JP3129179B2 - U-shaped steel sheet pile straightening method and straightening jig - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for straightening a U-shaped steel sheet pile, which is used for civil engineering and construction purposes, 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, steel sheet piles manufactured by hot rolling are warped in the length direction due to internal stress as the cooling proceeds after sawing, and shape defects such as bending occur. Here, "warp" refers to a large bend or end bend in the direction perpendicular to the sheet pile wall 2 of the U-shaped steel sheet pile 1 as shown in FIG. 1, and "bend" means a U-shaped steel sheet pile as shown in FIG. Sheet pile wall 2 of sheet pile 1
Mean a large bend in the direction parallel to the end. JIS
In the A 5528 standard, regarding the bending of U-shaped steel sheet pile,
For a length of 10m or less, the total length x 0.12% or less, and for those exceeding 10m, it is specified as (total length-10m) x 0.10% + 12mm or less. The total length is 0.25% or less, and for those exceeding 10m, it is specified as (total length-10m) x 0.20% + 25mm or less.

[0003] Correction of such a shape defect is generally performed by a roller straightening machine. In this roller straightening machine, for example, three rollers are arranged below the four upper rollers in a staggered manner with the upper rollers. Therefore, the front and rear ends of the steel sheet pile cannot exert a sufficient straightening effect. In particular, it is difficult to correct a warp or bending defect at the front and rear ends with a roller straightening machine, and after the roller straightening, it is general to correct only the front and rear ends with a press straightening machine. FIG.
Fig. 3 illustrates a straightening operation by the press straightening machine when a bending occurs in the U-shaped steel sheet pile 1 as a material to be straightened.

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 bending, one of the right and left rods is fixed depending on the bending direction. The pressing is performed by pressing the outer surface of the flange of the material to be corrected with the other rod. At this time, the jigs 6 and 8 for supporting one flange outer surface 4 of the U-shaped steel sheet pile 1 as a material to be corrected are mounted on the opposite side of a pressing rod (not shown) for applying a pressing force, as shown in FIG. It is common to place a part and restrict the movement of the material to be corrected.

[0005] However, in the case of the U-shaped steel sheet pile having high rigidity against bending in the left-right direction among the U-shaped steel sheet piles, FIG.
As shown in FIG. 4B and FIG. 4B, the bending is not corrected by pressing the flange outer surface 4 on one side with a press, and the width of the material to be corrected is narrow as shown by the dotted line in FIG. In addition to deforming the cross-sectional shape in a certain direction, there have been problems such as the local depression of the pressed flange as shown in FIG. 4 (b). Such a problem has been remarkable particularly when the bending of a U-shaped steel sheet pile having an arm portion between a flange portion and a joint portion (claw portion) is to be corrected.

[0006]

SUMMARY OF THE INVENTION A first object of the present invention is to solve the drawbacks of the above-mentioned conventional method for straightening a "bend" of a U-shaped steel sheet pile in the lateral direction and a jig used for straightening. An object of the present invention is to provide a straightening method and a jig used for the method.

A more specific object of the present invention is to provide a steel sheet pile having a high bending rigidity in a lateral direction, such as a U-type sheet pile having an arm portion between a flange portion and a joint portion (claw portion). In addition to eliminating the stagnation of the refining process, preventing delays in customer delivery, and improving the efficiency of straightening work by improving straightening of products, products that could not be corrected by conventional straightening methods An object of the present invention is to provide a correction method capable of improving the yield by relieving a shape defect and a jig used for the correction method.

[0008]

SUMMARY OF THE INVENTION In order to easily correct the bending of a steel sheet pile having high bending stiffness in the lateral direction of the product, the present inventor has proposed not only pressing the outer surface of the flange on one side, but also another method. The present invention has been completed based on the knowledge obtained through extensive experimental results that it is effective to simultaneously press one flange inner surface in the same direction. That is, the gist of the present invention is as follows.

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

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

(3) The first jig having a surface for pressing the outer surface of the flange of the U-shaped steel sheet pile and the second jig for pressing the inner surface of the flange can be attached to and detached from the first jig. (2) characterized in that the U
Straightening jig for steel sheet pile.

(4) An adjustment mechanism capable of changing the relative position in the product width direction of the second jig pressing the inner surface of the flange with respect to the first jig having a surface pressing the outer surface of the flange of the U-shaped steel sheet pile. The jig is provided at a connection portion between the two jigs.
The jig for correcting a U-shaped steel sheet pile according to (2) or (3).

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A press straightening method according to the present invention and a jig used therefor 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 bending of a U-shaped sheet pile according to the present invention. FIG. 6 shows a conventional press straightening method for removing bending of a U-shaped steel sheet pile for comparison. In these cases, a U-shaped steel sheet pile having an arm between the flange and the joint is used.
The example which uses a shape steel sheet pile is shown.

According to the straightening method of the present invention, the outer surface 13 of one side flange 12 of the U-shaped steel sheet pile 10 as the material to be straightened is pressed at the same time as the other flange 14 as shown by the pressing force by an arrow in FIG. Since the inner surface 15 is pressed in the same direction, the external force does not concentrate on only one side of the flanges 14 and 16, so that the width of the product is narrowed and local deformation such as local dents on the flanges 14 and 16 is prevented. Does not occur.

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

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

FIG. 7 shows an example of a jig used in the straightening method of the present invention. The jig is used to contact and press the outer surface 13 of the flange 12 of the U-shaped steel sheet pile 10 as a material to be straightened. It comprises 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 is simply referred to as jig A, and the second jig is referred to as jig B.

In FIG. 7, a jig A and a jig B are appropriately connected by a connecting portion 24. For example, the jigs A and B
May be fixed by bolts 26 through screw holes 28 provided on the jig B side. As a form of this connection, an integral structure may be used, but other than that, a simple fitting, a connection by a pin and a pin hole, etc. are also conceivable. However, the above-mentioned fitting screw type is the simplest and most reliable structure and is preferred.

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

The jig A and the jig B are configured so that they can be attached at the connecting portion and separated for easy removal in the illustrated example in order to facilitate the handling. It is 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, for example, as shown in FIG. -One is attached to the pressing part and two are attached to the support side of the material to be corrected. However, since a specific correction operation may be performed in the same manner as the conventional correction operation, further description is omitted.

In the straightening jig shown in FIG. 7, the jig A and the jig B are connected by a connecting portion. The relative positions of the jigs A and B may be adjusted. As a result, the pressing force when simultaneously pressing the outer surface of the flange and the inner surface of the other flange at the same time according to the dimensional fluctuation (width fluctuation) of the material to be corrected is efficiently distributed, and the material to be rolled is efficiently prevented from being locally deformed. Bending correction becomes possible.

In such an embodiment, as shown in FIG. 8, the connecting portion 24 between the jig A20 and the jig B22 is formed as a kind of slide type, and for example, a screw type fixing mechanism is provided thereto. Is also good.

FIG. 7 shows a joint portion (
Although a steel sheet pile having an arm between the claw and the flange is illustrated, a general U-shaped sheet pile (without the above-mentioned arm) may be used, and the jig shape may be slightly changed according to the product shape. Thus, the effect of the present invention is the same. Although the figure shows a U-shaped example of the posture of the material to be corrected, the same applies to the inverted U-shaped posture, in which only the jig is turned upside down in accordance with the shape of the material to be corrected. The effects of the present invention can be exhibited.

[0026]

Next, the operation and effect of the present invention will be described in detail with reference to examples. (Example 1) The result 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 machine having a horizontal hydraulic cylinder, and the jig interval on the support side (see FIG. 3) was 1.2 m. As a straightening method, in order to remove the left-right bending over the entire length of the material to be corrected, a method was employed in which the material to be corrected was intermittently fed in the longitudinal direction at a pitch of 1.2 m each time the press was corrected, and the pressing operation was repeated. As the jig used in the press straightening method according to the present invention, a combination of two jigs (jig A and jig B) as shown in FIG. Correction by a conventional method, which corrects left-right bending only with A, was also performed.

Table 2 shows a comparison of the level of the product left and right bends after the straightening method according to the present invention and the conventional straightening method. As can be seen from the results of this table, according to the press straightening method of the present invention, the bending is significantly reduced before and after the straightening, whereas the conventional press straightening method hardly reduces the bending level before and after the straightening. On the contrary, a defect due to a defective product width or a local deformation of the flange occurs.

[0029]

[Table 1]

[0030]

[Table 2]

(Embodiment 2) A press straightening method according to the present invention is applied to a general U-type without an arm between a joint and a flange.
The result of applying the method to a sheet steel sheet pile will be exemplified below. The dimensions of the material to be straightened are as shown in Table 3, and the press straightening was performed using a press machine having a horizontal hydraulic cylinder, and the jig interval on the support side (see FIG. 3) was 1.2 m.

As a straightening method, press work was performed on both ends (about 1.2 m each) of the material to be straightened in order to remove left and right bends that 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. For this purpose, the conventional method of correcting the right and left end bending using only the jig A was also performed.

Table 4 shows a comparison of the level of the product left and right bends 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, compared to the conventional press straightening method, the end bending is significantly reduced before and after straightening, and the bending straightening is realized in a short time, According to the straightening method of the present invention, it is understood that the straightening can be efficiently performed.

[0034]

[Table 3]

[0035]

[Table 4]

[0036]

As is clear from the above embodiments, the use of the press straightening method and the straightening jig according to the present invention allows
It is possible to efficiently correct the shape steel sheet pile in a short time and effectively, especially for a steel sheet pile having a cross-sectional shape with large bending rigidity in the lateral direction such as a U-type steel sheet pile having an arm, without causing product defects. Press straightening is possible, and its industrial utility value is extremely large.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view of a warpage failure of a steel sheet pile.

FIG. 2 is a schematic explanatory view of a bending failure 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 view of a small defect in the press-straightening full width of a steel sheet pile, and FIG. 4 (b) is an explanatory view of a local deformation defect of a flange.

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

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

FIG. 7 is an explanatory diagram 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: connecting part 26: bolt 28: screw hole 30: press ram head connecting part

Claims (4)

(57) [Claims] In a method for correcting a lateral bending generated in a hot rolling step of a U-type steel sheet pile by using a press, an outer surface of one flange of the steel sheet pile is pressed while an inner surface of the other flange is pressed. A method for correcting a U-shaped steel sheet pile, which comprises pressing. 2. A first jig having a surface for pressing an outer surface of a flange on one side of a U-shaped sheet pile, and a second jig connected to the first jig and having a surface for pressing an inner surface of the other flange. A jig for correcting a U-shaped steel sheet pile, characterized by combining both. 3. A fitting part capable of attaching and detaching a second jig for pressing an inner surface of a flange to a first jig having a surface for pressing an outer surface of a flange of a U-shaped steel sheet pile. The jig for correcting a U-shaped steel sheet pile according to claim 2, wherein the jig is provided at a connecting portion. 4. An adjusting mechanism capable of changing a relative position in a product width direction of a second jig pressing an inner surface of a flange with respect to a first jig having a surface pressing an outer surface of a flange of a U-shaped steel sheet pile. The jig is provided at a connecting portion of the jig.
Or a jig for correcting a U-shaped steel sheet pile according to 3.