JP4400280B2 - Manufacturing method of U-shaped steel sheet pile - Google Patents

Description

  The present invention is a U-shaped steel sheet pile mainly used for civil engineering, and in particular, a U-shaped steel sheet pile suitable for correcting warpage generated in a hat-type steel sheet pile having a joint support part or an arm part between a flange part and a joint part. It relates to a manufacturing method.

  Patent Document 1 and Patent Document 2 disclose a method for correcting a roller of a U-shaped steel sheet pile. The U-shaped steel sheet pile (hat-type steel arrow) 200 cooled through the rolling process is warped toward the web portion 201 as shown in FIG. 5, that is, is warped upward, or as shown in FIG. It warps to 202 side, that is, it warps downward. In the roller straightening method, the U-shaped steel sheet pile that has warped in this way is bent back and forth by the upper and lower rollers alternately by applying a force that causes the U-shaped steel sheet pile to be plastically deformed, and the warpage of the U-shaped steel sheet pile is removed. ing.

Here, the upper and lower rollers used for correcting the warp are generally arranged as shown in FIG. That is, the upper roller _{301 1,} 301 _2, 301 3, 301 ₄ and the lower rollers _{302 1,} 302 _2, 302 _3, 302 4, 302 ₅ and are arranged in alternately in the sheet passing direction of the U-shaped steel sheet pile 200 and for the vertical direction, than the lower portion of the outer peripheral surface of the upper roller ₃₀₁ 1-301 _4, the upper portion of the outer peripheral surface of the lower roller ₃₀₂ 1-302 ₅ is located above. That is, the upper and lower rollers are arranged such sheet passing path zigzag between the upper roller ₃₀₁ 1-301 ₄ and the lower roller ₃₀₂ 1-302 ₅ is formed. In this way, the upper and lower rollers are arranged, the U-shaped steel sheet pile 200 is passed through the plate passage, the U-shaped steel sheet pile 200 is bent back and forth alternately, and the warp of the U-shaped steel sheet pile 200 is removed.

In the roller correction method disclosed in Patent Document 2, the web portion, the flange portion, and the joint support portion are particularly arranged so that the web portion, the flange portion, and the joint support portion (arm portion) can be restrained from the vertical direction. An upper and lower roller integrated with a portion corresponding to (arm portion) is used. This prevents the joint support 202 from being deformed by repeated bending deformation of the U-shaped steel sheet pile 200.
JP-A-55-70418 Japanese Patent Laid-Open No. 9-94614

  If the shape of the U-shaped steel sheet pile after rolling is somewhat deformed when the upper and lower rollers have a shape that can be constrained even to the joint support portion as disclosed in Patent Document 2, the warp cannot be corrected appropriately. For example, when the flange part becomes higher than the expected dimension due to the difference in shrinkage due to roller wear or cooling, the height between the web part and the joint support part (total height) is the expected dimension. If the pressure is higher than the upper roller, the lower roller is in contact with the lower end of the flange (the end of the joint support side) and pressure is applied, while the upper roller is in contact with the web and pressure is applied. As a result, the shape in the cross section tends to collapse. As a result, the shape change is accompanied for the purpose of correcting the warp of the U-shaped steel sheet pile. With this, the warp cannot be corrected appropriately.

As described above, if the U-shaped steel sheet pile is restricted as in the upper and lower rollers disclosed in Patent Document 2, when a dimensional error occurs in the U-shaped steel sheet pile, the dimensional error cannot be handled. . However, if the joint support portion is not restrained by the upper and lower rollers, the joint support portion is deformed by repeated bending deformation of the U-shaped steel sheet pile as described above.
The present invention has been made in view of the above problems, while reducing the restraint part of the U-shaped steel sheet pile by the upper and lower rollers for correction, without affecting the shape of the U-shaped steel sheet pile such as the joint support portion, It aims at providing the manufacturing method of the U-shaped steel sheet pile which can correct the curvature of a U-shaped steel sheet pile appropriately.

A method for manufacturing a U-shaped steel sheet pile according to the invention of claim 1 is a method for manufacturing a U-shaped steel sheet pile having a web portion, a flange portion, a joint portion, and a joint support portion that extends from the flange portion and supports the joint portion. By performing hot rolling to make the thickness of the web portion thicker than the thickness of the joint support portion, the temperature of the web portion is made higher than the temperature of the joint support portion at the end of hot rolling, and the heat In the cooling step after the intermediate rolling step, utilizing the difference in thermal shrinkage between the web portion and the joint support portion generated due to the temperature difference between the temperature of the web portion and the temperature of the joint support portion, The U-shaped steel sheet pile is warped toward the web portion side to be unidirectional, and the U-shaped steel sheet pile warped to the web portion side by the roller correction to the web portion in the straightening step after the cooling step. Bend back in the opposite direction, Characterized in that it corrected the serial warp.

  Moreover, the manufacturing method of the U-shaped steel sheet pile which concerns on invention of Claim 2 is a manufacturing method of the U-shaped steel sheet pile which concerns on invention of Claim 1, In the said hot rolling process, the state which becomes a reverse U character in an up-down direction The U-shaped steel sheet pile is passed through, and the U-shaped steel sheet pile is rolled while blowing cooling water from above to the joint supporting portion of the U-shaped steel sheet pile. In the hot rolling process, the cooling water blown from above the U-shaped steel sheet pile is dammed by the protruding joint portion and accumulated on the joint support portion. And

According to the present invention, after hot rolling and cooling, the U-shaped steel sheet pile is warped to the web portion side, and then the U-shaped steel sheet pile is bent in the direction opposite to the warping direction by stretching the web by correcting the roller to the web portion. Since the warp is corrected by returning, the warp of the U-shaped steel sheet pile can be corrected without giving the U-shaped steel sheet pile repeated bending deformation in the reverse direction. Thereby, a deformation | transformation of the joint support part at the time of correcting curvature can be prevented. On the other hand, since the correction of the warp can be realized only by the roller correction of the web portion, the upper and lower rollers used for the roller correction do not require the constrained portion of the joint support portion.
In addition, according to the invention described in claim 2, since the temperature difference between the temperature of the web portion and the temperature of the joint support portion can be clarified, the difference in thermal shrinkage between the web portion and the joint support portion in the cooling process is utilized. Warpage to the web part side of the U-shaped steel sheet pile can be reliably generated.

The best mode for carrying out the present invention (hereinafter referred to as an embodiment) will be described in detail with reference to the drawings.
This embodiment is applied to the rolling equipment of a U-shaped steel sheet pile having a joint support part or an arm part between the flange part and the joint part, that is, a hat-type steel sheet pile.
FIG. 1 shows an example of the configuration of the equipment. As shown in FIG. 1, the hat steel sheet pile rolling equipment includes a hot rolling mill 1, a hot sawing machine 2, a cooling floor 3, a roller straightening machine 10, and an inspection floor 4. In the hat-type steel sheet pile rolling equipment, the hot-type steel sheet pile is hot-rolled by the hot rolling mill 1, and the hot-rolled steel sheet pile is cut by the hot saw cutter 2 and then cut. The hat-type steel sheet pile is cooled by the cooling floor 3, the warpage of the cooled hat-type steel sheet pile is corrected by the roller straightening machine 10, and the corrected hat-type steel sheet pile is inspected by the inspection floor 4.

The present invention particularly relates to the hot rolling mill 1 and the roller straightening machine 10. Next, the hot rolling mill 1 and the roller straightening machine 10 will be described in detail.
Specifically, the hot rolling mill 1 performs rolling under the following conditions. Here, FIG. 2 shows the shape of the hat-type steel sheet pile 100 during hot rolling.
As shown in FIG. 1, the hot rolling mill 1 includes a rough mill 1 a, an intermediate mill 1 b, and a finishing mill 1 c in the sheet passing direction of the hat-type steel sheet pile. In the hot rolling mill 1, the hat-type steel sheet pile is rolled in an inverted U posture, that is, with the web portion 101 on the upper side and the joint support portion 103 on the lower side as shown in FIG. Moreover, when the thickness of the web part 101 is tw, the thickness of the flange part 102 is tf, and the thickness of the joint support part 103 is tb, these dimensions on the outlet side in the hot rolling mill 1 are as follows ( 1) Roll so as to satisfy the equation.
tw>tb> tf (1)

The hat-type steel sheet pile 100 rolled under such conditions in the hot rolling mill 1 is sawn to a predetermined length by the sawing devices 2a and 2b constituting the hot sawing machine 2, and then cooled. Cooled in floor 3.
Here, as described above, since the hat-type steel sheet pile is hot-rolled so as to have a size satisfying the expression (1), the temperature of the web portion 101 is Tw, the temperature of the flange portion 102 is Tf, When the temperature of the joint support part 103 is Tb, these temperatures before delivery of the hat-type steel sheet pile 100 to the exit side of the hot rolling mill 1 or the cooling floor 3 are in the relationship as shown in the following equation (2). Become.
Tw>Tb> Tf (2)

  Here, since the temperature Tw of the web part 101 is higher than the temperature Tb of the joint support part 103, this temperature difference causes the web part 101 and the joint support part in the cooling process of the hat-type steel sheet pile 100 in the cooling bed 3. A thermal contraction difference occurs between the current temperature and the current temperature. That is, in the cooling process, the web portion 101 contracts more than the joint support portion 103. Due to the difference in heat shrinkage, the hat-type steel sheet pile 100 is warped toward the web portion as shown in FIG.

  Furthermore, in the hot rolling mill 1, rolling is performed while cooling water is applied to the joint support portion of the hat-type steel sheet pile 100 from above. On the other hand, a hat-type steel sheet pile 100 is passed through the hot rolling mill 1 in an inverted U posture. Therefore, the joint 104 formed so as to protrude from the surface of the joint support portion 103 and the lower end of the flange portion 102 have a so-called bank effect, and cooling water is accumulated on the joint support portion 103. Thereby, especially the joint support part 103 is strongly cooled with cooling water. As a result, the temperature difference between the web portion 101 and the joint support portion 103 at the end of rolling becomes clear, and the hat-type steel sheet pile 100 is surely warped. In other words, for the purpose of generating an upward warp in the hat-type steel sheet pile 100, the web portion 101 and the joint support portion 103 can have a plate thickness difference in the hot rolling mill 1 to generate the temperature difference. If the cooling effect by the cooling water as described above is obtained, it is possible to generate the temperature difference while suppressing the plate thickness difference.

The final finish rolling is preferably performed after the web temperature reaches the Ar ₃ transformation temperature so that warpage deformation due to transformation expansion of the steel material does not occur during cooling.
The hat-type steel sheet pile that has been warped in this way is sent to the roller straightening machine 10 through the cooling floor 3.
The roller straightening machine 10 is configured to cold straighten the hat-type steel sheet pile 100 with a plurality of upper and lower rollers. Since the hat-type steel sheet pile carried into the roller straightening machine 10 is in the upward warping state as described above, the roller straightening machine 10 is configured to correct only the upward warping. FIG. 3 shows an example of a specific configuration of the roller straightening machine 10.

As shown in FIG. 3, the roller straightening machine 10 has an upper roller 11 ₁ , 11 ₂ , 11 ₃ , 11 ₄ and a lower side as to the arrangement in the plate passing direction, similar to the conventional one shown in FIG. roller _{12 1,} 12 _2, 12 _3, 12 4, 12 ₅ and are arranged in alternating, as upper roller ₁₁ 1 to 11 ₄ are the same height, roll position setting of the lower roller ₁₂ 1 to 12 ₅ change Possible to adjust the reduction.

In the present embodiment, the lower rollers forming the role of a repeat corrective vertically, the lower rollers 12 ₃ from the inlet side third of hat-type metal sheet pile 100 in the configuration of the present embodiment is arranged to escape downward, the upper the roller ₁₁ 1, 11 ₂ as a fulcrum, the lower roller 12 ₂ is the pressure on the upper web portion 101, but is stretched acts on the web portion 101 of the cambered lower rollers 12 ₃ continues, so that not a fulcrum Let go down. As a result, the upper rollers 11 ₂ and 11 ₃ arranged on both sides do not correct the downward warping by supporting the three points. Subsequent roller straightening, corrected for poor ones cambered, in three-point bending by the upper roller 11 _3, 11 ₄ and the lower roller 12 _4, to implement the correction of remedial purposes of cambered again, correction accuracy Can be increased.

Further, the shape of the upper and lower rollers will be described here. 4, viewed in the sheet passing direction of the hat-type metal sheet pile upper roller 21 (corresponding to the upper roller ₁₁ 1 to 11 ₄₎ and the lower rollers 22, 22, (corresponding to the lower roller ₁₂ 1 to 12 ₅₎ It is a figure. Specifically, FIG. 4 shows a state in which the lower rollers 22 and 22 have escaped in the vertical direction with respect to the arrangement of the upper rollers 21 and 21.

The upper rollers 21 and 21 have a shape capable of restraining the outer surface of the hat-type steel sheet pile 100 from the web portion 101 to the intermediate portion of the flange portion 102. The lower rollers 22 and 22 have a shape capable of restraining the inner surface of the hat-type steel sheet pile 100 from the web portion 101 to the intermediate portion of the flange portion 102. That is, the upper roller 21, 21 and the lower roller 22, 22 have a shape that allows the web portion 101 to be rolled down from the web portion 101 to the middle of the flange portion 102. Further, outer rollers (wall rollers) 23 and 23 are arranged on both sides of the lower rollers 22 and 22. The distance L between the outer rollers 23 and 23 is substantially the same as the full width (distance between joints) w of the hat-type steel sheet pile 100 (see FIG. 2). This prevents the full width w of the hat-type steel sheet pile 100 from spreading due to the force received by the lower rollers 22, 22 when correcting the upper warp of the hat-type steel sheet pile 100.
Such roller straightener 10, the upper roller ₁₁ 1 to 11 ₄ and the U-shaped steel sheet pile 100 into the sheet passing path formed between the lower roller ₁₂ 1 to 12 ₅ is passing plate, U-type metal sheet piles 100 Is bent continuously only in one direction on the lower side to correct the warp of the hat-type steel sheet pile.

Next, the effect in this embodiment is demonstrated.
As described above, by setting the thickness tw of the web portion 101 on the exit side of the hot rolling mill 1 to be larger than the thickness tb of the joint support portion 103, on the exit side of the hot rolling mill 1, The temperature Tw of 101 is set higher than the temperature Tb of the joint support portion 103. As a result, in the cooling process of the hat-type steel sheet pile 100 on the cooling floor 3, a heat shrinkage difference is generated between the web portion 101 and the joint support portion 103 due to the temperature difference, and the hat-type steel sheet pile is caused by the heat shrinkage difference. 100 is warped. Then, the U-shaped steel sheet pile 100 is bent back in the direction opposite to the warping direction by roller correction of the web portion 101 by the roller straightening machine 10 to correct the warpage. Thereby, the correction | amendment of the curvature of the U-shaped steel sheet pile 100 is implement | achieved, without giving a bending deformation to the hat-type steel sheet pile 100 repeatedly. Therefore, since the warp is corrected without repeatedly bending the hat-shaped steel sheet pile 100, it is possible to prevent the joint support portion 103 from being deformed. Further, since the correction of the warp can be realized only by the roller correction of the web portion 101, it is not necessary to provide the restraint portion of the joint support portion 103 on the upper and lower rollers 21 and 22 used for the roller correction. Even if a dimensional error occurs, the warp of the hat-type steel sheet pile 100 can be corrected appropriately.

In addition, as a method of correcting the upper warp, a method of performing the contraction of the length of the joint support portion 103 is also conceivable. However, as applied to the present invention, the method of performing the method by correcting the web portion 101 by the roller and expanding it. It is easier.
Further, if it is assumed that a difference in sheet thickness is given to the web portion 101 and the joint support portion 103 and the heat shrinkage difference due to the temperature difference after the rolling is used, the hat-type steel sheet pile is first warped downward. It is also possible to give. However, in this case, in order to correct the downward warping, the length of the web portion 101 must be changed in the longitudinal direction so as to coincide with the length of the joint support portion 103. It is necessary to compress or extend the joint support 103. However, in this case, it is difficult to compress the length of the web portion 101, and it is also difficult to correct the downward warp by extending only the length of the joint support portion 103 by roller correction. Therefore, as in the case where the present invention is applied, it is easier to perform a method in which the web portion 101 is first warped and then stretched by roller correction.

Further, as described above, the web on the outlet side of the hot rolling mill 1 is obtained by passing the hat-type steel sheet pile 100 in a reverse U posture in the hot rolling mill 1 and accumulating cooling water on the joint support portion 103. The temperature difference between the portion 101 and the joint support portion 103 can be clarified, and as a result, the hat-type steel sheet pile 100 can be surely warped.
For example, since the joint 104 protrudes from both surfaces of the joint support portion 103, the hat-type steel sheet pile 100 is passed through the U posture opposite to the reverse U posture, and cooling water is accumulated on the joint support portion 103. You can also think about it. However, if the hat-type steel sheet pile 100 is passed in the U posture, the cooling water is also accumulated in the web portion 101 by being surrounded by the flange portion 102. Thus, the web part 101 is also cooled by the cooling water, and the temperature difference between the web part 101 and the joint support part 103 cannot be clarified. For this reason, the temperature difference between the web portion 101 and the joint support portion 103 can be made clearer by passing the hat-type steel sheet pile 100 in the inverted U posture.

  Further, as shown in the equation (1), the thickness tf of the flange portion 102 is made as thin as possible. Here, when the hat-type steel sheet pile 100 is less contracted than the web portion 101 and the joint support portion 103 during the cooling process, an internal stress of compression is generated in the flange portion 102. If stress remains in the flange portion 102 in a state where the hat-type steel sheet pile 100 is warped, the residual stress facilitates the stretching of the web portion 101 of the hat-type steel sheet pile 100 by the roller straightening machine 10 to bend back. It works effectively.

Next, examples will be described.
In the examples, as shown in Table 1 below, the temperature of the web part, the flange part, and the joint support part after finish rolling is measured for the draining rolling and watering rolling with respect to the joint support part 103, and natural cooling is performed. The amount of warping after and the amount of warping after roller correction were measured.

  Here, in the embodiment, as the hat-type steel sheet pile, the web part thickness tw is 13.2 mm, the flange part thickness tf is 9.0 mm, the joint support part thickness tb is 12.4 mm, the total width w is 900 mm, and the total height. The one having h (see FIG. 2) of 312 mm was used. Further, the draining rolling is rolling performed by draining water so that water does not accumulate on the joint support portion in the hot rolling mill 1, and the flood rolling is performed on the joint supporting portion by the hot rolling mill 1. Rolling is performed by accumulating water. Moreover, after natural cooling means after cooling in the cooling floor 3.

As shown in Table 1, in both draining rolling and water rolling, warping occurred after natural cooling, and the warping could be corrected by subsequent roller correction. In addition, the temperature difference between the web part and the joint support part was 20 ° C. in the draining rolling, but the temperature difference between the web part and the joint support part can be increased up to 60 ° C. by using water rolling. did it. As a result, after water rolling, the amount of warpage after natural cooling increased, which clearly resulted in warping.
And the result which can correct | amend the curvature which generate | occur | produced in the hat-type steel sheet pile by roller correction was able to be obtained.

It is a block diagram which shows the example of a structure of the rolling equipment of embodiment of this invention. It is a figure which shows the shape of a hat-type steel sheet pile. It is a figure which shows the example of a structure of the roller straightening machine of the said rolling equipment. It is a figure which shows the shape of the up-and-down roller of the said roller straightening machine. It is a figure which shows the U-shaped steel sheet pile (hat-type steel sheet pile) of an upward curvature. It is a figure which shows the U-shaped steel sheet pile (hat-type steel sheet pile) of a downward curvature. It is a figure which shows the example of a structure of the up-and-down roller used by the conventional roller correction.

Explanation of symbols

1 hot rolling mill 2 hot sawing machine 3 cooling bed 4 test bed 10 roller straightening machine 11 ₁ to 11 _4, 21 upper roller 12 ₁ to 12 _5, 22 lower rollers 100, 200 hat-type metal sheet pile 101,201 web Part 102 flange part 103,202 joint support part 104 joint

Claims (2)

In the method of manufacturing a U-shaped steel sheet pile having a web part, a flange part, a joint part and a joint support part extending from the flange part and supporting the joint part,
By performing hot rolling to make the thickness of the web part thicker than the thickness of the joint support part, the temperature of the web part is made higher than the temperature of the joint support part at the end of hot rolling,
In the cooling step after the hot rolling step, utilizing the difference in thermal shrinkage between the web portion and the joint support portion generated due to the temperature difference between the temperature of the web portion and the temperature of the joint support portion. , Warp the U-shaped steel sheet pile to the web part side,
In the straightening step after the cooling step, the warp is corrected by bending back a U-shaped steel sheet pile warped to the web portion side in a direction opposite to the warp direction by roller straightening to the web portion. Manufacturing method of U-shaped steel sheet pile. In the hot rolling step, the U-shaped steel sheet pile is passed through in a state of being inverted U-shaped in the vertical direction, and the U-shaped steel sheet steel is blown from above with respect to the joint support portion of the U-shaped steel sheet pile. The sheet pile is rolled, and the joint has a shape protruding with respect to the surface of the joint support part,
2. The manufacturing of a U-shaped steel sheet pile according to claim 1, wherein in the hot rolling step, cooling water sprayed from above the U-shaped steel sheet pile is dammed by the protruding joint portion and collected on the joint support portion. Method.

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