JPH0118803B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for rolling angle iron, and aims to provide a so-called size-free rolling method that allows angle iron of various sizes to be rolled by sharing a rolling roll. When rolling angle iron (including equilateral angle iron, scalene angle iron, and scalene angle iron and thickness angle iron; the same shall apply hereinafter), a hole shape (closed hole shape) is cut between the upper and lower rolls,
A common practice is to roll the material by passing it through several holes. FIG. 1 shows an example of the hole shape in that case. However, in this type of rolling method, the shape of the hole is determined by the size of the shape steel to be rolled, even for the same equilateral angle shape, so a hole shape (rolling roll) for each size is required for every stand. For this reason, it is necessary to rearrange the rolls every time the size is changed, and the time required for this roll rearrangement work is a major factor in reducing productivity. In addition, in this rolling, flaws are likely to occur on the surface of the rolled material due to the abrasive action caused by lateral pressure in the groove, the rolls are subject to severe wear and rolls must be replaced frequently, and roll modifications are required to prevent wear. It has many problems, such as a high roll consumption rate because it requires a large amount of cutting. The present invention has been researched and developed in view of the problems of the conventional groove rolling method, and it suppresses roll wear and rolling defects, and also allows angle steel of any side and thickness to be rolled using a common rolling roll. The purpose of the present invention is to provide a size-free rolling method that allows for rolling. For this reason, the present invention uses a flat plate material as a rolling material, and rolls this material into a shape by a rolling mill line consisting of a 4-axis rolling mill and a 3-axis rolling mill, without using a conventional slotted rolling mill. It is a method for forming steel, and the rolling process involves the following steps:
In the initial rolling, a 4-axis rolling mill has upper and lower horizontal rolls with open holes in the shape of a mountain in the center and a pair of vertical rolls.The vertical rolls apply width reduction while the upper and lower horizontal rolls roll the material in the center. By rolling down, the material is centered while forming the original shape of the shape steel peak at the center in the width direction of the material, and in the subsequent intermediate rolling, the horizontal lower roll having the peak at the center and the roll axis are horizontal. A triaxial rolling mill having a pair of upper rolls having a convex roll surface that is inclined to have 4
(a) In a three-axis rolling mill, each upper roll is in contact with the upper surface of each side in the width direction of the material bordering on the top of the original shape part, and the horizontal lower roll is in contact with the lower surface of the material. By doing so, the area of the material is reduced while ensuring the fullness of the original shape part. (B) In the 4-axis rolling mill, the shape of the material toe and the width of the material are adjusted using vertical rolls. (A) and (B) above. Each rolling process is performed one or more times to obtain a flat intermediate rolled material, and then 4-axis rolling is performed using upper and lower horizontal rolls having chevron-shaped openings and a pair of vertical rolls for toe restraint. The machine pre-bends the flat rolled material to an angle shallower than the product angle.
Thereafter, using a three-axis rolling mill having a lower horizontal roll having a chevron-shaped roll surface and a pair of upper rolls whose roll axes are inclined with respect to the horizontal, the lower horizontal roll rolls into the flange of the chevron-shaped rolled material. Finish rolling is performed so that each upper roll touches the outer surface of each flange. Next, embodiments of the present invention will be described based on the drawings. 2 and 3 show the case where the present invention is applied to the rolling of equilateral angle steel. In the present invention, a flat plate material 1 is used as the material, and this material 1 is as shown in FIG. Rolling is carried out by a rolling mill row consisting of a 4-axis rolling mill A and a 3-axis rolling mill B. First, in the initial rolling by the above-mentioned rolling mill row, a 4-axis rolling mill A ₀ having upper and lower horizontal rolls 2 and 3 with open holes with a mountain shape in the center and a pair of vertical rolls 4 and 4 rolls the shaped steel. The protrusion formation of the original shape part m, which is to become the basis of the mountain part, and the centering of the material 1 are performed. That is, in this initial rolling, the vertical rolls 4,
4, while applying width reduction for width adjustment, the upper and lower horizontal rolls 2 and 3 in which chevron-shaped holes are formed apply reduction to the center of the material 1, thereby forming the original shape part m in the center of the material. is formed, and furthermore, the material 1 is centered by forming this original shape part m. In the subsequent medium-term rolling, a 3-axis rolling mill and a 4-axis rolling mill each having a lower roll and a pair of inclined upper rolls are used to adjust the shape and width of the toe of the material and to ensure that the original shape is filled with meat. The area of the material is reduced and stretched. In this embodiment, the material 1 has a horizontal lower roll 5 having a peak in the center, and a pair of upper rolls 6, 6 whose roll axes are inclined with respect to the horizontal and have a convex roll surface. A 3-axis rolling mill B ₁ , a 4-axis rolling mill A ₁ having upper and lower horizontal rolls 7 and 8 having open holes with a mountain-shaped center and a pair of vertical rolls 9 and 9, and the above-mentioned 3-axis rolling mill. Like _B1 , it is sequentially rolled by a triaxial rolling mill _B2 having a horizontal lower roll 10 and a pair of upper rolls 11, 11, and is rolled to a predetermined thickness and side length while remaining flat. In the three-axis rolling mills B ₁ and B ₂ , each upper roll is in contact with the upper surface of each side in the width direction of the material bordering on the top of the original shape part m, and the horizontal lower roll is in contact with the lower surface of the material, so that the thickness of the original part m is reduced. Rolling is carried out over the entire width of the side including the original shape part so as to ensure sufficient filling. That is, both upper rolls 6, 6 and 11, 11 inclined with respect to the material 1 apply a vertical reduction to the flat portions on both sides of the original part m, and also apply a horizontal reduction to the original part m. The area of the material 1 is reduced and stretched while ensuring the fullness of the original shape. Further, in the four-axis rolling mill _A1 , the toe shape and material width of the material 1 are adjusted by the vertical rolls 9, 9. In such intermediate rolling, the rolling by the 4-axis rolling mill A and the rolling by the 3-axis rolling mill B may be performed one after the other, or the material may be reciprocated between the rolling mills until it reaches a predetermined thickness and side length. You can force it. Further, by appropriately combining rolling mills B and A, it is possible to continuously roll the material. The material is formed into a flat state close to the product size by the above-mentioned intermediate rolling and then subjected to finish rolling. Prior to such finish rolling, preliminary bending is performed to bend the flat material 1 to an angle shallower than the product angle.
This pre-bending is performed at each cross-sectional area of the material at the initial stage of biting into the finish rolling machine, when a thick material is rolled from the flat shape of intermediate rolling to the shape of angle iron. This is because the upper and lower horizontal rolls 12, 13 and vertical rolls 14, 14, and the horizontal rolls 12, 1
A 4-axis rolling mill A ₂ having a chevron-shaped open die with a shallower angle than the product angle between the three is used to roll (mainly bend) a flat material. Note that in this step, the vertical rolls 14, 14
The toes are also molded. In the finish rolling process, the horizontal lower roll 15 is rolled by a three-axis rolling mill B _F having a lower horizontal roll 15 having a chevron-shaped roll surface and a pair of upper rolls 16, 16 whose roll axes are inclined with respect to the horizontal. is rolled so that it hits the inside surface of the flange of the mountain-shaped rolled material (material 1), and each upper roll 16 hits the outside surface of each flange, and the angle of the top of the mountain is brought out here and it is finished to a predetermined dimensional accuracy. It will be done. The upper rolls 16, 16 of this rolling mill _BF contact the material over the entire width of each side, but as a general rule, no reduction is applied in the horizontal direction as in the triaxial rolling mill _B2 in the intermediate rolling. The above-mentioned triaxial rolling mill B _F includes entry press rolls 17, 17, and 18 that press down each side and the top of the rolled material, and a guide that restrains the toe part to evenly control the elongation of the left and right sides. Rollers 19, 19 are provided, respectively. In the method of the present invention as described above, it is possible to roll angle steel of any side length (and shape width) and thickness by adjusting the position of the vertical rolls of the 4-axis rolling mill and adjusting the roll opening. Moreover, it is applicable not only to the rolling of equilateral angle shape steels as in the embodiments, but also to scalene angle shape steels and scalene angle shape steels. [Example] A Equilateral angle steel of each size from AB50 x 50 to AB75 x 75 was rolled by the method of the present invention and the conventional groove rolling method, and the total caliber number, average roll unit consumption, and surface of both were The degree of occurrence of scratches is compared and shown in Table 1. As the rolling procedure, the process shown in FIG. 2 was adopted in the present invention, and the process shown in FIG. 4 was adopted in the conventional method.

[Table] As can be seen from the table, in the present invention, the number of calibers is significantly smaller than that of the conventional method, and the roll consumption rate and occurrence of surface scratches are significantly reduced compared to the conventional method. The sizes (JIS sizes) formed by rolling using common rolling rolls in these examples are as follows. AB50×50×4mm AB65×65×6mm 〃 50×50×5mm 〃 65×65×8〃 〃 50×50×6〃 〃 70×70×6〃 〃 60×60×4〃 〃 75×75×6 〃 〃 60×60×5〃 〃 75×75×9〃 〃 65×65×5〃 〃 75×75×12〃 B Table 2 shows the results of size-free rolling according to the present invention. The table shows two sizes (AB50×
50 x 5, AB75 x 75 x 6) equilateral angle steel for the second
The figure shows the width and wall thickness dimensions at each rolling stage when the same rolling rolls are used for manufacturing in the rolling process shown in the figure.

[Table] *Thickness of horizontal roll rolling part The rolling method of the present invention described above has the following effects. (i) Angle steel can be manufactured from a flat plate material using only a 3-axis rolling mill and a 4-axis rolling mill, and angle steel of any side length and thickness can be rolled using the common rolling rolls of each of the above rolling mills. can do. Therefore, the size can be changed without having to change the rolls as frequently as in the past, and the time required to change the rolls can be shortened and the productivity of the product can be significantly increased. In addition to this, the present invention has various other excellent effects, such as reducing the labor required to change the rolls and reducing wear of the rolls and rolling defects on the product since no holes are used. (ii) In intermediate rolling, by applying triaxial rolling equipped with a horizontal lower roll and a pair of upper rolls with inclined roll axes, vertical reduction is applied to the flat parts on both sides of the original shape part of the mountain part of the section steel, and Since rolling is performed by applying a reduction in the horizontal direction to the original shape part, it is possible to efficiently reduce the area and stretch the material while ensuring that the original shape part is sufficiently filled with meat. (iii) In addition, after mid-term rolling, in which the material is rolled in a flat state, the rolled material is pre-bent at an angle shallower than the product angle, and then finish rolling is performed to finish it into the final shape, resulting in poor biting in the finishing mill. It is possible to obtain a product of good quality without any troubles such as vibration or occurrence of vibration, and without defects such as scratches and sink marks, and without producing ridges.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing an example of a groove shape in conventional groove rolling. FIG. 2 is an explanatory diagram showing the rolling of equilateral angle steel according to the present invention in the order of steps. FIG. 3 is a plan view of a rolling mill row used for implementing the present invention. FIG. 4 is an explanatory diagram showing a rolling process in a comparative example with respect to an example of the present invention. In the figure, 1 is the material, 2 and 3 are upper and lower horizontal rolls, 4 is a vertical roll, 5 is a lower horizontal roll, 6 is an upper roll, 7 and 8 are upper and lower horizontal rolls, 9 is a vertical roll,
10 is the horizontal lower roll, 11 is the upper roll, 12,1
3 is an upper and lower horizontal roll, 14 is a vertical roll, 15 is a horizontal lower roll, 16 is an upper roll, m is an original part, A ₀ ,
A ₁ and A ₂ indicate a 4-axis rolling mill, and B ₁ , B ₂ , and B _F indicate a 3-axis rolling mill.

Claims (1)

[Scope of Claims] 1. When rolling an angle-shaped steel using a flat plate-shaped material as a rolling material using a rolling mill row consisting of a 4-axis rolling mill and a 3-axis rolling mill, first, in the initial rolling, the central portion is A 4-axis rolling machine with upper and lower horizontal rolls with open-hole shapes and a pair of vertical rolls,
By applying width reduction with vertical rolls and rolling down the center part of the material with upper and lower horizontal rolls, centering of the material is performed while forming a protruding original shape part of the shape steel mountain part in the center part in the width direction of the material.In the subsequent medium-term rolling,
A 3-axis rolling mill has a horizontal lower roll having a ridge in the center, a pair of upper rolls whose roll axes are inclined with respect to the horizontal and have a convex roll surface, and a 3-axis rolling mill with a ridge-shaped opening in the center. Upper and lower horizontal rolls having a hole shape, 1
(a) In the 3-axis rolling mill, each upper roll is in contact with the upper surface of each side in the width direction of the material bordering on the top of the original shape, and the horizontal lower roll is By rolling the material so that it is in contact with the lower surface of the material, the area of the material is reduced while ensuring the fullness of the original part. , Perform each of the above rolling (a) and (b) one or more times to obtain a flat intermediate rolled material, and then use upper and lower horizontal rolls having chevron-shaped openings and a pair of toe restraints. A 4-axis rolling mill with vertical rolls is used to pre-bend the flat rolled material to an angle shallower than the product angle.
Thereafter, using a three-axis rolling mill having a lower horizontal roll having a chevron-shaped roll surface and a pair of upper rolls whose roll axes are inclined with respect to the horizontal, the lower horizontal roll rolls into the flange of the chevron-shaped rolled material. A method for rolling angle iron, characterized in that finish rolling is performed by hitting the outer surface of each flange with each upper roll hitting the outer surface of each flange.