JPH0832332B2 - Universal rolling method for profile with flange - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for universally rolling a profile having flanges such as H-section steel and I-section steel, and relates to a method for rolling a profile that improves the web center deviation. Is provided.

[Prior Art] A section member having a flange, such as H-section steel and I-section steel, which is generally used as a building member, is formed by a universal rolling machine having upper and lower horizontal rolls and left and right vertical rolls.
This universal rolling mill can produce various types of web thickness and flange thickness by changing the gap between the upper and lower horizontal rolls and the gap between the flange of the material to be rolled and the vertical rolls, and it is suitable for mass production. This is an effective method. However, in recent years, as the high dimensional accuracy of building members has been strongly demanded, it has become difficult for the conventional universal rolling method to form a product shape / dimension satisfying this requirement. Hereinafter, this point will be specifically described by taking an H-shaped steel as an example.

FIGS. 8 (a) and 8 (b) show the situation when H-section steel is rolled by the conventional universal rolling method, in which the axis C of the upper and lower horizontal rolls 2a and the left and right vertical rolls 2b is the same. It is on the axis.

The web 1a of the H-section steel 1 is moved by the upper and lower horizontal rolls 2a.
Also, the flange 1b consists of the left and right vertical rolls 2b and the horizontal roll 2a.
Is rolled to a predetermined thickness by the side surface of the. Horizontal roll
The projected contact length l _w between the 2a and the web 1a and the projected contact length l _f between the vertical roll 2b and the flange 1b are respectively expressed by equation (1),
It can be expressed by equation (2).

However, R _H : Horizontal roll radius R _V : Vertical roll radius Δt _w : Web actual reduction amount Δt _f : Flange actual reduction amount In general universal rolling mill, 2R _V / R _H ≈1.5 Since the reduction amount is larger than the web reduction amount, generally l _f > l _w , and the flange 1b comes into contact with the roll before the web 1a. The phenomenon that the flange comes into contact with the roll prior to the web causes a defective product shape called a web center deviation as described below. The occurrence status of the web center deviation will be described with reference to FIGS.

The H-shaped steel 1 traveling on the roller table 3 is first flanged by the side surface of the horizontal roll 2a and the vertical roll 2b.
1b is rolled and after this the web 1a by horizontal roll 2a
Is rolled. In the figure, a-a and b-b respectively show the web biting start position and the flange biting start position. Since the flange width changes every time the H-section steel 1 passes through the rolling mill, the distance h ₁ from the upper surface of the roller table 3 before and after rolling to the center x ₁ −x ₁ of the web 1 a is from the upper surface of the roller table 3. It may be smaller than the distance h ₂ from the gap center y ₁ −y ₁ of the upper and lower horizontal rolls 2a. It is well known that the roller table 3 is adjusted in the vertical direction each time it passes through the rolling mill so that h ₁ and h ₂ match each other. However, the vertical position of the roller table 3 can be adjusted by following the fluctuation of the flange width. Fine-tuning is extremely difficult. Therefore, in such a rolling situation, when the flange 1b is bitten in advance, the restraint range of the flange restrained by the side surface of the horizontal roll 2a and the vertical roll 2b is lower than the upper flange as shown by the hatched portion. Is bigger. In this state, the web 1a for moving the web 1a into the horizontal roll 2a is moved upward, and as a result, the center position x ₁ −x ₁ of the web 1a is replaced with y ₁ −y ₁ , and the center position of the flange width is changed. Moved above x ₁ −x ₁ by Δx, causing web centering. Various means for preventing such web center deviation have been conventionally proposed.

For example, in Japanese Examined Patent Publication No. 46-19167, for the purpose of making the web biting position on the horizontal roll substantially coincide with or precede the flange biting position, the ratio of the vertical roll diameter to the horizontal roll diameter is small, That is, a means has been proposed in which the horizontal roll diameter is made larger than the vertical roll diameter, or the vertical roll diameter is made smaller than the horizontal roll diameter, or the rolling pass schedule is adjusted together. However, increasing the horizontal roll diameter increases the scale of the rolling mill housing, which is economically disadvantageous. On the other hand, reducing the vertical roll diameter leads to a reduction in roll unit and roll strength. Further, it is almost impossible to make the amount of web reduction larger than that of the flange in all rolling passes. Therefore, the biting of the flange inevitably precedes the biting of the web, resulting in the deviation of the web center.

Further, in Japanese Patent Publication No. 47-49415, there is disclosed a method in which the vertical roll axis is moved in the rolling direction so that the web of the material to be rolled and the flange bite into the roll at the same position, thereby making the width of the web uniform in the width direction. is suggesting. Generally, the roll setting accuracy and the temperature distribution of the rolled material cause variations in the dimension of the rolled material before biting into the rolling mill.Therefore, always set the biting position of the web and flange of the rolled material to the roll. It is difficult to control so that they coincide with each other, and even in this method, the flange engagement position may precede the web engagement position.

In Japanese Patent Application Laid-Open No. 63-199001, a taper flange H-section steel is manufactured in which a vertical roll axis is moved during rolling in a rolling direction or an anti-rolling direction to continuously or intermittently change a flange width in a longitudinal direction. The universal rolling method has been proposed. However, this method includes the case where the flange bite point precedes the web bite point, and although it is effective for changing the flange width, the web center deviation is not improved.

Further, the applicant of the present application, in Japanese Patent Application Laid-Open No. 1-5601, makes the web stretching and the flange stretching coincident with each other when moving the vertical roll axis in the rolling direction, and the contact projection length of the flange and the contact projection length of the web A method for preventing the rolling web wave of the thin web H-section steel by moving the vertical roll axis in the rolling direction within a range up to twice the difference was proposed. This method includes the case where the flange engagement position precedes the web engagement position, as in the case of the above-mentioned Japanese Patent Laid-Open No. 63-199001, and is effective for preventing rolling web waves. Even if there was, the web center bias could not be improved.

[Problems to be Solved by the Invention] The present invention, in the universal rolling of a profile having a flange, regardless of the ratio between the horizontal roll diameter and the vertical roll diameter and the rolling pass schedule, using the conventional rolling mill train, An object of the present invention is to provide a profile having an improved web center deviation by always rolling the web biting start position earlier than the flange biting start position.

[Means and Actions for Solving the Problems] FIGS. 1 (a) and 1 (b) are views showing the relationship between the universal rolling mill for carrying out the present invention and the H-section steel of the material to be rolled. It consists of a pair of left and right vertical rolls 2b and a pair of upper and lower horizontal rolls 2a, and the axis c ₁ of this vertical roll is L in the rolling direction (arrow direction) by a moving device (not shown) with respect to the axis d ₁ of the horizontal roll. It is provided so that it can be moved. The case of H-section steel will be described in detail below as an example.

In the rolling of H-section steel, the biting start position aa of the web and the biting start position bb of the flange are the horizontal roll axis position d ₁ , the vertical roll axis position c ₁ and the contact projection during rolling. _Calculated from the lengths l _w and l _f . The reduction of the web 1a starts at a position separated from the horizontal roll axis position d ₁ by the distance of the projected contact length l _w of the web in the rolling inward direction, and the position where the roll gap is the narrowest, that is, the upper and lower horizontal rolls. Shaft core position
Completed at d ₁ . The reduction of the flange 1b is started at a position separated from the vertical roll axis position c ₁ by a distance of the contact projection length l _f of the flange in the rolling inlet side direction, and the vertical roll 2b and the horizontal roll are rolled.
This is completed at the position where the gap on the side surface of 2a is the narrowest, that is, at the vertical roll axis position c ₁ . As described above, when comparing the contact projection lengths of the web and the flange, in general universal rolling, the flange contact projection length l _f is larger than the web contact projection length l _w in most cases. The biting position bb of the flange precedes the biting position aa of the web. By moving the vertical roll axis in the rolling direction for each rolling pass by a distance equal to or more than the preceding distance Δl of the flange biting start position a-a from the web biting start position b-b, the web biting is always performed. It is theoretically possible to make the engagement start position precede the flange engagement position.

In actual rolling, the web thickness and flange thickness after actual rolling may vary from the target thickness due to differences between rolling steel bars, rattling of the rolling mill within the bars, temperature conditions of the material being rolled, etc. Considering the above, the difference Δl ′ between the substantial projected length of flange contact and the projected length of web contact can be expressed by equation (3).

Where l _f ′: Substantial flange contact projection length l _w ′: Substantial web contact projection length α _f : Fluctuation value of flange reduction (estimated from backlash of rolling mill and temperature condition difference of rolled material) α _w : Fluctuation value of web reduction (estimated from backlash of rolling mill, temperature condition difference of rolled material) Δt _f : Flange reduction (calculated from target flange thickness) Δt _w : Web reduction (calculated from target thickness of web) In other words, if the amount of movement from the horizontal roll axis position to the vertical roll axis position is set to be larger than Δl ′, the flange biting start position b− is always maintained even if the rolling environment condition changes.
The web biting start position a-a can precede b. The lower limit of the amount of movement of the vertical axis of the vertical roll in the present invention means this Δl ', and the actual reduction amount of the web and the flange of the present invention is the reduction amount calculated from the respective target thickness ( Delta] t _w, in Delta] t _f), means a value obtained by adding the respective amount of reduction varies value (α _w, α _f). In addition, the upper limit of the vertical roll axis movement amount with respect to the horizontal roll axis position d ₁ is H
It is limited by the amount of flange thickness deviation in the cross section of shaped steel. As shown in FIGS. 2 (a) and 2 (b), when the vertical roll axial center movement amount B is set to be extremely large with respect to the horizontal roll axial center position d ₁ , the flange portion 1b causes the vertical roll 2b and the horizontal roll 2a.
The portion e ₁ -e ₂ pinched by the side surfaces of and becomes smaller, and as a result, the thickness deviation Δt occurs in the flange portion over the range e ₂ -e ₃ . Therefore, when the present invention is applied to the intermediate universal rolling, it is necessary to regulate the upper limit value of the vertical movement amount of the vertical roll axis so as to be within the allowable value capable of shaping the thickness deviation Δt in the finishing universal rolling in the subsequent stage. When the present invention is applied to finish universal rolling, the upper limit value of the vertical roll axial movement amount must be regulated so that an excessive thickness deviation Δt exceeding the allowable value does not remain after final finish rolling. Of course. That is, the upper limit of the vertical roll shaft core movement amount in the present invention is set to the maximum distance from the horizontal roll shaft core position within the range in which the flange portion can be pressed, as described above. Therefore, the range of the actual vertical roll axis movement amount B is the lower limit value of the movement amount.
The B _L and the upper limit value of the movement amount are represented by B _U , which is expressed by the following equation (4).

B _L <B ≦ B _U (4) When the vertical roll axis is moved in the rolling direction within the range of the formula (4), in the conventional universal rolling, as shown in FIG.
Even when the web center deviation becomes worse as shown in (b), the web is bitten in advance as shown in (a) and (b) of FIG. 3, so the center X ₁ -X ₁ of the web 1a and the flange While the center of 1b remains the same, the center of the gap between the upper and lower horizontal rolls 2a Y ₁ −
The web 1a is guided to Y _1, and the deviation of the web center can be prevented. Further, as shown in FIGS. 5A and 5B, the distance h ₁ from the upper surface of the roller table 3 to the center x ₁ −x ₁ of the web 1a
Is equal to the distance h ₂ from the upper surface of the roller table 3 to the gap center y ₁ −y ₁ of the upper and lower horizontal rolls 2a, but if the material to be rolled is warped, the flange
1b bites in advance with respect to the web 1a, and as shown by the hatched portion, the flange restraint range restrained by the side surface of the lower horizontal roll 2a and the vertical roll 2b is larger in the upper flange than in the lower flange. . In this state, the web 1a is horizontal roll 2a
Since the web 1a is bitten in, the web 1a is moved downward and the web center is biased. Even in such a case, by applying the present invention, the flange as shown in FIGS.
It is possible to prevent the web center deviation by guiding the web 1a to the gap center y ₁ -y ₁ of the upper and lower horizontal rolls while correcting the warp of the material to be rolled by biting the web 1a ahead of the 1b. In addition,
The present invention can be similarly applied to the case where the material to be rolled is warped.

[Example] Hereinafter, an example in which the present invention is applied to an intermediate universal rolling mill when H-section steel having a web height of 900 mm and a flange width of 300 mm is rolled will be described. In this embodiment, the material is roughly rolled by a breakdown rolling mill, rolled for several passes by an intermediate universal rolling mill, and rolled to a product shape by a finishing universal rolling mill. Based on past rolling performance data from the intermediate universal rolling mill, considering the backlash of the rolling mill and the temperature condition difference of the material to be rolled, the vertical roll axis movement is performed so that the biting of the web precedes the biting of the flange in any pass. The amount was 30 mm for each pass. The results are shown in FIGS. 6 and 7. FIG. 6 shows the upper flange piece in the length direction of the steel material finished up to the product shape in two cases, 1.5 m inside from the tip and 1.5 m inside from the rear end, in the case of the conventional method and when the present invention is applied. It shows the result of measuring the difference between the width and the width of the lower flange piece, that is, the value corresponding to the amount of deviation of the web thickness center position from the flange shaft center position. Here, the flange piece width is the distance from the flange tip to the web surface in the cross section of the H-section steel. As is apparent from this figure, the deviation of the web center position (web center deviation) is greatly improved by applying the present invention. Similarly to FIG. 6, FIG. 7 shows one of the flange on the drive motor side (DS) and the flange on the non-drive motor side (FS) in the conventional method and when the present invention is applied. It is the result of measuring the difference between the upper flange piece width and the lower flange piece width in the length direction of the steel slab, and it can be seen that the deviation of the web center position (web center deviation) is significantly improved over the entire length of the steel material. . The vertical roll axis movement amount is within the range of the vertical roll axis movement amount lower limit value B _L and the vertical roll axis movement amount upper limit value B _U described above, even if uniformly set for each pass, for each pass. Even if changed, the same effect can be obtained.

[Effects of the Invention] According to the present invention, a well-known universal rolling machine capable of moving the vertical roll axis position with respect to the horizontal roll axis position is used to constantly bite the web with respect to the biting start position of the flange. Rolling can be performed with the starting position preceded, and a shaped steel having a flange with extremely high dimensional accuracy can be obtained economically and easily.

[Brief description of drawings]

Fig. 1 shows a universal rolling state of H-section steel according to the present invention, Fig. 1 (a) is a schematic plan view showing a state in which a material to be rolled is caught in a horizontal roll and a vertical roll, and Fig. 1 (b) shows ( I)
A schematic cross-sectional view taken along the vertical roll axis c ₁ in the figure, FIGS. 2 (a) and 2 (b) are plan and cross-sectional schematic views for explaining an embodiment of the present invention, and FIGS. 3 (a) and 3 (b) are rolled materials. The plane and side schematic views for explaining the embodiment of the present invention when the center position of the web thickness does not coincide with the center position of the upper and lower horizontal roll gaps. FIGS. 4 (a) and 4 (b) show that the tip of the material to be rolled is FIG. 5 (a) and FIG. 5 (b) are plan and side schematic views for explaining the embodiment of the present invention in a state where the rolled material is rolled in a state where the tip of the material to be rolled is warped upward in the conventional method. And FIG. 6 is a schematic plan view and a side view, FIG. 6 is a histogram of the difference in flange width between the conventional universal rolling method and the universal rolling method of the present invention, and FIG. 7 is a rolling material length direction between the conventional method and the present invention method. Graphs comparing the width difference of the flange pieces of Fig. 8 (a) and (b) are the conventional H Plan and side schematic showing a universal rolling conditions of the steel. 1 ... H-section steel, 1a ... web, 1b ... flange, 2a ...
Horizontal roll, 2b ... Vertical roll

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-2-147102 (JP, A) JP-A-56-122601 (JP, A) JP-B 46-19167 (JP, B1) JP-B 47- 49415 (JP, B1)

Claims (1)

[Claims] 1. A universal rolling mill comprising a horizontal roll for rolling down a web of a profile having a flange and a vertical roll for rolling down a flange. In the universal rolling method of moving to and rolling the profile, it is possible to roll the web biting in advance of the flange biting on the condition of the horizontal roll diameter, vertical roll diameter and the actual reduction amount of the web and flange. Set the lower limit of the amount of movement from the horizontal roll axis position to the vertical roll axis position,
Moreover, the upper limit of the vertical roll axis movement amount is set to the maximum distance from the horizontal roll axis position within a range in which the flange portion can be clamped between the vertical roll and the side surface of the horizontal roll. A universal rolling method for a profile having a flange, characterized in that the amount is set between the lower limit and the upper limit and rolling is performed.