Steel pipe manufacturing method, tower, and foundation

Abstract

The present invention provides a method for manufacturing steel pipes that facilitates the selection of intermediate products required for the final product and the replenishment of intermediate products used in the final product. [Solution] A method for manufacturing steel pipes S1 comprises: a first design step S11 which is the basic design of steel pipes to be used in one or more construction projects; a second design step S12 which is the detailed design of steel pipes; a material procurement step S13 which is before the second design step and involves procuring steel materials for manufacturing steel pipes; a first storage step S14 which is after the material procurement step and involves storing the materials; an intermediate product manufacturing step S15 which involves processing the materials and manufacturing intermediate products; a second storage step S16 which involves storing the intermediate products; and a final product assembly step S17 which involves welding and assembling the intermediate products into a final product that becomes a steel pipe. After the intermediate product manufacturing step, the specifications and quantity of intermediate products required for the final product assembly step are selected.

Description

TECHNICAL FIELD

[0001] The present invention relates to a method for manufacturing a steel pipe, a tower, and a foundation.

BACKGROUND ART

[0002] Conventionally, a method for manufacturing a steel pipe, in which a material is processed to produce the steel pipe, is known (see, for example, Patent Document 1). This method for manufacturing a steel pipe discloses that highly versatile products are secured in advance as inventory.

PRIOR ART DOCUMENTS

PATENT DOCUMENTS

[0003]

PATENT DOCUMENT 1

SUMMARY OF THE INVENTION

PROBLEMS TO BE SOLVED BY THE INVENTION

[0004] However, the method for manufacturing a steel pipe of Patent Document 1 has room for improvement in the method of stocking the steel pipe as the final product.

[0005] The present invention has been made in view of such problems, and an object of the present invention is to provide a method for manufacturing a steel pipe, which enables the final product to be manufactured in a relatively short period of time, and facilitates the selection of intermediate products required for the final product and the replenishment of the intermediate products used for the final product, as well as a tower or a foundation manufactured by this method for manufacturing a steel pipe.

MEANS FOR SOLVING THE PROBLEMS

[0006] To solve the above problems, the present invention proposes the following means. (1) One aspect of the present invention is a method for manufacturing one or more steel pipes, comprising: a first design step which is a basic design of the steel pipe to be used in a construction project; a second design step which is a detailed design of the steel pipe after the first design step; a material procurement step which is before the second design step which is a procurement of steel materials for manufacturing the steel pipe; a first storage step which is after the material procurement step which is a storage step for storing the materials; an intermediate product manufacturing step which is a process for processing the materials procured in the material procurement step which is a process for manufacturing one or more intermediate products; a second storage step which is after the intermediate product manufacturing step which is a storage step for storing the one or more intermediate products; a final product assembly step which is a process for processing the one or more intermediate products manufactured in the intermediate product manufacturing step or the one or more intermediate products stored in the second storage step based on information from the second design step which are welded and assembled into a final product which is a steel pipe and lengthened; and a shipping step which is a shipping step which is a shipping step for shipping the final product, wherein after the intermediate product manufacturing step which is a process for selecting the specifications and quantity of the intermediate products required for the final product assembly step, an intermediate product allocation system is selected.

[0007] In this invention, the first design process involves performing a basic design of the steel pipes to be used in the construction project, and the second design process involves performing a detailed design of the steel pipes after the first design process. In the material procurement process, steel materials for manufacturing steel pipes are procured before the second design process. In the first storage process, the materials are stored after the material procurement process. In the intermediate product manufacturing process, the materials procured in the material procurement process are processed to manufacture one or more intermediate products. In the second storage process, one or more intermediate products are stored after the intermediate product manufacturing process. In the final product assembly process, one or more intermediate products manufactured in the intermediate product manufacturing process, or one or more intermediate products stored in the second storage process, are processed based on the information from the second design process, welded and assembled into a long steel pipe as the final product. Finally, in the shipping process, the final product is shipped. In other words, the first storage process involves storing the raw materials, and the second storage process involves storing one or more intermediate products.

[0008] Here, after the intermediate product manufacturing process, the specifications and quantities of intermediate products required for the final product assembly process are selected by the intermediate product allocation system. As described above, since steel materials for manufacturing the final product are procured before the second design process, the final product can be manufactured in a relatively short period of time. The intermediate product allocation system selects the specifications and quantities of intermediate products required for the final product assembly process, making it easy to select the intermediate products needed for the final product manufactured in the final product assembly process.

[0009] (2) Aspect 2 of the present invention is a method for manufacturing steel pipes as described in (1), wherein the intermediate product used in the final product assembly process is cut to a predetermined length based on the information of the second design process. In this invention, for example, where n is a natural number, the length of the final product may be longer than n times the length of the intermediate product and shorter than (n+1) times the length of the intermediate product. Even in this case, the final product can be constructed to a desired length by using an intermediate product that has been cut to a predetermined length shorter than the length of the intermediate product.

[0010] (3) A third aspect of the present invention is a method for manufacturing steel pipes as described in (1) or (2), wherein the intermediate product allocation system comprises: a first storage unit that stores information regarding the requirements and performance of the steel pipes output in the second design process; a second storage unit that stores information regarding the specifications and quantities of the intermediate products stored in the second storage process; and a first control unit that, by looking at one or more construction projects, selects a combination of the intermediate products from the intermediate products stored in the second storage unit to form the final product that satisfies the requirements and performance of the steel pipes stored in the first storage unit, wherein the first control unit calculates at least one of the plate thickness difference between the intermediate products used in one or more construction projects, the cost of the final product, the weight of the final product, and the delivery date of the final product.

[0011] In this invention, the first control unit can select a combination of intermediate products from among the intermediate products stored in the second storage unit, by overseeing multiple construction projects, in order to create a final product that satisfies the requirements and performance of the steel pipe stored in the first storage unit.

[0012] (4) Aspect 4 of the present invention may be a method for manufacturing steel pipes according to any one of (1) to (3), wherein the intermediate product allocation system comprises a second control unit that re-selects the combination of intermediate products to be used in the manufacture of the final product based on the calculation results of the first control unit. In this invention, the second control unit re-selects a combination of intermediate products to be used in the manufacture of the final product based on the calculation results of the first control unit, thereby minimizing at least one of the following: the difference in plate thickness between intermediate products used in one or more construction projects, the cost of the final product, the weight of the final product, and the delivery date of the final product.

[0013] (5) Embodiment 5 of the present invention is a method for manufacturing steel pipes according to any one of (1) to (4), wherein the second control unit re-selects a combination of intermediate products such that at least one of the following is minimized: the difference in plate thickness between the intermediate products selected by the first control unit, the cost of the final product manufactured using the intermediate products selected by the first control unit, the weight of the final product manufactured using the intermediate products selected by the first control unit, and the delivery time of the final product manufactured using the intermediate products selected by the first control unit. In this invention, the second control unit can re-select a combination of intermediate products such that at least one of the following is minimized: the difference in plate thickness between intermediate products, the cost of the final product manufactured using the intermediate products, the weight of the final product manufactured using the intermediate products, and the delivery time of the final product manufactured using the intermediate products.

[0014] (6) Aspect 6 of the present invention may be a method for manufacturing steel pipes according to any one of (1) to (5), comprising: an inventory adjustment system that determines the specifications and quantities of materials necessary to replenish the intermediate products used in one or more construction projects, wherein the inventory adjustment system comprises: a third storage unit that stores information regarding the specifications and quantities of the intermediate products selected by the intermediate product allocation system; a third control unit that determines the specifications and quantities of materials necessary to replenish the intermediate products based on information regarding the specifications and quantities of the intermediate products stored in the third storage unit in one or more construction projects, or past performance; and a first instruction unit that transmits the specifications and quantities of materials determined by the third control unit to the material procurement process.

[0015] In this invention, the third control unit determines the specifications and quantities of materials necessary to replenish the intermediate products based on information regarding the specifications and quantities of intermediate products stored in the third storage unit, or based on past performance. By determining the specifications and quantities of materials necessary to replenish the intermediate products used in one or more construction projects, the inventory adjustment system facilitates the replenishment of intermediate products used in the final product. Furthermore, the first instruction unit can more accurately replenish the intermediate products used in the construction project by transmitting the material specifications and quantities determined by the third control unit to the material procurement process.

[0016] (7) Embodiment 7 of the present invention may be a method for manufacturing a steel pipe according to any one of (1) to (6), wherein the invention comprises an inspection step for inspecting the required quality of the final product, and in the inspection step, welding defects and positional information when the steel pipe is welded and assembled are linked and output. In this invention, based on the welding defect and location information output in the inspection process, the location of the welding defect can be reached and the welding defect can be quickly repaired.

[0017] (8) Embodiment 8 of the present invention is a tower or foundation for wind power generation manufactured by the method for manufacturing steel pipes described in any one of (1) to (7). In the present invention, a tower or a foundation can be manufactured by a steel pipe manufacturing method that manufactures a final product in a relatively short period of time, and facilitates selection of intermediate products required for the final product and replenishment of the intermediate products used in the final product.

Effects of the Invention

[0018] In the steel pipe manufacturing method of the present invention, the final product which is a steel pipe can be manufactured in a relatively short period of time, and selection of intermediate products required for the final product and replenishment of the intermediate products used in the final product can be easily performed.

Brief Description of the Drawings

[0019] [Figure 1] It is a front view showing the outline of a wind turbine provided with the foundation and the tower of the first embodiment of the present invention. [Figure 2] It is a flowchart showing the steel pipe manufacturing method in the first embodiment of the present invention. [Figure 3] It is a perspective view of a material used in the same steel pipe manufacturing method. [Figure 4] It is a perspective view illustrating a state where a material is being processed in the same steel pipe manufacturing method. [Figure 5] It is a perspective view illustrating a state where a plurality of short pipes are arranged in the axial direction in the same steel pipe manufacturing method. [Figure 6] It is a flowchart showing the steel pipe manufacturing method in the second embodiment of the present invention.

Modes for Carrying Out the Invention

[0020] (First Embodiment) Hereinafter, a first embodiment of the steel pipe manufacturing method, the tower, and the foundation according to the present invention will be described with reference to Fig. 1 to Fig. 5.

[0021] [Configuration of Foundation and Tower] As shown in Fig. 1, the foundation 10 and the tower 15 of the present embodiment are provided in a wind turbine 1 for wind power generation. For example, the wind turbine 1 includes the foundation 10, the tower 15, a nacelle 20, and a plurality of blades 25.

[0022] The foundation 10 and tower 15 are formed from steel pipes. The foundation 10 and tower 15 are final products manufactured by the steel pipe manufacturing method described later. The foundation 10 is a so-called steel pipe pile. The foundation 10 is constructed by arranging a plurality of short pipes (intermediate products) 11 in the direction of the axis O1 of the short pipes 11 and welding them together. In this example, the outer diameters of the plurality of short pipes 11 are equal to each other, and the inner diameters of the plurality of short pipes 11 are equal to each other. Although not shown in the figures, the shape may also be such that only the outer diameter of the short pipe 11 at the first side (upper) end in the direction of the axis O1 is reduced. Although not shown in the diagram, each short pipe 11 is constructed by welding the ends of curved material (steel plate) 12 (see Figure 4), as described later, to each other. Foundation 10 extends vertically. The lower end of foundation 10 is fixed to the seabed (not shown). Foundation 10 is located in the sea (underwater) W1.

[0023] The tower 15 is constructed similarly to the base 10. In this example, the outer diameters of the multiple short pipes 16 provided by the tower 15 gradually decrease as you move toward the first side in the direction of the axis O1. The tower 15 extends vertically and protrudes above the water surface. The lower end of the tower 15 is joined to the upper end of the foundation 10. A transition piece (not shown) may be provided at the connection between the tower 15 and the foundation 10. The nacelle 20 is joined to the upper end of the tower 15. The nacelle 20 has a main shaft and a generator, which are not shown. The main shaft extends along the horizontal plane. The generator is fixed to the first end of the main shaft. Multiple blades 25 are fixed to the second end of the main shaft.

[0024] Wind turbine 1, configured as described above, operates as follows. When multiple blades 25 receive wind, the main shaft rotates. This rotation of the main shaft generates electricity in a generator fixed to it.

[0025] In the following explanation, we will use the example where the steel pipe (final product) is the foundation 10. For this reason, the foundation 10 will also be referred to as the steel pipe (final product) 10.

[0026] [Method of manufacturing steel pipes] Next, the manufacturing method for steel pipes according to this embodiment (hereinafter simply referred to as the manufacturing method) will be described. Figure 2 is a flowchart of the manufacturing method S1 in the first embodiment of the present invention. Figure 2 also shows a block diagram of the inventory management system 50, which will be described later. The manufacturing method S1 comprises a first design process S11, a second design process S12, a material procurement process S13, a first storage process S14, an intermediate product manufacturing process S15, a second storage process S16, a final product assembly process S17, an inspection process S18, and a shipping process S19.

[0027] Furthermore, in manufacturing method S1, an inventory management system 50 is used. The inventory management system 50 includes an intermediate product allocation system 51 and an inventory adjustment system 61. The configuration of the intermediate product allocation system and the inventory adjustment system is not limited. For example, the intermediate product allocation system 51 includes a first storage unit 52, a second storage unit 53, a first control unit 54, and a second control unit 58. The first memory unit 52 stores information regarding the requirements and performance of the steel pipe 10, which will be output in the second design process S12, which will be explained in detail later.

[0028] The necessary performance of the steel pipe 10 referred to here is, for example, the structural performance and natural frequency of the steel pipe 10. In terms of structural performance, this means the total strength or partial strength equivalent to one or more of the tensile strength, compressive strength, bending strength, shear strength, and bending stiffness required of the steel pipe 10. The second memory unit 53 stores information regarding the specifications and quantity (number) of the multiple short pipes 11 stored in the second storage process S16, which will be explained in detail later. The specifications of the short pipes 11 refer to the plate thickness of the short pipes 11, the material of the steel used to form the short pipes 11, etc.

[0029] The first control unit 54 selects a combination of multiple short pipes 11 from among the multiple short pipes 11 stored in the second storage unit 53 to form a final product that satisfies the requirements and performance of the steel pipe 10 stored in the first storage unit 52. The first control unit 54 calculates at least one of the following for use in a construction project: the difference in plate thickness between adjacent short pipes 11 in the direction of axis O1, the cost of the steel pipe 10, the weight of the steel pipe 10, and the delivery date of the steel pipe 10 (the period required to carry out the entire manufacturing method S1). The second control unit 58 re-selects a combination of multiple short pipes 11 to be used in the manufacture of the steel pipe 10 based on the calculation results of the first control unit 54.

[0030] The second control unit 58 may re-select a combination of multiple short pipes 11 such that at least one of the following is minimized: the difference in plate thickness between the short pipes 11 selected by the first control unit 54, the cost of the steel pipe 10 manufactured using the short pipes 11 selected by the first control unit 54, the weight of the steel pipe 10 manufactured using the short pipes 11 selected by the first control unit 54, and the delivery time of the steel pipe 10 manufactured using the short pipes 11 selected by the first control unit 54. Alternatively, it may select the combination in a way that satisfies the customer's requirements, regardless of whether any of the other elements are minimized. To perform calculations in a way that minimizes at least one of multiple calculation results, not only simple calculations but also optimization methods using, for example, machine learning or genetic algorithms can be employed.

[0031] This method allows calculation by setting the objective function so that each element or combination of elements is minimized. Alternatively, one may use machine learning methods such as Random Forest or LightGBM, or optimization algorithms such as Gradient Descent, Linear Programming, or Nonlinear Programming. Alternatively, for example, one could set arbitrary weights (coefficients) according to the type and circumstances of the construction project for each of the calculation results of the difference in plate thickness between the short pipes 11, the cost of the steel pipes 10, the weight of the steel pipes 10, and the delivery date of the steel pipes 10, and then select a combination of multiple short pipes 11 by calculating so that the sum of the calculation results multiplied by each weight (coefficient) is minimized. Alternatively, for example, in the second storage process S16, a combination of short pipes 11 may be selected by choosing the short pipe 11 with the smallest plate thickness from among the multiple short pipes 11 stored, and gradually increasing the plate thickness of the short pipe 11 until it can be manufactured into a shape that satisfies the required performance of the steel pipe 10. In other words, it is sufficient that the combination of short pipes 11 satisfies the required performance of the steel pipe 10, and the method of calculation is not limited to minimizing at least one of the multiple calculation results.

[0032] The inventory adjustment system 61 includes a third storage unit 62, a third control unit 63, and a first instruction unit (instruction unit) 64. The third memory unit 62 stores information regarding the specifications and quantities of multiple short pipes 11 selected by the intermediate product allocation system 51. The third control unit 63 determines the specifications and quantity of material 12 necessary to replace the multiple short pipes 11 based on information regarding the specifications and quantities of the multiple short pipes 11 stored in the third storage unit 62, or based on past performance. It is preferable that past performance is stored in a storage unit such as the third storage unit 62.

[0033] One method for determining the specifications and quantity of material 12 needed to replace the multiple short pipes 11 based on information regarding the specifications and quantity of the multiple short pipes 11 stored in the third storage unit 62 is to make the specifications and quantity of material 12 needed to replace the multiple short pipes 11 the same as the specifications and quantity of the multiple short pipes 11 stored in the third storage unit 62. Furthermore, the information regarding the specifications and quantities of the multiple short pipes 11 stored in the third storage unit 62 can also be considered information regarding the total output value of the third storage unit 62. One method for determining the specifications and quantities of materials 12 needed to replace multiple short pipes 11 based on past performance is to rank the specifications of shipped steel pipes 10, including those from past construction projects, and the specifications of multiple short pipes 11 stored in the third storage unit 62 in descending order of quantity, and to prioritize replacement of the specifications with higher rankings. Alternatively, steel plate thickness information may be extracted from the specifications of shipped steel pipes 10, including those from past construction projects, and the specifications of multiple short pipes 11 stored in the third storage unit 62, and ranked in descending order of usage and frequency, with priority given to replacement of steel plates with higher rankings.

[0034] The first instruction unit 64 transmits the specifications and quantity of the material 12 determined by the third control unit 63 to the material procurement process S13.

[0035] The inventory management system 50 is configured using one or more information processing devices, such as a personal computer or a server. The first storage unit 52, the second storage unit 53, and the third storage unit 62 are each configured using storage devices such as magnetic hard disk drives or semiconductor memory devices. The first control unit 54, the second control unit 58, and the first instruction unit 64 are configured using a processor such as a CPU (Central Processing Unit) and memory (main memory). The first control unit 54, the second control unit 58, and the first instruction unit 64 function when the processor executes a program. Furthermore, all or part of the functions of the first control unit 54, the second control unit 58, and the first instruction unit 64 may be implemented using hardware such as an ASIC (Application Specific Integrated Circuit), a PLD (Programmable Logic Device), or an FPGA (Field Programmable Gate Array). The above program may be recorded on a computer-readable recording medium. Computer-readable recording media include, for example, portable media such as flexible disks, magneto-optical disks, ROMs, CD-ROMs, and semiconductor memory devices (e.g., SSDs: Solid State Drives), as well as storage devices such as hard disks and semiconductor memory devices built into computer systems. The above program may also be transmitted via a telecommunications line.

[0036] The manufacturing method S1 of this embodiment is intended for a single construction project to construct a wind turbine 1. In the first design process S11, the basic design of the steel pipes 10 to be used in the construction project is carried out. The basic design of the steel pipes 10 here refers to processes such as deciding whether to use steel pipe piles or concrete piles as the foundation, designing the maximum diameter of the foundation (e.g., 10m), and estimating the thickness and weight of the foundation plate.

[0037] In the material procurement process S13, prior to the second design process S12, multiple steel materials (steel plates) 12 for manufacturing the steel pipe 10 are procured, as shown in Figure 3. For example, each material 12 is formed in the shape of a flat plate. For example, the material 12 may have multiple types of materials 12a and 12b with different plate thicknesses. In this case, it is desirable to limit the plate thickness for one outer diameter, or the plate thickness of the material (steel plate) 12, to seven types or less, preferably five types or less, and more preferably three types or less. The material procurement process S13 may be performed after the first design process S11, or it may be performed before the first design process S11.

[0038] In the second design process S12, after the first design process S11, the detailed design of the steel pipe 10 is performed. The detailed design of the steel pipe 10 here refers to the process of considering changes to the plate thickness of the steel pipe 10, from the initial 100 mm in the detailed design to 95 mm, 90 mm, etc., while considering the positional relationship between the steel pipe 10 and the water surface and performing structural calculations for the steel pipe 10. In the second design process S12, the length (length information) of the steel pipe 10 may be set, or the specifications and quantities of the multiple short pipes 11 used in the final product assembly process S17 may be set.

[0039] However, the contents of the basic design and detailed design of the steel pipe 10 are not limited to these. The contents of the basic design of the steel pipe 10 only need to be the first to be carried out in the overall design of the steel pipe 10, and the contents of the detailed design of the steel pipe 10 only need to be carried out following the basic design of the steel pipe 10. The first design process S11 and the second design process S12 may be combined and referred to as the design process.

[0040] In the first storage process S14, after the material procurement process S13, multiple materials 12 are stored in a warehouse or a storage area within the factory where intermediate products are manufactured. In the intermediate product manufacturing process S15, as shown in Figure 4, multiple materials 12 procured in the material procurement process S13 are processed to manufacture multiple short pipes 11. The materials 12 stored in the first storage process S14 may also be used to manufacture the multiple short pipes 11. A known bending device 100 can be used to process the material 12. The bending device 100 is used to bend the material 12 into a cylindrical shape. Then, multiple short pipes 11 are manufactured by butting the ends of the bent material 12 together and welding them.

[0041] Welding methods include electric resistance welding, CO2 welding, submerged arc welding, electrogas welding, and electroslag welding. In welding the ends of curved material 12 together, the groove shape can be V-groove, K-groove, or X-groove, and the presence or absence of a root gap is irrelevant. For V-groove welds, it is preferable to weld downwards from the radially outer side towards the radially inner side to ensure weld quality, and it is also preferable to use a backing plate. For K-groove and X-groove welds, it is efficient to weld simultaneously from both the radially inner and outer sides of the steel pipe.

[0042] Multiple materials 12 may be arranged in the circumferential direction of the short pipe 11 and connected to each other to form a single short pipe 11. Multiple short pipes 11 with different thicknesses may be manufactured using materials 12a and 12b, which have different thicknesses. The intermediate product manufacturing process S15 is preferably carried out, for example, during periods when the factory equipped with the bending machine 100 is operating at a low rate (factory downtime). By manufacturing intermediate products during factory downtime, the factory's operating rate can be leveled out, and the risk of delivery delays due to manufacturing problems, etc., can be reduced.

[0043] In the second storage process S16, multiple short pipes 11 are stored after the intermediate product manufacturing process S15. After the intermediate product manufacturing process S15, the intermediate product allocation system 51 selects the specifications and quantity of the short pipes 11 required for the final product assembly process S17. It is also possible to select short pipes 11 that are so-called over-spec, exceeding the required quality of the steel pipe (final product) 10. The required quality here refers to, for example, the thickness of the steel pipe (final product) 10 or the strength of the steel plate that will be used as the material for the short pipes 11. In other words, as long as the required quality is exceeded, it is not necessarily required that all of the short pipes 11 used in the same construction project have the same specifications (plate thickness). This allows for the rapid supply of stored short pipes 11 and shortens the delivery time of the wind turbine 1. Then, in the second storage process S16, the inventory adjustment system 61 determines the specifications and quantity of materials 12 necessary to replenish the short pipes 11 used in the construction project. Note that this determination by the inventory adjustment system 61 may be performed in a process other than the second storage process S16.

[0044] For example, it is desirable to consolidate the plate thickness for a single outer diameter, or the plate thickness of the material (steel plate) 12 required for storage as an intermediate product, into no more than seven types, preferably no more than five types, and more preferably no more than three types, including thick to thin plates. In this case, the plate thickness of the material (steel plate) 12 to be consolidated is selected from a range of 6 mm to 100 mm, preferably from 19 mm to 80 mm, more preferably from 30 mm to 70 mm, and even more preferably from 40 mm to 60 mm, and is stored or processed as an intermediate product.

[0045] Such materials (steel plates) 12 have a yield strength or 0.2% proof stress of at least 215 MPa or more and 550 MPa or less, and a tensile strength of 400 MPa or more and 720 MPa or less, and include, for example, general structural rolled steel materials such as SS330, SS400, SS490 and SS540 as specified in JIS G3101, welded structural rolled steel materials such as SM400A, SM400B, SM400C, SM490A, SM490B, SM490C, SM490YA, SM490YB, SM520B, SM520C and SM570 as specified in JIS G3106, and high-performance steel materials for bridges such as SBHS400 and SBHS500 as specified in JIS G3140. The specifications for the material (steel sheet) 12 described above are merely examples, and the material (steel sheet) 12 is not necessarily limited to the above specifications, but may be an equivalent product, as long as it can be formed into an intermediate product.

[0046] In the final product assembly process S17, multiple short pipes 11 manufactured in the intermediate product manufacturing process S15, or multiple short pipes 11 stored in the second storage process S16, are processed based on the information from the second design process S12. Then, the multiple short pipes 11 are welded together to form a steel pipe 10, making it a long final product. It is desirable that the welding at this time be the same method as when the short pipes 11 were manufactured. Alternatively, the entire process from the short pipes 11 to the steel pipe 10 may be manufactured in the factory, or the materials (steel plates) 12 or the short pipes 11 may be transported to a yard near the site and welded together to form the steel pipe 10. Furthermore, the short pipes 11 used in the final product assembly process S17 may be cut to a predetermined length based on the information from the second design process S12. By manufacturing them in large quantities as intermediate products in this way, manufacturing costs can be suppressed. For example, as shown in Figure 5, multiple short pipes 11 are arranged in the direction of the axis O1. Each short pipe 11 may be supported by a support member 105. Then, adjacent short pipes 11 are welded together in the direction of axis O1. Once the final product assembly process S17 is completed, the process moves on to the inspection process S18.

[0047] In inspection step S18, the required quality of the final product is inspected. Inspection step S18 may be performed using a quality inspection system (not shown), for example, ultrasonic testing, magnetic particle testing, magnetic testing, laser testing, etc. In inspection step S18, the output may be information that links the location information of welding defects when the steel pipe 10 is welded together. The welding defects referred to here mean, for example, information indicating the presence or absence of surface defects such as undercuts, pinholes, and cracks, and internal defects such as blowholes, slag inclusions, and poor penetration, at the locations where the ends of the curved material 12 are butted together and the locations where the short pipes 11 are welded together. The welding defects may also refer to, for example, the identification number information of the steel pipe 10. Location information refers, for example, to information about the location where a defect is located in the steel pipe 10. The linking is performed, for example, by using welding defect details and location information as fields, and representing multiple fields as a single record. In addition, to streamline the inspection process S18, inspection may be performed using unmanned machinery such as drones or remote operation, or the roundness and deformation state of the steel pipe 10 when welded together may be measured using a laser or the like. Once inspection process S18 is completed, the process moves on to shipping process S19.

[0048] Furthermore, the manufacturing method S1 may include a repair step after the inspection step S18 for repairing welding defects.

[0049] In the shipping process S19, the final product is shipped. In the shipping process S19, if the short pipes 11 and steel pipes 10 are manufactured in the factory, they are shipped by sea or land transport. If the steel pipes 10 are manufactured in a yard near the site, they may be shipped by sea or land transport, or they may be shipped by moving them using cranes or the like. By performing the above steps, the steel pipe 10 is manufactured and shipped. Furthermore, the inspection in inspection process S18 may be performed on the welded joint when manufacturing the short pipe 11.

[0050] In addition, the short pipe 11 manufactured in the intermediate product manufacturing process S15 may be just one.

[0051] As described above, in the manufacturing method S1 of this embodiment, the basic design of the steel pipe 10 to be used in the construction project is performed in the first design process S11, and the detailed design of the steel pipe 10 is performed in the second design process S12 after the first design process S11. In the material procurement process S13, steel materials 12 for manufacturing steel pipes 10 are procured before the second design process S12. In the first storage process S14, the materials 12 are stored after the material procurement process S13. In the intermediate product manufacturing process S15, the materials 12 procured in the material procurement process S13 are processed to manufacture multiple short pipes 11. In the second storage process S16, multiple short pipes 11 are stored after the intermediate product manufacturing process S15. In the final product assembly process S17, the multiple short pipes 11 manufactured in the intermediate product manufacturing process S15, or the multiple short pipes 11 stored in the second storage process S16, are processed based on the information from the second design process S12, and then welded and assembled as the final product, a steel pipe 10, to make it longer. Finally, in the shipping process S19, the final product is shipped. In other words, the material 12 is stored in the first storage step S14, and the multiple short pipes 11 are stored in the second storage step S16.

[0052] Here, after the intermediate product manufacturing process S15, the intermediate product allocation system 51 selects the specifications and quantity of the short pipes 11 required for the final product assembly process S17. As described above, since the steel material 12 for manufacturing the final product (steel pipe 10) is procured before the second design process S12, the final product can be manufactured in a relatively short period of time. The intermediate product allocation system 51 selects the specifications and quantity of the short pipes 11 required for the final product assembly process S17, thereby making it easy to select the material 12 required for the final product to be manufactured in the final product assembly process S17.

[0053] The short pipes 11 used in the final product assembly process S17 may be cut to a predetermined length based on the information from the second design process S12. For example, where n is a natural number, the length of the final product (steel pipe 10) may be longer than n times the length of the short pipes 11 and shorter than (n+1) times the length of the short pipes 11. Even in this case, the final product can be constructed to the desired length using short pipes 11 cut to a predetermined length that is shorter than the length of the short pipes 11.

[0054] Here, the inventory adjustment system 61 determines the specifications and quantities of materials 12 needed to replenish the short pipes 11 used in the construction project, thereby facilitating the replenishment of the short pipes 11 used in the final product (steel pipe 10). The intermediate product allocation system 51 includes a second control unit 58. Accordingly, the second control unit 58 re-selects the combination of short pipes 11 to be used in the manufacture of the final product based on the calculation results of the first control unit 54, thereby minimizing at least one of the following: the difference in plate thickness between the short pipes 11 used in the construction project, the cost of the final product, the weight of the final product, and the delivery date of the final product.

[0055] The second control unit 58 re-selects a combination of multiple short pipes 11 such that at least one of the following is minimized: the difference in plate thickness between the short pipes 11, the cost of the steel pipes 10, the weight of the steel pipes 10, and the delivery time of the steel pipes 10.

[0056] The inventory adjustment system 61 includes a third storage unit 62, a third control unit 63, and a first instruction unit 64. Therefore, the third control unit 63 determines the specifications and quantity of materials 12 necessary to replenish the short pipes 11 based on information regarding the specifications and quantity of short pipes 11 stored in the third storage unit 62, or based on past performance. By determining the specifications and quantity of materials necessary to replenish the short pipes 11 used in the construction project, the inventory adjustment system 61 makes it easy to replenish the short pipes 11 used in the steel pipes 10. The first instruction unit 64 then transmits the specifications and quantity of the material 12 determined by the third control unit 63 to the material procurement process S13, thereby enabling more accurate replenishment of the short pipes 11 used in the construction project. The data stored in the inventory adjustment system 61 is updated after each construction project, making it possible to consolidate the specifications of the intermediate products to be stored and the materials (steel plates) 12 needed to replenish those intermediate products, thereby further reducing procurement costs.

[0057] Manufacturing method S1 includes an inspection step S18. Therefore, based on the welding defect and location information output in the inspection step S18, workers can reach the location of the welding defect and promptly repair it. Furthermore, in this embodiment, the foundation 10 can be manufactured by a manufacturing method S1 that allows for the production of the final product in a relatively short period of time, as well as the selection of materials 12 required for the final product and the replenishment of materials 12 used in the final product. For example, when construction is carried out on-site, a solidified material such as soil cement or concrete may be injected inside or outside the steel pipe 10.

[0058] Furthermore, manufacturing method S1 may be applicable to multiple construction projects.

[0059] (Second Embodiment) Next, a second embodiment of the present invention will be described with reference to Figure 6. The same reference numerals are used for parts identical to those in the previous embodiment, and their descriptions will be omitted. Only the differences will be described. As shown in Figure 6, the manufacturing method S2 of this embodiment is intended for multiple construction projects involving the construction of the wind turbine 1. In manufacturing method S2, the first control unit 54A is provided instead of the first control unit 54 of the intermediate product allocation system 51.

[0060] The first control unit 54A selects a combination of multiple short pipes 11 stored in the second storage unit 53 from among multiple short pipes 11, by surveying multiple construction projects, in order to create a final product that satisfies the requirements and performance of the steel pipe 10 stored in the first storage unit 52. In this context, "overseeing multiple construction projects" means, for example, looking at and optimizing multiple construction projects as a whole, and more specifically, it refers to the following steps. In other words, if there is a certain inventory of multiple short pipes 11, and all of that inventory is taken to a particular construction project, and it is determined that "all or some of the short pipes 11 do not meet the performance requirements of this construction project," then all or some of those short pipes 11 can be moved to another construction project, thereby ensuring that the overall performance requirements are met across multiple construction projects. In other words, as long as the performance requirements are met, it is not necessary for all of the multiple short pipes 11 used in the same construction project to be of the same specifications (plate thickness).

[0061] Furthermore, the timing of each stage, such as the first design stage S11, in multiple construction projects may be staggered or synchronized.

[0062] As described above, the manufacturing method S2 of this embodiment allows for the production of the final product, which is a steel pipe 10, in a relatively short period of time, and also facilitates the selection of the short pipes 11 required for the final product and the replacement of the short pipes 11 used in the final product. Furthermore, the intermediate product allocation system 51 includes a first storage unit 52, a second storage unit 53, a first control unit 54A, and a second control unit 58. Therefore, the first control unit 54A can select from multiple combinations of short pipes 11 stored in the second storage unit 53, by surveying multiple construction projects, to form a final product that satisfies the requirements and performance of the steel pipe 10 stored in the first storage unit 52.

[0063] Although the first and second embodiments of the present invention have been described in detail above with reference to the drawings, the specific configuration is not limited to these embodiments, and modifications, combinations, deletions, etc., of the configuration are also included without departing from the spirit of the present invention. Furthermore, it goes without saying that each of the configurations shown in each embodiment can be used in appropriate combinations. For example, in the first and second embodiments, the manufacturing methods S1 and S2 do not necessarily have to include the inspection step S18.

[0064] The second control unit 58 does not need to re-select a combination of multiple short pipes 11 so that at least one of the following is minimized: the difference in plate thickness between the short pipes 11, the cost of the steel pipe 10, the weight of the steel pipe 10, and the delivery date of the steel pipe 10. The intermediate product allocation system 51 does not need to have at least one of the first storage unit 52, the second storage unit 53, the first control unit 54, and the second control unit 58. The inventory adjustment system 61 does not necessarily have to have at least one of the third storage unit 62, the third control unit 63, and the first instruction unit 64. [Explanation of Symbols]

[0065] 10 Foundation (steel pipes, final products) 11 Short pipe (intermediate product) 51 Intermediate Product Allocation System 52 1st memory section 53 2nd memory section 54,54A First Control Unit 58 Second Control Unit 61 Inventory Adjustment System 62 Third memory section 63 Third Control Unit 64 1st instruction part S1, S2 Manufacturing Method (Method for manufacturing steel pipes) S11 1st design process S12 2nd design process S13 Material Procurement Process S14 1st storage process S15 Intermediate product manufacturing process S16 2nd storage process S17 Final Product Assembly Process S18 Inspection Process S19 Shipping Process

Claims

1. A method for manufacturing steel pipes, A first design process which is the basic design of the steel pipe used in one or more construction projects, A second design process, which is the detailed design of the steel pipe, follows the first design process described above. Prior to the second design process, a material procurement process for procuring steel materials for manufacturing the steel pipe, A first storage step for storing the materials, following the material procurement step, An intermediate product manufacturing process which involves processing the materials procured in the material procurement process to manufacture one or more intermediate products, A second storage step, which occurs after the intermediate product manufacturing step, for storing one or more of the intermediate products, A final product assembly process involves processing one or more intermediate products manufactured in the intermediate product manufacturing process, or one or more intermediate products stored in the second storage process, based on information from the second design process, and welding and assembling them as a final product to form a steel pipe, thereby lengthening the product; The shipping process for shipping the aforementioned final product, Equipped with, A method for manufacturing steel pipes, wherein, after the intermediate product manufacturing process, the specifications and quantity of the intermediate products necessary for the final product assembly process are selected by an intermediate product allocation system.

2. The method for manufacturing a steel pipe according to claim 1, wherein the intermediate product used in the final product assembly process is cut to a predetermined length based on the information from the second design process.

3. The aforementioned intermediate product allocation system is: A first storage unit stores information regarding the necessity and performance of the steel pipe output in the second design process, A second storage unit stores information regarding the specifications and quantity of the intermediate products stored in the second storage process, A first control unit selects a combination of intermediate products from the intermediate products stored in the second storage unit, by surveying one or more construction projects, to obtain the final product that satisfies the requirements and performance of the steel pipe stored in the first storage unit, Equipped with, The method for manufacturing a steel pipe according to claim 1, wherein the first control unit calculates at least one of the difference in plate thickness between the intermediate products used in one or more construction projects, the cost of the final product, the weight of the final product, and the delivery date of the final product.

4. The method for manufacturing a steel pipe according to claim 3, wherein the intermediate product allocation system includes a second control unit that re-selects a combination of the intermediate products to be used in the manufacture of the final product based on the calculation results of the first control unit.

5. The second control unit is, The difference in plate thickness between the intermediate products selected by the first control unit, The cost of the final product manufactured using the intermediate product selected by the first control unit, The weight of the final product manufactured using the intermediate product selected by the first control unit, and Delivery date of the final product manufactured using the intermediate product selected by the first control unit, A method for manufacturing a steel pipe according to claim 4, wherein the combination of intermediate products is re-selected such that at least one of the is minimized.

6. The system includes an inventory adjustment system that determines the specifications and quantities of materials necessary to replenish the intermediate products used in one or more of the aforementioned construction projects, The aforementioned inventory adjustment system is A third storage unit stores information regarding the specifications and quantities of the intermediate products selected by the intermediate product allocation system, A third control unit that determines the specifications and quantities of materials necessary to replenish the intermediate products based on information regarding the specifications and quantities of the intermediate products stored in the third memory unit for one or more construction projects, or based on past performance, A first instruction unit transmits the specifications and quantity of the material determined by the third control unit to the material procurement process, A method for manufacturing a steel pipe according to claim 1, comprising:

7. The system includes an inspection process for inspecting the required quality of the final product, The method for manufacturing a steel pipe according to claim 1, wherein in the inspection step, the location information of the welding defects when the steel pipe is welded and assembled is linked and output.

8. A tower or foundation for wind power generation, manufactured by the method for manufacturing steel pipes described in claim 1.

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