JP2002035848A - Bending method for wide-flange shape steel and bending equipment for wide-flange shape steel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bending method for a wide-flange shape steel capable of working the wide-flange shape steel into a shape whose both sidefaces are smooth in bending work for the wide-flange shape steel with a desired curvature and a bending method for bending equipment suitable for executing such a method. SOLUTION: The bending work for the wide-flange shape steel and equipment therefor comprises the process wherein a deformation center line in the longitudinal structural portion of the wide-flange shape steel to be bend-worked is displaced to the inner diameter side, compressive stresses acting on the inner diameter side is reduced, and the bending work with a desired curvature with the elongation deformation on the outer diameter side of the wide-flange shape steel as a subject. And the equipment for bending work having a pair of fixed rollers 10 disposed on the outer side in bending work, press roller 12 for pressing the wide-flange shape steel being a work piece placed along the both fixed rollers from the inner diameter side, is provided with a buckling preventing mechanism consisting of an outside pressing roller 14 disposed on the vicinity of the intermediate position of the fixed rollers, and an inner side pressing roller 16 disposed opposing to the outside pressing roller and clamping the lateral structural portion on the outside of the wide-flange shape steel from the inner side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an H-shaped steel bending method and apparatus for bending an H-shaped steel used in various types of buildings and civil engineering works at a desired curvature. The present invention relates to an H-shaped steel bending method and a bending apparatus provided with a buckling prevention mechanism for bending into a desired shape without buckling.

[0002]

2. Description of the Related Art H-shaped steel is a high-strength structural material, and is widely used as a reinforcing material or an auxiliary material as well as a main material in various construction works and civil engineering works. It is also used as an indispensable material in earth retaining works and shoring works.

[0003] Since such H-shaped steels are usually manufactured and sold as straight materials of various dimensions, H-shaped steels of the standard and dimensions selected according to the application are cut into desired dimensions.
Further, welding is performed as necessary, or auxiliary fasteners are used to suit the on-site application.

[0004] In addition, there are many cases in which not only a straight material but also a structure which is bent at an appropriate curvature is used to form a structure having a curved portion such as an arc, an annular, a dome, or a tunnel. .

[0005] In order to form such an arc-shaped or other curved portion, an H-section steel is placed between a strong fixed roller and a movable roller provided with a strong pressurizing device by hydraulic pressure or the like, and the movable roller is used to raise the yield point or above. In many cases, a method of applying a pressing force to cause permanent deformation is adopted.

[0006] During such bending, an elongation stress acts on the outer diameter side of the curved portion, and a compressive stress acts on the inner diameter side. Generally, a steel material elongates relatively easily under a strong tensile stress, but hardly shrinks even when a strong compressive stress acts. In particular, since the H-shaped steel has a strong structure both vertically and horizontally as is clear from its cross-sectional structure, bending processing is difficult.

[0007] For example, one of the upper and lower horizontal structure portions is an outer surface,
When a strong stress is applied with the other as the inner surface, the outer diameter side can be relatively easily responded to by elongation of the steel material, but the compressive force acts on the inner diameter side of the curved part, which tends to cause irregular deformation, and in extreme cases, Buckles and becomes unusable as steel.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has been made in consideration of the above circumstances, and is intended to be used for bending an H-shaped steel capable of forming a smooth shape both inside and outside when bending the H-shaped steel at a desired curvature. It is an object to provide a method and a bending apparatus suitable for performing the method.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to reduce the compressive stress acting on the inner diameter side by shifting the deformation center line in the vertical structure of the H-section steel to be bent to the inner diameter side.
The problem is solved by a method of bending an H-shaped steel, which performs bending at a desired curvature mainly by elongation deformation on the outer diameter side of the H-shaped steel.

In order to carry out the above-mentioned method for bending an H-section steel, a pair of fixed rollers 10 arranged on the outer diameter side at the time of bending and a cover placed along the both fixed rollers. In an H-shaped steel bending apparatus having a press roller 12 for pressing an H-shaped steel as an object to be processed from an inner diameter side, an outer pressing roller 14 and an outer pressing roller arranged near the middle of the fixed rollers 10 are provided. An H-shaped steel bending apparatus having a buckling prevention mechanism including a first inner pressing roller 16 which is disposed to face the outer-diameter-side lateral structure portion of the H-shaped steel from the inside is adopted. This device can solve the above problem.

The buckling prevention mechanism may further include a second inner pressing roller 18 that faces the press roller 12 and sandwiches the inner side lateral structural member of the H-shaped steel from the inside. In addition, both of these pressing rollers or both of them can be a plurality of rollers.
Further, the first inner pressing roller 16 and the second inner pressing roller 18 may be supported by an integral frame.

According to the method for bending an H-shaped steel according to the present invention, as shown in FIG. 1, the deformation center line of the H-shaped steel to be bent is shifted as much as possible to the inner diameter side during the bending. As a result, in a state where no consideration was given, irregular deformation or buckling occurred due to a large difference between the elongation stress on the outer diameter side and the compression stress on the inner diameter side under the pressing force from below. Since the deformation center line shifts to the inner diameter side, the compressive stress acting on the inner diameter side is greatly reduced, and the bending is mainly performed by the extension stress on the outer diameter side. Therefore, irregular deformation and buckling of the H-shaped steel are prevented, and bending with a desired curvature can be performed with a high yield.

The structure of an apparatus for realizing the method for bending an H-section steel according to the present invention is disclosed by a second invention. On the outer diameter side of the H-section steel to be bent, an outer pressing roller 14 is provided in the vicinity of the middle of the fixed roller 10 disposed at an interval corresponding to the curvature of the bending processing, and H is disposed opposite to the pressing roller. There is provided a first buckling prevention mechanism including an inner pressing roller 16 for holding the outer diameter side transverse member of the mold steel from the inside.

The outer pressing roller 14 and the inner pressing roller 16 automatically move upward while maintaining a constant interval as the press roller 12 moves upward. As a result of providing such a first buckling prevention mechanism, irregular deformation which occurs first in the outer diameter side horizontal structure portion when the buckling phenomenon occurs is prevented, and the outer diameter side horizontal structure portion and the vertical structure portion are prevented from being deformed. The extension deformation is promoted, and as a result, the deformation center line is moved to the inner diameter side, whereby irregular deformation and buckling of the H-shaped steel are prevented.

In this case, particularly when bending with a strength to reduce the radius of curvature is performed, in order to further apply a bending stress to the H-shaped steel, it is opposed to the press roller 12 which is in contact with the inner diameter of the H-shaped steel. And the second inner pressing roller 18 for holding the inner side lateral structural member of the H-section steel from the inside
, The second buckling prevention mechanism can be added to both the inner and outer lateral structure portions.

Here, the first inner pressing roller 16
And the second inner pressing roller 18 are fixed so as to maintain a constant interval. As a result of the provision of the second buckling prevention mechanism for the inner and outer lateral structure portions of the H-shaped steel, the deformation center line of the H-shaped steel can be further moved to the inner diameter side, and the compressive force acting on the inner diameter side of the curved portion Is dispersed, irregular deformation and buckling of the H-section steel are prevented, and bending with a small radius of curvature becomes possible. In addition, these both holding rollers 16,
18 may be configured as a plurality of rollers and fixed so as to keep the distance between the upper and lower rollers constant.

[0017]

Next, an embodiment of the present invention will be disclosed with reference to the accompanying drawings. FIGS. 2A and 2B show an example of a basic configuration of an H-section steel bending apparatus according to the present invention. The apparatus according to the present invention is for applying a pressing force from a pair of fixed rollers 10 and 10 disposed on the outer diameter side of the H-shaped steel and the inner diameter side of the H-shaped steel near the middle of these fixed rollers 10 and 10. Press roller 12. The H-shaped steel interposed between the rollers 10 and 10 and the press roller 12 is pressed by the press roller 12 while being sent to the left or right and continuously receives required bending stress.

Here, an outer holding roller 14 is provided near the middle between the fixed rollers 10 and 10 provided on the outer diameter side of the H-section steel. In this case, the arrangement of the outer pressing roller 14 is determined in consideration of the size of the H-section steel, the curvature to be processed, and the like.
The necessary movement is permitted according to the pressing force from Step 2. Further, an inner pressing roller 16 that sandwiches the outer lateral structure portion of the H-shaped steel is provided to face the outer pressing roller 14. According to the pressing movement of the press roller 12,
The outer pressing roller 14 and the inner pressing roller 16 are
It moves automatically while maintaining a constant interval with the press roller 12.

The outer pressing roller 14 and the inner pressing roller 16 are combined to constitute a mechanism for preventing buckling of the H-shaped steel. For the purpose, both rollers are basically disposed on the same mounting base. , The outer lateral structure portion of the H-shaped steel is securely held. FIG. 2B is a view taken in the direction of the arrows BB in FIG. 2A, and the inner pressing roller 16 is divided into two and disposed on both sides of the H-shaped steel vertical structure.

FIGS. 3A and 3B show H according to the present invention.
It shows another configuration example of a bending machine for die steel, in which, in addition to an upper first inner pressing roller 16, a second inner pressing roller 18 is disposed at a position facing the lower press roller 12. A buckling prevention mechanism is also added to the inner side lateral structural member of the H-shaped steel to be bent. Also in this case, as shown in FIG. 1B, which is a view taken in the direction of arrow BB in FIG. 1A, the inner pressing rollers 18 are disposed on both sides of the H-shaped steel vertical structural member. In this case, the first inner pressing roller 16 and the second inner pressing roller 18 are fixed so as to maintain a constant interval.

FIG. 4 shows still another configuration example (only one side of the inner pressing roller is shown) of the apparatus for bending an H-section steel according to the present invention. This configuration example shows a structure suitable for performing strong bending with a smaller radius of curvature. Inner pressing rollers 26A, 26B on the upper side,
Four inner pressing rollers 28A and 28B are provided on the lower side in total, and these rollers are provided on both sides of the H-shaped steel vertical structural member, so a total of eight rollers are provided. Things. Although it is structurally complicated, the objectives of more reliably preventing irregular deformation and preventing buckling can be achieved. In this case, the inner pressing rollers 26A, 26B,
28A and 28B are fixed so as to keep a constant interval.

The first inner pressing roller 16 and the second inner pressing roller 18 may be supported by an integral frame.
6A, 26B and the inner pressing rollers 28A, 28B may be supported by an integral frame. As a result, the objects of more reliably preventing irregular deformation and preventing buckling can be achieved.

[0023]

According to the method for bending an H-shaped steel according to the present invention, the bending is performed in a state where the deformation center line existing near the center of the vertical structure of the H-shaped steel is shifted to the inner diameter side.
As a result, the bending deformation is mainly performed by the elongation deformation on the outer diameter side of the H-section steel, and the compressive force acting on the inner diameter side becomes extremely small. This takes into consideration the characteristic that the steel is easy to elongate and deform, but is extremely unlikely to undergo compressive deformation, and is unlikely to undergo irregular deformation and buckling due to a large compressive force. Therefore, according to the method for bending an H-shaped steel according to the present invention, it is possible to perform bending at a desired curvature with a high yield even for a large-sized H-shaped steel having high strength.

Further, according to the apparatus for bending an H-shaped steel according to the present invention, an apparatus which has a simple structure and is suitable for executing the above-mentioned bending method can be obtained. Such H
When performing bending at a desired curvature, the bending machine for a section steel prevents irregular deformation, which can be a sign of a buckling phenomenon initially occurring in both the upper and lower lateral structural portions of the H-section steel, by an inner restraining roller as a buckling prevention mechanism. It is configured as follows. As a result, the bending stress applied to the H-shaped steel from the main bending apparatus acts on the entire H-shaped steel on average, and the deformation center line shifts, thereby achieving the initial purpose.

[Brief description of the drawings]

FIG. 1 is a model diagram showing the principle of a method for bending an H-shaped steel according to the present invention.

FIGS. 2A and 2B are a front view (A) and a BB view (B) showing a configuration example of an H-section steel bending apparatus according to the present invention.

FIGS. 3A and 3B are a front view (A) and a BB view (B) showing another example of the configuration of the H-section steel bending apparatus according to the present invention.

FIGS. 4A and 4B are a front view (A) and a BB view (B) showing still another configuration example of the H-section steel bending apparatus according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Fixed roller 12 Press (pressure) roller 14 Outer pressing roller 16 First inner pressing roller 18 Second inner pressing roller 26A, 26B: 28A, 28B Each pair of inner pressing rollers

Claims (5)

[Claims] 1. A deformation center line in a vertical structure portion of an H-shaped steel to be bent is shifted to an inner diameter side, a compressive stress acting on an inner diameter side is reduced, and an elongation deformation on an outer diameter side of the H-shaped steel is mainly performed. H is characterized by performing a bending process with a curvature.
Bending method for mold steel. 2. A method according to claim 1, wherein the first member is provided on an outer diameter side when bending.
In an H-shaped steel bending apparatus having a pair of fixed rollers and a press roller for pressing an H-shaped steel as a workpiece placed along the both fixed rollers from the inside diameter side, in the vicinity of the middle of the both fixed rollers A buckling prevention mechanism comprising: an outer pressing roller disposed at a first position; and a first inner pressing roller disposed opposite to the outer pressing roller and sandwiching an outer diameter side lateral structure portion of the H-shaped steel from the inside. An apparatus for bending an H-shaped steel, comprising: 3. The buckling prevention mechanism further includes a second inside pressing roller facing the press roller and holding the inner side lateral structure portion of the H-shaped steel from the inside. The bending apparatus for an H-shaped steel according to the above. 4. The H according to claim 2, wherein a plurality of the first inner pressing rollers are provided, and a plurality of the second inner pressing rollers are provided.
Bending equipment for section steel. 5. The H-section steel bending apparatus according to claim 2, wherein the first inner pressing roller and the second inner pressing roller are supported by an integral frame. .