JPH0760356A - Straightening method for h-shape steel - Google Patents

Abstract

PURPOSE:To straighten bend and camber of a large H-shaped steel. CONSTITUTION:Plural caterpillars 1 are arranged in two upper and lower tiers and also in zigzag, and the straightening of an H-shaped steel is performed by rotating these caterpillars 1 in two upper and lower ties and pressurizing both ends 3a of the flange of an H-shaped steel 2 with the caterpillars. This is the straightening method of an H-shaped steel in which the locus in the advancing direction of the caterpillar pressurizing the ends 3a of the flange of the H-shaped steel is a circular-arc shape with a specific curvature. The straightening is performed in pressurizing both side faces of the flange 3 of the H-shaped steel 2 with rollers provided with rotary shafts in the width direction of the flange. With this method, reduction of the width and local deformation of the H-shaped steel are not occurred after the straightening.

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 large H-section steel which has been difficult to straighten.

[0002]

2. Description of the Related Art Since H-section steel as manufactured by hot rolling or welding has a bend or warp in whole or locally, it is usually shipped straight after being cold straightened. Is.

As a cold straightening method, press straightening or roller straightening is often used. The press straightening method is
Since this is a method of appropriately deforming with a press fitting while observing the shape before correction, it is inefficient and is not suitable for mass production.
On the other hand, the roller straightening method is a method of straightening H-section steel by repeatedly bending it with a large number of rollers, which is efficient and is installed and used as an online facility in a factory.

FIGS. 8 and 9 are explanatory views showing a contact state between a straightening roller and an H-shaped steel in a conventional roller straightening method. As shown in these drawings, the conventional roller straightening machine has a loading method in which the web surface 24 of the H-section steel 22 is loaded by the outer peripheral surface of the roller 21 as shown in FIG. As described above, there are two types of flange reduction method in which the end surface 23a of the flange 23 of the H-section steel 22 is loaded by the outer peripheral surface of the roller 31.

[0005]

However, the above-described conventional roller straightening method has the following problems, whichever rolling method is adopted. That is, the drawback of the web reduction method is that, in the case of H-section steel having a wider flange width than the web plate thickness, the load by the roller is converted into the slack of the web, so that the flange is not sufficiently bent and deformed. Only the local contact areas of the web and the plastic are plastically deformed and, in severe cases, even cracks may occur.

In the technique disclosed in Japanese Patent Publication No. 57-61488, the shape of the roll holding the web is devised in order to suppress such local deformation.
Given the demand for thinner web thickness products, such a method does not essentially solve the problem.

A drawback of the flange reduction method is that when the flange width is wide and a large bending load is required, the flange end face which is in contact with the roller is crushed and the flange width is greatly reduced.

Such a problem is caused by a reduction in load due to an increase in roller spacing and an increase in roller diameter, as in the techniques disclosed in JP-B-56-40646 and JP-A-53-141158. To some extent this is mitigated by the increased contact area between the roller and the flange, but with such means,
Inevitably, not only does this lead to an increase in the size of equipment and an increase in construction costs, but the length of the uncorrectable portions at both ends of the H-section steel also becomes longer if the roller spacing is increased, so these means are naturally limited. Become.

As described above, it is apparent that the H-section steel having a large cross section cannot be effectively corrected by either the conventional web reduction method or the flange reduction method, but the web reduction method is unavoidable. It is currently adopted.

In order to solve the drawbacks of the above two methods, as shown in FIG. 10, for example, as in the technique disclosed in Japanese Patent Publication No. 57-11728, the flange 23 and the web 24 are simultaneously pressed by the roll 41. Although a method has been proposed, this method also inevitably exposes the above-mentioned problems if the mechanism is complicated and the web thickness is further reduced.

Further, in the technique disclosed in Japanese Patent Publication No. 56-45684, a method has been proposed for reducing the surface pressure applied to the flange when the flange is pressed. However, in this method, the circumference of the portion in contact with the flange is proposed. Since the speeds are different, deformation is induced in the direction in which the flange falls, the load at the portion that starts contact with the flange and the portion that comes out of contact with the flange becomes high, and as a straightening machine, a special H-shaped steel machine There was a problem such as becoming.

The present invention has been made in order to solve the above-mentioned problems of the prior art, and it is possible to correct the bending and warping of a large H-section steel without requiring a huge capital investment. It is intended to provide a method for straightening H-section steel.

[0013]

According to the method for straightening H-section steel according to the present invention, a plurality of caterpillars are arranged in two stairs in a vertical direction and in a zigzag manner, and while the caterpillars in the upper and lower two stages are rotated, the H It corrects by pressing both ends of the flange of shaped steel.

Further, the locus in the traveling direction of the caterpillar that presses the end portion of the H-shaped steel flange of the caterpillar is an arc shape having a predetermined curvature. Furthermore, in addition to the above-mentioned straightening method, straightening is performed while pressing both side surfaces of the H-section steel flange with rollers having a rotation axis in the width direction of the flange.

[0015]

When the H-section steel is straightened by the H-section straightening method according to the present invention, the contact area of the caterpillar pressing both ends of the H-section steel flange is smaller than that in the conventional roller straightening method. Since it becomes large, the surface pressure per unit area becomes small, the flange of the H-section steel is not locally deformed, and the width of the flange is not reduced or deformed.

Further, it is advantageous to disperse the load if the track in the traveling direction of the caterpillar when the H-shaped steel flange is pressed by the caterpillar has a predetermined curvature. Further, when the straightening is performed as described above and at the same time, both flange surfaces of the H-section steel are pressed and corrected by the rollers having the rotation axis in the width direction of the flange, the flange of the H-section steel does not fall.

The distance between the vertical center of rotation of the plurality of caterpillars arranged in the two upper and lower stages, the installation interval of the front and rear caterpillars, or the number of installed caterpillars depends on the sectional size of the H-section steel to be corrected. In order to perform the repeated bending deformation the same number of times as in the conventional roller straightening, it is desirable that the number is several to ten or more. It is also possible to provide a pair of caterpillars only in the front stage portion where the load is large, and to configure the rear stage portion with a normal web or flange roller straightening.

Of course, it can be applied to both a cantilever type and a double-sided type straightening machine, and if the caterpillar part is made detachable, the conventional type roller straightening is possible, and other than H-section steel. It can be applied to shaped steel by simply changing the conventional type roll. Then, by properly laying a guide for properly inserting into the pair of caterpillars, a space adjusting device for the pair of caterpillars, a vertical position adjusting device, and a driving device, it is possible to continuously and effectively produce H-section steel of various cross-sectional dimensions. Correction is possible.

[0019]

EXAMPLE A straightening method for H-section steel according to the first example of the present invention will be described with reference to FIG. FIG. 1A is a side view showing this correction method, and FIG. 1B is a front view showing this correction method. In this straightening method, a plurality of tracks 1 are arranged in a zigzag pattern so as to face each other, and a load is alternately applied to the end surface 3a of the flange 3 of the H-shaped steel 2. In addition, the code | symbol 4 in a figure is a web of H-section steel.

In this straightening method, as shown in FIG. 2A, the end face 3a of the flange of the caterpillar 1 and the H-shaped steel 2 is formed.
The contact area with the contact area (contact area A is indicated by diagonal lines) is shown in FIG.
As shown in, the contact state between the roller 21 and the flange end surface 3a of the H-section steel 2 in the case of the conventional flange pressing method by the roller 21 is compared with the case where the contact is linear contact (the contact portion B is shown by diagonal lines). , Much larger. Therefore, the contact pressure per unit area of the end surface 3a of the flange 3 becomes extremely small, so that the collapse of this portion due to the load is almost eliminated as compared with the conventional roller straightening method.

FIG. 3 shows a second embodiment in which a locus 5 in the advancing direction of the caterpillar of a portion of the caterpillar 1 which is in contact with the end face 3a of the H-shaped steel flange 3 has a slight curvature in advance. This is advantageous for load distribution.

FIG. 4 shows that, in addition to the first or second embodiment of the present invention described with reference to FIG. 1 or FIG. 2, a vertical roll 6 for pressing the flange 3 of the H-section steel 2 from the Y direction is provided. It is explanatory drawing which shows the 3rd Example which corrects, (a) is a side view, (b) is a front view. In the case of this embodiment, it is possible to prevent the flange 3 from falling when a load is applied to the flange end 3a of the H-shaped steel by the caterpillar 1.

H-section steels having a flange width of 250 mm, a web height of 250 mm, a wall thickness of 14 mm and a web portion of 9 mm shown in Table 1 were straightened by the straightening machine shown in Table 1 based on the first embodiment.

[0024]

[Table 1]

Upon the correction, the intermesh that can exhibit the same correction effect between the conventional method and the method of the present invention was examined, and as shown in Table 2, the results are shown in Table 2. , The result is that less intermesh is required than the conventional method. This is considered to be because the method of the present invention does not consume wasteful energy for local deformation of the web and can provide effective repeated bending, so that the intermesh can be reduced. And
The fact that the number of intermesh is small means that the power for correction, that is, the power cost can be saved.

[0026]

[Table 2]

FIG. 5 is a graph showing the distribution of the wall thickness of the H-section steel web in the web axial direction after straightening. As can be seen from FIG. 5, in the case of the conventional method, as the web center approaches the flange portion,
While the wall thickness is greatly reduced, it can be understood that in the case of the method of the present invention, the wall thickness of the portion near the flange is not significantly reduced, and good correction is performed. .

FIG. 6 is a graph in which the height of the straightened web of an H-section steel having a length of 12 m is plotted from the front end to the rear end. In the case of the method of the present invention, the web height is not decreased over the entire length, whereas the web height is greatly reduced at the front and rear ends in the case of being straightened by the conventional method. Understand that

FIG. 7 is a graph showing how the hardness of the straightened web changes from the surface of the flange toward the web center. In the conventional method, the hardness of the web near the flange is greatly increased, whereas in the method of the present invention, the hardness of the web does not change so much,
From this point as well, it can be understood that good correction is performed. Table 3 is a list of the methods of the present invention described above in comparison with the conventional methods.

[0030]

[Table 3]

In the straightening method of the present invention, a caterpillar mark was found at the end of the flange, but as described above, there was no change in dimensions or hardness, and it was found that there was no problem in practical use.

[0032]

According to the present invention, it is possible to efficiently correct the shape of a large H-section steel and improve the product quality.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a first embodiment of a correction method of the present invention, (a) is a side view and (b) is a front view.

FIG. 2 is an explanatory diagram showing a difference in surface pressure from a conventional flange reduction method, in which (a) is the case of the method of the present invention and (b) is the case of the conventional method.

FIG. 3 is an explanatory view showing a second embodiment in which a contact portion with a flange portion of the caterpillar has a curvature in order to make the surface pressure applied to the caterpillar more uniform.

FIG. 4 is an explanatory view showing a third embodiment of the present invention,
(A) is a side view and (b) is a front view.

FIG. 5 is a graph showing how the change in web thickness differs between the method of the present invention and the conventional method.

FIG. 6 is a graph showing how the web height changes at each position in the longitudinal direction between the method of the present invention and the conventional method.

FIG. 7 is a graph showing how the change in web hardness differs between the method of the present invention and the conventional method.

FIG. 8 shows a conventional roller straightening method using a web reduction method.

FIG. 9 is a roller straightening method using a conventional flange reduction method.

FIG. 10 is a conventional roller straightening method using a web and flange simultaneous reduction system.

[Explanation of symbols]

 1 Caterpillar 2 H-section steel 3 H-section steel flange 3a Flange end surface 4 H-section steel web 5 Track of caterpillar 6 Vertical roll

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Masayoshi Matsuda, 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Nihon Kokan Co., Ltd. (72) Misao Makinohara, 1-2-1, Marunouchi, Chiyoda-ku, Tokyo No. Nihon Steel Pipe Co., Ltd. (72) Inventor Susumu Furukawa 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Nihon Steel Pipe Co., Ltd.

Claims (3)

[Claims] 1. A plurality of caterpillars are arranged in upper and lower two stages in a zigzag manner, and the two upper and lower caterpillars are rotated and corrected by pressing both ends of the flange of the H-shaped steel with the caterpillars. A characteristic H-shaped steel straightening method. 2. The straightening method for H-section steel according to claim 1, wherein the track in the traveling direction of the caterpillar that presses the end portion of the H-section steel flange of the caterpillar is an arc shape having a predetermined curvature. 3. The straightening method for H-section steel according to claim 1, wherein both sides of the flange of the H-section steel are straightened while being pressed by rollers having a rotation axis in the width direction of the flange.