, the guide structure includes a T-shaped guide groove 161 radially formed thereon along the guide module 1, and a T-shaped guide key 162 slidably connected to the T-shaped guide groove 161 on the wedge block 32; the wedge block 32 is provided with a second lubricating oil inlet hole 324, and the contact surface between the T-shaped guide key 162 and the T-shaped guide groove 161 is provided with a second lubricating oil outlet hole 325 communicating with the second lubricating oil inlet hole 324.

[0035] Specifically, the T-shaped guide key 162 has multiple second lubricating oil outlet holes 325 on both sides and the rear end of its contact surface with the T-shaped guide groove 161; the wedge block 32 has a second main oil passage 326 communicating with the second lubricating oil inlet hole 324, and a second branch oil passage 327 is provided between the second main oil passage 326 and the multiple second lubricating oil outlet holes 325. Specifically, each second lubricating oil inlet hole 324 on the wedge block 32 is independently supplied with oil through a corresponding second oil supply passage 125, and the rear end of the guide module 1 has multiple second oil supply connectors 122 that communicate with and supply oil to the multiple second oil supply passages 125 respectively.

[0036] More preferably, the inner wall lubrication assembly includes a nozzle bracket 13 located at the front of the guide module 1, a lubricating oil nozzle 14 located on the nozzle bracket 13, and a third oil supply passage 126 communicating with the lubricating oil nozzle 14; the rear end of the guide module 1 is provided with a third oil supply connector 123 communicating with the third oil supply passage 126 for oil supply. This allows the lubricating oil to be sprayed evenly onto the inner wall of the tube to be formed, which helps reduce the friction between the module 33 and the tube to be formed.

[0037] As a further limitation of this application, a U-shaped dustproof strip 34 is installed in the gap between two adjacent wedges 32. The top two ends of the U-shaped dustproof strip 34 have bent structures that fit into the top of the wedges 32. During the use of the expanding head, foreign objects will not fall between the expanding cone 2 and the wedges 32, making cleaning convenient and improving work efficiency.

[0038] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A high-precision expanded-diameter cone, characterized in that: It includes a connecting section, a conical section, and a guide section arranged sequentially from front to back; The outer diameter of the conical section gradually decreases from front to back, and a ring of V-shaped grooves is distributed around the outer periphery of the conical section in a circumferential array. The V-shaped grooves slide in conjunction with the diameter expansion module on its outer side. The high-precision expanded-diameter cone has a through hole in the middle for a piston rod to pass through. The connecting section is fixedly connected to the end of the piston rod, and the guide section is used to guide it to slide along the axial direction of the guide module.

2. The high-precision expanded-diameter cone according to claim 1, characterized in that: The length of the guide section is not less than one-third of the overall length of the conical section.

3. The high-precision expanded-diameter cone according to claim 1, characterized in that: The V-groove has a grooving angle of 90° to 150°.

4. A high-precision expanded-diameter cone according to claim 3, characterized in that: The outer periphery of the conical section has 12 V-shaped grooves arranged in a circumferential array.

5. A high-precision expanded-diameter cone according to claim 1, characterized in that: The surface hardness of the conical section is greater than the core hardness.

6. A high-precision expanded-diameter cone according to claim 5, characterized in that: The surface hardness of the conical section is HRC58-62, and the core hardness is HRC35-40.

7. A high-precision expanded-diameter cone according to claim 1, characterized in that: The material of the expanded cone is 30CrNiMo8, 42CrMo or GCr15.

8. A high-precision expanded-diameter cone according to claim 1, characterized in that: The diameter expansion module includes multiple sets of diameter expansion components that slide and engage with the V-groove. Each diameter expansion component includes a module, a wedge, and a slider arranged in sequence. The side of the slider away from the wedge is a V-shaped surface that is adapted to fit and slides with the V-groove.

9. A high-precision expanded-diameter cone according to claim 1, characterized in that: The guide module includes a front guide ring and a rear guide ring, the diameter expansion module is disposed between the front guide ring and the rear guide ring, and the connecting section and the guide section are slidably connected to the front guide ring and the rear guide ring, respectively.

10. A deep-sea pipe forming equipment, characterized in that: The invention includes a guide module, an expansion module, and a high-precision expansion cone as described in any one of claims 1-9. The high-precision expansion cone passes through the middle of the guide module and can slide along its axial direction. The expansion module includes multiple sets of expansion components that slide in cooperation with the V-groove. The multiple sets of expansion components surround the outer periphery of the conical section.

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