JPH0147241B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for rolling H-section steel.

Conventionally, in universal rolling of H-beam steel,
The inner width allowance of the horizontal roll was determined within the dimensional tolerances of web height and flange thickness, and thereby H-beam steels with variations within the web height tolerance range were manufactured. That is, as shown in Figures 1 and 2, the internal width W of the horizontal roll is determined by the product dimensions web height (H) and its tolerance (±△H), flange thickness (t ₂ ) and its tolerance (± From the relationship △t ₂ ), the following equation is obtained.

Wmax=δ'{H+△H)-2( _t2- △ _t2 )δ}-P Wmin=δ'{H-△H)-2( _t2 +△ _t2 )δ}-P However, Wmax : Maximum internal width of the horizontal roll Wmin: Minimum internal width of the horizontal roll δ′: Web internal width hot shrinkage allowance δ: Flange thickness hot shrinkage allowance P: Margin allowance t ₂ : Flange thickness Therefore, the internal width of the horizontal roll The width usage allowance △ is determined by the following formula.

Δ=Wmax−Wmin This inner width usage allowance is generally 3 to 4 mm from the relationship between product yield, roll unit consumption (roll wear amount/rolled product amount), and web height accuracy. The variation in web height of actual products can be reduced to some extent by adjusting the flange thickness, but the maximum variation is about 2 to 2.5 mm. When precision of web height H is required,
A matching horizontal roll must be prepared and manufactured.

In the construction industry, when using rolled H-section steel, the accuracy of the web height is poor, so it is necessary to measure the actual product each time and perform on-site work.

Therefore, an object of the present invention is to improve the accuracy of the web height of H-section steel, and to increase the allowance for the inner width of the horizontal rolls, thereby reducing the roll consumption rate and improving the rolling yield. The object of the present invention is to obtain a method for rolling H-beam steel that can be rolled.

The rolling method of the present invention is characterized in that a web height rolling roll is installed separately from the H-beam finishing universal mill immediately after the universal mill to adjust the web height.

In universal rolling of H-section steel, depending on the horizontal roll width of a certain roll chance, there is an inversely proportional relationship between the flange thickness _t2 and web height H of the H-section steel, as shown in Figure 3. Manufactured within tolerances. In order to improve this, a web height adjustment device is installed to constrain the web height during rolling.

As shown in FIG. 4, this web height adjustment device 10 is configured so that the upper and lower horizontal rolls 1 are divided into two in the axial direction, and each horizontal roll 1 can be adjusted and moved in the axial direction. . As shown,
Since the flange of the H-section steel 4 is rolled while being restrained between the vertical roll 2 and each horizontal roll 1, the height of the web is precisely regulated.

The web height adjustment device may be installed directly on the finishing universal mill or, as shown in FIG. 5, on the exit side of the finishing universal mill 3.

According to experiments, the amount of reduction possible in the web height constraint rolling at this time falls within the shaded range shown in FIG. When decreasing the web height H of H-shaped steel, the web height reduction rate _H becomes positive and buckling occurs in the web outside the shaded area, and when increasing the web height H, the web height reduction rate H becomes positive.
_H is negative and outside the shaded area, dents on the outside of the flange and web thinning occur. For this reason, in the case of H-beam steel of normal dimensions, the limit for web height H adjustment is about 2.5 mm.

As a result, the web height H is |△H|max≦1
It can be stored in mm. In addition, since the flange thickness does not need to be increased by widening the inner width, the rolling yield is improved accordingly, and the width of the horizontal roll used can be expanded by more than 1.5 times compared to the conventional method.

Next, a web height adjusting device 10 for carrying out the rolling method of the present invention will be described with reference to FIGS. 7 and 8. The web height adjustment device 10 is made up of a horizontal roll 1 and a vertical roll 2. The vertical rolls 2 that roll the flange 41 of the H-section steel 4 from the outside are the same as the conventional ones. The horizontal roll 1 is divided into two in the axial direction and is configured to be movable in the axial direction, and rolls the inside of the flange 41 while holding the web 42 of the H-beam 4.

The horizontal roll 1 is a feature of the present invention, and its details are shown in FIG. Horizontal roll 1 is
A plurality of spacers 12 of an appropriate width are inserted into the center of the arbor 11, and roll rings 13 are placed on both sides of the spacers 12.
Insert the collar 14 of appropriate width on both sides.
is inserted and tightened with nuts 15 from both sides.

The width of the spacer 12 is adjusted according to the required dimensions of the H-shaped steel.
The outer diameter of the roll ring 13 and the width of the collar 14 are determined. Such a change in dimensions may be performed at the same time as the change in rolls of the finishing universal mill, prior to the start of rolling of H-beams of various sizes.

The results obtained by the rolling method of the present invention are shown in FIG.
Figure A shows the relationship between the horizontal roll usage allowance, the dimensional tolerance ΔH of the web height H, and the dimensional tolerance Δt ₂ of the flange thickness t ₂ . In the figure, the dashed-dotted line shows the results obtained by the method of the present invention, and the solid line shows the results obtained by the conventional method. Figure B shows the relationship between the horizontal roll allowance and the rolling reduction _H of the web height adjusting device of the present invention.

As can be seen from FIG. 9, according to the rolling method of the present invention, the amount of rolling that can be rolled per pair of finishing mill horizontal rolls is increased by more than 1.5 times.

[Brief explanation of drawings]

Figure 1 is a partial front view of a conventional universal mill for H-section steel. FIG. 2 is an explanatory diagram showing the main dimensions of H-beam steel. FIG. 3 is a graph showing the relationship between the horizontal roll allowance, web height dimensional tolerance, and flange thickness dimensional tolerance according to the conventional method. FIG. 4 is an explanatory diagram showing the rolling method of the present invention. FIG. 5 is an explanatory diagram showing a modification of the method of the present invention. FIG. 6 is a graph showing the results of experiments to determine the amount of reduction possible in web height constraint rolling. FIG. 7 is a front view of a web height adjusting device that implements the rolling method of the present invention. FIG. 8 is a longitudinal sectional view of a horizontal roll used in the web height adjustment device. FIG. 9 is a graph showing the effect of the rolling method of the present invention. 1: Horizontal roll, 2: Vertical roll, 3: Finishing universal mill, 4: H-beam, 10: Web height adjustment device, 41: Flange, 42: Web.

Claims (1)

[Claims] 1 Immediately after the finishing universal mill for H-section steel, a web height adjustment device is installed separately from the mill, which is equipped with a horizontal roll that is divided into two parts in the axial direction and can be moved and adjusted in the axial direction. , a method for rolling H-beam steel characterized by performing constrained rolling of web height.