JPH08174024A - Method and device for manufacturing cut t shape steel - Google Patents

Abstract

PURPOSE: To provide a method and device for manufacturing a cut T shape steel formed by cutting the web of a H shape steel with high efficiency, by securing the straightness of the cut T shape steel after cutting, and reducing the man-hour and term of works. CONSTITUTION: Before cutting the web 2 of a H shape steel 1, the flanges 3 of the H shape steel 1 are screwed down by a roll straightening machine consisting of web screw-down rolls 10a and 10b and vertical rolls 20a and 20b. Consequently, straightening is performed so that a bending stress caused by the web screw-down rolls 10a and 10b and a compression stress caused by the vertical rolls 20a and 20b are loaded on the web section of the H shape steel 1, the residual stress of a fillet part is reduced, and the bend of the cut T shape steel after cutting the web is controlled.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a cut T-section steel which can ensure straightness and effectively produce high efficiency in producing a cut T-section steel obtained by cutting an H-section steel web. And the device.

[0002]

2. Description of the Related Art Conventionally, T-section steel has been used as a steel material for construction, but in recent years, its application is expanding as a section steel for shipbuilding as a hull reinforcing member. Since this T-shaped steel is easy to manufacture, it is common to cut the web of the H-shaped steel into the shape shown in FIG. However,
When the H-section steel web is gas-cut, for example, bending toward the flange 3 side occurs as shown in FIG. 7. This is shown in FIG.
As shown in Fig. 1, compressed into a web 2 of rolled H-section steel 1,
The flanges 3 and 3 have a tensile residual stress, and the web 2
It is a phenomenon that occurs because the disconnection of this releases it. This phenomenon has become more prominent with the recent trend toward thin web H-section steel for the purpose of reducing the unit consumption of steel materials.

When the bend shown in FIG. 7 is corrected and straightened,
The web 2 is compressed to cause buckling as shown in FIG. 9, and the commercial value is significantly reduced. In order to prevent this, in general, the web 2 of the H-section steel 1 is preheated and cut, or a part of the web 2 is cut as described in JP-A-4-81225. By leaving it and then cutting it, the web 2 is bent as shown in FIG. Cut T-section steels 5, 5 cut in this way
Generally, the straightening is performed by using a roll straightening machine, a press straightening machine, or a straightening device as described in JP-A-4-81225.

[0004]

As described above, in the conventional method for manufacturing the cut T-section steel, the residual stress in the web 2 of the H-section steel 1 and the flanges 3 and 3 at the cut surface of the web is not reduced. Therefore, for example, even if a cutting machine capable of high-speed cutting such as a laser cutting machine or a plasma arc cutting machine is used, a method of preheating the web 2 or cutting a part of the web 2 uncut should be adopted. I had no choice but to cut it with high efficiency.

Further, it is common to use a roll straightening machine or a press straightening machine to straighten the cut T-section steels 5 and 5 after the H-section steel 1 is cut. In that case, the cut T-section steel 5 is used. In many cases, the cutting place of No. 5, 5 and the straightening machine are separated from each other in the equipment layout. Therefore, the cut T after cutting
The number of man-hours for handling the shaped steels 5 and 5 is increased, and the work period is often long due to problems such as the correction timing, and the work cannot be said to have good productivity.

The present invention has been made in order to solve the above-mentioned problems, and secures the straightness of the cut T-section steel after cutting, shortens the man-hour and the construction period, and highly efficiently produces the H-section steel web. The object is to obtain a method and an apparatus for producing a cut T-shaped steel obtained by cutting.

[0007]

[Means for Solving the Problems]

(1) In the method for producing a cut T-section steel according to the present invention, before the H-section steel web is cut, the flange of the H-section steel is reduced by a roll straightening machine including a web reduction roll and a vertical roll. Correct the bending stress of the web rolling roll and the compressive stress of the vertical roll on the web section of the H-section steel to reduce the residual stress in the fillet and control the bending of the cut T-section steel after web cutting. It was done like this.

(2) Further, the reduction ratios of both flanges by the vertical rolls are set to different values, and (3) or the bending of the cut T-shape formed by cutting the straightened H-section steel web is continued. I tried to correct it.

(4) Further, the apparatus for carrying out the above-mentioned manufacturing method is a web reduction roll for reducing the H-section steel web to correct the bending, and a vertical roll for reducing both side surfaces of the H-section steel flange. Further, a roll straightening machine equipped with a device for applying a rolling force in the web height direction is arranged on this vertical roll, and a cutting device for cutting the web is continuously arranged after this roll straightening machine.

[0010]

For example, when the cut T-section steel is manufactured by gas cutting the H-section steel in the rolling direction, the cut T-section steel is bent toward the flange side. This is because there is residual stress of compression in the web and tensile stress in the flange due to strain inside the H-section steel caused by the temperature non-uniformity of the flange and the web that occurs during the cooling process of the hot-rolled H-section steel. This is a phenomenon that occurs because the residual stress is released by cutting. Such a phenomenon is solved by straightening both flanges of H-section steel with a roll straightening machine having a vertical roll before cutting the web to control the curved shape after cutting the web.

Further, even if both the flanges of the H-section steel before the web cutting are pressed by the vertical rolls of the roll straightening machine at an even reduction rate, the shape of the cut T-section steel after the web cutting cannot secure the straightness. Is solved by controlling the reduction ratio of both flanges of the H-section steel before web cutting to control the two cut T-section steels after web cutting to have substantially the same curved shape.

Further, when the cut T-section steel after cutting the web of the H-section steel cannot secure the straightness by the above-mentioned method, the flange of the H-section steel before the web-cutting is rolled by the above-mentioned method. It is solved by controlling the bending shape by straightening the flange of the cut T-section steel that has become two pieces by the web cutting, and then by cutting the web.

Further, the number of manufacturing steps by any one of the above methods,
To shorten the construction period and cut the H-section steel web with high efficiency to produce a cut T-section steel, place a roll straightening machine with a vertical roll before cutting the web, and then cut the H-section steel web. The solution is to arrange the cutting devices for cutting in series.

[0014]

1 is a side view schematically showing an embodiment of a roll straightening machine according to the present invention, and FIG. 2 is a front view thereof. In the figure, 1 is an H-section steel, 10a and 10b are web-pressing rolls which are alternately provided above and below the H-section steel 1 in a staggered manner to reduce a web, and 20a and 20b are provided on both sides of a flange of the H-section steel 1. A vertical roll for rolling down the flange, which is not shown, is equipped with a device for rolling down the vertical rolls 20a and 20b in the web height direction of the H-section steel 1, and is used to cut the hot-rolled web before cutting. The bending of the H-section steel 1 is straightened by this roll straightening machine. In addition, here, the vertical roll 20a,
Although the example in which 20b is installed on all stands is shown, the vertical rolls 20a and 20b are the web reduction rolls 10a, 10b, ...
If it is installed on at least one or more stands that are bent by the above, the effect can be exhibited.

FIG. 5 is a schematic view showing the stress state of the cross section of the H-section steel 1 when the web 2 is rolled down by the web rolling method. A compression and a tensile stress are applied to the web 2 by bending by a web pressing roll 10a which is a web pressing means, and a similar stress is also applied to a connecting portion (fillet portion) 4 between the web 2 and the flanges 3 and 3. On the other hand, the flanges 3 and 3 are bent by the reduction of the web 2,
Compressive and tensile stresses exist in the longitudinal direction of the toes, respectively. However, in this stress state, the tensile stress in the fillet portion 4 in the longitudinal direction cannot be eliminated.
Therefore, by applying compressive stress to the flanges 3 and 3 simultaneously with bending of the web 2 by the vertical rolls 20a and 20b of the roll straightener as shown in FIGS. 1 and 2, in addition to the residual tensile stress, the plasticity is added to this portion. It is designed to give distortion.

When the residual stresses in the fillets 4 and 4 of the H-section steel 1 are different, the load distribution of the vertical rolls 20a and 20b of the roll straightener is changed by the left and right flanges 3 and 3. However, in this case, the asymmetry of the residual stress cannot be known until after the cut T-section steel is cut. Therefore, in many cases, a large rolling force is applied to both flanges 3 and 3 and after cutting, An efficient method is to make the bend as shown in FIG. 10 and then correct the bend of the cut T-section steel.

It is desirable to install the vertical rolls 20a and 20b of the roll straightener for applying a compressive stress to the bending of the web 2 at each stage of the conventional web pressing rolls 10a and 10b. The effect can be exhibited by any of the driving. Of course, either a cantilever type or a both-end type straightener can be applied. And
By properly laying a guide for properly inserting the H-section steel 1 into the roll straightening machine of the present invention, a vertical roll set interval adjusting device, a vertical position adjusting device and a driving device according to the present invention, H of various cross-sectional dimensions It is possible to continuously and effectively correct the residual stress of the shaped steel.

In the H-section steel 1 thus corrected, not only the residual stress is removed, but also the vertical bending and the horizontal bending are effectively corrected by the roll straightening machine. The web 2 of the shaped steel 1 can be passed through a high speed cutting device such as a laser cutting machine or a plasma arc cutting machine for cutting at high speed.

Further, as shown in FIG. 3, in a production line comprising a roll straightening machine 30 according to the present invention, a high-speed cutting device 31, transport tables 32 and 33 of cut T-section steel, and an unloading table 34 of cut T-section steel. By arranging a straightening device 35 for finally correcting the bending of the two cut T-shaped steels 5 and 5 after cutting between the transport tables 32 and 33, and passing the cut T-shaped steel 5 through the straightening device 35. , The man-hour and the construction period of the cut T-section steel 5 formed by cutting the web 2 of the H-section steel 1 can be further shortened.

Example 1. Next, Tables 1 to 3 show comparative examples of the manufacturing method according to the present invention and the conventional manufacturing method. Table 1 shows the dimensions of the material to be straightened (H-shaped steel) and the specifications of the actual roll straightening machine, Table 2 is an intermesh comparing the present invention with a conventional web straightening method, and Table 3 is a comparison with the conventional method. It shows the effect of the present invention.

[0021]

[Table 1]

[0022]

[Table 2]

[0023]

[Table 3]

Table 3 shows that the present invention maintains the straightness of the H-section steel after cutting the web and realizes high efficiency cutting. In the combination of the roll straightening machine and the laser cutting machine according to the present invention, the curved shape after cutting the web was almost straight as shown in Fig. 6 (b), and finishing straightening was not necessary.

Example 2. Tables 4 to 6 show other examples of the manufacturing method according to the present invention and the conventional manufacturing method in comparison. Table 4 shows the dimensions of the material to be straightened (H-shaped steel) and the specifications of the actual roll straightening machine, Table 5 is an intermesh comparing the present invention with a conventional web straightening method, and Table 6 is a comparison with the conventional method. It shows the effect of the present invention.

[0026]

[Table 4]

[0027]

[Table 5]

[0028]

[Table 6]

In the present embodiment, after the first web 2 of the H-section steel 1 was cut, the two cut T-section steels 5 and 5 that were cut each showed different bends, so the vertical roll 2
Correction was performed by increasing the rolling force of 0a and 20b. By the straightening according to the present embodiment, the bending of the cut T-section steels 5 and 5 after cutting the web 2 is as shown in FIG.
After that, finish straightening was performed, but buckling of the web during straightening did not occur. It can be seen that high efficiency cutting is realized by this example.

[0030]

As is apparent from the above description, according to the present invention, the following effects can be obtained. In addition,
In the following description, the same numbers as those given in the claims are attached,
Describe the effect of each. (1) In the method for producing a cut T-section steel according to the present invention, before the H-section steel web is cut, the flange of the H-section steel is reduced by a roll straightening machine composed of a web reduction roll and a vertical roll to obtain H To correct the bending stress of the web rolling roll and the compressive stress of the vertical roll to the web section of the shaped steel, reduce the residual stress of the fillet part and control the bending of the cut T-shaped steel after web cutting. As a result, not only a high-speed cutting method can be adopted, but also the straightness of the cut T-section steel can be secured, and a high-efficiency and high-quality cut T-section steel can be manufactured.

(2) Further, in the manufacturing method of the above (1), since the rolling reductions of both flanges by the vertical rolls are set to different values, the same effect as the above (1) can be obtained.

(3) Further, in the manufacturing method of (1) or (2), the bending of the cut T-section steel formed by cutting the straightened H-section steel web is continuously corrected. Therefore, it is possible to obtain substantially the same effect as the above (1).

(4) In the apparatus for carrying out the above method, a web pressing roll for pressing down the H-section steel web to correct the bending, a vertical roll for pressing down both side surfaces of the H-section steel flange, and this vertical roll. A roll straightening machine equipped with a device for applying a rolling force in the web height direction is arranged, and a cutting device for cutting the web is continuously arranged after this roll straightening machine, which enables high-speed cutting of the H-section steel web. As a result, not only the cutting time can be shortened, but also the straightening of the cut T-section steel after cutting becomes unnecessary. Therefore, it is possible to reduce the number of man-hours and the construction period, and it is possible to manufacture a high-quality cut T-section steel with high efficiency.

[Brief description of drawings]

FIG. 1 is a side view schematically showing an embodiment of a roll straightening machine according to the present invention.

FIG. 2 is a front view of FIG.

FIG. 3 is a layout view of an embodiment of the present invention.

FIG. 4 is a perspective view of cut T-section steel.

FIG. 5 is an explanatory view showing a stress state in a conventional H-section steel straightening method.

FIG. 6 is an explanatory view showing a bent state of the cut T-section steel after cutting the web.

FIG. 7 is an explanatory view showing a bent state of the cut T-section steel obtained by cutting the web without reducing the residual stress of the H-section steel.

FIG. 8 is an explanatory diagram showing an example of residual stress of an H-section steel manufactured by a conventional manufacturing method.

FIG. 9 is an explanatory diagram showing a buckling situation that occurs when the cut steel of FIG. 7 is straightened.

FIG. 10 is an explanatory view showing another bent state of the cut T-section steel manufactured by the conventional manufacturing method.

[Explanation of symbols]

 1 H-shaped steel 2 Web 3 Flange 4 Fillet part 5 Cut T-shaped steel 10a, 10b Web rolling roll 20a, 20b Vertical roll 30 Roll straightening machine 31 Cutting machine 35 Bending straightening machine

Claims (4)

[Claims] 1. A cut T formed by cutting an H-section steel web.
In the method for manufacturing a section steel, the flange of the section H steel is reduced by a roll straightening machine composed of a web reduction roll and a vertical roll before cutting the web of the section H steel to obtain a web cross section of the section H steel. The cut T is characterized in that the bending stress of the web rolling roll and the compressive stress of the vertical roll are corrected so as to be applied, and the residual stress of the fillet portion is reduced to control the bending of the cut T-shaped steel after web cutting. Shaped steel manufacturing method. 2. The method for producing a cut T-section steel according to claim 1, wherein the reduction ratios of both flanges by the vertical rolls are set to different values. 3. The production of a cut T-section steel according to claim 1, wherein the bending of the cut T-section steel formed by cutting the straightened H-section steel web is continuously corrected. Method. 4. A cut T formed by cutting an H-section steel web.
In a manufacturing apparatus for shaped steel, a web reduction roll that reduces the H-shaped steel web to straighten the bend, a vertical roll that reduces both side surfaces of a flange of the H-shaped steel, and a reduction force in the web height direction to the vertical roll. An apparatus for producing a cut T-section steel, in which a roll straightening machine equipped with a feeding device is arranged, and a cutting device for cutting a web is continuously arranged after the roll straightening machine.