Straightening device and method for steel sheet piles, and method for manufacturing steel sheet piles

Abstract

A technique for simultaneously correcting warping and width-direction deformation of sheet piles is provided. The correction device, used to correct sheet piles having joints at both ends in the width direction, comprises: a roller correction section in which multiple upper rollers and multiple lower rollers are alternately arranged; and a pair of vertical rollers positioned downstream of the sheet pile in the transport direction, the separation distance between the pair of vertical rollers being set narrower than the total width of the sheet pile. A method for manufacturing sheet piles involves using the correction device with the roller correction section and vertical rollers, and after correction by the roller correction section, applying pressure towards the central joint head in the width direction of the sheet pile using the pair of vertical rollers as a correction step.

Description

Technical Field

[0001] The present invention relates to a straightening device, a straightening method, and a manufacturing method for such sheet piles, wherein the sheet piles are generally U-shaped sheet piles having a web portion, flange portions on both sides thereon, and joint portions at both ends outside the flange portions; and cap-shaped sheet piles having an arm portion between the flange portion and the joint portion, etc., which are sheet piles having joint portions at both ends in the width direction. Background Technology

[0002] Due to the increasing scale of civil engineering and the development of new construction methods, steel sheet piles with various cross-sectional shapes have been developed. They are roughly divided into U-shaped steel sheet piles with joints directly set at both ends in the width direction of the flange and cap-shaped steel sheet piles with arms set between the flange and the joint. Figure 3 This is a diagram showing the cross-sectional shape of the U-shaped steel sheet pile 110. Figure 4 This is a diagram showing the cross-sectional shape of the cap-shaped sheet pile 120. The distance between the outer edges of the left and right joints 104 is called the total width W.

[0003] As a method for manufacturing the aforementioned sheet piles, a caliber roll is generally used to shape continuously cast sheets or steel sheets adjusted to a suitable size and shape into the target shape and then hot-rolled. It is known that U-shaped and cap-shaped sheet piles, after this rolling process and cooling, deform in the length (transport) direction due to the difference in rolling end temperature caused by the thickness difference between the flange portion 102 and the web portion 101. Specifically, for example, deformation occurs as follows: Figure 5 The cap-shaped sheet pile 120 shown exhibits a deformation known as upward warping, where the web portion 101 is the inner side, resulting in a shape resembling... Figure 6 The hat-shaped sheet pile 120 shown has a bending deformation, known as downward warping, with the arm 103 side as the inner side.

[0004] To remove such warping and obtain a straight product, a cold straightening process is generally performed before the product leaves the factory. For example, in the roller straightening method, rollers are used to constrain the upper and lower parts of the web portion 101 of the sheet pile that has warped, and forces are applied alternately from top to bottom to the extent that the sheet pile undergoes local plastic deformation, thereby bending and returning to its original position to eliminate the warping.

[0005] Figure 7 The general configuration of rollers 2 and 3 of the straightening device 21 in the roller straightening method is shown. In the through-plate direction F of the sheet pile 100, the upper roller 2 on the upper side of the web portion 101 and the lower roller 3 on the lower side of the web portion 101 are arranged alternately.

[0006] Moreover, the lowermost end of the outer periphery of each of the upper and lower rollers 2 and 3 is lower than the uppermost end of the outer periphery of each of the lower rollers 3, so that the sheet pile 100 passes through the through-plate path (through line P) which has alternating concave and convex shapes in the vertical direction.

[0007] As a result, the sheet pile 100 is supported at three points between the upper roller 2 and the lower roller 3, and is alternately subjected to bending and return from the upper and lower directions, thereby eliminating warping.

[0008] For example, in Patent Document 1, the method for correcting a cap-shaped sheet pile involves setting the width-direction spacing between the side rollers to gradually decrease from the upstream side to the downstream side of the through-plate path. Then, the web portion, two flange portions, and two arm portions are clamped between the roller surfaces of the upper and lower rollers, and the cap-shaped sheet pile is passed through the through-plate path by clamping the two joint portions from the outside in the width direction on the roller surfaces of the side rollers. This alternating and repeated bending and retraction of the web portion, two flange portions, and two arm portions in the up-and-down direction corrects the warping of the cap-shaped sheet pile and reduces the overall width of the cap-shaped sheet pile.

[0009] In addition, Patent Document 2 discloses a technique for straightening the shape of H-beams. The roller straightening machine includes a horizontal roller and straightens the bending by pressing down the web of the H-beam. It has a vertical roller that presses down the two sides of the flange of the H-beam and a device that generates a pressing force through the vertical roller in the height direction of the web. The horizontal roller and the vertical roller are offset in the axial direction of the horizontal roller in such a way that the bending stress caused by the pressing down of the web and the compressive stress caused by the vertical roller are loaded on the web cross section. By applying a strong axial bending of the H-beam simultaneously with the bending up and down, the shape of the H-beam is straightened.

[0010] Existing technical documents Patent documents Patent Document 1: Japanese Patent Application Publication No. 2017-131899 Patent Document 2: Japanese Patent Application Publication No. 08-174071 Summary of the Invention

[0011] The problem that the invention aims to solve However, the aforementioned prior art has the following unresolved problems.

[0012] The technology disclosed in Patent Document 1 is a correction technique for cap-shaped sheet piles and cannot be applied to U-shaped sheet piles. Furthermore, there is a problem that changing the width spacing between the side rollers and the tilt angle of the side rollers requires time.

[0013] Furthermore, the technology disclosed in Patent Document 2 pertains to the straightening of H-beams and cannot be applied to U-shaped sheet piles or cap-shaped sheet piles. That is, due to the significant increase in the number of vertical rollers pressing down on both sides of the flange, the equipment investment cost is enormous, and it is difficult to predict the appropriate conditions for the sheet piles.

[0014] This invention was made in view of the above-mentioned problems, and its object is to provide a technology applicable to sheet piles, U-shaped sheet piles, and cap-shaped sheet piles with joints at both ends in the width direction, which allows for easy modification of the set width and simultaneous correction of warping and deformation in the width direction of the sheet piles by changing the set value of each product at the same manufacturing time. Furthermore, it provides a maintainable, cost-effective, and efficient correction technology.

[0015] Methods for solving problems The sheet pile straightening device of the present invention, developed to solve the above-mentioned problems and achieve the above-mentioned objectives, is characterized in that it is a device for straightening sheet piles having joints at both ends in the width direction, and includes: a roller straightening section, wherein a plurality of upper rollers and a plurality of lower rollers are arranged alternately; and a pair of vertical rollers, which are arranged downstream of the sheet pile in the transport direction, further than the roller straightening section, and the separation distance between the pair of vertical rollers is set to be narrower than the total width of the sheet pile product.

[0016] It should be noted that, regarding the straightening device for sheet piles involved in this invention, the following are considered to be more preferred solutions: a. The aforementioned roller straightening part has a mating head straightening part, which applies pressure to the aforementioned joint at at least one of the aforementioned plurality of lower rollers or at least one of the aforementioned plurality of upper rollers to straighten the total width of the aforementioned steel sheet pile product, and the separation distance of the aforementioned mating head straightening part is wider than the aforementioned separation distance of the aforementioned pair of vertical rollers. b. The aforementioned pair of vertical rollers are composed of longitudinally placed flat rollers; c. The aforementioned separation distance between the pair of vertical rollers is configured to be adjustable according to the total width of the aforementioned sheet pile product; d. The separation distance WL of the aforementioned pair of vertical rollers and the total width W of the aforementioned sheet pile product satisfy the following formula (1). 0.70≤WL / W≤0.98 ···(1).

[0017] The steel sheet pile straightening method of the present invention, developed in order to solve the above-mentioned problems and achieve the above-mentioned objectives, is characterized in that, using any of the above-mentioned steel sheet pile straightening devices, after the steel sheet pile with joints at both ends in the width direction is straightened by the aforementioned roller straightening part, the aforementioned pair of vertical rollers are used to apply pressure to the aforementioned joints toward the center in the width direction of the aforementioned steel sheet pile.

[0018] The steel sheet pile manufacturing method of the present invention, developed in order to solve the above-mentioned problems and achieve the above-mentioned objectives, is characterized by having a straightening process for the steel sheet pile using the above-mentioned straightening method.

[0019] The effects of the invention According to the present invention, the difference between the product ends and the total width in the product length direction of U-shaped sheet piles and cap-shaped sheet piles with joints at both ends in the width direction can be corrected to be smaller than before correction. Furthermore, the number of vertical rollers can be significantly reduced, resulting in excellent maintainability and cost-effectiveness, and the vertical rollers can be adjusted efficiently. Attached Figure Description

[0020] Figure 1 This is a schematic diagram showing the roller configuration of a straightening device for sheet piles according to one embodiment of the present invention, (a) showing a side schematic view and (b) showing a top view.

[0021] Figure 2 The graph shows the results of investigating the total width in the length direction before and after straightening the sheet pile using the straightening device of the above embodiment. (a) shows the case without using vertical rollers, and (b) shows the case of pressing down using vertical rollers.

[0022] Figure 3 This is a cross-sectional view showing an example of a U-shaped sheet pile that is the object of correction according to the present invention.

[0023] Figure 4 This is a cross-sectional view showing an example of a cap-shaped sheet pile that is the object of correction according to the present invention.

[0024] Figure 5 This is a schematic diagram illustrating the upward curve of a cap-shaped sheet pile.

[0025] Figure 6 This is a schematic diagram illustrating the downward warping of a cap-shaped sheet pile.

[0026] Figure 7 These are schematic diagrams illustrating the general configuration of rollers in conventional roller straightening methods. (a) shows a schematic side view, and (b) shows a top view.

[0027] Figure 8 (a) is a schematic diagram showing the shape of the roller in the roller straightening section, and (b) is a schematic diagram showing the cap-shaped steel sheet pile as the straightening material.

[0028] Figure 9 This is a graph showing the results of an investigation into the total width in the length direction before and after correction, under conventional correction conditions without the use of vertical rollers. Detailed Implementation

[0029] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. It should be noted that in this embodiment, the shape of the sheet pile is described with the web portion located above the flange portion (so-called inverted U-shape), but of course, the application scope of the present invention also includes other shapes (e.g., U-shape).

[0030] The inventors of this application used a 10H cap-shaped steel sheet pile (with a cross-sectional moment of approximately 10,000 × 10⁻⁶ per 1m wall width) in roller straightening. -8 m 4 A detailed investigation was conducted into the dimensional variation of the total width W of the product ( / m).

[0031] Figure 7 This is a schematic diagram showing the roller configuration of a conventional roller straightening device 21 used for the investigation. In the roller straightening device 21, a total of nine sets of rollers 2 and 3 are arranged alternately (upper and lower) across the through-plate path (through line) P. The upper roller 2 has a roller surface shaped along the convex outer surface of the sheet pile 100, and the lower roller 3 has a roller surface shaped along the concave inner surface of the sheet pile 100.

[0032] Figure 8 (a) is a schematic diagram showing the shape of the roller in the conventional roller straightening device 21. Figure 8 (b) is a schematic diagram showing the cap-shaped sheet pile 120 as the straightening material. Figure 8 (a) is a schematic diagram of the left half of the upper and lower rollers 2 and 3 as viewed from the through-plate direction F. The upper roller 2 has an upper roller sleeve 5 for pressing down the web portion 101 of the cap-shaped sheet pile 120 and an upper roller sleeve 9 for pressing down the outer arm portion 103, fitted into its upper shaft 4. The lower roller 3 has a lower roller sleeve 7 for pressing down the web portion 101 of the cap-shaped sheet pile 120 and a lower roller sleeve 10 for pressing down the outer arm portion 103, fitted into its lower shaft 6. Figure 8 In embodiment (a), the lower shaft 6 is also fitted with an outer roller 11 on the outer edge of the constraint joint portion 104. The cap-shaped sheet pile 120 is a specification 10H product with an effective width W0=900mm, an effective height H=230mm, and a web thickness t=10.8mm.

[0033] As a survey, use Figure 7 and Figure 8 The roller straightening device 21 shown was used to investigate the total width W in the length direction before and after straightening under conventional straightening conditions. The results are shown in... Figure 9 Before correction, the total width W at the center of the product's length direction is about 5mm larger than that at both ends, and the total width W at the center of the length direction is greater than the allowable value (928~942mm, indicated by double-dotted lines). In addition, the total width at the beginning and end ends is narrower than other parts, and this tendency remains even after width correction using the outer roller 11.

[0034] In the roller straightening of sheet piles 100, it is necessary to repeatedly bend back to eliminate warping and keep the total width W in the length direction of the product within the allowable range. However, there is a problem: if the set width of the outer roller 11 is too small to reduce the total width W, localized warping will occur. On the other hand, if the set width of the outer roller 11 is too wide, the constraint force in the width direction decreases, the variation in the total width in the length direction increases, or the warping correction effect cannot be improved.

[0035] This invention was made based on further research conducted on the insights gained from these surveys.

[0036] Figure 1 This is a schematic diagram showing the roller configuration of a straightening device for sheet piles according to one embodiment of the present invention. (a) shows a schematic side view, and (b) shows a top view. In this embodiment, the straightening device 20 for the sheet pile 100 is formed by a roller straightening section 1 and a vertical roller 12. Figure 1 In this example, in the roller straightening section 1, a total of nine sets of rollers 2 and 3 are arranged alternately on the upper and lower surfaces of the sheet pile 100. The vertical roller 12 is positioned at a predetermined distance from the final axis (ninth axis) of the roller straightening section 1. In this embodiment, a flat roller is used as the vertical roller. The axial distance LL between the vertical roller 12 and the final axis of the roller straightening section 1 is preferably greater than the sum of the maximum radii of each roller, and less than half the length of the sheet pile 100 being straightened.

[0037] For the 120-type sheet pile of product specification 10H, the straightening conditions of the roller straightening section 1 were fixed at the same level, and the results were investigated. Figure 2 (a) Conditions for not using vertical rollers Figure 2 (b) The total width W before and after correction under the condition that the vertical roller on one side is screwed in by 20 mm. The survey results are shown in Figure 2 Furthermore, the correction conditions of the roller straightening section 1 at this time are shown in Table 1. The pressing amount (mm) shown in Table 1 represents the upward push of the lower roller 3 relative to the straight line P of the sheet pile 100.

[0038] Table 1

[0039] Without using vertical roller 12 Figure 2 Under condition (a), before correction, the difference in total width W between the beginning and end of the product and the center is 4~10mm, but when vertical roller 12 is used... Figure 2Under condition (b), after correction, the difference in total width W between the beginning and end ends decreases to less than 1 mm. Furthermore, in particular, no deformation occurs at the joint or flange portion, resulting in a product with a good shape. In contrast, under condition (a) without the vertical roller 12, after warpage correction, the difference in total width between the beginning and end ends and the center of the product is too large, requiring correction using pressing.

[0040] The effects of the present invention can be seen from the above.

[0041] It should be noted that this embodiment shows product specification 10H for cap-shaped sheet piles, but the same effect has been confirmed for other cross-sectional dimensions (e.g., U-shaped sheet pile 2W, cap-shaped sheet pile 25H). Furthermore, when multiple vertical rollers are arranged behind the roller straightener for straightening, the same straightening effect as with a pair of vertical rollers has been confirmed, and the number of vertical rollers can be arbitrary.

[0042] In this embodiment, by setting the separation distance WL between the pair of vertical rollers 12 to be narrower than the total width W of the sheet pile 100, the total width W of the sheet pile 100 can be corrected, which is therefore preferable. Furthermore, regarding the relationship between the separation distance of the outer roller 11 of the roller correction section 1 (which serves as the joint correction section) and the separation distance WL between the pair of vertical rollers 12, in order to fully utilize the pressing effect of the vertical rollers 12, it is preferable that the separation distance of the outer roller 11 is wider than the separation distance WL between the pair of vertical rollers 12. Moreover, it is preferable that the separation distance WL between the pair of vertical rollers 12 is within the range of 0.70 to 0.98 times the total width W of the sheet pile 100. If it is less than the lower limit, dimensional deviations and material blockage between the vertical rollers 12 may occur due to localized plastic deformation of the sheet pile 100; on the other hand, if it is greater than the upper limit, the pressing effect of the total width W of the vertical rollers may not be fully utilized.

[0043] To prevent the outer edge of the joint portion 104 of the sheet pile 100 from moving up and down, the vertical rollers are preferably flat rollers. Furthermore, it is preferable that the separation distance WL between the pair of vertical rollers 12 can be adjusted according to changes in the total width W of the sheet pile 100.

[0044] The present invention relates to a method for straightening sheet piles, which is a method for straightening sheet piles using a straightening device 20 comprising a roller straightening section 1 and a vertical roller 12 as described in the above embodiment. This method uses the roller straightening section 1 to straighten the warping of sheet piles having joints at both ends in the width direction, and controls the total width W within a specified range. Then, the deviation of the total width W is reduced by pressing down the joints 104 at both ends using the vertical roller 12.

[0045] In the method for manufacturing sheet piles according to the present invention, the hot rolling process of the sheet pile 100 can be performed using conventional methods. Specifically, the following process can be used: after heating the continuously cast sheet or the steel sheet shaped to a suitable form in a heating furnace, hot rolling is performed using multi-stage die rolls. After cooling, the hot-rolled sheet pile 100 is passed through the straightening device 20 of the above embodiment and the above-described straightening method is applied.

[0046] Industrial availability This invention is preferably applied to situations where the total width needs to be controlled when straightening long steel bars that have warped due to hot rolling.

[0047] Explanation of reference numerals in the attached figures 1: Roller straightening section; 2: Upper roller; 3: Lower roller; 4: Upper shaft; 5: Upper roller sleeve (for pressing down the web); 6: Lower shank shaft; 7: Sleeve for lower roller (used for pressing down the web); 9: Upper roller sleeve (for pressing down the arm); 10: Sleeve for lower roller (for pressing down the arm); 11: Outer roller (outer constraint roller); 12: Vertical roller; 20: Corrective device; 21: Conventional roller straightening devices; 100: Steel sheet piles; 101: Web portion; 102: Flange portion; 103: Arm; 104: Joint; 110: U-shaped steel sheet piles; 120: Hat-shaped steel sheet pile; F: Through-board direction (transportation direction); P: Through the line; O: Reference position.

Claims

1. A straightening device for sheet piles, which is a device for straightening sheet piles having joints at both ends in the width direction, characterized in that, have: Roller straightening section, wherein multiple upper rollers and multiple lower rollers are arranged alternately; and A pair of vertical rollers are positioned downstream of the sheet pile in the transport direction, further than the roller straightening section. The separation distance of the pair of vertical rollers is set to be narrower than the total width of the sheet pile, so as to apply pressure to the joint by means of the pair of vertical rollers toward the center of the width direction of the sheet pile.

2. The straightening device for sheet piles as described in claim 1, characterized in that, The roller straightening section includes a joint head straightening section, which applies pressure to the joint portion at at least one of the plurality of lower rollers or at least one of the plurality of upper rollers to straighten the overall width of the sheet pile product. The separation distance of the head correction part is wider than the separation distance of the pair of vertical rollers.

3. The straightening device for sheet piles as described in claim 1, characterized in that, The pair of vertical rollers are composed of longitudinally placed flat rollers.

4. The straightening device for steel sheet piles as described in claim 2, characterized in that, The pair of vertical rollers are composed of longitudinally placed flat rollers.

5. The straightening device for sheet piles as described in any one of claims 1 to 4, characterized in that, The separation distance between the pair of vertical rollers is configured to be adjustable according to the total width of the sheet pile product.

6. The straightening device for sheet piles as described in any one of claims 1 to 4, characterized in that, The separation distance WL between the pair of vertical rollers and the total width W of the sheet pile product satisfy the following formula (1): 0.70≤WL / W≤0.98 ···(1).

7. The straightening device for sheet piles as described in claim 5, characterized in that, The separation distance WL between the pair of vertical rollers and the total width W of the sheet pile product satisfy the following formula (1): 0.70≤WL / W≤0.98 ···(1).

8. A method for correcting sheet piles, characterized in that, Using the straightening device for sheet piles according to any one of claims 1 to 7, after the sheet piles with joints at both ends in the width direction are straightened by the roller straightening unit, The joint is pressurized by the pair of vertical rollers directed toward the center of the sheet pile in the width direction.

9. A method for manufacturing steel sheet piles, characterized in that, A straightening process for sheet piles using the straightening method of claim 8.

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