JPH09174101A - Method for manufacturing profile having web and flange and press preforming apparatus - Google Patents

Abstract

(57) [PROBLEMS] To reduce the amount of tongue generated at the end of a material to be rolled in rolling a profile having a web portion and a flange portion, and improve yield and production efficiency. SOLUTION: A rough material shaped by a breakdown rolling machine or a rough shaped material cast by a continuous casting method is used as a raw material, and a shaped material including a web portion and a flange portion is formed,
In a method of manufacturing by an intermediate rolling process by an intermediate rough universal rolling machine and an edging rolling machine and a finishing rolling process by a finishing universal rolling machine, a web reduction is performed in a rolling step in the intermediate rolling process before rolling by the intermediate rolling process. 2 of both ends in the length direction of the rolled material
A method for manufacturing a profile having a web portion and a flange portion, wherein the width region of 0 to 80% is reduced in the web plate thickness direction by a pair of press dies.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a profile having a web portion and a flange portion, such as H-section steel, I-section steel and channel steel, and a press preforming apparatus, and an end portion (tip portion and tip portion). The present invention relates to a method for improving productivity (yield, efficiency, etc.) by reducing shape defects at the tail end.

[0002]

2. Description of the Related Art First, a conventional means for producing an H-section steel using a universal rolling machine by using a rough-section material having an H-shaped cross section as a raw material will be described. In the rolling process shown in FIG. 4, first, in the breakdown rolling machine 1, the rough shaped material 70 is roll-molded from the rectangular shaped steel piece 50 or the H-shaped rough shaped steel piece 60 manufactured by the continuous casting method. Subsequently, the first intermediate rough universal rolling mill 2a and the first edging rolling mill 2 provided near the first intermediate rough universal rolling mill 2a.
b, a second intermediate rough universal rolling mill 3a and a finishing universal rolling mill via an intermediate material 80 by rolling processing by a second edging rolling mill 3b provided in proximity to the second intermediate rough universal rolling mill 3a. 4, H-shaped steel 90 is rolled and manufactured.

In recent years, the near net shape (Near-ne
The shape of the cross section is H
It has also been attempted to directly or continuously cast a crude material 70 having a cross-sectional shape closer to that of the H-shaped steel 90 as compared with the rough-section steel slab 60 to omit or simplify the breakdown rolling mill 1.

By the way, in this rolling process, as the intermediate rolling progresses, a tongue as shown in FIG. 5a grows, and if it grows long, it comes into contact with guides and rolls and buckles just before it is caught in the rolling mill. It becomes a double tongue as shown in FIG. 5b, and if this is caught, there is a high risk of troubles such as breaking the roll.

In order to prevent this, hot sawing machines HS ₁ and HS ₂ are arranged on the line of the first intermediate rough universal rolling machine 2a as shown in FIG. As shown in FIG. 6, the tongues at both ends H ₁ and H ₂ of the intermediate material 80 are cut during or after the rolling by the machine 2a. As a result, the yield is reduced,
Since it takes time to cut the tongue, there is a problem that the production efficiency is reduced.

The growth of the tongue in the intermediate rolling is suppressed,
In order to improve the yield and efficiency, preform the end of the rough material 70 in the process before the intermediate rolling to suppress the stretching of the web portion in the intermediate rolling or promote the stretching of the flange portion. Is effective.

A technique for shortening the tongue in the intermediate rolling step by press-forming the ends of the rectangular cross-section steel slab 50, the H-shaped rough cross-section steel slab 60, or the rough profile 70 is disclosed in JP-A-57-149001.
Those described in Japanese Patent Application Laid-Open No. 57-177802 and Japanese Patent Application Laid-Open No. 1-143701 are well known.

First, in Japanese Patent Laid-Open No. 57-149001, "A preform is formed by compression while restraining the periphery of both ends of a steel slab in the longitudinal direction, so that the both ends of the slab are subjected to web reduction in a rolling stage. A technique is disclosed in which a recessed portion corresponding to a desired shape of the shaped steel is formed in the portion. As shown in FIG. 7, the end surface of the rectangular cross-section steel piece 50 is fixed by the molds 8 and 8'through the window holes 101 provided in the upper and lower surfaces of the restraint member 10 for restraining the periphery of the rectangular cross-section steel piece 50. It is pressed.

At this time, the width w _D of the mold is set to be substantially equal to the width of the “portion subjected to web reduction in the rolling stage”, that is, the web inner diameter w _M of the rough material 70. Further, the reason why the peripheral restraint member 10 is necessary is to prevent the excess thickness of the pressed portion from flowing in the width direction of the cross section of the rectangular cross section steel piece 50 as shown in FIG. This is because

Japanese Unexamined Patent Publication (Kokai) No. 57-177802 discloses that "the flange of the material to be rolled and the leading and trailing ends of the web portion are pressed down to the finish dimension on the exit side of the breakdown rolling mill."
That technology is described. As shown in FIG. 9, this is done by connecting the ends of the rough material 70 to the horizontal molds 8 and 8'and the vertical molds 9,
It is a method of pressing down from the vertical and horizontal directions by 9 ', a so-called universal pressing method, which is a method of pressing to almost the finish size. In this case, the molds 8, 8 ', 9,
9'restrains the rough material 70 from four directions, up, down, left and right, and presses down, so that the restraining member as in the above-mentioned Japanese Patent Laid-Open No. 57-149001 is unnecessary.

Further, in Japanese Patent Application Laid-Open No. 1-143701, there is disclosed a technique of "pressing down the inner surface of the beam blank from above and below with a mold while simultaneously restraining the front end and / or the rear end of the beam blank and both sides of the flange." Has been done.
As shown in FIGS. 10 (a) and 10 (b), this is because the H-shaped rough section steel slab 60 is constrained on both sides of the flange by the flange clamp device 11, and the H-section coarse section slab is supported by the tip restraint member 12. Since the length direction of 60 is constrained, it is possible to prevent a defective end shape similar to that in FIG.

However, these three known techniques have problems in the following two points. 1. In order to prevent the edge shape defect during preforming, pressing down or restraining from the top, bottom, left and right of the cross section of the material to be rolled (in some cases, further in the length direction of the material to be rolled) is essential. Further, particularly in the application of the technique of JP-A-57-149001, since the inner wall of the peripheral restraint member 10 after preforming receives the pressure from the material to be rolled, the restraint member 10 must be removed separately. Requires equipment. Further, JP-A-57-177802
When pressing down to almost the finish size as in Japanese Patent Publication, the pressing pressure required becomes enormous, resulting in a large scale of equipment.

2. As in Japanese Patent Laid-Open No. 57-149001, press-roll forming of the entire portion of the material to be rolled that undergoes web reduction at the rolling stage, i.e., press-forming of the entire web width at the end of the material to be rolled, In the initial stage of, the web part was not rolled down at the end of the rolled material,
Only the flange will be rolled. At this time,
Since the flange portion is restrained from extending in the lengthwise direction by the web portion (which is not subjected to rolling reduction), the flange width expansion amount increases and the flange elongation decreases. As a result, the flange width at the end of the material to be rolled is significantly larger than the flange width at other portions, causing fluctuations in the flange width in the length direction of the material to be rolled, and reducing the amount of tongue by the amount by which the flange elongation has decreased. The effect becomes smaller. Therefore, the conventional press reduction molding technique has problems in terms of equipment cost and tongue reduction effect, and it has been earnestly desired to reduce the tongue amount with as simple equipment as possible.

[0014]

SUMMARY OF THE INVENTION The problem to be solved by the present invention is tongue at the end of the material to be rolled, which is a factor that hinders the yield and efficiency in the production of a profile having a web portion and a flange portion. To reduce the amount.

[0015]

The feature of the present invention is that prior to rolling in the intermediate rolling step, the end portion of the material to be rolled is preformed by a relatively simple mechanism, and the tongue is effectively tanged after the intermediate rolling step. It is a point to provide a press reduction molding method and a press die pair that can improve the yield and efficiency by suppressing. That is, the gist of the present invention is the following two points.

(1) Using a rough shaped material shaped by a breakdown rolling mill or a rough shaped material cast by a continuous casting method as a raw material, a shaped material consisting of a web portion and a flange portion is cut with an intermediate rough universal rolling mill and edging. In a method of manufacturing by an intermediate rolling process by a rolling mill and a finishing rolling process by a universal rolling machine, prior to rolling by the intermediate rolling process, the length of the material to be rolled among the parts subjected to web reduction in the rolling stage of the intermediate rolling process A method for manufacturing a profile having a web portion and a flange portion, wherein the width region of 20 to 80% of both ends in the depth direction is reduced in the web plate thickness direction by a pair of press dies.

(2) A press for applying a pressure reduction in the thickness direction to the web portion at the end in the length direction of the rough shape material in the pre-stage of manufacturing a shape member having a web portion and a flange portion by universal rolling. One of a pair of press dies, which is a preforming device, comprising a parallel straight line portion for applying a reduction and an inclined straight line portion or a curved portion for smoothly connecting the reduction area and the non-reduction area. A press die, wherein a restraining member for suppressing the generation of tongues is provided at the end of the parallel straight portion of the die, and the press die pair is rotatable about an axis in the pressure reducing direction. Press preforming device having a pair.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION The operation of the technique of the present invention will be described in detail below. FIG. 1 shows an end preforming shape of a rolled material according to the present invention. The web thickness t _W , the web inner width W _M (this is equal to the width of the portion subjected to the web reduction in the rolling step in the intermediate rolling process), the flange width B, and the flange thickness t _F at the end of the rough profile 70. The portion 71 is in a state of being recessed with a width W _D , a length L, and a reduction amount Δt _W by a press die. In this case, it is important that the magnitude relationship between the inner web width W _M of the rough shaped material 70 and the preforming width W _D is W _M > W _D, that is, preforming is performed while leaving an unrolled region in the web width direction. Is. There are two reasons for this.

1. Preforming the entire width of the web (W _M =
W _D) Then, in the initial rolling stage in a subsequent intermediate rolling process, the ends of the rolled material is the sole reduction of the flange portion. As a result, since the web portion is not deformed at the end portion, the tongue growth is suppressed, but at the same time, the elongation in the length direction of the rolled material of the flange portion is also suppressed, so that the rolled flange portion widens, The flange width B is significantly increased.
This leads to fluctuations in width in the final product. Further, since the elongation of the flange portion in the length direction of the rolled material is suppressed, the effect of shortening the tongue is finally diminished.

2. Preforming the entire width of the web (W _M =
W _D) Then, the excess thickness to move to the web width direction is increased,
The same end shape defect as in FIG. 8 occurs, and the biting property into the rolling mill deteriorates. In order to prevent this, the surrounding restraint member 10 as shown in FIG. 7 becomes necessary.

Therefore, the preformed shape of the end of the material to be rolled must be such that it suppresses the growth of the tongue and at the same time promotes the elongation of the flange in the longitudinal direction of the material to be rolled at the initial stage of intermediate rolling. I have to. Further, it is necessary to suppress the movement of the excess thickness in the web width direction during preforming as much as possible.

The inventors studied the relationship between proper W _M and W _D , including model experiments, and as a result, 0.2 W _M ≤W _D ≤0.
We found that 8W _M is a proper value. W _D <0.2
If W _M , almost no effect of preforming is seen. Conversely, if W _D > 0.8 W _M , the end shape defect as shown in Fig. 8 becomes large and biting into the intermediate coarse universal rolling mill occurs. In addition, the flange width variation in the length direction of the material to be rolled becomes greater than the flange width control capability of the edging rolling mill, and the tongue shortening effect does not appear.

On the other hand, as shown in FIG. 1, at the time of preforming, a tongue is generated as a result of the movement of the extra thickness in the length direction of the material to be rolled. It is also important to suppress this as much as possible. For this purpose, as shown in FIG. 2, a parallel straight line portion S for applying a reduction and an inclined straight line portion for smoothly connecting the reduction region and the non-reduction region. Alternatively, the restraint member 6 may be installed almost vertically at the end of the parallel straight line portion of one of the pair of press dies 5 and 5 ′ (the upper die 5 in FIG. 2) composed of the curved portion C.

Further, in order to preform the web portions at both ends of the rough material 70 by one preforming apparatus, after preforming the web portion at one end, the web portion at the other end is preformed. Before preforming the part, it is necessary to move and position the rough shape material or the preforming device, and to rotate the press die half a turn around the pressing shaft. For this, as shown in FIG.
A pair of press dies 5, 5'supported by 13, 13 '(here, an example of a hydraulic press) is rotated by a drive motor M through a worm gear 14 about a pressing shaft AA' by a half rotation. The device may be configured.

Next, FIG. 3 shows a situation in which preforming is performed using this pair of molds. The web portion 71 of the rough material 70 has the end portion of the web portion 71 while the tip end is restrained from becoming a tongue by the restraint member 6.
As in 1 ', the thickness is reduced in the thickness direction. In this case, the movement of the surplus to the central portion in the length direction or the movement of the surplus to the width direction of the web increases.

By applying the above-mentioned technique of the present invention,
It is possible to suppress the elongation of the web portion of the intermediate material 80 in the lengthwise direction during the rolling in the intermediate rolling step, and to prevent the tongue that hinders the yield and efficiency.

[0027]

EXAMPLES An example of universal rolling of H-section steel based on the above-described means of the present invention will be described below. FIG.
In the above, the press preforming device 7 according to the present invention is installed behind the breakdown rolling mill 1, and after the rough rolling by the breakdown rolling mill 1, the rough shaped material is produced under the conditions shown in Table 1.
Both ends of 70 were press preformed. The definition of each condition item in Table 1 is shown in FIG.

After that, rolling was performed according to the pass schedule shown in Table 3 by the first intermediate rough universal rolling machine 2a and the first edging rolling machine 2b having the specifications shown in Table 2.
The rolling conditions are those for the first intermediate rough universal rolling mill 2a-first edging rolling mill 2b for H488 × 300 × 11/18. Table 3 S _W, S _F, the S _B shown in FIG. 11.

[0029]

[Table 1]

[0030]

[Table 2]

[0031]

[Table 3]

Conventionally, in the case of rolling without preforming, Table 3
The tongue length is about 1.0 at both ends in the 7th pass.
m, which was reduced to about 0.6 m by the application of the present invention. As a result, it took about 40 seconds to cut the tongue with the conventional hot saws HS ₁ and HS ₂ .
This is unnecessary and the efficiency is improved by about 10%, and the defective parts at both ends of the rolled material are reduced, resulting in a yield of about 0.2%.
Improved.

Although hot rolling of H-section steel is taken as an example in the present embodiment, it can be applied to shape steels other than H-section steel, such as I-section steel and channel steel. It is needless to say that the present invention can be applied to the rolling of shaped materials other than steel.

[0034]

According to the effects of the present invention, the amount of tongue generated at the end of the material to be rolled can be reduced in the universal rolling of the profile having the web portion and the flange portion, and the yield and the production efficiency can be improved. It has become possible.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an end preforming shape of a material to be rolled according to the present invention.

FIG. 2 is a press preforming apparatus of the present invention, (a) is a side view and (b) is a front view.

3A and 3B are diagrams showing an implementation state of edge preforming of a material to be rolled according to the present invention, in which FIG. 3A is a side view and FIG. 3B is a front view.

FIG. 4 is an explanatory view showing an example of a rolling process for producing an H-section steel.

FIG. 5 (a) is an explanatory view showing a tongue shape generated at both ends of a material to be rolled in universal rolling of H-section steel, (b).
FIG. 3 is an explanatory view showing a double tongue that occurs when the grown tongue bites into the universal rolling mill.

6 (a) and (b) are for preventing double tongue,
FIG. 4 is an explanatory view showing a situation where the tongues at both ends of the material to be rolled are cut by a hot sawing machine provided in the rolling line of the first intermediate coarse universal rolling mill 2a.

FIG. 7 is an explanatory view showing a situation of press preforming of an end portion of a rolled material according to a conventional technique.

FIG. 8 is an explanatory diagram showing an end shape defect that occurs when a web portion of a material to be rolled is pressed and pressed without a peripheral restraint member.

FIG. 9 is an explanatory view showing a situation of press preforming of an end portion of a rolled material according to a conventional technique.

FIG. 10 is an explanatory view showing a state of pre-forming of an end portion of a rolled material according to a conventional technique, (a) is a side view, and (b) is a front view.

FIG. 11 is a symbol explanatory view of the section steels shown in the examples.

[Explanation of reference numerals] 1: Breaking rolling mill 2a: First intermediate rough universal rolling mill 2b: First edging rolling mill 3a: Second intermediate rough universal rolling mill 3b: Second edging rolling mill 4: Finishing universal rolling mill 5 5 ': Press die pair according to the present invention 6: Restraint member attached to the press die according to the present invention 7: Press preforming apparatus according to the present invention 8, 8': Horizontal die pair in the prior art 9 , 9 ': Vertical mold pair 10 in the conventional technique: Peripheral restraint member 101 in the conventional technique 101: Window provided in the peripheral restraint member in the conventional technique 11: Flange clamp device 12 in the conventional technique 12: Tip restraint member 13 in the conventional technique, 13 ': Pressing machine (example of hydraulic pressing machine) 14: Worm gear 50: Rectangle section billet 60: H-section rough section steel 70: Coarse shaped material 71: Web portion of coarse shaped material 71 ′: Recessed portion pressed down by web portion of coarse shaped material 72: Flange portion of coarse shaped material 80: Intermediate material 81: Web portion of intermediate material 82: Intermediate material flange 90: H-shaped steel

Claims (2)

[Claims] 1. A profile comprising a web part and a flange part, using a rough profile shaped by a breakdown rolling machine or a rough profile cast by a continuous casting method as a raw material,
In a method of manufacturing by an intermediate rolling process by an intermediate rough universal rolling machine and an edging rolling machine and a finishing rolling process by a finishing universal rolling machine, a web reduction is performed in a rolling step in the intermediate rolling process before rolling by the intermediate rolling process. 2 of both ends in the length direction of the rolled material
A method for manufacturing a profile having a web portion and a flange portion, wherein the width region of 0 to 80% is reduced in the web plate thickness direction by a pair of press dies. 2. A prepress for applying a reduction in the thickness direction to the web portion at the end in the length direction of the rough shape material at the pre-stage of manufacturing a profile having a web portion and a flange portion by universal rolling. A molding apparatus, which comprises one of a pair of press dies composed of a parallel straight line portion for applying a reduction and an inclined straight line portion or a curved portion for smoothly connecting a reduction region and an unreduction region. A press die pair characterized in that a restraint member for suppressing the generation of tongues is provided at the ends of the parallel straight portions of the die, and the press die pair is rotatable about an axis in the pressure reducing direction. Press preforming apparatus having a.