Method for correcting opening width of joint in hat-shaped steel sheet pile, method for manufacturing hat-shaped steel sheet pile, and apparatus for manufacturing hat-shaped steel sheet pile

Abstract

To provide a method for correcting an opening width of a joint in a hat-shaped steel sheet pile, which improves production efficiency.SOLUTION: The straightening method includes a rolling step and a straightening step. When the hat-shaped steel sheet pile (10) immediately after passing through the rolling machine (21) is viewed along the pass line (PL), both of the arms (13A, 13B) are inclined to the same side with respect to the horizontal line (HL) and overhang. In the straightening step, when the finish-rolling is performed, the hat-shaped steel sheet pile (10) immediately after passing through the rolling machine (21) is pressed from the outer side in the widthwise direction by the pair of tools (22) to straighten the opening (141B) of the joint (14B). The pair of tools (22) are spaced apart from each other in the width direction of the pass line (PL) so as to sandwich the pass line (PL) therebetween on the exit side of the rolling mill (21).SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a hat-shaped steel sheet pile, and more particularly to a method for correcting an opening width of a joint in a hat-shaped steel sheet pile, a manufacturing method for a hat-shaped steel sheet pile, and a manufacturing device for a hat-shaped steel sheet pile. [Background technology]

[0002] Steel sheet piles are used in civil engineering and construction, for example, for river and harbor revetments. There are hat-shaped steel sheet piles, U-shaped steel sheet piles, and straight steel sheet piles. Among these, hat-shaped steel sheet piles are widely used due to their excellent workability and high rigidity. Hereinafter, hat-shaped steel sheet piles will also be referred to simply as steel sheet piles.

[0003] A hat-shaped steel sheet pile is usually manufactured by the following process. First, a heated rectangular material (typically a slab) is rough-rolled to form a rough-shaped material. Next, the rough-shaped material is intermediate-rolled to form an intermediate material. The intermediate material has a shape roughly similar to that of the hat-shaped steel sheet pile. Furthermore, the intermediate material is finish-rolled to form a long hat-shaped steel sheet pile. In the finish rolling, bending is performed on the portion corresponding to the joint, thereby forming a joint with an opening. Then, the long hat-shaped steel sheet pile is cut and shaped to fit the dimensions of the final product. In this way, the final hat-shaped steel sheet pile is manufactured.

[0004] However, during the finish rolling process in the manufacturing process of steel sheet piles, the opening width of the joint may become larger than the desired width. If the opening width becomes too large, there is a risk that the joint will come loose when joining the steel sheet piles. Therefore, to address this issue, it is necessary to set a standard (upper limit) for the opening width of the product and ensure that the upper limit is not exceeded during the manufacturing process.

[0005] Japanese Patent Application Laid-Open Publication No. 2019-195828 (Patent Document 1) discloses a method for correcting the opening width of a joint in a hat-shaped steel sheet pile using an offline press straightening machine. The straightening method in Patent Document 1 includes a flange support process and a joint pressing process. The press straightening machine includes a vertical moving unit and left and right horizontal moving units. In the flange support process, the vertical moving units support the web and the inner surfaces of a pair of flanges. Furthermore, one horizontal moving unit is moved from the outer side in the width direction toward the inner side in the width direction to support the outer surface of one flange. In the joint pressing process, the other horizontal moving unit is moved from the outer side in the width direction toward the inner side in the width direction, and the joint on the other side of the steel sheet pile is pressed by a joint straightening tool attached to the horizontal moving unit. Patent Document 1 states that this reduces and corrects the opening width of the joint on the other side. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 2019-195828 Summary of the Invention [Problem to be solved by the invention]

[0007] However, the method for correcting the joint opening width described in Patent Document 1 is a technology for correcting manufactured steel sheet piles using an offline press straightening machine, which requires a straightening process separate from the manufacturing process, which limits the production efficiency of hat-type steel sheet piles.

[0008] An object of the present disclosure is to provide a method for correcting the opening width of a joint in a hat-shaped steel sheet pile, a manufacturing method for a hat-shaped steel sheet pile, and a manufacturing device for a hat-shaped steel sheet pile, which can improve production efficiency. [Means for solving the problem]

[0009] A straightening method according to the present disclosure is a method for straightening the opening width of a joint in a hat-type steel sheet pile. The straightening method includes a rolling process and a straightening process. In the rolling process, a material is passed through a rolling mill equipped with upper and lower grooved rolls to perform finish rolling. In the rolling process, finish rolling is performed so that both arms of the hat-type steel sheet pile extend at an inclination to the same side with respect to the horizontal line when the hat-type steel sheet pile immediately after passing through the rolling mill is viewed along the pass line. In the straightening process, during the finish rolling, a pair of tools press the hat-type steel sheet pile immediately after passing through the rolling mill from the outside in the width direction to straighten the opening width of the joint of the hat-type steel sheet pile. The pair of tools are arranged at an outlet side of the rolling mill, spaced apart in the width direction of the pass line so as to sandwich the pass line therebetween.

[0010] The manufacturing method of the hat-shaped steel sheet pile according to the present disclosure includes a preparation process, a rolling process, a straightening process, and a shaping process. In the preparation process, a material to be the hat-shaped steel sheet pile is prepared. In the rolling process, the material is passed through a rolling mill equipped with upper and lower groove rolls to perform finish rolling, thereby manufacturing the hat-shaped steel sheet pile. In the rolling process, finish rolling is performed so that both arms of the hat-shaped steel sheet pile extend at an inclination to the same side with respect to the horizontal line when the hat-shaped steel sheet pile immediately after passing through the rolling mill is viewed along the pass line. In the straightening process, during the finish rolling, a pair of tools press the hat-shaped steel sheet pile immediately after passing through the rolling mill from the outside in the width direction to straighten the width of the opening of the joint of the hat-shaped steel sheet pile. The pair of tools are arranged at a distance from each other in the width direction of the pass line on the outlet side of the rolling mill so as to sandwich the pass line between them. In the shaping process, the overall shape of the hat-shaped steel sheet pile is shaped.

[0011] The manufacturing device for a hat-type steel sheet pile according to the present disclosure includes a rolling mill and a pair of tools. The rolling mill is arranged on a pass line and includes an upper groove type roll and a lower groove type roll. The pair of tools are arranged on the outlet side of the rolling mill, spaced apart in the width direction of the pass line so as to sandwich the pass line therebetween. The pair of tools are cylindrical with central axes extending in the vertical direction. The tools are driven rollers whose central axes are supported and rotatable about the central axis. [Effects of the Invention]

[0012] According to the present disclosure, the production efficiency of hat-shaped steel sheet piles can be improved. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a perspective view showing a schematic configuration of a hat-type steel sheet pile. [Figure 2] FIG. 2 is a front view of the hat-shaped steel sheet pile immediately after finish rolling. [Figure 3] FIG. 3 is a perspective view showing a schematic configuration of a manufacturing device for a hat-type steel sheet pile. [Figure 4] FIG. 4 is a front view showing a schematic configuration of the rolling mill. [Figure 5] FIG. 5 is a top view of a manufacturing device for a hat-type steel sheet pile. [Figure 6] FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. [Figure 7] FIG. 7 is a diagram showing the relationship between the longitudinal position and the opening width of the joint in a hat-type steel sheet pile. DETAILED DESCRIPTION OF THE INVENTION

[0014] A straightening method according to an embodiment is a method for straightening a width of an opening of a joint in a hat-type steel sheet pile. The straightening method includes a rolling process and a straightening process. In the rolling process, a material is passed through a rolling mill equipped with upper and lower grooved rolls to perform finish rolling. In the rolling process, finish rolling is performed so that both arms of the hat-type steel sheet pile extend at an inclination to the same side with respect to the horizontal line when the hat-type steel sheet pile immediately after passing through the rolling mill is viewed along the pass line. In the straightening process, during the finish rolling, a pair of tools press the hat-type steel sheet pile immediately after passing through the rolling mill from the outside in the width direction to straighten the width of the opening of the joint of the hat-type steel sheet pile. The pair of tools are arranged at an outlet side of the rolling mill, spaced apart in the width direction of the pass line so as to sandwich the pass line therebetween (first configuration).

[0015] In the correction method according to the first configuration, the joint of the hat-shaped steel sheet pile is bent by finish rolling, and the opening width of the joint is corrected immediately after the finish rolling. That is, while the finish rolling is being performed, the opening width of the joint is corrected online by a pair of tools arranged on the delivery side of the finish rolling mill. Therefore, according to the first configuration, the opening width of the joint can be corrected in the rolling process of the hat-shaped steel sheet pile, and the production efficiency of the hat-shaped steel sheet pile can be improved.

[0016] Furthermore, in the rolling process of the first configuration, finish rolling is performed so that both arms of the hat-shaped steel sheet pile immediately after passing through the rolling mill are inclined to the same side relative to the horizontal line when viewed along the pass line. When a hat-shaped steel sheet pile having such a shape is pressed from the outside in the width direction with a pair of tools, the width of the opening of one of the pair of joints is corrected. Specifically, when the hat-shaped steel sheet pile is viewed along the pass line, the width of the opening of the joint having an opening facing the opposite side of the inclined side of the arm relative to the horizontal line is corrected. In other words, according to the first configuration, the width of the opening of one of the joints can be selectively corrected.

[0017] In the first configuration, the tool may be cylindrical with a central axis extending in the vertical direction (second configuration). In this case, a relatively simple configuration is required to support the tool, making it easy to adjust the position of the tool.

[0018] In the second configuration, the tool may be a driven roller whose central axis is supported and rotatable around the central axis (third configuration). In this case, the roller can freely rotate following the movement of the hat-shaped steel sheet pile in the rolling direction. Therefore, according to the third configuration, the material passing speed of the hat-shaped steel sheet pile and the peripheral speed of the roller tend to match, so that the occurrence of defects in the hat-shaped steel sheet pile due to sliding between the hat-shaped steel sheet pile and the roller can be suppressed.

[0019] A manufacturing method of a hat-shaped steel sheet pile according to an embodiment includes a preparation step, a rolling step, a straightening step, and a shaping step. In the preparation step, a material to be the hat-shaped steel sheet pile is prepared. In the rolling step, the material is passed through a rolling mill equipped with upper and lower groove rolls to perform finish rolling, thereby manufacturing the hat-shaped steel sheet pile. In the rolling step, finish rolling is performed so that both arms of the hat-shaped steel sheet pile extend at an inclination to the same side with respect to the horizontal line when the hat-shaped steel sheet pile immediately after passing through the rolling mill is viewed along the pass line. In the straightening step, during the finish rolling, a pair of tools press the hat-shaped steel sheet pile immediately after passing through the rolling mill from the outside in the width direction, thereby straightening the width of an opening of a joint of the hat-shaped steel sheet pile. The pair of tools are arranged at an outlet side of the rolling mill, spaced apart in the width direction of the pass line so as to sandwich the pass line therebetween. In the shaping step, the overall shape of the hat-shaped steel sheet pile is shaped (fourth configuration).

[0020] In the manufacturing method according to the fourth configuration, the joint of the hat-shaped steel sheet pile is bent by finish rolling, and the opening width of the joint is corrected immediately after the finish rolling. That is, while the finish rolling is being performed, the opening width of the joint is corrected online by a pair of tools arranged on the outlet side of the finish rolling mill. Therefore, according to the fourth configuration, the opening width of the joint can be corrected in the rolling process of the hat-shaped steel sheet pile, and the production efficiency of the hat-shaped steel sheet pile can be improved.

[0021] The manufacturing method according to the fourth configuration may further include a first measuring step and a setting step. In the first measuring step, for the hat-shaped steel sheet pile manufactured in the rolling step, when the hat-shaped steel sheet pile is viewed along the pass line, a width of an opening is measured at a joint having an opening facing the opposite side of the inclined side of the arm with respect to the horizontal line. In the setting step, the position of each tool in the width direction of the pass line is set after the measurement in the first measuring step. In the setting step, if the width measured in the first measuring step exceeds a first predetermined range, the spacing between the tools is changed to set the positions of the tools, and if the width measured in the first measuring step is within the first predetermined range, the positions of the tools are set without changing the spacing between the tools (fifth configuration).

[0022] In the rolling process, the magnitude of the force with which the tools press the hat-shaped steel sheet pile from both sides in the width direction changes by changing the distance between the tools. Therefore, by changing the distance between the tools, the magnitude of the pressing force of the tools can be controlled, and the amount of correction of the width of the joint opening can be adjusted. In a manufacturing method according to a fifth configuration, the width of the opening is measured in a joint of a hat-shaped steel sheet pile previously manufactured, which has an opening facing the opposite side of the inclined side of the arm with respect to the horizontal line. That is, the width of the opening corrected in the previous correction process is measured. Furthermore, the width-direction position of the tool pressing the hat-shaped steel sheet pile is set according to the measured width of the opening. As a result, when manufacturing a hat-shaped steel sheet pile next to the measured hat-shaped steel sheet pile, the width-direction position of the tool in the correction process can be determined based on information about the measured hat-shaped steel sheet pile. Therefore, the correction effect in the correction process when manufacturing the next hat-shaped steel sheet pile can be improved.

[0023] In the manufacturing method according to the fifth configuration, in the straightening process, the hat-shaped steel sheet pile is pressed from the outside in the width direction by the tools so that the pressing force of one of the tools is greater than the pressing force of the other tool, thereby further straightening the bending of the hat-shaped steel sheet pile in the width direction (sixth configuration).

[0024] In the sixth configuration, the pressing force of one of the pair of tools is greater than the pressing force of the other tool, so that bending in the width direction of the hat-shaped steel sheet pile can be corrected. For example, by increasing the pressing force of the tool on the left side in the width direction compared to the tool on the right side, bending of the hat-shaped steel sheet pile to the left in the width direction can be corrected. Thus, according to the sixth configuration, in the correction process, not only the width of the joint opening but also bending of the hat-shaped steel sheet pile in the width direction can be corrected simultaneously.

[0025] The manufacturing method according to the sixth configuration can further include a second measurement step of measuring a bending in the width direction of the hat-shaped steel sheet pile measured in the first measurement step. In addition, the setting step can further include changing the center position between the tools to set the position of the tool when the bending measured in the second measurement step exceeds a second predetermined range, and setting the position of the tool without changing the center position between the tools when the bending measured in the second measurement step is within the second predetermined range (seventh configuration).

[0026] In the straightening process, the balance of the magnitude of the force with which the tools press the hat-shaped steel sheet pile from both sides in the width direction changes by changing the center position between the tools. Therefore, by changing the center position between the tools, the difference in the pressing force between one tool and the other tool can be controlled, and the amount of straightening of the hat-shaped steel sheet pile in the width direction can be adjusted. In the seventh configuration, in addition to measuring the opening width, the width direction bending of the hat-shaped steel sheet pile is also measured. Furthermore, the width direction position of the tool pressing the hat-shaped steel sheet pile is set according to the measured bending. Therefore, according to the seventh configuration, when manufacturing a hat-shaped steel sheet pile next to the measured hat-shaped steel sheet pile, the width direction position of the tool in the straightening process can be determined based on the information on the opening width and bending of the measured hat-shaped steel sheet pile. Therefore, the opening width can be corrected more effectively in the straightening process when manufacturing the next hat-shaped steel sheet pile, and the bending can also be corrected more effectively.

[0027] A manufacturing device for a hat-type steel sheet pile according to an embodiment includes a rolling mill and a pair of tools. The rolling mill is arranged on a pass line and includes an upper groove type roll and a lower groove type roll. The pair of tools are arranged at the exit side of the rolling mill, spaced apart in the width direction of the pass line so as to sandwich the pass line therebetween. The pair of tools are cylindrical with a central axis extending in the vertical direction. The tools are driven rollers whose central axis is supported and rotatable about the central axis (eighth configuration).

[0028] In the manufacturing apparatus according to the eighth configuration, a pair of tools are arranged at a distance from each other on the delivery side of the rolling mill, sandwiching the pass line between them. Therefore, in this manufacturing apparatus, the hat-shaped steel sheet pile rolled by the rolling mill is pressed in the width direction by the pair of tools at the delivery side of the rolling mill. Therefore, according to the eighth configuration, the width of the joint opening of the hat-shaped steel sheet pile can be corrected immediately after rolling, thereby improving the production efficiency of the hat-shaped steel sheet pile. Furthermore, since the tool is cylindrical with a central axis extending in the vertical direction, the structure for supporting the tool is relatively simple, making it easy to adjust the tool position. Furthermore, since the tool is a driven roller, the material passing speed of the hat-shaped steel sheet pile and the peripheral speed of the roller tend to match. Therefore, it is possible to suppress the occurrence of defects on the hat-shaped steel sheet pile due to sliding between the roller and the hat-shaped steel sheet pile.

[0029] In the manufacturing apparatus according to the eighth configuration, the tools may be provided so that their positions in the width direction can be changed (ninth configuration). In this case, for example, the interval between the tools can be changed. The magnitude of the force with which the tools press the hat-shaped steel sheet pile from both sides in the width direction varies depending on the interval between the tools. Therefore, by changing the interval between the tools, the magnitude of the pressing force from both sides of the hat-shaped steel sheet pile can be controlled and the amount of correction of the width of the joint opening can be adjusted. Therefore, for example, an operator can measure the shape of the rolled hat-shaped steel sheet pile in advance and change the interval between the tools according to the shape, thereby correcting the width of the joint opening suitable for that shape.

[0030] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In each drawing, the same or equivalent components are designated by the same reference numerals, and the same description will not be repeated.

[0031] [Hat-shaped steel sheet pile] First, with reference to Figs. 1 and 2, the configuration of a hat-shaped steel sheet pile to which a straightening method and a manufacturing method according to the present embodiment are applied will be described.

[0032] 1 is a perspective view showing a schematic configuration of a hat-shaped steel sheet pile 10. The hat-shaped steel sheet pile in this embodiment is mainly a general hat-shaped steel sheet pile as specified in JIS A 5523:2021. Its shape will be specifically described below.

[0033] 1, a hat-shaped steel sheet pile 10 includes a web 11, a pair of flanges 12A and 12B, a pair of arms 13A and 13B, and a pair of joints 14A and 14B. The hat-shaped steel sheet pile 10 has an elongated shape. The direction in which the hat-shaped steel sheet pile 10 extends is sometimes referred to as the longitudinal direction.

[0034] The web 11 has an elongated shape extending in the longitudinal direction of the hat-shaped steel sheet pile 10, and has a width in a direction perpendicular to the longitudinal direction. Hereinafter, the width direction of the web 11 may be simply referred to as the width direction. Also, the direction perpendicular to the longitudinal direction and the width direction may be referred to as the height direction.

[0035] 2 is a front view of the hat-shaped steel sheet pile 10 immediately after finish rolling. Referring to FIGS. 1 and 2, the web 11 is disposed at the center of the hat-shaped steel sheet pile 10 in the width direction.

[0036] The flanges 12A and 12B have an elongated shape extending in the longitudinal direction of the hat-shaped steel sheet pile 10. The flanges 12A and 12B are connected to both ends of the web 11 in the width direction. Specifically, the flange 12A is connected to one end of the web 11 in the width direction, and the flange 12B is connected to the other end of the web 11 in the width direction. The flanges 12A and 12B protrude from the end of the web 11 on the same side in the height direction. That is, the flange 12A and the flange 12B are disposed symmetrically with respect to the web 11 in the width direction.

[0037] The arms 13A and 13B extend in the width direction from the flanges 12A and 12B. Specifically, the arms 13A and 13B each extend from an end of the flange 12A or 12B that is not connected to the web 11 to the side opposite the web 11 in the width direction.

[0038] In the final product, the hat-shaped steel sheet pile 10, the arms 13A and 13B protrude along a horizontal line HL. For convenience, Fig. 2 shows the arms 13A and 13B in a state inclined with respect to the horizontal line HL. This state is the state immediately after finish rolling, which will be described later.

[0039] The joints 14A and 14B are provided at the widthwise ends of the arms 13A and 13B. Specifically, the joints 14A and 14B are provided at the ends of the arms 13A and 13B that are not connected to the flanges 12A and 12B.

[0040] The pair of joints 14A, 14B have openings 141A, 141B on different sides relative to the web 11. Specifically, the pair of joints 14A, 14B have a substantially C-shape in a front view of the hat-shaped steel sheet pile 10, and the openings of the C-shape face different sides in the height direction. In the example shown in Fig. 2, the opening 141A of the joint 14A opens on the side where the web 11 is arranged, and the opening 141B of the joint 14B opens on the side opposite to the side where the web 11 is arranged.

[0041] [Manufacturing equipment] Next, with reference to Figs. 3 to 5, a method for correcting the opening width of the joints 14A, 14B in the hat-shaped steel sheet pile 10 according to this embodiment and the configuration of a manufacturing device used in the manufacturing method of the hat-shaped steel sheet pile 10 will be described.

[0042] 3 is a perspective view showing a schematic configuration of a manufacturing apparatus 20 for the hat-shaped steel sheet pile 10. Referring to FIG. 3, the manufacturing apparatus 20 includes a rolling mill 21 and a pair of tools 22. The manufacturing apparatus 20 is used in a finish rolling process in the manufacturing process of the hat-shaped steel sheet pile 10.

[0043] FIG. 4 is a front view showing a schematic configuration of the rolling mill 21. Referring to FIG. 4, the rolling mill 21 is arranged on a pass line PL and includes an upper grooved roll 211 and a lower grooved roll 212. The upper grooved roll 211 and the lower grooved roll 212 are arranged above and below in the vertical direction, with the pass line PL sandwiched therebetween. The upper grooved roll 211 and the lower grooved roll 212 are rolling rolls that are asymmetrical in the vertical direction. In the example shown in FIG. 4, the upper grooved roll 211 has a convex shape, and the lower grooved roll 212 has a concave shape that corresponds to the convex shape of the upper grooved roll 211.

[0044] The pass line PL is the center line of the conveying path through which the hat-shaped steel sheet pile 10, which is the material to be rolled, passes, and is a straight line substantially parallel to a horizontal plane. In other words, the pass line PL is a straight line substantially intersecting the vertical direction perpendicularly. When the hat-shaped steel sheet pile 10 is rolled using the rolling mill 21, the pass line PL becomes substantially parallel to the longitudinal direction of the hat-shaped steel sheet pile 10. When viewed along the pass line PL, the horizontal direction perpendicular to the pass line PL is called the width direction of the pass line PL. When the hat-shaped steel sheet pile 10 is rolled using the rolling mill 21, the width direction of the pass line PL substantially coincides with the width direction of the hat-shaped steel sheet pile 10. In this case, the height direction of the hat-shaped steel sheet pile 10 substantially coincides with the vertical direction.

[0045] Fig. 5 is a top view of the manufacturing apparatus 20. Referring to Fig. 5, a pair of tools 22 are arranged at an outlet side of the rolling mill 21, spaced apart in the width direction of the pass line PL so as to sandwich the pass line PL therebetween. The outlet side of the rolling mill 21 is the outlet side of the hat-shaped steel sheet pile 10 in the rolling mill 21. The pair of tools 22 are provided so that their positions in the width direction can be changed. The positions of the pair of tools 22 in the width direction can be changed independently of each other. That is, the pair of tools 22 are installed so that the interval and center position thereof in the width direction can be freely changed.

[0046] The pair of tools 22 may come into contact with the side of the hat-shaped steel sheet pile 10 during rolling. When the hat-shaped steel sheet pile 10 comes into contact with the tools 22 during rolling, the hat-shaped steel sheet pile 10 receives a pressing force from the tools 22. As a result, the pair of tools 22 press the hat-shaped steel sheet pile 10 from the outside in the width direction of the pass line PL. Therefore, the pair of tools 22 may have any shape as long as they can press the hat-shaped steel sheet pile 10 from the outside in the width direction of the pass line PL. For example, they may be plate-shaped. However, as in this embodiment, the pair of tools 22 are preferably cylindrical with a central axis X extending in the vertical direction. Furthermore, the pair of tools 22 are more preferably driven rollers that are supported at the central axis X and are rotatable around the central axis X. A driven roller is a non-driven roller.

[0047] Next, a method for correcting the opening width of the joints 14A, 14B in the hat-shaped steel sheet pile 10 according to this embodiment and a manufacturing method for the hat-shaped steel sheet pile 10 will be described with reference to FIGS.

[0048] [Manufacturing method] The manufacturing method according to the present embodiment manufactures the hat-shaped steel sheet pile 10. The manufacturing method for the hat-shaped steel sheet pile 10 includes a preparation step, a rolling step, a straightening step, and a shaping step.

[0049] (preparation process) In the preparation step, a material to be the hat-shaped steel sheet pile 10 is prepared. The material is an intermediate material to be subjected to finish rolling by a rolling mill 21. This intermediate material has a shape that is roughly similar to the shape of the hat-shaped steel sheet pile 10. The intermediate material is manufactured by rough rolling and intermediate rolling in a hot state.

[0050] (Rolling process) Referring to FIG. 3, in the rolling process, a material is passed through a rolling mill 21 equipped with an upper perforated roll 211 and a lower perforated roll 212 (FIG. 4) to perform finish rolling, thereby manufacturing a hat-type steel sheet pile 10. Further, referring also to FIG. 2, in the rolling process, when the hat-type steel sheet pile 10 immediately after passing through the rolling mill 21 is viewed along the pass line PL, finish rolling is performed so that both of the arms 13A and 13B extend at an inclination to the same side with respect to the horizontal line HL. In this embodiment, as shown in FIG. 2, in the hat-type steel sheet pile 10 after finish rolling, both of the arms 13A and 13B extend at an inclination downward in the vertical direction with respect to the horizontal line HL. The angles formed by each of the arms 13A and 13B and the horizontal line HL are about 1 to 2 degrees. The inclination direction of the arms 13A and 13B can be affected by, for example, the difference in peripheral speed between the upper perforated roll 211 and the lower perforated roll 212, the difference in temperature and friction coefficient between the front and back of the material to be rolled, and the like. However, in the production of actual products, even if the manufacturing conditions in a single manufacturing facility fluctuate slightly, the direction of the inclination is thought to remain unchanged.

[0051] (straightening process) 5, in the straightening process, when finish rolling is being performed, a pair of tools 22 is used to press the hat-shaped steel sheet pile 10 immediately after passing through the rolling mill 21 from the outer side in the width direction to straighten the widths of the openings 141A, 141B of the joints 14A, 14B. The outer side in the width direction means the side opposite to the web 11 with respect to the joints 14A, 14B in the width direction of the hat-shaped steel sheet pile 10.

[0052] In the straightening process, the hat-shaped steel sheet pile 10 immediately after passing through the rolling mill 21 is pressed from the outside in the width direction, so the distance between the pair of tools 22 is set to be shorter than the length in the width direction of the hat-shaped steel sheet pile 10. In other words, the distance (interval) between the pair of tools 22 is narrower than the overall width of the hat-shaped steel sheet pile 10.

[0053] Fig. 6 shows how the joints 14A, 14B of the hat-shaped steel sheet pile 10 are pressed by a pair of tools 22. Fig. 6 is a cross-sectional view taken along line VI-VI in Fig. 5. In the straightening process, as described above, the hat-shaped steel sheet pile 10, in which both arms 13A, 13B are inclined to the same side in the vertical direction with respect to the horizontal plane, is pressed from the outside in the width direction by the pair of tools 22.

[0054] In the straightening process, the width W of the opening 141B of one joint 14B of the pair of joints 14A, 14B is straightened. Specifically, of the pair of joints 14A, 14B, the width of the opening 141B of the joint 14B having the opening 141B facing the side opposite to the inclined side of the arms 13A, 13B with respect to the horizontal line HL when the hat-shaped steel sheet pile 10 is viewed along the pass line PL is straightened.

[0055] In this embodiment, the opening 141B of the pair of openings 141A, 141B of the pair of joints 14A, 14B is corrected because the arms 13A, 13B are inclined with respect to the horizontal line HL. As shown in FIG. 6 , the joint 14B having the opening 141B is pressed by the tool 22. At this time, the tool 22 contacts the end 142B of the joint 14B on the vertical opening side, and a pressing force acts on this end 142B. Therefore, in the joint 14B having the opening 141B, the end 143B on the opposite side from the vertical opening serves as a fulcrum, and the end 142B in contact with the tool 22 is pushed inward. This allows the width W of the opening 141B to be corrected to be narrower.

[0056] In contrast, in the other joint 14A, the tool 22 does not contact the end 142A on the vertical opening side, but contacts the end 143A on the opposite side from the vertical opening. Therefore, the width of the opening 141A of the joint 14A is not narrowed. In this manner, in this embodiment, the width W of the opening 141B of one joint 14B is selectively corrected.

[0057] When the hat-shaped steel sheet pile 10, whose arms 13A and 13B are inclined with respect to the horizontal line HL, is pressed from the outside in the width direction, the inclined arms 13A and 13B are expected to be inclined more greatly by the pressing of the pair of tools 22. Therefore, even if the inclination of the arms 13A and 13B of the hat-shaped steel sheet pile 10 is gentle with respect to the horizontal line HL before being pressed from the outside in the width direction, in the straightening process, in the joint 14B having the opening 141B, the end 142B on the opening side in the vertical direction of the joint 14B is pressed, and in the joint 14A, the end 143A on the opposite side to the opening in the vertical direction of the joint 14A is pressed.

[0058] In the straightening process, the hat-shaped steel sheet pile 10 is pressed from the outside in the width direction by the tools 22 so that the pressing force of one of the tools 22 is greater than the pressing force of the other tool 22, and further, the bending in the width direction of the hat-shaped steel sheet pile 10 can be straightened. For example, when the hat-shaped steel sheet pile 10 has a bending on the left side in the width direction with respect to the traveling direction along the pass line PL, the hat-shaped steel sheet pile 10 is pressed from the outside in the width direction by the tools 22 so that the pressing force of the left tool 22 is greater than the pressing force of the right tool 22, thereby straightening the bending of the hat-shaped steel sheet pile 10. Specifically, the center positions of the tools 22 are arranged to the right of the center in the width direction of the web 11 with respect to the traveling direction of the hat-shaped steel sheet pile 10, thereby generating a difference in pressing force and straightening the left bending of the hat-shaped steel sheet pile 10.

[0059] In the straightening process, the hat-shaped steel sheet pile 10 is restrained by a pair of tools 22. The hat-shaped steel sheet pile 10 is also restrained by an upper perforated roll 211 and a lower perforated roll 212 of the rolling mill 21 during finish rolling except just before the rolling of the hat-shaped steel sheet pile 10 is completed. In the straightening process, it is preferable that the hat-shaped steel sheet pile 10 immediately after passing through the rolling mill 21 is not restrained by any member other than the tool 22 at the installation position of the tool 22.

[0060] (Forming process) In the shaping process, the overall shape of the hat-shaped steel sheet pile 10 is shaped. In the shaping process, for example, a known roller straightener can be used. In this embodiment, as described above, the arms 13A and 13B are inclined in the straightening process after finish rolling. Therefore, if the inclination of the arms 13A and 13B remains until just before the shaping process, the inclination is straightened in the shaping process. Alternatively, if necessary, shape defects such as bending, warping, or twisting of the hat-shaped steel sheet pile 10 may be straightened. The shaping process is performed after the hat-shaped steel sheet pile 10 after the straightening process is cut to the length of the final product. In the shaping process, the hat-shaped steel sheet pile 10 is shaped into the shape of the final product.

[0061] The manufacturing method according to this embodiment further includes a first measuring step, a second measuring step, and a setting step. In this embodiment, the first measuring step and the second measuring step are performed after the shaping step.

[0062] (First measurement process) In the first measurement step, for the hat-shaped steel sheet pile 10 manufactured in the rolling step, when the hat-shaped steel sheet pile 10 is viewed along the pass line PL, the width W of the opening 141B is measured at the joint 14B having the opening 141B facing the opposite side of the inclined sides of the arms 13A, 13B with respect to the horizontal line HL. In this embodiment, since the first measurement step is performed after the shaping step, the inclination of the arms 13A, 13B of the hat-shaped steel sheet pile 10 is corrected at the time of the first measurement step. In this case, the opening to be measured is determined from the shape of the hat-shaped steel sheet pile 10 before the shaping step. That is, in the first measurement step, the width W of the opening 141B corrected in the previous correction step is measured. The measurement is performed using, for example, a vernier caliper. The width W of the opening 141B is the shortest distance between the inner part 141a in the width direction and the outer part 141b in the width direction of the joint 14B constituting the opening 141B. The width W of the opening 141B is measured at a plurality of points in the longitudinal direction of the hat-shaped steel sheet pile 10.

[0063] (Second measurement process) In the second measurement step, the bending of the hat-shaped steel sheet pile 10 measured in the first measurement step is measured in the width direction. The bending of the hat-shaped steel sheet pile 10 is evaluated, for example, by the deviation of the position of the hat-shaped steel sheet pile 10 in the width direction from a line connecting the front and rear ends of the hat-shaped steel sheet pile 10 in the longitudinal direction. Specifically, at one of both side parts of the hat-shaped steel sheet pile 10, a vertical line is stretched between the ends of the joints 14A or 14B located at the front and rear ends of the hat-shaped steel sheet pile 10, respectively, and the distance in the width direction between the side part and the vertical line is measured. The maximum distance is the bending amount of the hat-shaped steel sheet pile 10. When the vertical line does not overlap with the side part and there is a gap between the vertical line and the side part when viewing the hat-shaped steel sheet pile 10 from above, the hat-shaped steel sheet pile 10 is bent convexly toward the opposite side from the side part with respect to the center line. On the other hand, when the level string overlaps with the side portion, the hat-shaped steel sheet pile 10 is bent convexly toward the side portion with respect to the center line.

[0064] (Setting process) In the setting process, the position of each tool 22 in the width direction of the pass line can be set. The setting process is performed after measurements in the first measurement process and the second measurement process. In the setting process, if the width measured in the first measurement process exceeds a first predetermined range, the spacing between the tools 22 is changed to set the position of the tool 22, and if the width measured in the first measurement process is within the first predetermined range, the position of the tool 22 is set without changing the spacing between the tools 22. The first predetermined range is a range that satisfies a predetermined standard for the width W of the opening 141B.

[0065] In the straightening process, the magnitude of the force with which the tools 22 press the hat-shaped steel sheet pile 10 from both sides in the width direction changes by changing the distance between the tools 22. Therefore, by changing the distance between the tools 22, the magnitude of the pressing force of the tools 22 can be controlled and the amount of straightening of the width W of the opening 141B of the joint 14B can be adjusted. For example, by reducing the distance between the tools 22, the amount of straightening of the width W of the opening 141B of the joint 14B can be increased.

[0066] In the setting step, if the curvature measured in the second measurement step exceeds a second predetermined range, the center position between the tools 22 is changed to set the position of the tools 22, and if the curvature measured in the second measurement step is within the second predetermined range, the position of the tools 22 is set without changing the center position between the tools 22. The second predetermined range is the tolerance range of the curvature of the hat-shaped steel sheet pile 10. The tolerance range of the curvature of the hat-shaped steel sheet pile 10 is determined in accordance with JIS A 5523:2021.

[0067] In the straightening process, the balance of the magnitude of the force with which the tools 22 press the hat-shaped steel sheet pile 10 from both sides in the width direction is changed by changing the center position between the tools 22. Therefore, by changing the center position between the tools 22, the difference in the pressing force between one tool 22 and the other tool 22 can be controlled, and the amount of straightening of the bow in the width direction can be adjusted. For example, if the center position between the tools 22 is located to the right of the center of the width direction of the web 11, the amount of straightening of the left bow of the hat-shaped steel sheet pile 10 can be increased by placing the center position between the tools 22 further to the right of the center of the width direction of the web 11.

[0068] [effect] In the straightening step of the manufacturing method according to this embodiment, the joints 14A, 14B of the hat-type steel sheet pile 10 are bent by finish rolling, and the opening width W of the joint 14B is straightened immediately after the finish rolling. That is, while the finish rolling is being performed, the opening width W of the joint 14B is straightened online by a pair of tools 22 arranged on the outlet side of the finish rolling mill 21. Therefore, according to this embodiment, the width W of the opening 141B of the joint 14B can be straightened in the rolling step of the hat-type steel sheet pile 10, and the production efficiency of the hat-type steel sheet pile 10 can be improved.

[0069] The tools 22 that press the hat-shaped steel sheet pile 10 are cylindrical with a central axis X extending in the vertical direction. Therefore, the structure for supporting the tools 22 is relatively simple, and it is easy to adjust the position of the tools 22. For example, an eccentric support structure can be used as the support structure for the tools 22, and in this case, it is possible to easily adjust the distance (opening) between the tools 22.

[0070] Moreover, the cylindrical tool 22 having the central axis X extending in the vertical direction has an outer peripheral surface extending in the vertical direction, which presses the hat-shaped steel sheet pile 10. Therefore, for example, even if the hat-shaped steel sheet pile 10 warps in the vertical direction and moves in the vertical direction, the hat-shaped steel sheet pile 10 can continue to be pressed by the tool 22.

[0071] The cylindrical tool 22 is a driven roller rotatable around the central axis X. Therefore, the roller can freely rotate following the movement of the hat-shaped steel sheet pile 10 in the rolling direction. Therefore, according to this embodiment, the material passing speed of the hat-shaped steel sheet pile 10 and the peripheral speed of the roller tend to match, so that the occurrence of scratches on the hat-shaped steel sheet pile 10 due to sliding between the hat-shaped steel sheet pile 10 and the roller can be suppressed. However, the tool 22 may be a driven roller.

[0072] In the present embodiment, the pressing force of one of the pair of tools 22 is greater than the pressing force of the other tool 22. Therefore, in the correction process, the correction of the width W of the opening 141B of the joint 14B and the correction of the bending in the width direction of the hat-shaped steel sheet pile 10 can be performed simultaneously.

[0073] In this embodiment, the width W of the opening 141B straightened in the previous straightening process is measured. Furthermore, the widthwise position of the tool 22 that presses the hat-shaped steel sheet pile 10 is set according to the value of the measured width W of the opening 141B. As a result, when a hat-shaped steel sheet pile next to the measured hat-shaped steel sheet pile 10 is manufactured, the widthwise position of the tool 22 in the straightening process can be determined based on information about the measured hat-shaped steel sheet pile 10. Therefore, the straightening effect in the straightening process when the next hat-shaped steel sheet pile is manufactured can be improved.

[0074] In this embodiment, in addition to measuring the width W of the opening 141B, the bending of the hat-shaped steel sheet pile 10 in the width direction is also measured. Furthermore, the position of the tool 22 in the width direction for pressing the hat-shaped steel sheet pile 10 is set according to the measured bending. Therefore, when a hat-shaped steel sheet pile next to the measured hat-shaped steel sheet pile 10 is manufactured, the position of the tool 22 in the width direction in the straightening process can be determined based on information on the opening width and bending of the measured hat-shaped steel sheet pile 10. Therefore, the straightening effect of the opening width in the straightening process when the next hat-shaped steel sheet pile is manufactured can be improved, and the straightening effect of the bending can also be improved.

[0075] In addition, in the present embodiment, when the hat-shaped steel sheet pile 10 is manufactured first, the position of the tool 22 in the straightening process may be set with reference to the shape of a hat-shaped steel sheet pile manufactured without using the manufacturing method of the present embodiment. That is, the opening width and bending of the joint of the hat-shaped steel sheet pile manufactured without using the straightening method of the present embodiment are measured in advance, and the position of the tool 22 in the width direction in the straightening process when the hat-shaped steel sheet pile 10 is manufactured first can be set based on the results.

[0076] Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments, and various modifications are possible without departing from the spirit of the present disclosure.

[0077] In the above embodiment, the arms 13A, 13B of the hat-shaped steel sheet pile 10 are inclined downward in the vertical direction with respect to the horizontal line HL in the straightening process. However, the arms 13A, 13B of the hat-shaped steel sheet pile 10 may be inclined upward in the vertical direction with respect to the horizontal line HL in the straightening process. In this case, the opening to be straightened is the opening 141A of the joint 14A. [Example]

[0078] The present disclosure will be described in more detail below with reference to examples, although the present disclosure is not limited to the following examples.

[0079] In order to confirm the effects of the present disclosure, hat-shaped steel sheet piles were manufactured using the straightening method of the present disclosure (Example) and not using the method (Comparative Example). That is, in the Example, the hat-shaped steel sheet pile was manufactured by pressing the hat-shaped steel sheet pile immediately after passing through the rolling mill from the outside in the width direction with a pair of tools during finish rolling. At that time, the distance between the pair of tools was set to -5 mm with respect to the total width of the hat-shaped steel sheet pile. In contrast, in the Comparative Example, the hat-shaped steel sheet pile was manufactured without pressing the hat-shaped steel sheet pile immediately after passing through the rolling mill from the outside in the width direction during finish rolling. In the Example and the Comparative Example, the hat-shaped steel sheet piles were manufactured under the same conditions except that the hat-shaped steel sheet pile was pressed with the tools.

[0080] In the hat-shaped steel sheet piles manufactured using each method, the opening width of the joint on the side to be straightened was measured at multiple locations in the longitudinal direction. Figure 7 shows the measurement results. The horizontal axis of Figure 7 indicates the position from the leading end (TOP) to the trailing end (BOT) in the longitudinal direction of the hat-shaped steel sheet pile, and the vertical axis of Figure 7 indicates the opening width of the measured joint. Referring to Figure 7, in the comparative example, the opening width near the TOP and BOT in the longitudinal direction was increased compared to the opening width at the center in the longitudinal direction. On the other hand, in the example, no significant increase in the opening width was observed from the TOP to the BOT in the longitudinal direction.

[0081] As described above, it has become clear that by manufacturing a hat-shaped steel sheet pile using the correction method of the present disclosure, it is possible to suppress an increase in the opening width over the entire longitudinal length of the hat-shaped steel sheet pile. [Explanation of symbols]

[0082] 10: Hat-shaped steel sheet pile 11:Web 12A, 12B: Flange 13A, 13B: Arms 14A, 14B: Joint 141A, 141B: Opening 20: Manufacturing equipment 21: Rolling mill 211: Upper hole type roll 212: Lower hole type roll 22: Tools

Claims

1. A method for correcting the opening width of a joint in a hat-shaped steel sheet pile, a rolling process in which a material is passed through a rolling mill equipped with upper grooved rolls and lower grooved rolls to perform finish rolling, wherein the finish rolling is performed so that both arms of the hat-shaped steel sheet pile extend obliquely to the same side with respect to a horizontal line when the hat-shaped steel sheet pile immediately after passing through the rolling mill is viewed along a pass line; a correction step of correcting a width of an opening of a joint of the hat-shaped steel sheet pile by pressing the hat-shaped steel sheet pile immediately after passing through the rolling mill from the outside in the width direction using a pair of tools arranged at an outlet side of the rolling mill and spaced apart in a width direction of the pass line so as to sandwich the pass line therebetween, while the finish rolling is being performed; A correction method comprising:

2. The correction method according to claim 1, A straightening method, wherein the tool is cylindrical and has a central axis extending in the vertical direction.

3. The correction method according to claim 2, The straightening method, wherein the tool is a driven roller that is supported by the central shaft and is rotatable around the central shaft.

4. A manufacturing method of a hat-shaped steel sheet pile, a preparation step of preparing a material to be the hat-shaped steel sheet pile; a rolling process for manufacturing the hat-shaped steel sheet pile by passing the material through a rolling mill equipped with upper-diameter rolls and lower-diameter rolls to perform finish rolling, wherein the finish rolling is performed so that both arms of the hat-shaped steel sheet pile extend obliquely to the same side with respect to a horizontal line when the hat-shaped steel sheet pile immediately after passing through the rolling mill is viewed along a pass line; a correction step of correcting a width of an opening of a joint of the hat-shaped steel sheet pile by pressing the hat-shaped steel sheet pile immediately after passing through the rolling mill from the outside in the width direction using a pair of tools arranged at an outlet side of the rolling mill and spaced apart in a width direction of the pass line so as to sandwich the pass line therebetween, while the finish rolling is being performed; a shaping step of shaping the overall shape of the hat-shaped steel sheet pile; A manufacturing method comprising:

5. The manufacturing method according to claim 4, further comprising: a first measuring step of measuring a width of the opening of the joint having the opening facing a side opposite to the inclined side of the arm with respect to the horizontal line when the hat-shaped steel sheet pile manufactured in the rolling step is viewed along the pass line; a setting step of setting positions of the pass lines of the respective tools in the width direction after measurement in the first measuring step; Equipped with In the setting process, if the width measured in the first measurement process exceeds a first predetermined range, the spacing between the tools is changed to set the position of the tools, and if the width measured in the first measurement process is within the first predetermined range, the position of the tools is set without changing the spacing.

6. The manufacturing method according to claim 5, In the straightening step, the hat-shaped steel sheet pile is pressed from the outside in the width direction by the tools so that the pressing force of one of the tools is greater than the pressing force of the other tool, thereby further straightening the bending in the width direction of the hat-shaped steel sheet pile.

7. The manufacturing method according to claim 6, further comprising: A second measuring step of measuring a bending of the hat-shaped steel sheet pile in the width direction for the hat-shaped steel sheet pile measured in the first measuring step, The setting step further comprises changing the center position between the tools to set the position of the tool when the curvature measured in the second measurement step exceeds a second predetermined range, and setting the position of the tool without changing the center position when the curvature measured in the second measurement step is within the second predetermined range.

8. A manufacturing device for hat-type steel sheet piles, a rolling mill disposed on the pass line and including upper grooved rolls and lower grooved rolls; a pair of cylindrical tools each having a central axis extending in a vertical direction, the cylindrical tools being arranged at an outlet side of the rolling mill and spaced apart in a width direction of the pass line so as to sandwich the pass line therebetween; Equipped with The manufacturing apparatus, wherein the tool is a driven roller that supports the central axis and is rotatable around the central axis.

9. The manufacturing apparatus according to claim 8, The manufacturing device, wherein the tool is provided so that its position in the width direction can be changed.

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