JPH09182916A - Straightening method of u-shaped steel sheet pile and straightening jig - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently straighten a large bend and edge bend by pressing the outer face of flange and inner face of another flange of the steel sheet pile. SOLUTION: Because the outer face 13 of one side flange 12 of the U-shaped steel sheet pile 10 in pressed, at the same time, the inner face 15 of another flange 14 is pressed in the same direction, external force is not concentrated to one side only of the flanges 14, 16. Accordingly, a narrow product width and local deformation of dent, etc., to the flanges 14, 16 are not caused. The jig used for straightening consists of a first jig 20 to press in contact with the outer face 13 of flange 12 and a second jig 22 to press with straddling the flange 12 and in contact with the inner face of 15 of flange 14, the two jigs are appropriately connected with a connecting part 24. By imparting press force to a press ram head connecting part 30, both flange faces are pressed respectively through each jig 20, 22, thus, straightening is executed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a press straightening method for a U-shaped steel sheet pile used in, for example, civil engineering and construction, in particular, a U-shaped steel sheet pile having an arm portion between a flange portion and a joint portion (claw portion). It is about.

[0002]

2. Description of the Related Art Conventionally, a steel sheet pile manufactured by hot rolling is warped in the length direction due to internal stress as the cooling progresses after sawing, and defective shapes such as bending occur. Here, the "warp" means a large bend or an end bend in a direction at right angles to the sheet pile wall 2 of the U-shaped steel sheet pile 1 as shown in Fig. 1, and the "bend" is the U-shaped steel as shown in Fig. 2. Sheet pile wall 2 of sheet pile 1
It means a large bend and a bend in the direction parallel to. JIS
Regarding the bending of U-shaped steel sheet pile in the A 5528 standard,
For lengths of 10 m or less, total length x 0.12% or less, for lengths of 10 m or more, (total length -10 m) x 0.10% + 12 mm or less, and warp for lengths of 10 m or less The total length x 0.25% or less, and the length over 10 m is defined as (total length -10 m) x 0.20% + 25 mm or less.

The correction of such a shape defect is generally performed by a roller straightening machine, and this roller straightening machine has, for example, three rollers arranged below the four upper rollers in a zigzag pattern with the upper rollers. Therefore, the front and rear ends of the steel sheet pile cannot exhibit a sufficient straightening effect. In particular, the warp and bending defects at the front and rear ends are difficult to be corrected by the roller straightening machine, and it is common to correct only the front and rear ends by the press straightening machine after the roller straightening. FIG.
The figure shows the straightening operation by the press straightening machine when the U-shaped steel sheet pile 1 as the material to be straightened is bent.

Generally, press straightening work is performed by repeatedly pressing with a pair of right and left pressing rods or downward pressing rods of a straightening machine. When performing right and left bend correction, either the right or left rod is fixed depending on the bending direction. , The other rod presses the outer surface of the flange of the material to be straightened. At this time, on the side opposite to the pressing rod (not shown) that gives the pressing force, as shown in the figure, two jigs 6 and 8 for supporting one flange outer surface 4 of the U-shaped steel sheet pile 1 which is the material to be corrected are provided. It is common to install it at a location and restrain the movement of the material to be straightened.

However, in the case of a U-shaped steel sheet pile having a high rigidity against bending in the left-right direction among the U-shaped steel sheet piles, FIG.
And as shown in Fig. 4 (b) respectively, even if the outer surface 4 of the flange on one side is pressed by a press, the bending is not corrected, and as shown by the dotted line in Fig. 4 (a), the width of the material to be straightened is narrow. In addition to deforming the cross-sectional shape in the same direction, there was a problem that the pressed flange was locally dented as shown in FIG. 4 (b). Such a problem was particularly remarkable when trying to correct the bending of the U-shaped steel sheet pile having the arm portion between the flange portion and the joint portion (claw portion).

[0006]

SUMMARY OF THE INVENTION A first object of the present invention is to solve the drawbacks of the conventional method for straightening the "bending" of the U-shaped steel sheet pile as described above and the jig used for the straightening. A straightening method and a jig used therefor.

A further specific object of the present invention is a steel sheet pile having a high bending rigidity in the lateral direction of the product, such as a U-shaped steel sheet pile having an arm portion between a flange portion and a joint portion (claw portion) among U-shaped steel sheet piles. "Bending" is efficiently corrected and the efficiency of the correction work is improved to eliminate the stagnation in the adjusting process and prevent delays in customer delivery, and products that cannot be corrected by conventional correction methods. It is an object of the present invention to provide a correction method and a jig used for the correction method that can improve the yield by repairing a defective shape.

[0008]

In order to easily press-correct the bending of a steel sheet pile having a high bending rigidity in the lateral direction of the product, the present inventor has already pressed the outer surface of the flange on one side. The present invention has been completed based on the knowledge obtained by a huge amount of experimental results that it is effective to press the inner surface of one flange at the same time in the same direction. That is, the gist of the present invention is as follows.

(1) In a method of correcting the lateral bending generated in the hot rolling process of a U-shaped steel sheet pile by using a press, the outer surface of one flange of the steel sheet pile is pressed and the inner surface of the other flange is simultaneously pressed. A method for straightening a U-shaped steel sheet pile, which comprises pressing.

(2) A first jig having a surface that presses the outer surface of one side flange of a U-shaped steel sheet pile, and a second jig that has a surface that is connected to the first jig and that presses the inner surface of the other flange. U characterized by combining both ingredients
Straightening jig for shaped steel sheet pile.

(3) For the first jig having a surface for pressing the outer surface of the flange of the U-shaped steel sheet pile, a fitting portion capable of mounting and dismounting the second jig for pressing the inner surface of the flange is provided on both jigs. U of the above (2), characterized in that it is provided at the connecting portion of
Straightening jig for shaped steel sheet pile.

(4) An adjusting mechanism capable of changing the relative position in the product width direction of the second jig for pressing the inner surface of the flange with respect to the first jig having the surface for pressing the outer surface of the flange of the U-shaped steel sheet pile. The above is characterized in that it is provided at the connecting portion of both jigs.
(2) A straightening jig for the U-shaped steel sheet pile described in (3).

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION A press straightening method and a jig used therefor according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 5 is a schematic explanatory view of a press straightening method for removing the bending of the U-shaped steel sheet pile according to the present invention. For comparison, a conventional press straightening method for removing the bending of the U-shaped steel sheet pile is shown in FIG. In addition, in these cases, U-shaped steel sheet piles having an arm portion between the flange portion and the joint portion are used.
An example of using a shaped steel sheet pile will be shown.

According to the straightening method of the present invention, the outer surface 13 of the one side flange 12 of the U-shaped steel sheet pile 10 as the material to be straightened is pressed while the other flange 14 is pressed, as indicated by the pressing force indicated by an arrow in FIG. In order to press the inner surface 15 in the same direction, the external force is not concentrated on only one side of the flanges 14 and 16, so that the width of the product is narrowed and the flanges 14 and 16 are locally deformed such as local dents. Does not occur.

At this time, the pressing force for pressing the outer surface 13 of the one-side flange 12 and the pressing force for pressing the inner surface 15 of the flange 14 may be the same or slightly different, but the product width In order to prevent fluctuation and local deformation of the flange, it is preferable to press both surfaces with the same pressing force as much as possible.

In this respect, according to the conventional method, as shown in FIG. 6, since the pressing force is applied only to the outer surface 13 of the flange 12 on one side of the U-shaped steel sheet pile 10, the flange 12 on one side is locally pressed. Local deformation such as dents will occur.

FIG. 7 shows an example of a jig used in the straightening method of the present invention. It shows a jig for contacting and pressing the outer surface 13 of the flange 12 of the U-shaped steel sheet pile 10 as the material to be straightened. It is composed of one jig 20 and a second jig 22 for straddling the flange 12 and contacting and pressing the inner surface 15 of the other flange 14. Hereinafter, the first jig will be simply referred to as the jig A, and the second jig will be simply referred to as the jig B.

In FIG. 7, the jig A and the jig B are appropriately connected by a connecting portion 24. For example, the jigs A and B are connected.
May be appropriately fitted and then fixed by a bolt 26 through a screw hole 28 provided on the jig B side. The form of this connection may be a one-piece structure, but in addition to that, simple fitting, connection by pins and pin holes, and the like are also conceivable. However, the above-described fitting screw type is preferable because it has the simplest and most reliable structure.

After the above construction, in the case of the illustrated example, by applying a pressing force to the press ram head connecting portion 30 provided on the jig A, the same pressing force is applied to the jigs A and B. The straightening method of the present invention is carried out by pressing the respective flange surfaces.

In order to facilitate handling of the jig A and the jig B, in the illustrated example, the jig is attached at the connecting portion and can be separated for easy removal. Also good.

In any case, in order to correct the bending of the U-shaped steel sheet pile by the press straightening method according to the present invention, a jig composed of a combination of jigs A and B is used, for example, as shown in FIG.・ Use one by attaching to the pressing part and two on the supporting side of the material to be straightened. However, since the specific correction operation may be performed in the same manner as the conventional one, further description will be omitted.

In the straightening jig shown in FIG. 7, the jig A and the jig B are joined by a connecting portion. Alternatively, the relative positions of the jig A and the jig B may be adjusted. As a result, the pressing force when pressing the outer surface of the flange and the inner surface of the other flange at the same time is appropriately distributed according to the dimensional fluctuation (width fluctuation) of the material to be straightened, and the material to be rolled is efficiently deformed without local deformation. Bending correction is possible.

In this embodiment, as shown in FIG. 8, the connecting portion 24 of the jig A20 and the jig B22 is a kind of slide type, and a screw type fixing mechanism is provided on the connecting portion 24. Good.

Incidentally, in FIG. 7, the joint portion (
Although a steel sheet pile having an arm portion between the claw portion and the flange has been exemplified, a general U-shaped steel sheet pile (without the above-mentioned arm portion) may be used, and the jig shape may be slightly changed according to the product shape. Therefore, the effect of the present invention is the same. Although the U-shape is shown as an example of the posture of the material to be corrected in the figure, the same applies to the posture of the inverted U-shape, and the jig is simply turned upside down according to the shape of the material to be corrected. The effect of the present invention can be exhibited.

[0026]

EXAMPLES Next, the functions and effects of the present invention will be specifically described by way of examples. (Example 1) The results of applying the press straightening method according to the present invention to a U-shaped steel sheet pile having an arm portion between a joint portion and a flange portion will be exemplified below.

The dimensions of the material to be straightened are as shown in Table 1. Press straightening was performed using a press having a horizontal hydraulic cylinder, and the jig spacing (see FIG. 3) on the supporting side was 1.2 m. As a straightening method, in order to remove left-right bending over the entire length of the material to be straightened, a method of repeating the pressing work while intermittently feeding the material to be straightened in the longitudinal direction at a pitch of 1.2 m for each straightening was adopted. Further, as the jig used in the press straightening method according to the present invention, a jig in which two jigs (jigs A and B) as shown in FIG. 7 are combined is adopted, and the jig is used for comparison. Correction was also performed by the conventional method in which the left and right bends were corrected by A alone.

Table 2 shows a comparison of the left and right bending levels of products after straightening by the straightening method of the present invention and the conventional straightening method. As can be seen from the results in this table, according to the press straightening method of the present invention, the bending is significantly reduced before and after the straightening, whereas in the conventional press straightening method, the bending level is hardly reduced before and after the straightening. On the contrary, there are defects in the product width and local deformation of the flange.

[0029]

[Table 1]

[0030]

[Table 2]

(Embodiment 2) In the press straightening method according to the present invention, a general U having no arm portion between the joint portion and the flange portion is used.
The result applied to the shaped steel sheet pile is illustrated below. The dimensions of the material to be straightened are as shown in Table 3, the press straightening was performed by using a press machine having a horizontal hydraulic cylinder, and the jig spacing (see FIG. 3) on the supporting side was 1.2 m.

As a straightening method, a press work was performed on both ends (about 1.2 m) of the material to be straightened in order to remove the left and right bends which could not be completely removed by the roller straightening in the previous step. Further, as a jig used for carrying out the press straightening method according to the present invention, a combination of two jigs (jig A and jig B) as shown in FIG. Therefore, the conventional method was used to correct the left and right end bends only with the jig A.

Table 4 shows a comparison of the left and right bending levels of the products after straightening by the straightening method of the present invention and the conventional straightening method.
From the results shown in this table, according to the press straightening method of the present invention, as compared with the conventional press straightening method, the edge bending is significantly reduced before and after straightening, and the bending straightening is realized in a short time, According to the correction method of the present invention, it is understood that the bend can be corrected efficiently.

[0034]

[Table 3]

[0035]

[Table 4]

[0036]

As is apparent from the above embodiments, when the press straightening method and straightening jig according to the present invention are used, U
Straightening of shaped steel sheet piles can be performed efficiently in a short time, and particularly for steel sheet piles having a cross-sectional shape with large bending rigidity in the lateral direction, such as U-shaped steel sheet piles having arms, effectively without causing product defects. Press straightening is possible, and its industrial utility value is extremely high.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view of a warp defect of a steel sheet pile.

FIG. 2 is a schematic explanatory view of a defective bending of a steel sheet pile.

FIG. 3 is a schematic explanatory view of a bending press straightening method for a steel sheet pile.

FIG. 4 (a) is an explanatory diagram of a press straightening small width small defect of a steel sheet pile, and FIG. 4 (b) is an explanatory diagram of flange local deformation defect.

FIG. 5 is an explanatory view of a press straightening method of the present invention.

FIG. 6 is an explanatory diagram of a conventional press straightening method.

FIG. 7 is an explanatory view of an example of a press straightening jig of the present invention.

FIG. 8 is an explanatory view of another embodiment of the press straightening jig of the present invention.

[Explanation of symbols]

 10: Steel sheet pile 12, 14: Flange 13: Outer surface 15: Inner surface 20: Jig A 22: Jig B 24: Connection part 26: Bolt 28: Screw hole 30: Press ram head connection part

Claims (4)

[Claims] 1. A method for straightening a lateral bend generated in a hot rolling process of a U-shaped steel sheet pile by using a press, wherein the outer surface of one flange of the steel sheet pile is pressed and the inner surface of the other flange is simultaneously pressed. A method for straightening a U-shaped steel sheet pile characterized by pressing. 2. A first jig having a surface that presses the outer surface of one side flange of a U-shaped steel sheet pile, and a second jig that is connected to the first jig and has a surface that presses the inner surface of the other flange. A jig for straightening U-shaped steel sheet piles, which is a combination of both. 3. A fitting part capable of attaching and detaching a second jig for pressing the inner surface of the flange to a first jig having a surface for pressing the outer surface of the flange of the U-shaped steel sheet pile is provided on both jigs. The correction jig for a U-shaped steel sheet pile according to claim 2, wherein the correction jig is provided at a connecting portion. 4. An adjustment mechanism capable of changing the relative position in the product width direction of a second jig that presses the inner surface of the flange with respect to a first jig that has a surface that presses the outer surface of the flange of a U-shaped steel sheet pile. The jig is provided at a connecting portion of the jig.
Or the correction jig for the U-shaped steel sheet pile described in 3.