WO2022009575A1 - 鋼管の真円度予測モデルの生成方法、鋼管の真円度予測方法、鋼管の真円度制御方法、鋼管の製造方法、及び鋼管の真円度予測装置 - Google Patents
鋼管の真円度予測モデルの生成方法、鋼管の真円度予測方法、鋼管の真円度制御方法、鋼管の製造方法、及び鋼管の真円度予測装置 Download PDFInfo
- Publication number
- WO2022009575A1 WO2022009575A1 PCT/JP2021/021415 JP2021021415W WO2022009575A1 WO 2022009575 A1 WO2022009575 A1 WO 2022009575A1 JP 2021021415 W JP2021021415 W JP 2021021415W WO 2022009575 A1 WO2022009575 A1 WO 2022009575A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- roundness
- steel pipe
- pipe
- press
- steel
- Prior art date
Links
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21D39/00—Application of procedures in order to connect objects or parts, e.g. coating with sheet metal otherwise than by plating; Tube expanders
- B21D39/08—Tube expanders
- B21D39/20—Tube expanders with mandrels, e.g. expandable
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21D5/00—Bending sheet metal along straight lines, e.g. to form simple curves
- B21D5/01—Bending sheet metal along straight lines, e.g. to form simple curves between rams and anvils or abutments
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K9/00—Arc welding or cutting
- B23K9/02—Seam welding; Backing means; Inserts
- B23K9/025—Seam welding; Backing means; Inserts for rectilinear seams
-
- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
- G05B23/00—Testing or monitoring of control systems or parts thereof
- G05B23/02—Electric testing or monitoring
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06N—COMPUTING ARRANGEMENTS BASED ON SPECIFIC COMPUTATIONAL MODELS
- G06N20/00—Machine learning
Definitions
- the present invention is a method for generating a roundness prediction model for a steel pipe, which generates a roundness prediction model for predicting the roundness of the steel pipe after the pipe expansion process in the steel pipe manufacturing process using the press bend method. It relates to a degree prediction method, a steel pipe roundness control method, a steel pipe manufacturing method, and a steel pipe roundness prediction device.
- a steel plate having a predetermined length, width, and plate thickness is press-processed into a U-shape and then press-formed into an O-shape. Then, a manufacturing technique of a steel pipe (so-called UOE steel pipe) in which the butt portion is welded to form a steel pipe and the diameter thereof is further expanded (so-called expanded pipe) to increase the roundness is widely used.
- UOE steel pipe steel pipe
- expanded pipe expanded pipe
- U It is sometimes called a character-shaped molded body
- the butt part is welded to make a steel pipe, and finally the pipe is formed.
- a technique of inserting a pipe expanding device inside a steel pipe to expand the inner diameter of the steel pipe has been put into practical use.
- the pipe expansion device is provided with a plurality of pipe expansion tools having a curved surface obtained by dividing an arc into a plurality of pipes, and the curved surface of the pipe expansion tool is brought into contact with the inner surface of the steel pipe to expand the steel pipe and adjust the shape of the steel pipe. Used.
- the number of 3-point bending presses is increased, the roundness of the steel pipe after the pipe expansion process is improved, but it takes a long time to form the steel pipe into a U-shaped cross section.
- the number of three-point bending presses is reduced, there is a problem that the cross-sectional shape of the steel pipe becomes close to a polygonal shape and it is difficult to make a circular shape. Therefore, the number of three-point bending presses (for example, 5 to 13 times for a steel pipe having a diameter of 1200 mm) is empirically determined according to the dimensions of the steel pipe for operation.
- the operating conditions of the press bend process for improving the roundness of the steel pipe after the pipe expansion process many proposals have been made regarding the setting method.
- Patent Document 1 is a method for performing a three-point bending press as few times as possible, and a plurality of tube expansion tools arranged in the circumferential direction of the tube expansion device are deformed by the three-point bending press. A method of expanding the tube by contacting it with an undeformed portion is described.
- the radius of curvature of the outer peripheral surface of the punch used for the three-point bending press and the radius of curvature of the outer peripheral surface of the pipe expansion tool satisfy a predetermined relational expression, so that the steel pipe after the pipe expansion step can be used. It describes how to improve the roundness.
- Patent Document 3 describes at least a part of a steel sheet when performing a three-point bending press as a manufacturing method capable of efficiently manufacturing a steel pipe having a high roundness without requiring an excessive pressing force in the press bend process. Describes a method of providing a lightly machined portion having a very slight curvature as compared with other regions, or providing an unprocessed portion in which bending is omitted. Further, according to Patent Document 3, in the seam gap reducing step, a pressing force is applied to a portion separated by a predetermined distance from the center of the lightly machined portion or the unprocessed portion without restraining the lightly machined portion or the unprocessed portion. It is stated that it should be done. Normally, an O-press device is used in the seam gap reducing step performed after the press bend step.
- Patent Document 4 after forming a non-circular preform (a molded body having a U-shaped cross section) by a three-point bending press, a non-circular preform is used instead of the normal O-press process.
- a method of reducing the seam gap by applying a pressing force from the outside of the non-circular preform by a pressing tool arranged at the top so as to face the lower supporting roll while being supported by two lower supporting rolls. (Hereinafter referred to as "closing press method”) is described.
- a pressing force is applied from the outside of the non-circular preform by a pressing tool, so that the device configuration is simplified and it is necessary to prepare a die according to the outer diameter of the steel pipe like an O-press device.
- Patent Document 4 intentionally imparts a relatively slightly formed region to a part of the three-point bending press, and forms a U-shaped cross section in the closing press method used in the seam gap reducing step. It describes how to apply a pressing force to that area of the body.
- Non-Patent Document 1 describes a method of analyzing the influence of the operating conditions of the pipe expansion process on the roundness of the steel pipe after the pipe expansion process by calculation using the finite element method.
- the method described in Patent Document 1 is a method of improving the roundness of a steel pipe after a pipe expanding process by associating the pressing position of a three-point bending press with the pressing position of a pipe expanding tool.
- the steel pipe manufacturing process includes at least a press bend process, a seam gap reduction process, a welding process, and a pipe expansion process. Therefore, in the method described in Patent Document 1, since the influence of the operating conditions of other processes on the roundness of the steel pipe after the pipe expansion process is not taken into consideration, the roundness of the steel pipe after the pipe expansion process is not necessarily improved. It may not be possible to make it.
- Patent Document 2 is the same as the method described in Patent Document 1, in that the radius of curvature of the outer peripheral surface of the punch used for the three-point bending press, which is the operating condition of the press bend process, and the pipe expansion, which is the operating condition of the pipe expanding process.
- This is a method of improving the roundness of a steel pipe after a pipe expansion step by making the radius of curvature of the outer peripheral surface of the tool satisfy a predetermined relational expression.
- the method described in Patent Document 2 has a problem that, like the method described in Patent Document 1, the influence of processes other than the press bend process such as the seam gap reducing process cannot be considered.
- the method described in Patent Document 3 changes the processing conditions of the three-point bending press in the press bend process according to the position of the steel sheet and makes the conditions related to the forming conditions in the seam gap reduction process, thereby expanding the pipe. This is a method for improving the roundness of the steel pipe later.
- the method described in Patent Document 3 has a problem that the roundness of the steel pipe after the pipe expansion process varies even under the same forming conditions when the plate thickness and the material of the steel plate as the material vary.
- Patent Document 4 is also a steel pipe after the pipe expansion step by setting the conditions for forming the U-shaped cross section into the molded body in the press bend process and the forming conditions in the seam gap reducing step. It is a method to improve the roundness of. However, even with the method described in Patent Document 4, there is a problem that the roundness of the steel pipe after the pipe expansion process varies even under the same forming conditions when the plate thickness and the material of the steel plate as the material vary.
- Non-Patent Document 1 by analyzing the pipe expansion process using the finite element method as an offline calculation, the influence of the operation parameters of the pipe expansion process on the roundness is quantitatively performed. Can be predicted.
- the method described in Non-Patent Document 1 also has a problem that the influence of the operating conditions of other processes on the roundness cannot be taken into consideration. Further, when such numerical analysis is performed, there is a problem that it is difficult to predict the roundness online because the calculation takes a long time.
- the present invention has been made to solve the above problems, and is a perfect circle that accurately and quickly predicts the roundness of a steel pipe after a pipe expansion process in a steel pipe manufacturing process composed of a plurality of processes. It is an object of the present invention to provide a method of generating a roundness prediction model of a steel pipe capable of generating a degree prediction model. Another object of the present invention is a method for predicting the roundness of a steel pipe, which can accurately and quickly predict the roundness of the steel pipe after the pipe expansion step in the manufacturing process of the steel pipe composed of a plurality of steps. The purpose is to provide a roundness prediction device.
- Another object of the present invention is to provide a method for controlling the roundness of a steel pipe, which can accurately control the roundness of the steel pipe after the pipe expansion step in the manufacturing process of the steel pipe composed of a plurality of steps. ..
- Another object of the present invention is to provide a method for manufacturing a steel pipe capable of manufacturing a steel pipe having a desired roundness with a high yield.
- the method for generating the roundness prediction model of the steel pipe according to the present invention is a press bend step of processing a steel plate into a U-shaped cross-section molded body by pressing a plurality of times with a punch, and a seam gap of the U-shaped cross-section molded body.
- the steel pipe manufacturing process including a seam gap reduction step of reducing the number of portions to make an open pipe, a welding step of joining the ends of the open pipe to each other, and a pipe expansion step of expanding the inner diameter of the steel pipe to which the ends are joined.
- the input data includes an operation condition data set including one or more parameters selected from the operation parameters of the press bend process and one or two or more parameters selected from the operation parameters of the seam gap reduction process, and the pipe expansion step.
- an operation condition data set including one or more parameters selected from the operation parameters of the press bend process and one or two or more parameters selected from the operation parameters of the seam gap reduction process
- the pipe expansion step By executing the numerical calculation using the roundness of the steel pipe as the output data a plurality of times while changing the operating condition data set, the roundness of the steel pipe after the pipe expansion step corresponding to the operating condition data set is executed.
- the operation condition data set is input data, and after the pipe expansion step.
- Includes a roundness prediction model generation step that generates a roundness prediction model offline by machine learning using the roundness of the steel pipe as output data.
- the basic data acquisition step may include a step of calculating the roundness of the steel pipe after the pipe expansion step from the operating condition data set using the finite element method.
- the roundness prediction model may include one or more parameters selected from the operation parameters of the pipe expansion process as the operation condition data set.
- the manufacturing process of the steel pipe includes an edge bending step of imparting a bend to the widthwise end portion of the steel sheet prior to the press bend step, and the roundness prediction model is the edge bending as the operating condition data set. It is preferable to include one or more parameters selected from the operation parameters of the process.
- the operation parameters of the press bend process may include the press position information on which the punch used in the press bend process presses the steel sheet and the press reduction amount, as well as the number of presses performed through the press bend process.
- machine learning it is preferable to use machine learning selected from neural network, decision tree learning, random forest, Gaussian process regression, and support vector regression.
- the method for predicting the roundness of a steel pipe according to the present invention is an operation condition of the manufacturing process of the steel pipe as an input of the roundness prediction model for the steel pipe generated by the method for generating the roundness prediction model for the steel pipe according to the present invention.
- the method for controlling the roundness of a steel pipe according to the first aspect of the present invention uses the method for predicting the roundness of a steel pipe according to the present invention, and the actual value of the attribute information of the steel plate before the start of the press bend process.
- the operation condition data set including the operation parameter setting value of the press bend process and the operation parameter setting value of the seam gap reduction process is acquired, and the acquired operation condition data set is input to the roundness prediction model.
- the roundness of the steel pipe after the pipe expansion process is predicted, and at least one of the set values of the operating parameters of the press bend process and the operating parameters of the seam gap reducing process is set so that the predicted roundness becomes smaller. Includes steps to reconfigure.
- the method for controlling the roundness of a steel pipe according to the second aspect of the present invention uses the method for predicting the roundness of a steel pipe according to the present invention, such as an end bending step, a press bend step, and a seam that constitute the manufacturing process of the steel pipe.
- the roundness information of the steel pipe after the pipe expansion process is predicted, and at least based on the predicted roundness information of the steel pipe.
- One or two or more operation parameters selected from the operation parameters of the reset target process, or one or two or more operations selected from the operation parameters of the molding process downstream from the reset target process. Includes steps to reset parameters.
- the roundness prediction device for a steel pipe reduces the seam gap portion of the U-shaped cross-section molded body in the press bend step of processing the steel plate into a U-shaped cross-section molded body by pressing the steel tube a plurality of times with a punch.
- the pipe expansion step in the steel pipe manufacturing process including a seam gap reduction step of forming an open pipe, a welding step of joining the ends of the open pipe, and a pipe expansion step of expanding the inner diameter of the steel pipe to which the ends are joined.
- a steel pipe roundness predictor that predicts the roundness of a steel pipe afterwards, with one or more parameters selected from the attribute information of the steel plate, and one or two or more selected from the operation parameters of the press bend process.
- the operation condition data set including one or two or more operation parameters selected from the operation parameters of the seam gap reduction process and the operation parameters of the seam gap reduction process is included as input data, and the roundness information of the steel pipe after the pipe expansion process is used as output data.
- the numerical calculation to be performed a plurality of times while changing the operating condition data set a plurality of sets of data of roundness information of the steel pipe after the pipe expansion process corresponding to the operating condition data set are used as learning data.
- the operation condition data set is used as input data, and the roundness information of the steel pipe after the pipe expansion process is used as output data.
- the roundness prediction model generation unit that generates the roundness prediction model by machine learning, the operation parameter acquisition unit that acquires the operation condition data set set as the operation condition of the steel pipe manufacturing process online, and the perfect circle.
- the roundness prediction model generated by the degree prediction model generation unit the roundness information of the steel pipe after the pipe expansion process corresponding to the operation condition data set acquired by the operation parameter acquisition unit is predicted online. It is equipped with a circularity prediction unit.
- the operation parameter acquisition unit includes a terminal device having an input unit for acquiring input information based on a user's operation and a display unit for displaying the roundness information, and the operation parameter acquisition unit is based on the input information acquired by the input unit. Then, a part or all of the operating condition data set in the manufacturing process of the steel pipe is updated, and the display unit shows the trueness of the steel pipe predicted by the roundness prediction unit using the updated operating condition data set. It is good to display the degree information.
- a circularity prediction model can be generated.
- the roundness of the steel pipe after the pipe expansion step in the steel pipe manufacturing process composed of a plurality of steps can be accurately and accurately performed. It can be predicted quickly.
- the method for controlling the roundness of a steel pipe according to the present invention it is possible to accurately control the roundness of the steel pipe after the pipe expansion step in the manufacturing process of the steel pipe composed of a plurality of steps.
- a steel pipe having a desired roundness can be manufactured with a high yield.
- FIG. 1 is a diagram showing a manufacturing process of a steel pipe according to an embodiment of the present invention.
- FIG. 2 is a diagram showing an example of a process of molding a U-shaped cross-section molded body using a press bend device.
- FIG. 3 is a diagram showing an example of a process of molding a U-shaped cross-section molded body using a press bend device.
- FIG. 4 is a diagram showing a configuration example of the O-press device.
- FIG. 5 is a diagram showing a configuration example of a closing press device.
- FIG. 6 is a diagram showing a configuration example of a pipe expansion device.
- FIG. 7 is a diagram showing a configuration example of a device for measuring the outer diameter shape of a steel pipe.
- FIG. 1 is a diagram showing a manufacturing process of a steel pipe according to an embodiment of the present invention.
- FIG. 2 is a diagram showing an example of a process of molding a U-shaped cross-section molded body using a press bend device
- FIG. 8 is a block diagram showing a configuration of a steel pipe roundness prediction device according to an embodiment of the present invention.
- FIG. 9 is a block diagram showing the configuration of the roundness offline calculation unit shown in FIG.
- FIG. 10 is a diagram showing an example of a change in the relationship between the press working amount and the roundness of the steel pipe after the pipe expansion process due to the change in the operating conditions of the press bend process.
- FIG. 11 is a diagram showing an example of a press reduction position and a press reduction amount for each reduction frequency.
- FIG. 12 is a diagram showing a flow of processing for predicting the roundness of a steel pipe after the pipe expansion process before the start of the press bend process.
- FIG. 13 is a diagram showing an example of a finite element model.
- FIG. 14 is a perspective view showing the overall configuration of the C press device.
- FIG. 15 is a cross-sectional view showing the configuration of the press mechanism.
- FIG. 16 is a diagram for explaining a method for controlling roundness of a steel pipe according to an embodiment of the present invention.
- FIG. 17 is a diagram showing a configuration of a steel pipe roundness prediction device according to an embodiment of the present invention.
- FIG. 1 is a diagram showing a manufacturing process of a steel pipe according to an embodiment of the present invention.
- a thick steel plate manufactured by a thick plate rolling process which is a pre-process of the steel pipe manufacturing process, is used as a steel sheet as a raw material.
- typical thick steel sheets have a yield stress of 245 to 1050 MPa, a tensile strength of 415 to 1145 MPa, a plate thickness of 6.4 to 50.8 mm, a plate width of 1200 to 4500 mm, and a length of 10 to 18 m.
- the widthwise end portion of the thick steel plate is pre-ground into a chamfered shape called a groove. This is to prevent overheating of the outer surface corner portion of the widthwise end portion and stabilize the welding strength in the subsequent welding process. Further, since the width of the thick steel plate affects the outer diameter after being formed into the steel pipe, it is adjusted to a predetermined range in consideration of the deformation history in the later process.
- an end bending process for bending the widthwise end of the steel sheet may be performed.
- the edge bending step is performed by a C press device, and edge bending processing (also referred to as crimping processing) is performed on the widthwise end portion of the steel sheet.
- the C press device includes a pair of upper and lower dies and a pair of upper and lower clamps for holding the central portion of the steel plate in the width direction. Since the length of the mold is shorter than the length of the steel plate, the end bending process is repeated while sequentially feeding the steel plate in the longitudinal direction. Such edge bending is performed on both ends of the steel sheet in the width direction.
- the operating parameters for specifying the machining conditions are the edge bending width, which is the length at which the die contacts the steel sheet from the widthwise end to the widthwise center, and the gripping force of the clamp. Examples thereof include the feed amount, feed direction, and number of feeds of the mold when the edge bending process is repeated in the longitudinal direction of the steel sheet.
- the subsequent press bend process is a process of processing a steel sheet into a U-shaped cross-section molded body by performing a three-point bending press by punching a plurality of times with a press bend device.
- the subsequent seam gap reducing step is a step of reducing the seam gap portion of the U-shaped cross-section molded body into an open pipe by using an O-press device.
- the closing press method described in Patent Document 4 may be used instead of the O-press device.
- the subsequent welding step is a step of restraining the seam gap portion formed at the end of the open pipe so that the ends are in contact with each other and joining the ends. As a result, the molded body becomes a steel pipe in which the ends are joined to each other.
- the subsequent pipe expansion step is a step of expanding the steel pipe by bringing the curved surface of the pipe expansion tool into contact with the inner surface of the steel pipe by using a pipe expansion device equipped with a plurality of pipe expansion tools having a curved surface obtained by dividing the arc into a plurality of sections. ..
- the steel pipe manufactured in this way is determined whether or not the quality such as material, appearance, and dimensions satisfies the predetermined specifications, and then the steel pipe is shipped as a product.
- the inspection step includes a roundness measuring step of measuring the roundness of the steel pipe.
- a forming process in a series of manufacturing processes in which a steel plate is formed into an open pipe and a pipe expansion process is performed after welding, an end bending process, a press bend process, a seam gap reduction process, and a pipe expansion process are referred to as a "forming process". Called. These steps are common as a step of applying plastic deformation to a steel sheet to control the dimensions and shape of a steel pipe.
- a step of applying plastic deformation to a steel sheet to control the dimensions and shape of a steel pipe.
- FIG. 14 is a perspective view showing the overall configuration of the C press device.
- the C press device 30 has a transport mechanism 31 for transporting the steel plate S in a direction along the longitudinal direction thereof, and a widthwise end portion of the steel plate S with the downstream side in the transport direction as the front.
- a press mechanism 32A that bends Sc to a predetermined curvature
- a press mechanism 32B that bends the other widthwise end Sd to a predetermined curvature
- the transfer mechanism 31 includes an interval adjusting mechanism (not shown) that adjusts the interval between the mechanisms 32A and 32B.
- the transfer mechanism 31 includes a plurality of rotationally driven transfer rolls 31a arranged in front of and behind the press mechanisms 32A and 32B, respectively.
- the reference numeral Sa in the drawing indicates the tip end portion (longitudinal front end portion) of the steel plate S.
- FIG. 15A shows a cross section in the width direction of the press mechanism 32A for bending one end Sc of the steel plate S in the width direction from the upstream side in the transport direction to the downstream side in the transport direction of the steel plate S.
- the press mechanism 32A and the press mechanism 32B are symmetrical and have the same configuration.
- the press mechanisms 32A and 32B push up the upper die 33 and the lower die 34 as a pair of dies arranged so as to face each other in the vertical direction and the lower die 34 together with the tool holder 35 (direction close to the upper die 33). It is provided with a hydraulic cylinder 36 as a mold moving means for mold clamping with a predetermined pressing force.
- the press mechanisms 32A and 32B may include a clamp mechanism 37 that grips the steel plate S inside the upper die 33 and the lower die 34 in the width direction.
- the length of the steel plate S of the upper mold 33 and the lower mold 34 in the longitudinal direction is usually shorter than the length of the steel plate S. In that case, the end bending process is performed a plurality of times while intermittently feeding the steel sheet S in the longitudinal direction by the transport mechanism 31 (see FIG. 14).
- the lower mold 34 in contact with the surface of the width direction ends Sc and Sd of the steel plate S to be end bent, which is outside in the bending direction, has a pressing surface 34a facing the upper mold 33.
- the upper mold 33 has a convex curved surface 33a facing the pressing surface 34a and having a radius of curvature corresponding to the inner diameter of the steel pipe to be manufactured.
- the pressing surface 34a has a concave curved surface shape that approaches the upper mold 33 toward the outside in the width direction.
- the pressing surface 34a of the lower mold 34 may be an inclined flat surface as long as it is a surface that approaches the upper mold 33 toward the outside in the width direction.
- those having an appropriate shape according to the thickness, outer diameter, etc. of the steel plate S may be designed and appropriately selected and used according to the material to be processed. be.
- FIG. 15B is a cross section in the width direction of the press mechanism 32A at the same position as in FIG. 15A, but shows a state in which the lower die 34 is pushed up by the hydraulic cylinder 36 and molded.
- the lower mold 34 is pushed up by the hydraulic cylinder 36, and the widthwise end Sc of the steel plate S is bent into a shape along the arcuate forming surface 33a of the upper mold 33.
- the width at which edge bending is performed (edge bending width) varies depending on the width of the steel sheet S, but is generally about 100 to 400 mm.
- FIG. 2 is a diagram showing an example of a process of molding a U-shaped cross-section molded body using a press bend device.
- reference numeral 1 indicates a die arranged in the transport path of the steel plate S.
- the die 1 is composed of a pair of left and right rod-shaped members 1a and 1b that support the steel plate S at two points along the transport direction, and the interval ⁇ D can be changed according to the size of the steel pipe to be formed.
- reference numeral 2 indicates a punch that can move in the direction of approaching and separating from the die 1.
- the punch 2 is connected to a punch tip portion 2a having a downwardly convex machined surface that is in direct contact with the steel plate S and presses the steel plate S in a concave shape, and a punch support that is connected to the back surface of the punch tip portion 2a and supports the punch tip portion 2a. It has a body 2b and. Normally, the maximum width of the punch tip portion 2a and the width (thickness) of the punch support 2b are equal to each other.
- FIG. 3 shows the steel plate S which has been subjected to the edge bending process in advance from the top to the bottom in the left column (first half (a) to (e) of the process) and then from the top to the bottom in the center column (second half of the process).
- FIG. 3 is a view illustrating a step of molding the molded body S 1 as shown in the right column diagram ((j)) by carrying out the (f) ⁇ (i)) and the bending feed processing and steel S.
- the arrows attached to the steel plate S and the punch 2 indicate the moving directions of the steel plate S and the punch 2 in each step.
- the molded article S 1 of the U-shaped cross section after processing in accordance with the present process the gap between the end portion is referred to as a "seam gap".
- examples of operating parameters that determine the operating conditions of the press bend process include the number of presses, press position information, press reduction amount, lower die interval, punch curvature, and the like.
- the number of presses is the total number of times the steel sheet is pressed in the width direction with a 3-point bending press. As the number of presses increases, the molded body having a U-shaped cross section has a smooth curved shape, and the roundness of the steel pipe after the pipe expansion process is improved.
- Press position information refers to the position in the width direction of the steel plate that is pressed by the punch. Specifically, it can be specified by the distance from one end of the steel sheet in the width direction or the distance with respect to the center of the steel sheet in the width direction. It is preferable to handle the press position information as data associated with the number of presses (the order from the first press to the Nth press).
- the press reduction amount refers to the push amount of the punch at each pressing position.
- the press reduction amount is defined as an amount in which the lower end surface of the punch tip portion 2a protrudes downward from the line connecting the points on the uppermost surface of the die 1 shown in FIG.
- the operating conditions of the press bend process are specified by 1 to N data sets, where the number of presses is N, the number of presses, the press position information, and the press reduction amount are set as a set of data sets.
- the lower die spacing is the spacing between the pair of left and right rod-shaped members 1a and 1b shown in FIG. 2, and is a parameter represented by ⁇ D in the figure.
- ⁇ D the curvature of the steel sheet changes locally even with the same press reduction amount, which affects the roundness of the steel pipe after the pipe expansion process. Therefore, it is preferable to use the lower die interval set according to the size of the steel pipe to be formed as the operation parameter of the press bend process. Further, when the lower die interval is changed each time the punch is pushed in, the data associated with the number of presses may be used as the operation parameter.
- the punch curvature is the curvature of the tip of the punch that presses. As the punch curvature increases, the local curvature applied to the steel sheet during the three-point bending press increases, which affects the roundness of the steel pipe after the pipe expansion process. However, it is difficult to change the punch curvature for each press when forming a single steel sheet, and it is recommended to use the punch curvature set according to the size of the steel pipe to be formed as the operating parameter of the press bend process. preferable.
- the seam gap reducing step is a step of reducing the seam gap of the U-shaped cross-section molded body formed by the press bend step, and bending force and compression so that the ends of the U-shaped cross-section molded body are close to each other. It gives power.
- a bending force or a compressive force is applied to the molded body having a U-shaped cross section, the seam gap is widened due to the springback at the time of unloading. Therefore, in anticipation of the occurrence of springback, a strong bending force and a compressive force are applied, and the molded body having a U-shaped cross section is deformed so as to be crushed in the vertical direction as a whole.
- FIG. 4 shows a configuration example of an O-press device generally used as a seam gap reduction step.
- O press apparatus is for imparting compressive deformation in the longitudinal direction of the molded body S 1 of U-shaped cross-section with upper mold 3 and the lower mold 4.
- the surface in contact with the molded body S 1 of the U-shaped cross section of the upper die 3 and the lower mold 4 is processed into a curved surface shape, by approaching the upper die 3 and the lower mold 4, U the lower part of the molded body S 1-shape cross-section is constrained along the curved surface of the lower mold 4.
- the upper portion of the molded body S 1 including the end portion receives the bending force and the compressive force by the upper mold 3, so that the ends are close to each other along the curved surface of the upper mold 3.
- the O-press reduction amount is a steel pipe whose target is the distance between the highest point of the inscribed surface of the upper die 3 and the lowest point of the inscribed surface of the lower die 4 when the die is pushed in. It is the value subtracted from the outer diameter of. Further, the ratio of the O-press reduction amount to the outer diameter of the steel pipe may be used and referred to as the O-press reduction rate.
- examples of the operating parameters for specifying the operating conditions of the seam gap reduction process include the O-press reduction amount, the O-press reduction position, the O-press die R, and the like.
- O and press pressing position means an angle between a line and the vertical line connecting the end portion and the center position in the width direction of the seam gap of the forming body S 1 having a U-shaped cross section.
- the O press die R refers to the curvature of the abutting region formed body S 1 in the upper mold 3 and the lower mold 4.
- O press reduction ratio becomes larger in the O press apparatus 3 o'clock section and the curvature in the vicinity at section 9 of the compact S 1 is the final roundness of the steel pipe is reduced by increasing.
- closing the press device As an apparatus for forming an open pipe S 2 from the molded body S 1, closing the press device is used as shown in FIG.
- the closing press device has lower tools 10a and 10b.
- the lower tools 10a and 10b are provided at intervals from each other, and each has a drive mechanism capable of reversing the rotation direction. Further, the lower tools 10a and 10b are supported via spring means 11a, 11b and the like.
- An upper tool 13 having a punch 12 is arranged so as to face the lower tools 10a and 10b. Force pushing through the punch 12 is applied to the molded body S 1 of U-shaped cross-section from the outside.
- the molded body S 1 of the U-shaped cross section is formed into an open pipe S 2 through two steps.
- a first step the molded body S 1, as shown schematically by the dashed line through the rotatable lower tool 10a, 10b, the area R1 to be applied bending deformation located on the right side of the seam gap G
- the press position is positioned so that is around 3 o'clock in the clock.
- a pressing force is applied by the punch 12, and after the pressing force is applied, the punch 12 is unloaded.
- the press position is set so that the region R2 located on the left side of the seam gap portion G to which bending deformation is to be applied is around 9 o'clock in the clock.
- a pressing force by the punch 12 is applied, unloading of the punch 12 after applying a pressing force is formed into an open pipe S 2 by being made.
- the press position in the first and second steps means the angle of the line connecting the center of the seam gap portion G and the center position in the width direction of the steel sheet (the angle formed by the alternate long and short dash line in FIG. 5). Further, the pressing force in the first and second step refers to pressing force applied to the molded body S 1 by punch 12.
- the open pipe S 2 abuts the end faces of the seam gap portions against each other and is welded by a welding machine (joining means) to form a steel pipe.
- a welding machine for example, a welding machine composed of three types of welding machines, a temporary welding machine, an inner surface welding machine, and an outer surface welding machine, is applied.
- the temporary welding machine continuously brings the surfaces abutted by the cage roll into close contact with each other in an appropriate positional relationship, and welds the close contact portion over the entire length in the pipe axial direction.
- the temporarily attached pipe is welded from the inner surface of the butt portion by the inner surface welder (submerged arc welding), and further welded from the outer surface of the butt portion by the outer surface welder (submerged arc welding).
- a pipe expansion device is inserted inside the steel pipe to increase the diameter of the steel pipe (so-called pipe expansion).
- 6 (a) to 6 (c) are views showing a configuration example of a tube expansion device.
- the tube expanding device includes a plurality of tube expanding dies 16 having a curved surface obtained by dividing an arc into a plurality of parts along the circumferential direction of the tapered outer peripheral surface 17.
- the pipe expanding die 16 is expanded by moving the steel pipe P using the steel pipe moving device.
- the first pipe expansion process is performed by retracting the pull rod 18 from the pipe expansion start position.
- each of the expansion dies 16 sliding in contact with the tapered outer peripheral surface 17 is displaced in the radial direction due to the wedge action, and the steel pipe P is expanded. Then, the unevenness of the cross-sectional shape of the steel pipe P becomes small, and the cross-sectional shape of the steel pipe P becomes close to a perfect circular shape.
- the pull rod 18 is advanced to the pipe expansion start position, the pipe expansion die 16 is returned to the inside in the axial vertical direction by the release mechanism, and then the steel pipe P is increased by the amount corresponding to the pitch (axial length) of the pipe expansion die 16. To move further. Then, after adjusting the tube expansion die 16 to a new tube expansion position, the above operation is repeated. As a result, the first pipe expansion treatment can be performed over the entire length of the steel pipe P for each pitch of the pipe expansion die 16.
- the operating parameters that determine the operating conditions of the pipe expansion process include the pipe expansion rate, the number of pipe expansion dies, the diameter of the pipe expansion dies, and the like.
- the pipe expansion rate is the ratio of the difference between the outer diameter after pipe expansion and the outer diameter before pipe expansion to the outer diameter before pipe expansion.
- the outer diameter before and after the expansion of the pipe can be calculated by measuring the circumference of the steel pipe.
- the tube expansion ratio can be adjusted by the stroke amount when the tube expansion die is expanded in the radial direction.
- the number of pipe expansion dies means the number of portions that come into contact with the steel pipes arranged in the circumferential direction when the pipes are expanded.
- the diameter of the expansion die means the curvature of the portion of each expansion die that abuts on the steel pipe.
- the operation parameter that can easily adjust the roundness after the pipe expansion process is the pipe expansion rate.
- the tube expansion rate increases, the curvature of the region in contact with the tube expansion die over the entire circumference is evenly applied according to the tube expansion die R, so that the roundness is improved.
- the fluctuation of the local curvature in the circumferential direction of the steel pipe can be suppressed, so that the roundness of the steel pipe after the pipe expansion step becomes better.
- the pipe expansion ratio is set so that the roundness of the steel pipe falls within a predetermined value at a pipe expansion rate smaller than the preset upper limit value of the pipe expansion rate.
- ⁇ Roundness measurement process> In the final inspection process of the steel pipe manufacturing process, the quality inspection of the steel pipe is performed and the roundness of the steel pipe is measured.
- the roundness measured in the roundness measuring step is an index showing the degree of deviation from the roundness of the outer diameter shape of the steel pipe. Normally, the closer the roundness is to zero, the closer the cross-sectional shape of the steel pipe is to a perfect circle.
- the roundness is calculated based on the outer diameter information of the steel pipe measured by the roundness measuring machine. For example, if the outer diameters of the pipes are equally divided in the circumferential direction at an arbitrary pipe length position and the outer diameters are measured at the opposite positions, and the maximum and minimum diameters are Dmax and Dmin, respectively, the roundness is Dmax-.
- the roundness does not necessarily have to be due to the difference between the maximum diameter and the minimum diameter.
- An equivalent temporary perfect circle (diameter) having the same area as the inner area of the curve is calculated from the figure showing the outer diameter shape of the steel pipe in a continuous diagram, and the steel pipe is based on the temporary perfect circle.
- the area deviated from the outer diameter shape may be defined as an image.
- the following method can be used.
- an arm 20 that can rotate 360 degrees around the substantially central axis of the steel pipe P, displacement meters 21a and 21b attached to the tip of the arm 20, and rotation of the arm 20.
- the rotation center of the arm 20 and the outer periphery of the steel pipe P are used by the displacement meters 21a and 21b for each minute angle unit of the rotation of the arm 20. The distance from the measurement point is measured, and the outer diameter shape of the steel pipe P is specified based on this measured value.
- FIG. 7 (b) As shown in FIG. 7 (b), a rotary arm 25 that rotates around the central axis of the steel pipe P and a pedestal (not shown) provided on the end side of the rotary arm 25 so as to be movable in the radial direction of the steel pipe P.
- a pair of pressing rollers 26a and 26b that abut on the outer and inner surfaces of the ends of the steel pipe P and rotate with the rotation of the rotary arm 25, and a pedestal that presses the pressing rollers 26a and 26b against the outer and inner surfaces of the steel pipe P.
- the prediction accuracy of the roundness prediction result by the roundness prediction model described later is verified by comparing with the measured value of the roundness obtained in the above inspection step. be able to. Therefore, it is possible to improve the prediction accuracy by adding the actual value of the prediction error to the prediction result of the roundness prediction model, which will be described later, in addition to the prediction result of the roundness prediction model.
- FIG. 8 is a block diagram showing a configuration of a steel pipe roundness prediction device according to an embodiment of the present invention.
- FIG. 9 is a block diagram showing the configuration of the roundness offline calculation unit 112 shown in FIG.
- the steel pipe roundness prediction device 100 is composed of an information processing device such as a workstation, and has a basic data acquisition unit 110, a database 120, and a roundness prediction device.
- a model generation unit 130 is provided.
- the basic data acquisition unit 110 includes an operating condition data set 111 and an operating condition data set 111 that quantify the factors that affect the roundness of the steel pipe through the press bend process, the seam gap reduction process, the welding process, and the pipe expansion process.
- the roundness offline calculation unit 112, which outputs the roundness after the pipe expansion process, is provided as an input condition.
- the operation condition data set 111 includes at least the attribute information of the steel plate as a material, the operation parameters of the press bend process, and the operation parameters of the seam gap reduction process. This is because these are factors that have a large effect on the roundness of the steel pipe after the pipe expansion process and have an influence on the variation in roundness.
- the operation parameters of the welding process and the operation parameters of the pipe expansion process may be included. The data used for the operating condition data set 111 will be described later.
- the basic data acquisition unit 110 changes various parameters included in the operating condition data set 111 and executes numerical calculation by the roundness offline calculation unit 112. Calculate the roundness of the steel pipe.
- the range for changing the parameters included in the operating condition data set 111 is determined based on the range that can be changed as normal operating conditions according to the size of the steel pipe to be manufactured, the specifications of the equipment of each process, and the like.
- the roundness offline calculation unit 112 calculates the shape of the steel pipe after the pipe expansion process by numerical analysis through a series of manufacturing processes from the press bend process to the pipe expansion process, and obtains the roundness of the steel pipe from the shape after the pipe expansion process. ..
- the series of manufacturing steps includes a press bend step, a seam gap reduction step, and a pipe expansion step.
- the roundness offline calculation unit 112 includes finite element model generation units 112a to 112c corresponding to each process, and a finite element analysis solver 112d.
- the roundness offline calculation unit 112 may include a finite element model generation unit corresponding to the edge bending process.
- the finite element model generation unit of the end bending process is an element inside the steel sheet based on the attribute information of the steel sheet. Perform the division. Element division is automatically performed based on preset element division conditions.
- the finite element model of the element-divided end bending process is sent to the finite element analysis solver 112d together with the calculation conditions in the end bending process.
- the calculation conditions in the edge bending process include the operating parameters of the edge bending process, and also specify all boundary conditions such as physical property values of the work material and tools, geometric boundary conditions, and mechanical boundary conditions. , Contains all the information needed to perform a finite element analysis.
- the shape and stress / strain distribution of the steel sheet obtained by the finite element analysis of the edge bending process are sent to the finite element model generation unit 112a of the press bend process as initial conditions for the work material of the press bend process.
- the finite element analysis solver 112d Since there are many commercially available general-purpose analysis software as the finite element analysis solver 112d, it can be utilized by appropriately selecting and incorporating them. Further, the finite element analysis solver 112d is mounted on a computer separate from the roundness offline calculation unit 112, and the input data including the finite element model and the output data as the calculation result are transferred between the roundness offline calculation unit 112. It may be in the form of transmitting and receiving with. This is because if a finite element model corresponding to each process is generated, numerical analysis can be performed by a single finite element analysis solver.
- the finite element method is a kind of approximate solution method in which a continuum is divided into a finite number of elements. Even though it is an approximate solution method, the finite element method seeks a solution that satisfies the force balance and displacement continuity at the node of the element, and obtains a highly accurate solution even when the deformation is non-uniform. Can be done.
- stress, strain, and displacement in an element are defined independently for each element, and are formulated as a problem for solving simultaneous equations by being associated with the displacement (velocity) of a node. At that time, a method of evaluating strain (increment) and stress by using the displacement (velocity) at the node of the element as an unknown is widely used.
- the finite element method is characterized by performing calculations based on the principle of virtual work expressed in integral form for the stress balance conditions in the element.
- the accuracy of the analysis result changes depending on the conditions such as element division.
- the calculation time required for analysis is usually long.
- the finite element method is characterized in that the basic equation of plastic mechanics can be used as a solution that satisfies the node or the element, and a solution can be obtained even for a problem that is difficult to solve by other methods. Therefore, it is possible to obtain solutions for the displacement, stress field, and strain field of the work piece, which are close to the actual phenomenon, even for a complicated machining history in the steel pipe manufacturing process.
- the finite element analysis solver may be replaced with various numerical analysis methods such as the slip line field method and the energy method, and an approximate solution method. As a result, the total calculation time can be shortened.
- the finite element analysis used in this embodiment executes elasto-plastic analysis and does not include temperature field analysis such as heat conduction analysis. However, when the processing speed is high and the temperature rise of the work material is large due to the heat generated by the processing, the heat conduction analysis and the elasto-plastic analysis may be coupled to perform the analysis.
- the elasto-plastic analysis of the present embodiment is a two-dimensional cross-section analysis for all of the press bend step, the seam gap reduction step, and the pipe expansion step, and when the steel plate is formed into a U-shaped cross section, an open pipe, or a steel pipe. It is sufficient to perform a numerical analysis on the cross section of the stationary part in the longitudinal direction.
- a finite element model generator that performs three-dimensional analysis including the tip and tail is provided. Just do it.
- the attribute information is given as input data.
- the end bending process is included as a pre-process of the press bend process
- the shape and stress / strain distribution of the obtained steel sheet as a result of the finite element analysis of the end bending process are applied to the work material of the press bend process.
- This is the initial condition.
- the finite element model generation unit 112a of the press bend process divides the elements inside the steel sheet based on the dimensions and shape of the steel sheet before the press bend process. Element division is automatically performed based on preset element division conditions.
- the distribution of stress and strain remaining inside may be assigned to each element based on the manufacturing history given to the steel sheet in the previous process. This is because in the press bend process, which mainly involves bending, the initial residual stress also affects the shape of the U-shaped molded body of the steel sheet after processing.
- the calculation conditions in the press bend process are sent to the finite element analysis solver 112d as input data.
- the calculation conditions in the press bend process include the operation parameters in the press bend process, and all other boundary conditions such as physical property values of the work material and tools, geometric boundary conditions, and mechanical boundary conditions. It shall contain all the information necessary to perform a finite element analysis that identifies.
- the finite element analysis solver 112d executes numerical analysis under the calculation conditions given above, and obtains the shape of the U-shaped molded body after the press bend process and the distribution of stress and strain remaining inside. The result calculated in this way is used for the input data of the next seam gap reduction step in the roundness offline calculation unit 112. Based on the calculated shape after the press bend process, the finite element model generation unit 112b of the seam gap reduction process performs element division inside the U-shaped molded body. Element division is automatically performed based on preset element division conditions. At this time, it is preferable to assign the stress and strain distributions calculated for the previous process to each element. For the same reason as above.
- the calculation conditions in the seam gap reduction process are sent to the finite element analysis solver 112d as input data.
- the calculation conditions in the seam gap reduction process include the operating parameters of the seam gap reduction process, and all other physical property values of the work material, tools, etc., geometric boundary conditions, mechanical boundary conditions, and the like. It shall contain all the information necessary to perform a finite element analysis with specified boundary conditions.
- the finite element analysis solver 112d numerical analysis is executed under the calculation conditions given above, and the shape of the open pipe after the seam gap reduction step and the distribution of stress and strain remaining inside are obtained. The result calculated in this way is used for the input data in the finite element model generation unit 112c of the next tube expansion step. At this time, also in the welding process of welding the seam gap portion of the open pipe, the residual stress and strain generated in the steel pipe after welding may be obtained by numerical analysis of the welding process.
- the shrinking process of the seam gap in such a welding process is elastic deformation
- the stress and strain inside the open pipe calculated by the finite element analysis is used for the analytical solution of the stress and strain on the curved beam by the beam theory.
- the stress / strain distribution after the welding process may be obtained by superimposing on the distribution of. This can shorten the calculation time.
- the finite element model generation unit 112c of the pipe expansion process divides the elements inside the steel pipe. Element division is automatically performed based on preset element division conditions. At this time, it is preferable to assign the stress and strain distributions calculated as described above to each element.
- the generated finite element model of the tube expansion process is sent to the finite element analysis solver 112d together with the calculation conditions in the tube expansion process.
- the calculation conditions in the pipe expansion process include the operating parameters of the pipe expansion process of the present embodiment, and also include all the boundary conditions such as the physical property values of the work material and tools, the geometric boundary conditions and the mechanical boundary conditions. It shall contain all the specified information necessary to perform the finite element analysis.
- finite element analysis solver 112d numerical analysis is executed under the calculation conditions given above, and the shape of the steel pipe after the pipe expansion process and the distribution of internal stress and strain are obtained.
- the calculated shape of the steel pipe has a non-uniform curvature distribution in the circumferential direction, and the roundness of the steel pipe is obtained according to the definition of roundness in the roundness measuring step.
- numerical analysis using the finite element method by the roundness offline calculation unit 112 may require a calculation time of about 1 to 10 hours for one operation condition data set (1 case).
- the database 120 stores the operation condition data set 111 and the corresponding data regarding the roundness of the steel pipe after the pipe expansion step.
- the data stored in the database 120 can be acquired offline. This is different from the database that is accumulated as the actual value of actual operation, and since the operating condition data set can be set arbitrarily, the operating conditions of the operating condition data set are less likely to be statistically biased and suitable for machine learning. It becomes a database. In addition, since the calculation results obtained by rigorous numerical analysis are accumulated and the learning data does not fluctuate with time, a useful database can be obtained as the data is accumulated.
- the roundness prediction model generation unit 130 is a steel pipe after the pipe expansion process for the operation condition data set 111 to be input based on the relationship between the roundness of the steel pipe and the operation condition data set 111 stored in the database 120.
- a roundness prediction model M learned by machine learning is generated to obtain the roundness of.
- the relationship between the operating conditions in each process and the roundness of the steel pipe after the pipe expansion process may show complicated non-linearity, and the accuracy is low in the modeling assuming linear linearity, and the non-linearity of neural networks, etc. Highly accurate prediction is possible by a machine learning method using a function having.
- modeling means replacing the input / output relationship in numerical calculation with an equivalent functional form.
- the number of databases required to generate the roundness prediction model M varies depending on the size of the steel pipe to be manufactured, but it is sufficient if there are 500 or more data. It is preferable to use 2000 or more data, and more preferably 5000 or more data.
- a known learning method may be applied.
- a known machine learning method such as a neural network may be used. Examples of other methods include decision tree learning, random forest, Gaussian process regression, support vector regression, and k-nearest neighbor method.
- the roundness prediction model M will be generated offline, but the roundness prediction model generation unit 130 is incorporated into the online control system, and a database that is calculated and accumulated offline at any time is used to periodically generate the roundness prediction model M.
- the roundness prediction model may be updated.
- the roundness prediction model M of the steel pipe after the pipe expansion process generated as described above has the following features. That is, as the attribute information of the steel plate as the material, for example, the yield stress, the plate thickness, etc., have a certain variation when manufacturing the steel plate, and the curvature of the steel plate at the time of punching in the three-point bending press in the press bend process. And affects the curvature after unloading. Therefore, by selecting the attribute information of these steel sheets as the input parameters of the roundness prediction model M that is generated offline, the attribute information such as the yield stress of the material and the plate thickness can be obtained as the perfect circle of the steel pipe after the pipe expansion process. The effect on the degree can be predicted.
- the seam gap reduction process is also a process of applying bending force and compressive force using a mold, etc., and since the curvature of the steel plate after unloading is changed by the yield stress, plate thickness, etc., these are roundness. It is used as an input parameter of the prediction model M.
- the press bend process is a process of applying discontinuous curvature imparting processing multiple times along the plate width direction of the steel sheet, a local curvature distribution occurs in the steel sheet along the plate width direction.
- the bending moment acting on the so-called "bent beam” changes depending on the curvature of the beam before deformation, and the press bend is performed.
- the bending moment applied in the seam gap reducing process is locally distributed according to the local curvature distribution of the steel plate applied in the process.
- the operating conditions of the press bend process affect the curvature distribution along the width direction of the steel sheet after the seam gap reduction process.
- FIG. 10 shows an O-press using an O-press device as a seam gap reduction process under the condition that the number of presses is 9 in the press bend process when manufacturing a steel pipe having an outer diameter of 30 inches and a pipe thickness of 44.5 mm. This is the result of measuring the roundness of the steel pipe after the pipe expansion process (the operating conditions of the pipe expansion process are the same) while changing the reduction ratio.
- FIG. 10 shows the result of changing the press reduction amount (final pass reduction amount) at the time of the final (9th) pressing by three levels while keeping other operating conditions in the press bend process constant.
- the O-press reduction rate which represents the press working amount in the seam gap reduction process, has an optimum value for reducing the roundness of the steel pipe after the pipe expansion process, and the optimum value is the press. It can be seen that it changes depending on the final press reduction amount of the press bend process, which is the operating condition of the bend process. That is, in order to reduce the roundness of the steel pipe after the pipe expansion process, it is necessary to change the operating conditions of the seam gap reduction process according to the operating conditions of the press bend process, and the press bend process and the seam gap reduction process. It can be seen that it is not always possible to set appropriate operating conditions simply by focusing on the fact that each operating condition affects the roundness of the steel pipe after the pipe expansion process as an independent parameter.
- the roundness prediction model of the present embodiment can take into consideration the influence of the operation parameters of such a plurality of manufacturing processes on the roundness of the steel pipe after the pipe expansion process, and is highly accurate. It is possible to predict the degree of circle.
- the roundness prediction model learned by machine learning is generated, even if the variable that is the input condition is changed, the roundness that is output can be calculated immediately, so it is used online. Even in that case, there is a feature that the operating conditions can be set or modified immediately.
- each parameter used for inputting the roundness prediction model will be described.
- the attribute information of the steel sheet used as the material includes the yield stress of the steel sheet, the tensile strength, the longitudinal elasticity coefficient, the plate thickness, the plate thickness distribution in the plate surface, the distribution of the yield stress in the plate thickness direction of the steel plate, the degree of the bow singer effect, and so on. Any parameter that affects the roundness of the steel pipe after the pipe expansion process, such as surface roughness, can be used. In particular, factors that affect the deformation state and springback of the steel sheet due to the three-point bending press in the press bend process, and factors that affect the deformation state and springback of the steel sheet due to compression and bending in the seam gap reduction process are used as indicators. It is preferable to do so.
- the distribution of the yield stress of the steel plate, the yield stress in the plate thickness direction of the steel plate, and the plate thickness directly affect the stress and strain states in the 3-point bending press.
- Tensile strength affects the stress state during bending deformation as a parameter that reflects the state of work hardening in bending.
- the Bauschinger effect affects the yield stress when the load due to bending deformation is reversed and the subsequent work hardening behavior, and affects the stress state at the time of bending deformation.
- the Young's modulus of the steel sheet affects the springback behavior after bending.
- the plate thickness distribution in the plate surface causes the distribution of bending curvature in the press bend process, and the surface roughness affects the friction state between the mold and the steel plate in the seam gap reduction process, so that the steel pipe after the pipe expansion process Affects the roundness of.
- the yield stress, the representative plate thickness, the plate thickness distribution information, and the representative plate width are the information measured in the quality inspection process of the thick plate rolling process, which is the manufacturing process of the steel sheet used as the raw material, and affect the deformation behavior in the press bend process and the seam gap reduction process. Since it affects the roundness, it is preferable to use it as the attribute information of the steel plate in the basic data acquisition unit 110.
- the yield stress is information that can be obtained from a tensile test of a small test piece for quality accuracy collected from a thick steel plate as a material, and an in-plane representative value of the steel plate as a material may be used.
- the representative plate thickness is a plate thickness that represents the in-plane plate thickness of the steel plate as a material, and when the plate thickness at the center of the width direction of the steel plate at an arbitrary position in the longitudinal direction of the steel plate is used or in the longitudinal direction. You may use the average value of the plate thickness of. Further, the average value of the plate thickness in the entire in-plane of the steel plate may be obtained and used as the representative plate thickness.
- the plate thickness distribution information refers to information representing the plate thickness distribution in the width direction of the steel sheet.
- a typical example is a steel plate crown.
- the crown represents the difference between the center portion in the width direction of the steel sheet and the plate thickness at a position separated from the end portion in the width direction of the steel plate by a predetermined distance (for example, 100 mm, 150 mm, etc. are used).
- the representative plate width is a representative value for the width of the steel plate as a material. If the width of the thick steel sheet used as the material varies, or when the widthwise end of the steel sheet is ground by groove processing, the width of the steel sheet may vary, resulting in variations in the outer diameter accuracy of the steel pipe used as the product. Affect.
- the above-mentioned attribute information of the steel sheet is information used for setting the operating conditions in the steel pipe manufacturing process as the information collected by the host computer in the online operation.
- the basic data acquisition unit 110 may select from among them so as to match the attribute information of the steel sheet collected by the online high-level computer in this way.
- ⁇ Operation parameters of edge bending process When the operation parameters of the edge bending process are used for inputting the roundness prediction model, the shape formed by the forming surface 33a of the upper die 33 used in the C press device 30 and the shape formed by the pressing surface 34a of the lower die 34. Parameters that specify the above can be used as operation parameters. Further, the edge bending width (width for performing edge bending molding), the pushing force (C press force), and the gripping force by the clamp mechanism 37 in the edge bending step may be used as operating parameters. This is because these are factors that can affect the deformation of the widthwise end portion of the steel sheet in the edge bending process. Further, when the three-dimensional deformation analysis is executed for the end bending process, the feed amount, the feed direction, and the number of feeds of the steel sheet may be used as the operation parameters of the end bending process.
- an arc having a plurality of radii of curvature may be given as a continuous shape, or may be given by an involute curve or the like, and has a geometrical cross section.
- Parameters for specifying the shape can be used.
- the cross-sectional shape when the cross-sectional shape is constructed by the parabolic shape, the cross-sectional shape can be specified by using the coefficients of the primary term and the quadratic term of the quadratic equation representing the parabola passing through the origin. It can be an operating parameter of the bending process.
- the mold control number for specifying the mold used in the end bending process may be used as an operation parameter of the end bending process.
- the operation parameters of the press bend process are used for inputting the roundness prediction model.
- the operating parameters of the press bend process include the local bending curvature of the steel sheet, such as the number of presses of the three-point bending press described above, press position information, press reduction amount, lower die spacing, punch curvature, etc., and their plate widths.
- Various parameters that affect the directional distribution can be used.
- FIGS. 11A and 11B show examples of the press reduction position and the press reduction amount when the punch is pressed 16 times and 10 times, respectively, on the steel plate having the same plate width.
- the press reduction position is information indicating the distance from the end portion in the width direction as a reference of the steel sheet, and this is used as the press reduction position information.
- the press reduction amount is described corresponding to each press reduction position, and such "reduction frequency", "press reduction position", and “press reduction amount” can be used as a set of data.
- the operation parameters of the press bend process are specified by the data of 16 sets and 10 sets, respectively, when the number of presses is 16 and 10.
- such a data set is used as an input of a roundness prediction model in the following form.
- the press reduction position and the press reduction amount when the press reduction is performed at the position closest to the end at one end of the steel sheet, and the press reduction at the other end of the steel sheet are the most. It is possible to use the press reduction position and the press reduction amount when the press reduction is performed at a position close to the end portion.
- the curvature at the portion corresponding to approximately 1 o'clock and the portion corresponding to approximately 11 o'clock in the steel pipe shown in FIG. 2 becomes large, and the U As a molded body having a character-shaped cross section, it has a horizontally long shape as a whole. Further, the closer the press reduction position is to the end portion of the steel sheet, the lower the position of the seam gap portion is, and the molded body having a U-shaped cross section has a horizontally long shape as a whole.
- the steel pipe formed into an open pipe and after undergoing the welding process and the pipe expansion process also has a horizontally long shape as a whole, which affects the roundness. Furthermore, the punch curvature when the press is pressed, the total number of times the press is pressed, and the distance between the lower dies when the press is pressed also affect the roundness.
- the prediction accuracy of the roundness prediction model can be further improved.
- data on the press reduction position and the press reduction amount are stored according to the number of reductions.
- the press reduction position and the press reduction amount in the subsequent press working without reduction are set to zero.
- the data for the 11th to 16th reductions is zero.
- the above operation parameters of the press bend process are information used as operation conditions set by the host computer in online operation.
- the basic data acquisition unit 110 may select a parameter to be used for inputting the roundness prediction model from the operation parameters of the press bend process collected by the online high-level computer in this way.
- the operation parameters of the seam gap reduction process are used for inputting the roundness prediction model.
- the O-press reduction amount, the O-press reduction position, and the O-press die R can be used as the operation parameters.
- the closing press method when the closing press method is used, the closing press reduction position and the closing press pressing force in each of the above-mentioned steps are used as operating parameters.
- an O-press device when used, it is preferable to use an O-press reduction amount.
- the above operation parameters of the seam gap reduction process are information used as operation conditions set by the host computer in online operation.
- the basic data acquisition unit 110 may select a parameter to be used for inputting the roundness prediction model from the operation parameters of the seam gap reduction process collected by the online high-level computer in this way.
- the pipe expansion rate can be used as the operation parameters of the pipe expansion process.
- the larger the pipe expansion rate the better the roundness of the steel pipe after the pipe expansion process.
- the calculation conditions of the basic data acquisition unit 110 are determined. At this time, since the pipe expansion ratio is information necessary for controlling the pipe expansion device, it can be specified by the set value set by the higher calculation value.
- the number of pipe expansion dies and the diameter of the pipe expansion dies may be used as the operation parameters of the pipe expansion process.
- the roundness prediction model M generated offline by the roundness prediction model generation unit 130 as described above is used to predict the roundness of the steel pipe after the pipe expansion process online.
- the operating condition data set set as the operating conditions of the steel pipe manufacturing process is acquired online (operation parameter acquisition step).
- This is an operating condition data set that is the input of the roundness prediction model generated as described above, and obtains the necessary data from the host computer that controls the steel pipe manufacturing process or the computer for controlling each forming process. It is a step.
- “online” means between a series of manufacturing processes from before the start of the steel pipe manufacturing process to the completion of the pipe expansion process.
- the roundness prediction of the steel pipe after the pipe expansion process can be carried out either before or during the start of the steel sheet manufacturing process.
- An operating condition data set to be input to the roundness prediction model M is appropriately generated according to the timing of prediction. That is, when predicting the roundness of the steel pipe after the pipe expansion process before the press bend process, the actual value (actual measurement value) for the attribute information of the steel plate as the raw material can be used, and the manufacturing after the press bend process is included.
- the operation parameters of the process the set values of the operation conditions preset in the host computer are used.
- the actual value (actual measurement value) for the attribute information of the steel plate as the material is used.
- the actual value of the operation parameter of the press bend process is used, and the set value of the operation condition preset by the upper computer is used as the operation parameter of the subsequent manufacturing process including the seam gap reduction process.
- the preset operating condition setting value is a setting value set based on the past operation results and is stored in the host computer in advance.
- a set of operating condition data sets acquired according to the timing of predicting the roundness of the steel pipe after the pipe expansion process is used as an input of the roundness prediction model, and the pipe expansion is an output. Predict the roundness of steel pipes after the process online. As a result, the operating conditions of the subsequent manufacturing process can be reset according to the predicted roundness of the steel pipe, so that the roundness of the steel pipe after the pipe expansion process can be further reduced.
- FIG. 12 shows the flow of the process of predicting the roundness of the steel pipe after the pipe expansion process before the start of the press bend process.
- the actual data regarding the attribute information of the steel plate as the material, the preset value (operation set value) set in advance as the operation condition of the press bend process, and the operation condition of the seam gap reduction process in advance is obtained from the host computer 140, and these information are acquired as the operation condition data set 111.
- the roundness target value preset as the target roundness of the steel pipe after the pipe expansion process is sent from the host computer 140 to the operating condition resetting unit 150.
- the roundness of the steel pipe after the pipe expansion process is predicted. Then, when the predicted roundness (predicted roundness value) and the target roundness (roundness target value) are compared and the predicted roundness is smaller than the roundness target value, Manufactures steel pipes without changing the set values of operating conditions for the press bend process, seam gap reduction process, and pipe expansion process. On the other hand, if the predicted roundness is larger than the roundness target value, the operating conditions of the press bend process or the seam gap reduction process are reset.
- the number of presses in the press bend process is increased once or twice or more, and the interval between the press reduction positions is reset to be short. This improves the roundness of the steel pipe after the pipe expansion process.
- the set value of the operating condition of the press bend process reset in this way is used again as the input data of the roundness prediction model M to perform roundness prediction again, and the predicted roundness is true. It may be confirmed whether or not it becomes smaller than the circularity target value, and the reset value of the operating condition of the press bend process may be determined.
- the reset operating conditions of the press bend process are sent to the operating condition control unit of the press bend process, and the operating conditions of the press bend process are determined. Even if the roundness target value is set small by repeating the roundness determination in the operating condition resetting unit 150 multiple times, the operating conditions of the appropriate press bend process can be set, which is more true. A steel pipe with good roundness can be manufactured.
- the O-press reduction amount is changed. For example, a plurality of O-press reduction amount conditions are input to the roundness prediction model M, and the O-press reduction amount condition that obtains the best roundness is selected and set from the conditions. In this way, the operating conditions of the seam gap reducing process that have been reset are sent to the operating condition control unit of the seam gap reducing process, and the operating conditions of the seam gap reducing process are determined. Both the operation parameters of the press bend process and the operation parameters of the seam gap reduction process may be reset.
- the resetting method is the same as above. The larger the number of operation parameters to be reset, the wider the control range of the roundness of the steel pipe after the pipe expansion process, and the smaller the roundness can be.
- the roundness is obtained by the variation of the attribute information of the steel sheet as the material and the interaction between the press bend process and the seam gap reduction process. Since the roundness prediction model that can consider the influence at the same time is used, it is possible to set appropriate operating conditions to improve the roundness of the steel pipe after the pipe expansion process, and it can be applied online more quickly. The operating conditions can be reset, and steel pipes with high roundness can be manufactured.
- the reset target process is selected from a plurality of forming processes constituting the steel pipe manufacturing process. Then, before the start of the reset target process, the roundness prediction model M is used to predict the roundness of the steel pipe after the pipe expansion process. Subsequently, one or more operation parameters selected from at least the operation parameters of the reset target process, or molding on the downstream side of the reset target process so that the roundness of the steel pipe after the pipe expansion process becomes small. Reset one or more operating parameters selected from the operating parameters of the machining process.
- the plurality of forming processes constituting the steel pipe manufacturing process include an end bending process, a press bend process, a seam gap reduction process, and a pipe expansion process in which the steel pipe is subjected to plastic deformation to process the steel pipe into a predetermined shape.
- any process is selected from these molding processes.
- the roundness of the steel pipe after the pipe expansion step is predicted by using the roundness prediction model M of the steel pipe.
- the forming process of the steel sheet has been completed for the forming process on the upstream side of the process to be reset, when the operation parameters of the forming process on the upstream side are used, the actual data is rounded.
- the prediction model M It can be used as an input for the prediction model M.
- the set value set in advance in the host computer or the like is used for inputting the roundness prediction model M of the steel pipe. In this way, the roundness of the steel pipe after the pipe expansion process for the target material can be predicted.
- the roundness predicted as the roundness of the steel pipe after the pipe expansion process falls within the roundness allowed as a product.
- the operation parameter to be reset may be an operation parameter in the reset target process or an operation parameter in the molding process downstream of the reset target process.
- the operating parameters of the forming process suitable for changing the roundness of the steel pipe after the pipe expansion step may be selected.
- both the operation parameters in the reset target process and the operation parameters in any molding process downstream from the reset target process may be reset. This is because when the difference between the predicted roundness and the roundness allowed as a product is large, the roundness of the steel pipe after the pipe expansion process can be effectively changed.
- Table 1 specifically shows the cases of the molding process selected as the process to be reset and the molding process in which the operation parameters can be reset correspondingly.
- Case 1 selects the end bending process as the reset target process in the steel pipe manufacturing process including the end bending process.
- the roundness of the steel pipe after the pipe expansion process is predicted by using the set values of the operation parameters in the forming process including the press bend process and the seam gap reduction process. If the predicted roundness is large, any operating parameters in each forming process of the edge bending process, the press bend process, the seam gap reduction process, and the pipe expansion process can be reset.
- the operation parameters to be reset may be not only the operation parameters of the edge bending process but also the operation parameters of other molding processing processes.
- the attribute information of the steel sheet is included as the input of the roundness prediction model M
- the actual data including the measured values related to the attribute information of the steel sheet before the start of the edge bending process which is the reset target process. Can be used for input.
- case 2 and case 3 the process to be reset can be selected and the operation parameter to be reset can be selected in the same way as in case 1.
- case 4 is a case where the pipe expansion process is set as the reset target process.
- the roundness of the steel pipe after the pipe expansion process is predicted by using the roundness prediction model M before the start of the pipe expansion process.
- at least the operation performance data in the press bend process and the seam gap reduction process can be used as the input of the roundness prediction model M.
- the actual data of the attribute information of the steel sheet and the operation actual data in the edge bending process may be used.
- the roundness of the steel pipe after the predicted pipe expansion process is compared with the roundness allowed as a product, and if the roundness is to be reduced, the operation parameters in the pipe expansion process are re-established.
- Set. It is preferable to use the pipe expansion rate as the operation parameter of the pipe expansion process to be reset.
- the amount of change from the initial setting value of the pipe expansion rate to be reset may be set based on the knowledge obtained from experience. However, if the input of the roundness prediction model M includes the pipe expansion rate of the pipe expansion process, the value of the reset pipe expansion rate is used as the input of the roundness prediction model M, and the steel pipe after the pipe expansion process is again used. You may predict the roundness and judge the suitability of the condition to be reset.
- the example shown in FIG. 16 is a case where the seam gap reduction step is selected as the reset target step, the press bend step is completed, and the U-shaped molded product is transferred for the seam gap reduction step.
- the operation record data in the press bend process is sent to the operation condition resetting unit 150.
- the operation performance data may be sent via a network from a control computer provided in each process that controls each molding process. However, it may be sent from the control computer of each forming process to the host computer 140 that controls the manufacturing process of the steel pipe, and then sent from the host computer 140 to the operating condition resetting unit 150.
- actual data on the attribute information of the steel sheet is sent from the host computer 140 to the operating condition resetting unit 150. Further, if necessary, operation record data in the end bending process may be sent.
- the set values are reset from the control computer of each process. It is sent to the unit 150. However, when the set values of the operation parameters of the seam gap reduction step and the pipe expansion step are stored in the upper computer 140, they may be sent from the upper computer 140 to the operation condition resetting unit 150.
- the high-level computer 140 sends a roundness target value determined according to the specifications of the steel pipe to be a product to the operating condition resetting unit 150.
- the operating condition resetting unit 150 predicts the roundness of the steel pipe after the pipe expansion process from this information using the roundness prediction model M online, and obtains the predicted roundness (roundness predicted value). Compare with the target roundness (roundness target value). When the roundness predicted value is smaller than the roundness target value, the operating condition resetting unit 150 does not change the set values of the operating conditions of the press bend process, the seam gap reduction process, and the pipe expansion process. Determine the operating conditions of the remaining forming process and manufacture steel pipes. On the other hand, when the predicted roundness is larger than the roundness target value, the operating condition resetting unit 150 resets at least the operating conditions of the seam gap reducing step or the operating conditions of the pipe expansion step. Specifically, the O-press reduction amount in the seam gap reduction step can be reset. In addition, the pipe expansion rate in the pipe expansion process can be reset. Furthermore, both the O-press reduction amount and the tube expansion rate can be reset.
- the operation condition resetting unit 150 uses the operation parameters reset in this way as the input data of the roundness prediction model M to predict the roundness again, and the predicted roundness is true. It may be confirmed whether or not it becomes smaller than the circularity target value, and the reset value of the operating conditions of the seam gap reduction step and the pipe expansion step may be determined.
- the operating conditions of the seam gap reduction process and the pipe expansion process that have been reset are sent to the respective control computers, and become the operating conditions of the seam gap reduction process and the pipe expansion process.
- the pipe expansion process is performed again for the steel pipe formed and welded into the open pipe.
- the roundness control of the steel pipe after the pipe expansion process in which is the target process for resetting may be executed. This is because the operation record data of the seam gap reduction process is obtained, and the accuracy of predicting the roundness of the steel pipe is further improved.
- the roundness in consideration of the influence on the roundness due to the interaction between the press bend step and the seam gap reducing step is taken into consideration. Since the prediction model M is used, it is possible to set appropriate operating conditions for improving the roundness of the steel pipe after the pipe expansion process, and it is possible to manufacture a steel pipe having a high roundness. In addition, it is possible to realize highly accurate roundness control that reflects variations in the attribute information of the steel sheet used as the material.
- FIG. 17 is a diagram showing a configuration of a steel pipe roundness prediction device according to an embodiment of the present invention.
- the roundness prediction device 160 for a steel pipe according to an embodiment of the present invention includes an operation parameter acquisition unit 161, a storage unit 162, a roundness prediction unit 163, and an output unit 164. ..
- the operation parameter acquisition unit 161 is provided with an arbitrary interface that can acquire, for example, the roundness prediction model M generated by the machine learning unit from the roundness prediction model generation unit 130.
- the operation parameter acquisition unit 161 may include a communication interface for acquiring the roundness prediction model M from the roundness prediction model generation unit 130.
- the operation parameter acquisition unit 161 may receive the roundness prediction model M from the machine learning unit 100b using a predetermined communication protocol.
- the operation parameter acquisition unit 161 acquires the operation conditions of the molding processing equipment (equipment for executing the molding processing process) from, for example, a control computer or a higher-level computer provided in the equipment used in each molding processing process.
- the operation parameter acquisition unit 161 may include a communication interface for acquiring operation conditions.
- the operation parameter acquisition unit 161 may acquire input information based on the user's operation.
- the roundness predictor 160 of the steel pipe further includes an input unit including one or more input interfaces for detecting the user input and acquiring the input information based on the user's operation.
- the input unit include, but are not limited to, a physical key, a capacitance key, a touch screen provided integrally with the display of the output unit, a microphone that accepts voice input, and the like.
- the input unit receives input of operation conditions for the roundness prediction model M acquired from the roundness prediction model generation unit 130 by the operation parameter acquisition unit 161.
- the storage unit 162 includes at least one semiconductor memory, at least one magnetic memory, at least one optical memory, or a combination of at least two of them.
- the storage unit 162 functions as, for example, a main storage device, an auxiliary storage device, or a cache memory.
- the storage unit 162 stores arbitrary information used for the operation of the roundness prediction device 160 of the steel pipe.
- the storage unit 162 may include, for example, the roundness prediction model M acquired from the roundness prediction model generation unit 130 by the operation parameter acquisition unit 161, the operation conditions acquired from the host computer by the operation parameter acquisition unit 161, and the trueness of the steel pipe.
- the roundness information predicted by the roundness predictor 160 is stored.
- the storage unit 162 may store a system program, an application program, and the like.
- the roundness prediction unit 163 includes one or more processors.
- the processor is a general-purpose processor or a dedicated processor specialized for a specific process, but is not limited thereto.
- the roundness prediction unit 163 is communicably connected to each component constituting the roundness prediction device 160 of the steel pipe, and controls the operation of the entire roundness prediction device 160 of the steel pipe.
- the roundness prediction unit 163 can be any general-purpose electronic device such as a PC (Personal Computer) or a smartphone.
- the roundness prediction unit 163 is not limited to these, and may be one or a plurality of server devices capable of communicating with each other, or may be another electronic device dedicated to the roundness prediction device 160 for steel pipes. good.
- the roundness prediction unit 163 uses the operating conditions acquired via the operation parameter acquisition unit 161 and the roundness prediction model M acquired from the roundness prediction model generation unit 130 to predict the roundness information of the steel pipe. Is calculated.
- the output unit 164 outputs the predicted value of the roundness information of the steel pipe calculated by the roundness prediction unit 163 to the device for setting the operating conditions of the forming processing equipment.
- the output unit 164 may include one or more output interfaces that output information and notify the user.
- the output interface is, for example, a display.
- the display is, for example, an LCD or an organic EL display.
- the output unit 164 outputs the data obtained by the operation of the roundness prediction device 160 of the steel pipe.
- the output unit 164 may be connected to the roundness prediction device 160 of the steel pipe as an external output device instead of being provided in the roundness prediction device 160 of the steel pipe.
- any method such as USB, HDMI (registered trademark), or Bluetooth (registered trademark) can be used.
- the output unit 164 may include, but is not limited to, a display that outputs information as a video, a speaker that outputs information as audio, and the like.
- the output unit 164 presents the predicted value of the roundness information calculated by the roundness prediction unit 163 to the user. The user can appropriately set the operating conditions of the molding processing equipment based on the predicted value of the roundness presented by the output unit 164.
- a more preferable form of the steel pipe roundness prediction device 160 after the pipe expansion step as described above is the roundness calculated by the input unit 165 for acquiring input information based on the user's operation and the roundness prediction unit 163. It is a terminal device such as a tablet terminal having a display unit 166 that displays a predicted value of information. This acquires input information based on the user's operation from the input unit 165, and updates a part or all of the operation parameters of the forming process equipment already input to the roundness prediction device 160 of the steel pipe by the acquired input information. It is something to do.
- the operation person in charge has already used the terminal device to acquire the operation parameter acquisition unit. It accepts the operation of modifying and inputting a part of the operation parameters of the molding processing equipment input to 161.
- the operation parameter acquisition unit 161 retains the initial input data for the operation parameters for which the correction input is not made from the terminal device among the operation parameters of the molding processing equipment, and changes only the operation parameters for which the correction input has been made. do.
- the operation parameter acquisition unit 161 generates new input data of the roundness prediction model M, and the roundness prediction unit 163 calculates the predicted value of the roundness information based on the input data.
- the calculated predicted value of the roundness information is displayed on the display unit 166 of the terminal device through the output unit 164.
- the person in charge of operation of the molding equipment or the person in charge of the factory can immediately confirm the predicted value of the roundness information when the operation parameter of the molding equipment is changed, and quickly change to the appropriate operation conditions. Can be done.
- Example 1 In this embodiment, a line pipe steel plate (API grade X60) having a plate thickness of 38.0 to 38.4 mm and a plate width of 2700 to 2720 mm is used, and a steel pipe having a diameter of 36 inches after the pipe expansion process is pressed by a press bend process and a seam gap.
- a roundness prediction model after the offline pipe expansion process was generated corresponding to the manufacturing conditions manufactured through the reduction process, the welding process, and the pipe expansion process.
- FIG. 13 illustrates an example of the finite element model generated by the finite element model generation unit of the seam gap reduction step used in this embodiment.
- the finite element analysis solver used was Abaqus 2019, and the calculation time per case was approximately 3 hours.
- the number of data sets stored in the database was 300, and Gaussian process regression using a dynamic basis function as a basis function was used as a machine learning model.
- the attribute information of the steel plate select the representative plate thickness (average plate thickness in the plane), plate width, and yield stress of the steel plate, specify the range that fluctuates as the operating condition from the manufacturing results, and calculate within that range. Changed the input data of.
- the number of press reductions and the press reduction position were selected as the operation parameters of the press bend process. At this time, the number of press reductions was changed in the range of 7 to 15 times with 11 times as the reference condition.
- the press reduction position was determined at equal intervals in the plate width direction according to the number of press reductions, and the press reduction position was determined according to the number of press reductions.
- the press reduction amount was set to a bending of 30 ° each time as the amount at which the tip of the punch reaches the position of 15.8 mm from the line connecting the uppermost portions of the rod-shaped members.
- the steel plate is placed on a die whose rod-shaped member spacing is set to 450 mm, and press reduction is started with reference to a position 1120 mm away from the center of the steel plate in the width direction by a punch having a machined surface having a radius of 308 mm. did.
- the press reduction is performed 5 times from the right side of the paper surface in FIG. 2 toward the center in the width direction under the condition of the plate feed pitch of 224 mm, and then the end portion on the left side of the paper surface in FIG. was moved to the vicinity of the rod-shaped member, and the left half of the steel plate was pressed 6 times from a position of 1120 mm from the end under the condition of a plate feed pitch of 224 mm.
- the O-press reduction rate was selected as the operating parameter of the seam gap reduction process, and the operating conditions were changed in the range of 1.0 to 3.0%.
- Other operating conditions include an upper mold having an arc surface with a radius R: 457.2 mm, a central angle ⁇ c: 60 °, and a flat surface connected to the arc surface at an angle ⁇ d: 30 °, and a radius R: 502.
- the conditions for using a lower mold having a concave arc surface of 0.9 mm were set.
- the pipe expansion rate which is an operation parameter of the pipe expansion process, was 1.0%, which was a constant value.
- the above analysis conditions are set in the roundness offline calculation unit, the analysis conditions are changed within the range of the above operating conditions, and the roundness after the pipe expansion process obtained by the analysis is calculated. The results were accumulated in the database. Then, a roundness prediction model was generated based on the accumulated database. In this embodiment, the roundness prediction model thus generated is applied online.
- the representative plate thickness and plate width of the steel plate were acquired as the actual data of the attribute information of the steel plate as the material from the host computer.
- the test data of the yield stress obtained in the inspection process of the thick plate rolling process was acquired.
- the set values of the operating conditions of the press bend process and the seam gap reduction process were acquired from the host computer.
- the set value of the operating conditions preset by the host computer is that the number of presses in the press bend process is 11 times, which is 1120 mm away from the central portion in the width direction of the steel sheet.
- the press pressing position was set at a pitch of 224 mm in the width direction of the steel sheet. Further, the press reduction amount at each press reduction position is a preset value of 15.8 mm. On the other hand, in the seam gap reduction process using the O-press apparatus, the condition that the O-press reduction rate is 2.0% is set as the set value of the operating conditions preset in the host computer. It was
- these set values and the representative plate thickness and plate width which are the actual data of the attribute information of the steel plate, are input to the roundness prediction model of the steel pipe after the pipe expansion process.
- Predicted roundness On the other hand, in the upper computer, the roundness target value is set to 10 mm, and the predicted roundness (roundness predicted value) of the steel pipe is compared with the roundness target value, and the predicted roundness is predicted.
- the degree exceeds the roundness target value the operating conditions of the press bend process are reset. The number of presses was selected as the operating condition to be reset. As a result, it was confirmed that in the invention example, the average value of roundness was 4.0 mm and the pass rate was 100%.
- the average value of roundness is 11.2 mm and the pass rate is 80%. there were.
- Example 2 In this embodiment, a steel pipe for line pipes (API grade X60) having a plate thickness of 50.0 to 50.4 mm and a plate width of 4450 to 4460 mm is used, and a steel pipe having a diameter of 56 inches after the pipe expansion process is pressed by a press bend process and a seam gap.
- a steel pipe for line pipes API grade X60
- a steel pipe having a diameter of 56 inches after the pipe expansion process is pressed by a press bend process and a seam gap.
- a roundness prediction model after the pipe expansion process was generated offline.
- the parameters of the attribute information of the steel plate, the operation parameters of the press bend process, and the operation parameters of the seam gap reduction process, which are input to the roundness prediction model of the steel pipe are the same as those in the first embodiment.
- the operating condition data set was set in the range of the representative plate thickness of 50.0 to 50.4 mm and the plate width of 4450 to 4460 mm, which are parameters of the attribute information of the steel plate.
- the lower die spacing of the press bend equipment is set to 620 mm, and a punch with a radius of curvature of the tip of 478 mm is used to press down the position 1824 mm away from the center of the steel plate in the width direction. It was the starting point of.
- the operating condition data set was set in the range of 7 to 15 times of press reduction in the press bend process.
- the number of press reductions preset in the host computer was 11 times. In this case, the press reduction is performed 5 times from the start point of one press reduction of the steel sheet toward the center side in the width direction of the steel plate with the feed amount pitch of 365 mm, and then from the start point of the other press reduction.
- the operating conditions for performing press reduction 6 times were set with the feed amount pitch set to 365 mm toward the center side in the width direction of the steel sheet.
- the press reduction amount was 33.8 mm for all press reductions.
- the start position of press reduction and the press reduction amount were set to constant set values.
- An O-press device was used in the seam gap reduction process.
- As the upper die of the O-press device one having an arc surface having a radius R: 704.0 mm and a central angle ⁇ c: 60 ° and having a flat surface connected to the arc surface at an angle ⁇ d: 30 ° was used.
- As the lower mold a mold having a concave arc surface with a radius R: 704.0 mm was used.
- the operation parameter in the seam gap reduction step was the O-press reduction rate, and the operation condition data set was set in the range of 1.0 to 3.0%.
- the O-press reduction rate preset in the host computer was 2.0%.
- the set value of the pipe expansion rate which is an operation parameter in the pipe expansion process, was 0.9%.
- the manufacturing conditions in the steel pipe forming process as described above are set, and the representative plate thickness and plate width, which are the parameters of the attribute information of the steel plate, the number of press reductions, which are the operation parameters in the press bend process, and the operation parameters of the seam gap reduction process.
- the number of datasets stored in the database is 300, and the roundness prediction is based on the roundness of the steel pipe after the pipe expansion process, using Gaussian process regression using the radial basis function as the basis function as a machine learning model. Generated the model offline.
- the roundness prediction model generated as described above is sent to the online operating condition resetting unit, accepts the operating condition data set acquired from the host computer as input, and predicts the roundness of the steel pipe after the pipe expansion process. Was configured to output. Then, in this embodiment, the press bend process is selected as the process to be reset, and before the start of the press bend process, the representative plate thickness and the plate width, which are the actual data of the attribute information of the steel plate, and the press bend process and the seam gap reduction. The operation setting value of the process was acquired from the upper computer to construct the operation condition data set, and the roundness of the steel pipe after the pipe expansion process was predicted using the roundness prediction model.
- the roundness target value is set to 14.2 mm for the target steel pipe, and the roundness is determined by comparison with the roundness predicted value.
- the operating conditions of the seam gap reduction process which is the molding process downstream of the reset target process, are reset.
- the operating condition to be reset was the O-press reduction rate.
- the average value of the roundness of the steel pipe after the pipe expansion step was 10.0 mm and the pass rate was 90% with respect to the target value of roundness of 14.2 mm.
- the average value of roundness is 14.4 mm.
- the pass rate was 60%.
- Example 3 In this embodiment, a steel pipe for line pipes (API grade X60) having a plate thickness of 38.0 to 38.4 mm and a plate width of 2700 to 2720 mm is used, and a steel pipe having a diameter of 36 inches after the pipe expansion process is subjected to an end bending process and press bend.
- a steel pipe for line pipes API grade X60
- a steel pipe having a diameter of 36 inches after the pipe expansion process is subjected to an end bending process and press bend.
- a roundness prediction model after the pipe expansion process was generated offline.
- the parameters of the attribute information of the steel sheet, the operation parameters of the press bend process, and the operation parameters of the seam gap reduction process, which are input to the roundness prediction model of the steel pipe are the same as those in the first embodiment. Further, the range of each operation parameter constituting the operation condition data set is also the same as that of the first embodiment.
- the same pair of upper and lower dies used for the C press device is used without changing for each steel plate, and the end bending width is selected as the operating parameter of the end bending process, and the range thereof.
- the operating condition data set in the basic data acquisition unit was changed so that Further, in this embodiment, the pipe expansion rate is selected as the operation parameter of the pipe expansion process, and the operation condition data set in the basic data acquisition unit is changed so that the pipe expansion rate changes in the range of 0.6 to 1.4%.
- the roundness prediction model generated as described above was incorporated into the roundness prediction device that executes the roundness prediction of steel pipes online.
- the roundness prediction device outputs the predicted value of the roundness of the steel pipe after the pipe expansion process by inputting the operation parameters in the steel pipe manufacturing process acquired online from the host computer.
- the roundness prediction device used in this embodiment is a tablet terminal, and the input information based on the operation of the operator is acquired from the input unit, and the molding process is input to the roundness prediction device by the acquired input information. It is possible to update some or all of the operating parameters of the equipment.
- This tablet terminal has a function of recognizing an operation parameter for which a correction input has been made by an operation of a manufacturing person and displaying a predicted value of roundness information reflecting the value of the correction input on a display unit.
- the operation parameter acquisition unit performs the actual data of the attribute information of the steel plate, the preset press bend process, and the seam gap reduction process.
- the operation setting value of the pipe expansion process is acquired from the upper computer.
- the roundness prediction unit outputs the roundness prediction value of the steel pipe after the pipe expansion process using the acquired operating condition data set as an input to the display unit of the tablet terminal.
- the operation person who manages the operation of the steel pipe manufacturing process confirms the displayed roundness predicted value, and the value set as the roundness target value of the target steel pipe (in this case). Compare with 7.0 mm).
- the operating condition of the edge bending width which is an operating parameter of the edge bending process, can be corrected by input from the operation panel of the C press device.
- the person in charge of operation has corrected the value of the end bending width, which is the operation parameter of the end bending process displayed on the display unit of the tablet terminal, in the range of 180 to 240 mm.
- the roundness prediction device in this embodiment updates the end bending width corrected by the operator to the corrected value as an input parameter of the roundness prediction model. Then, the roundness prediction device displays the roundness prediction value again on the tablet terminal while maintaining the values already acquired by the operation parameter acquisition unit for other inputs. The operator confirms the displayed roundness prediction value, determines the condition of the edge bending width, which is the operation parameter of the edge bending process, and sets a new set value for the operation panel of the C press device. I set it.
- the roundness predictor of this embodiment uses the roundness predictor of this embodiment to calculate the roundness target value.
- the roundness target value was 7.0 mm.
- the average value of roundness is 9.1 mm.
- the pass rate was 35%. That is, it was confirmed that the roundness prediction device according to this embodiment is effective in assisting the judgment of the person in charge of operation in the manufacturing process of the steel pipe.
- the perfect circle of a steel pipe capable of generating a roundness prediction model that accurately and quickly predicts the roundness of a steel pipe after a pipe expansion process in a steel pipe manufacturing process composed of a plurality of steps. It is possible to provide a method for generating a degree prediction model. Further, according to the present invention, a method for predicting the roundness of a steel pipe and a method for predicting the roundness of the steel pipe after the pipe expansion step in the manufacturing process of the steel pipe composed of a plurality of steps can be performed accurately and quickly.
- a degree prediction device can be provided.
- the present invention it is possible to provide a method for controlling the roundness of a steel pipe, which can accurately control the roundness of the steel pipe after the pipe expansion step in the manufacturing process of the steel pipe composed of a plurality of steps. Further, according to the present invention, it is possible to provide a method for manufacturing a steel pipe capable of manufacturing a steel pipe having a desired roundness with a high yield.
Abstract
Description
図1は、本発明の一実施形態である鋼管の製造工程を示す図である。図1に示すように、本発明の一実施形態である鋼管の製造工程では、素材となる鋼板として、鋼管の製造工程の前工程である厚板圧延工程によって製造される厚鋼板が用いられる。ここで、厚鋼板は、降伏応力245~1050MPa、引張強度415~1145MPa、板厚6.4~50.8mm、板幅1200~4500mm、及び長さ10~18mのものが代表的である。また、厚鋼板の幅方向端部は開先と呼ばれる面取り状の形状に予め研削される。これは、後の溶接工程において、幅方向端部の外面コーナー部の過加熱を防止して溶接強度を安定化させるためである。また、厚鋼板の幅は、鋼管に成形された後の外径に影響するため、後の工程における変形履歴を考慮して所定範囲に調整される。
端曲げ加工を行うCプレス装置について、図14、図15を用いて詳細に説明する。図14は、Cプレス装置の全体構成を示す斜視図である。図14に示すように、Cプレス装置30は、鋼板Sをその長手方向に沿う方向を搬送方向として搬送する搬送機構31と、鋼板Sの搬送方向下流側を前方として、一方の幅方向端部Scを所定の曲率に曲げ加工するプレス機構32Aと、他方の幅方向端部Sdを所定の曲率に曲げ加工するプレス機構32Bと、端曲げ加工を施す鋼板Sの幅に応じて、左右のプレス機構32A,32B間の間隔を調整する図示しない間隔調整機構と、を備えている。搬送機構31は、プレス機構32A、32Bの前後にそれぞれ配置された複数の回転駆動される搬送ロール31aからなる。なお、図中の符号Saは鋼板Sの先端部(長手方向前方端部)を示している。
図2は、プレスベンド装置を用いてU字状断面の成形体を成形する工程の一例を示す図である。図中、符号1は、鋼板Sの搬送経路内に配置されたダイを示している。ダイ1は、鋼板Sをその搬送方向に沿って2箇所で支持する左右一対の棒状部材1a,1bから構成されており、成形すべき鋼管のサイズに応じてその間隔ΔDが変更できるようになっている。また、符号2は、ダイ1に近接及び離隔する向きに移動可能なパンチを示している。パンチ2は、鋼板Sに直接接して鋼板Sを凹形状に押圧する下向き凸状の加工面を有するパンチ先端部2aと、パンチ先端部2aの背面に繋がり、パンチ先端部2aを支持するパンチ支持体2bと、を備えている。なお、通常、パンチ先端部2aの最大幅とパンチ支持体2bの幅(厚さ)とは等しくなっている。
シームギャップ低減工程は、プレスベンド工程により成形されたU字状断面の成形体のシームギャップを低減する工程であり、U字状断面の成形体の端部同士が近接するように曲げ力及び圧縮力を付与するものである。このとき、U字状断面の成形体に曲げ力や圧縮力を加えても、除荷する際のスプリングバックによってシームギャップが広がってしまう。このため、スプリングバックの発生を予め見越して、強い曲げ力や圧縮力を付与し、U字状断面の成形体が全体として縦方向につぶれるような変形を付与する。
オープン管S2は、その後、シームギャップ部の端面を相互に突合せ、溶接機(接合手段)により溶接して鋼管とする。溶接機(接合手段)としては、例えば仮付溶接機、内面溶接機、及び外面溶接機という3種類の溶接機で構成されるものを適用する。これらの溶接機において、仮付け溶接機は、ケージロールにより突き合せた面を適切な位置関係で連続的に密着させ、密着部をその管軸方向全長にわたって溶接する。次に、仮付けされた管は、内面溶接機により突き合せ部の内面から溶接(サブマージアーク溶接)され、さらに、外面溶接機により突き合せ部の外面から溶接(サブマージアーク溶接)される。
シームギャップ部を溶接された鋼管については、鋼管の内部に拡管装置を挿入して鋼管の直径を拡大(いわゆる拡管)する。図6(a)~(c)は、拡管装置の構成例を示す図である。図6(a)に示すように、拡管装置は、円弧を複数に分割した曲面を有する複数個の拡管ダイス16をテーパー外周面17の周方向に沿って備えている。拡管装置を利用して鋼管を拡管する際には、図6(b),(c)に示すように、まず、鋼管移動装置を用いて鋼管Pを移動することにより拡管ダイス16を拡管開始位置に合わせ、プルロッド18を拡管開始位置から後退させることによって1回目の拡管処理を行う。
鋼管の製造工程の最後となる検査工程では、鋼管の品質検査が行われ、鋼管の真円度が測定される。真円度測定工程において測定される真円度とは、鋼管の外径形状について、真円からのズレの程度を表す指標である。通常は、真円度がゼロに近いほど、鋼管の断面形状が完全な円に近い形状であることを示す。真円度は、真円度測定機によって計測された鋼管の外直径情報に基づいて算出される。例えば任意の管長位置で管を周方向に等分して対向する位置での外直径を計測し、それらのうちの最大径と最少径をそれぞれDmax、Dminとした場合、真円度はDmax-Dminで定義することができる。このとき、等分する数が多いほど、拡管工程後の鋼管における小さな凹凸も数値化した指標となり好ましい。具体的には4~36000等分した情報を用いるのが良い。より好ましくは360等分以上である。
図8は、本発明の一実施形態である鋼管の真円度予測装置の構成を示すブロック図である。図9は、図8に示す真円度オフライン計算部112の構成を示すブロック図である。
素材となる鋼板の属性情報としては、鋼板の降伏応力、引張強度、縦弾性係数、板厚、板面内の板厚分布、鋼板の板厚方向の降伏応力の分布、バウシンガー効果の程度、表面粗さ等、拡管工程後の鋼管の真円度に影響を及ぼす任意のパラメータを用いることができる。特に、プレスベンド工程における3点曲げプレスによる鋼板の変形状態やスプリングバックに影響を与える因子や、シームギャップ低減工程における圧縮・曲げ加工による鋼板の変形状態やスプリングバックに影響を与える因子を指標とするのが好適である。
端曲げ工程の操業パラメータを真円度予測モデルの入力に用いる場合には、Cプレス装置30で使用する上金型33の成形面33aがなす形状や下金型34の押圧面34aがなす形状を特定するパラメータを操業パラメータとして用いることができる。また、端曲げ工程における端曲げ加工幅(端曲げ成形を施す幅)、押し上げ力(Cプレス力)、及びクランプ機構37による把持力を操業パラメータとして用いてもよい。これらは、端曲げ工程における鋼板の幅方向端部の変形に影響を与え得る因子だからである。また、端曲げ工程について3次元変形解析を実行する場合には、鋼板の送り量、送り方向、及び送り回数を端曲げ工程の操業パラメータとしてもよい。
本実施形態では、プレスベンド工程の操業パラメータを真円度予測モデルの入力に用いる。プレスベンド工程の操業パラメータとしては、上記に記載した3点曲げプレスのプレス回数、プレス位置情報、プレス圧下量、下ダイ間隔、パンチ曲率等、鋼板の局所的な曲げ曲率と、それらの板幅方向の分布に影響を与える各種パラメータを用いることができる。特に、パンチが鋼板を押圧するプレス位置情報とプレス圧下量、プレスベンド工程を通じて行うプレス回数の全てを含む情報を用いるのが好ましい。これらの情報を全て含むとは、図11に示す方法が例示できる。
本実施形態では、シームギャップ低減工程の操業パラメータを真円度予測モデルの入力に用いる。シームギャップ低減工程として、Oプレス装置を用いる場合には、操業パラメータとして、Oプレス圧下量、Oプレス圧下位置、OプレスダイスRを用いることができる。一方、クロージングプレス法を用いる場合には、操業パラメータとして、上述した各ステップにおけるクロージングプレス圧下位置及びクロージングプレス押し付け力を用いる。特に、Oプレス装置を用いる場合には、Oプレス圧下量を用いるのが好適である。これは、Oプレス圧下量を大きくすると、上金型より拘束・押圧力を受ける点と下金型によって拘束される点の間の領域、主に鋼管の3時部及び9時部付近は拘束がなく、曲げ及び圧縮の変形が集中するため、その領域の曲率が増加することにより、最終的な真円度に影響を与えるからである。
上述した操業パラメータの他、拡管工程の操業パラメータを真円度予測モデルの入力に用いる場合には、拡管率を拡管工程の操業パラメータとして用いることができる。拡管率が大きいほど、拡管工程後の鋼管の真円度は向上するが、鋼管製品としての圧縮降伏強度の観点から拡管率の上限値が制限されるため、その範囲内での値を用いて基礎データ取得部110の計算条件を決定する。このとき、拡管率は、拡管装置を制御するために必要な情報であるため、上位計算値で設定された設定値により特定することができる。なお、拡管工程の操業パラメータとしては、拡管率の他、拡管ダイス枚数や拡管ダイス径を用いてもよい。
本実施形態では、上記のようにして真円度予測モデル生成部130によってオフラインで生成された真円度予測モデルMを用いて、オンラインで拡管工程後の鋼管の真円度を予測する。拡管工程後の鋼管の真円度予測にあたっては、まず、鋼管の製造工程の操業条件として設定される操業条件データセットをオンラインで取得する(操業パラメータ取得ステップ)。これは、上記のようにして生成した真円度予測モデルの入力となる操業条件データセットとして、鋼管の製造工程を統括する上位計算機又は各成形加工工程の制御用計算機から必要なデータを取得するステップである。ここで、「オンライン」とは、鋼管の製造工程の開始前から拡管工程が完了するまでの一連の製造工程の間を意味する。従って、必ずしもいずれかの成形加工工程で加工を実行中でなくてもよい。各成形加工工程の間で鋼板を次の工程に搬送するために待機している間も「オンライン」に含まれる。また、鋼管の製造工程の開始前であって素材となる鋼板を製造する厚板圧延工程が完了した後も「オンライン」に含めることができる。素材となる鋼板を製造する厚板圧延工程が完了すると、本実施形態の真円度予測モデルの入力となる操業条件データセットを取得できる状態になるからである。オンラインで使用するのは機械学習により学習した真円度予測モデルMであり、入力条件となる操業パラメータを設定すれば、即座に出力となる真円度を算出し、操業条件の再設定等を迅速に行うことができる。
本実施形態である拡管工程後の鋼管の真円度制御方法について説明する。図12は、拡管工程後の鋼管の真円度予測をプレスベンド工程の開始前に行う処理の流れを示す。図12に示すように、この処理では、素材となる鋼板の属性情報に関する実績データ、プレスベンド工程の操業条件として予め設定された設定値(操業設定値)、シームギャップ低減工程の操業条件として予め設定された設定値(操業設定値)が上位計算機140から得られ、これらの情報を操業条件データセット111として取得する。また、拡管工程後の鋼管の目標とする真円度として予め設定された真円度目標値が上位計算機140から操業条件再設定部150に送られる。
次に、図17を参照して、本発明の一実施形態である鋼管の真円度予測装置について説明する。
本実施例では、板厚38.0~38.4mm、板幅2700~2720mmのラインパイプ用鋼板(API グレード X60)を用い、拡管工程後の直径が36インチの鋼管をプレスベンド工程、シームギャップ低減工程、溶接工程、及び拡管工程を経て製造する製造条件に対応して、オフラインの拡管工程後の真円度予測モデルを生成した。本実施例に用いたシームギャップ低減工程の有限要素モデル生成部により生成された有限要素モデルの例を図13に例示する。使用した有限要素解析ソルバーはAbaqus2019であり、1ケース当たりの計算時間は概ね3時間であった。データベースに蓄積したデータセットの数は300、機械学習モデルとして基底関数に動径基底関数を用いたガウシアン過程回帰を用いた。
本実施例では、板厚50.0~50.4mm、板幅4450~4460mmのラインパイプ用鋼板(API グレード X60)を用い、拡管工程後の直径が56インチの鋼管をプレスベンド工程、シームギャップ低減工程、溶接工程、及び拡管工程を経て鋼管を製造する場合について、オフラインにて拡管工程後の真円度予測モデルを生成した。この場合、鋼管の真円度予測モデルの入力とする、鋼板の属性情報のパラメータ、プレスベンド工程の操業パラメータ、及びシームギャップ低減工程の操業パラメータは、実施例1と同一のものを選択した。但し、それらの操業パラメータの範囲は、実施例1とは異なる。鋼板の属性情報のパラメータである代表板厚は50.0~50.4mm、板幅は4450~4460mmの範囲で操業条件データセットを設定した。
本実施例では、板厚38.0~38.4mm、板幅2700~2720mmのラインパイプ用鋼板(API グレード X60)を用い、拡管工程後の直径が36インチの鋼管を端曲げ工程、プレスベンド工程、シームギャップ低減工程、溶接工程、及び拡管工程を経て鋼管を製造する場合について、オフラインにて拡管工程後の真円度予測モデルを生成した。この場合、鋼管の真円度予測モデルの入力とする、鋼板の属性情報のパラメータ、プレスベンド工程の操業パラメータ、及びシームギャップ低減工程の操業パラメータは実施例1と同一とした。また、操業条件データセットを構成する各操業パラメータの範囲も実施例1と同一とした。
1a,1b 棒状部材
2 パンチ
2a パンチ先端部
2b パンチ支持体
3 上金型
4 下金型
10a,10b 下側工具
11a,11b バネ手段
12 パンチ
13 上側工具
16 拡管ダイス
17 テーパー外周面
18 プルロッド
20 アーム
21a,21b 変位計
22 回転角度検出器
25 回転アーム
26a,26b 押圧ローラ
30 Cプレス装置
31 搬送機構
31a 搬送ロール
32A,32B プレス機構
33 上金型
33a 成形面
34 下金型
34a 押圧面
36 油圧シリンダ
37 クランプ機構
110 基礎データ取得部
111 操業条件データセット
112 真円度オフライン計算部
112a プレスベンド工程の有限要素モデル生成部
112b シームギャップ低減工程の有限要素モデル生成部
112c 拡管工程の有限要素モデル生成部
112d 有限要素解析ソルバー
120 データベース
130 真円度予測モデル生成部
140 上位計算機
150 操業条件再設定部
160 鋼管の真円度予測装置
161 操業パラメータ取得部
162 記憶部
163 真円度予測部
164 出力部
165 入力部
166 表示部
G シームギャップ部
M 真円度予測モデル
P 鋼管
R1,R2 領域
S 鋼板
S1 成形体
S2 オープン管
Claims (12)
- パンチによる複数回の押圧により鋼板をU字状断面の成形体に加工するプレスベンド工程、前記U字状断面の成形体のシームギャップ部を減少させオープン管とするシームギャップ低減工程、前記オープン管の端部同士を接合する溶接工程、及び端部同士が接合された鋼管の内径を拡大する拡管工程を含む鋼管の製造工程における、前記拡管工程後の鋼管の真円度を予測する真円度予測モデルを生成する鋼管の真円度予測モデルの生成方法であって、
前記鋼板の属性情報から選択した1又は2以上のパラメータ、前記プレスベンド工程の操業パラメータから選択した1又は2以上のパラメータ、及び前記シームギャップ低減工程の操業パラメータから選択した1又は2以上のパラメータを含む操業条件データセットを入力データに含み、前記拡管工程後の鋼管の真円度を出力データとする数値計算を、前記操業条件データセットを変更しながら複数回実行することにより、前記操業条件データセットと対応する前記拡管工程後の鋼管の真円度のデータの組を学習用データとしてオフラインで複数生成する基礎データ取得ステップと、
前記基礎データ取得ステップにおいて生成された複数の学習用データを用いて、前記操業条件データセットを入力データ、拡管工程後の鋼管の真円度を出力データとする真円度予測モデルをオフラインで機械学習により生成する真円度予測モデル生成ステップと、
を含む、鋼管の真円度予測モデルの生成方法。 - 前記基礎データ取得ステップは、有限要素法を利用して前記操業条件データセットから前記拡管工程後の鋼管の真円度を算出するステップを含む、請求項1に記載の鋼管の真円度予測モデルの生成方法。
- 前記真円度予測モデルは、前記操業条件データセットとして、前記拡管工程の操業パラメータの中から選択した1又は2以上のパラメータを含む、請求項1又は2に記載の鋼管の真円度予測モデルの生成方法。
- 前記鋼管の製造工程は、前記プレスベンド工程に先立って前記鋼板の幅方向端部に曲げを付与する端曲げ工程を含み、前記真円度予測モデルは、前記操業条件データセットとして、前記端曲げ工程の操業パラメータの中から選択した1又は2以上のパラメータを含む、請求項1~3のうち、いずれか1項に記載の鋼管の真円度予測モデルの生成方法。
- 前記プレスベンド工程の操業パラメータは、前記プレスベンド工程に用いるパンチが鋼板を押圧するプレス位置情報及びプレス圧下量と共に、前記プレスベンド工程を通じて行うプレス回数を含む、請求項1~4のうち、いずれか1項に記載の鋼管の真円度予測モデルの生成方法。
- 前記機械学習として、ニューラルネットワーク、決定木学習、ランダムフォレスト、ガウシアン過程回帰、及びサポートベクター回帰から選択した機械学習を用いる、請求項1~5のうち、いずれか1項に記載の鋼管の真円度予測モデルの生成方法。
- 請求項1~6のうち、いずれか1項に記載の鋼管の真円度予測モデルの生成方法により生成された鋼管の真円度予測モデルの入力として、前記鋼管の製造工程の操業条件として設定される操業条件データセットをオンラインで取得する操業パラメータ取得ステップと、
前記操業パラメータ取得ステップにおいて取得した前記操業条件データセットを前記真円度予測モデルに入力することにより、拡管工程後の鋼管の真円度情報を予測する真円度予測ステップと、
を含む、鋼管の真円度予測方法。 - 請求項7に記載の鋼管の真円度予測方法を用いて、前記プレスベンド工程の開始前に、前記鋼板の属性情報の実績値、前記プレスベンド工程の操業パラメータの設定値、及び前記シームギャップ低減工程の操業パラメータの設定値を含む操業条件データセットを取得し、取得した操業条件データセットを前記真円度予測モデルに入力することにより拡管工程後の鋼管の真円度を予測し、予測した真円度が小さくなるように前記プレスベンド工程の操業パラメータの設定値及び前記シームギャップ低減工程の操業パラメータの設定値の少なくとも一方を再設定するステップを含む、鋼管の真円度制御方法。
- 請求項7に記載の鋼管の真円度予測方法を用いて、前記鋼管の製造工程を構成する端曲げ工程、プレスベンド工程、シームギャップ低減工程、及び拡管工程の中から選択した再設定対象工程の開始前に、前記拡管工程後の鋼管の真円度情報を予測し、予測された鋼管の真円度情報に基づいて、少なくとも前記再設定対象工程の操業パラメータの中から選択した1又は2以上の操業パラメータ、又は、前記再設定対象工程よりも下流側の成形加工工程の操業パラメータの中から選択した1又は2以上の操業パラメータを再設定するステップを含む、鋼管の真円度制御方法。
- 請求項8又は9に記載の鋼管の真円度制御方法を用いて鋼管を製造するステップを含む、鋼管の製造方法。
- パンチによる複数回の押圧により鋼板をU字状断面の成形体に加工するプレスベンド工程、前記U字状断面の成形体のシームギャップ部を減少させオープン管とするシームギャップ低減工程、前記オープン管の端部同士を接合する溶接工程、及び端部同士が接合された鋼管の内径を拡大する拡管工程を含む鋼管の製造工程における、前記拡管工程後の鋼管の真円度を予測する鋼管の真円度予測装置であって、
前記鋼板の属性情報から選択した1又は2以上のパラメータ、前記プレスベンド工程の操業パラメータから選択した1又は2以上の操業パラメータ、及び前記シームギャップ低減工程の操業パラメータから選択した1又は2以上の操業パラメータを含む操業条件データセットを入力データとして含み、前記拡管工程後の鋼管の真円度情報を出力データとする数値計算を、前記操業条件データセットを変更しながら複数回実行することにより、前記操業条件データセットと対応する前記拡管工程後の鋼管の真円度情報のデータの組を学習用データとして複数生成する基礎データ取得部と、
前記基礎データ取得部において生成された複数の学習用データを用いて、前記操業条件データセットを入力データ、拡管工程後の鋼管の真円度情報を出力データとする真円度予測モデルを機械学習により生成する真円度予測モデル生成部と、
前記鋼管の製造工程の操業条件として設定される操業条件データセットをオンラインで取得する操業パラメータ取得部と、
前記真円度予測モデル生成部において生成された真円度予測モデルを用いて、前記操業パラメータ取得部により取得した前記操業条件データセットに対応する拡管工程後の鋼管の真円度情報をオンラインで予測する真円度予測部と、
を備える、鋼管の真円度予測装置。 - ユーザの操作に基づく入力情報を取得する入力部と、前記真円度情報を表示する表示部と、を有する端末装置を備え、
前記操業パラメータ取得部は、前記入力部が取得した入力情報に基づいて、前記鋼管の製造工程における操業条件データセットの一部又は全部を更新し、
前記表示部は、前記更新された操業条件データセットを用いて前記真円度予測部が予測した前記鋼管の真円度情報を表示する、請求項11に記載の鋼管の真円度予測装置。
Priority Applications (5)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP21837469.2A EP4151329A4 (en) | 2020-07-10 | 2021-06-04 | METHOD FOR GENERATING A STEEL PIPE ROUNDNESS PREDICTION MODEL, STEEL PIPE ROUNDNESS PREDICTION METHOD, STEEL PIPE ROUNDNESS CONTROL METHOD, STEEL PIPE MANUFACTURING METHOD AND STEEL PIPE ROUNDNESS PREDICTION APPARATUS |
BR112023000222A BR112023000222A2 (pt) | 2020-07-10 | 2021-06-04 | Método de geração de modelo de previsão de perda de circularidade de tubo de aço, método de previsão de perda de circularidade de tubo de aço, método de controle de perda de circularidade de tubo de aço, método de fabricação de tubo de aço, e dispositivo de previsão de perda de circularidade de tubo de aço |
KR1020237000675A KR20230022224A (ko) | 2020-07-10 | 2021-06-04 | 강관의 진원도 예측 모델의 생성 방법, 강관의 진원도 예측 방법, 강관의 진원도 제어 방법, 강관의 제조 방법 및, 강관의 진원도 예측 장치 |
CN202180047923.0A CN115768574A (zh) | 2020-07-10 | 2021-06-04 | 钢管的真圆度预测模型的生成方法、钢管的真圆度预测方法、钢管的真圆度控制方法、钢管的制造方法及钢管的真圆度预测装置 |
JP2021545740A JP6958776B1 (ja) | 2020-07-10 | 2021-06-04 | 鋼管の真円度予測モデルの生成方法、鋼管の真円度予測方法、鋼管の真円度制御方法、鋼管の製造方法、及び鋼管の真円度予測装置 |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2020118874 | 2020-07-10 | ||
JP2020-118874 | 2020-07-10 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2022009575A1 true WO2022009575A1 (ja) | 2022-01-13 |
Family
ID=79552402
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2021/021415 WO2022009575A1 (ja) | 2020-07-10 | 2021-06-04 | 鋼管の真円度予測モデルの生成方法、鋼管の真円度予測方法、鋼管の真円度制御方法、鋼管の製造方法、及び鋼管の真円度予測装置 |
Country Status (1)
Country | Link |
---|---|
WO (1) | WO2022009575A1 (ja) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN115090718A (zh) * | 2022-08-26 | 2022-09-23 | 中国能源建设集团山西电力建设有限公司 | 两大口径薄壁钢管管口对焊前的校形方法 |
WO2022215459A1 (ja) * | 2021-04-05 | 2022-10-13 | Jfeスチール株式会社 | 鋼管の真円度予測方法、真円度制御方法、製造方法、真円度予測モデルの生成方法、及び真円度予測装置 |
WO2022215458A1 (ja) * | 2021-04-05 | 2022-10-13 | Jfeスチール株式会社 | 鋼管の真円度予測モデルの生成方法、真円度予測方法、真円度制御方法、製造方法、及び真円度予測装置 |
Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP4870200B2 (ja) * | 2009-08-26 | 2012-02-08 | 新日本製鐵株式会社 | プレス成形加工システム、プレス成形加工方法、及びコンピュータプログラム |
JP2012170977A (ja) | 2011-02-21 | 2012-09-10 | Jfe Steel Corp | 鋼管の製造方法 |
JP2012250285A (ja) | 2011-05-31 | 2012-12-20 | Sms Meer Gmbh | 板材からスリット管を製造する方法及び装置 |
JP5541432B1 (ja) | 2013-05-24 | 2014-07-09 | Jfeスチール株式会社 | 鋼管の製造方法 |
JP6015997B1 (ja) | 2014-11-25 | 2016-10-26 | Jfeスチール株式会社 | 鋼管の製造方法及びその方法に使用するプレス金型 |
JP6519896B1 (ja) * | 2018-03-15 | 2019-05-29 | オムロン株式会社 | 学習装置、学習方法、及びそのプログラム |
-
2021
- 2021-06-04 WO PCT/JP2021/021415 patent/WO2022009575A1/ja unknown
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP4870200B2 (ja) * | 2009-08-26 | 2012-02-08 | 新日本製鐵株式会社 | プレス成形加工システム、プレス成形加工方法、及びコンピュータプログラム |
JP2012170977A (ja) | 2011-02-21 | 2012-09-10 | Jfe Steel Corp | 鋼管の製造方法 |
JP2012250285A (ja) | 2011-05-31 | 2012-12-20 | Sms Meer Gmbh | 板材からスリット管を製造する方法及び装置 |
JP5541432B1 (ja) | 2013-05-24 | 2014-07-09 | Jfeスチール株式会社 | 鋼管の製造方法 |
JP6015997B1 (ja) | 2014-11-25 | 2016-10-26 | Jfeスチール株式会社 | 鋼管の製造方法及びその方法に使用するプレス金型 |
JP6519896B1 (ja) * | 2018-03-15 | 2019-05-29 | オムロン株式会社 | 学習装置、学習方法、及びそのプログラム |
Non-Patent Citations (2)
Title |
---|
JOURNAL OF THE JAPAN SOCIETY FOR TECHNOLOGY OF PLASTICITY, vol. 59, no. 694, 2018, pages 203 - 208 |
REN, QIANG: "Numerical study on the X80 UOE pipe forming process", JOURNAL OF MATERIAL PROCESSING TECHNOLOGY, vol. 215, 2015, pages 264 - 277, XP029064198, DOI: 10.1016/j.jmatprotec.2014.08.013 * |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2022215459A1 (ja) * | 2021-04-05 | 2022-10-13 | Jfeスチール株式会社 | 鋼管の真円度予測方法、真円度制御方法、製造方法、真円度予測モデルの生成方法、及び真円度予測装置 |
WO2022215458A1 (ja) * | 2021-04-05 | 2022-10-13 | Jfeスチール株式会社 | 鋼管の真円度予測モデルの生成方法、真円度予測方法、真円度制御方法、製造方法、及び真円度予測装置 |
CN115090718A (zh) * | 2022-08-26 | 2022-09-23 | 中国能源建设集团山西电力建设有限公司 | 两大口径薄壁钢管管口对焊前的校形方法 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
WO2022009575A1 (ja) | 鋼管の真円度予測モデルの生成方法、鋼管の真円度予測方法、鋼管の真円度制御方法、鋼管の製造方法、及び鋼管の真円度予測装置 | |
WO2022009576A1 (ja) | 鋼管の真円度予測方法、鋼管の真円度制御方法、鋼管の製造方法、鋼管の真円度予測モデルの生成方法、及び鋼管の真円度予測装置 | |
Shinkin et al. | E ngineering calculations for processes involved in the production of large-diameter pipes by the sms meer technology | |
Ktari et al. | Modeling and computation of the three-roller bending process of steel sheets | |
Wong et al. | Effects of roller path and geometry on the flow forming of solid cylindrical components | |
Fan et al. | 3D finite element modeling and analysis of radial forging processes | |
Wen | On a new concept of rotary draw bend-die adaptable for bending tubes with multiple outer diameters under non-mandrel condition | |
JP6958776B1 (ja) | 鋼管の真円度予測モデルの生成方法、鋼管の真円度予測方法、鋼管の真円度制御方法、鋼管の製造方法、及び鋼管の真円度予測装置 | |
Samusev et al. | Continuous shaping of welded straight-seam pipe in the open stands of a pipe-welding system | |
Azizoğlu et al. | Finite Element Analysis of cold pilgering using elastic roll dies | |
JP7168047B1 (ja) | 鋼管の真円度予測モデルの生成方法、鋼管の真円度予測方法、鋼管の真円度制御方法、鋼管の製造方法、及び鋼管の真円度予測装置 | |
JP6958775B1 (ja) | 鋼管の真円度予測方法、鋼管の真円度制御方法、鋼管の製造方法、鋼管の真円度予測モデルの生成方法、及び鋼管の真円度予測装置 | |
RU2804572C1 (ru) | Способ генерирования модели прогнозирования овальности стальной трубы, способ прогнозирования овальности стальной трубы, способ регулирования овальности стальной трубы, способ изготовления стальной трубы и устройство для прогнозирования овальности стальной трубы | |
WO2023007925A1 (ja) | 鋼管の真円度予測方法、鋼管の真円度制御方法、鋼管の製造方法、鋼管の真円度予測モデルの生成方法、及び鋼管の真円度予測装置 | |
RU2817714C2 (ru) | Способ генерирования модели прогнозирования овальности стальной трубы, способ прогнозирования овальности стальной трубы, способ регулирования овальности стальной трубы, способ изготовления стальной трубы и устройство для прогнозирования овальности стальной трубы | |
JP7264314B2 (ja) | 鋼管の真円度予測モデルの生成方法、真円度予測方法、真円度制御方法、製造方法、及び真円度予測装置 | |
Wang et al. | Research on multi-roll roll forming process of thick plate | |
RU2799579C1 (ru) | Сособ прогнозирования овальности стальной трубы, способ регулирования овальности стальной трубы, способ изготовления стальной трубы, способ генерирования модели прогнозирования овальности стальной трубы и устройство для прогнозирования овальности стальной трубы | |
WO2022215459A1 (ja) | 鋼管の真円度予測方法、真円度制御方法、製造方法、真円度予測モデルの生成方法、及び真円度予測装置 | |
RU2817631C2 (ru) | Способ прогнозирования овальности стальной трубы, способ регулирования овальности стальной трубы, способ изготовления стальной трубы, способ генерирования модели прогнозирования овальности стальной трубы и устройство для прогнозирования овальности стальной трубы | |
Azizoğlu et al. | Finite element modeling of tube deformation during cold pilgering | |
RU2660464C1 (ru) | Способ производства сварных прямошовных труб большого диаметра для магистральных трубопроводов | |
Banerjee et al. | A simplified model for the estimation of forces in flow forming and its comparison with ideal deformation and FEM models | |
Zaides | Straightening of relatively flexible cylindrical parts. Part II. Stress state of the cylinder workpiece in transverse rolling between flat plates | |
RU2758399C1 (ru) | Способ правки концов бесшовных труб |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
ENP | Entry into the national phase |
Ref document number: 2021545740 Country of ref document: JP Kind code of ref document: A |
|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 21837469 Country of ref document: EP Kind code of ref document: A1 |
|
ENP | Entry into the national phase |
Ref document number: 2021837469 Country of ref document: EP Effective date: 20221213 |
|
ENP | Entry into the national phase |
Ref document number: 20237000675 Country of ref document: KR Kind code of ref document: A |
|
REG | Reference to national code |
Ref country code: BR Ref legal event code: B01A Ref document number: 112023000222 Country of ref document: BR |
|
ENP | Entry into the national phase |
Ref document number: 112023000222 Country of ref document: BR Kind code of ref document: A2 Effective date: 20230105 |
|
NENP | Non-entry into the national phase |
Ref country code: DE |