JPS60118330A - Manufacture of shape steel - Google Patents

Abstract

PURPOSE:To obtain shape steel whose corner part has a good shape by heating locally a part to be bent in the width direction of a plate material, detaining the plate material by upper and lower rolls for placing a heating part between them, compressing it in the width direction, increasing the thickness of the heating part, and executing bend working by the rolls. CONSTITUTION:A part to be bent A in the width direction of a long plate material 1 is brought to a temperature rise by flame heating and high frequency heating. The plate material 1 of both sides of the heating part A is placed between upper and lower rolls 2, 3, rotated and fed, and also the thickness of the heating part A is increased by applying a pressure by a roll 4' from both ends of the plate material 1. This heated and thickness increased plate material 1 is brought to bending roll works 5', 6', and shape steel of a prescribed shape is obtained. The corner part is increased in thickness and becomes a good bending part.

Description

[Detailed Description of the Invention] The present invention relates to a method for manufacturing a section steel, and aims to provide a method for easily and appropriately manufacturing a section steel from a plate material by bending ◇ Section steel As a manufacturing method, a method is generally used in which a thick inner material is sequentially rolled into a desired shape using a groove rolling mill, etc., but this method requires a large number of rolling mills and costs 4 Ks.
Even for the same type of section steel, the hole shape is determined by the size of the section steel to be rolled. Therefore, a hole shape (rolling roll) for each size is required for all stands, and for this reason, the hole shape is determined by the size of the section steel to be rolled. There are drawbacks such as the need for role reshuffling. In contrast to such a method using a groove rolling mill, there is a method of manufacturing steel sections by cold bending plate materials, and this method does not require a large number of rolling mills. Another advantage is that by using a plate material with the required width and thickness, it is possible to manufacture section steel of any size.

However, with this method, as shown in Figure 1 (a), a large radius is formed on the outside of the bent part (outside of the crest in the case of angle iron), and the thickness of that part is There is a problem that the thickness (single layer) is thinner than the other parts (t,), and in the case of thick materials, if the inner radius of the bent part is not made large, as shown in Figure 1 (b) A crack on the outside (
There is also the problem of causing C). Furthermore, since it is cold worked, there is also the problem that the angles of peaks etc. may not be constant depending on the thickness and material of the plate due to springback.

The present invention has been devised in view of the above-mentioned conventional problems, and aims to provide a method of manufacturing a section steel from a plate material by bending without causing the above-mentioned problems. For this purpose, after locally heating the plate material in its width direction, the thickness of the heating area is partially increased by applying compression in the width direction while restraining it with upper and lower rolls, and then the heating area is heated in the upper and lower rolls. The bending process is performed while reducing the pressure.

An embodiment of the present invention will be described below with reference to the drawings.

FIGS. 2(a) to 2(c) show an embodiment in which the present invention is applied to the manufacture of angle iron.

First, in the present invention, as shown in (a), in the width direction of the plate-shaped material (1), the center part where the peak part is to be formed is locally heated (
A) Do it. This heating can be performed by an appropriate method such as flame heating or high frequency heating.

Next, as shown in FIG. 2(b)K, compression is applied in the width direction of the plate-shaped material (1) K to partially increase the thickness of the heating part (A). This kind of partial thickening of only the heating part (A) is
The purpose of this is to prevent thinning of the bent portion due to the bending process described later. This processing is carried out using a 4-axis rolling mill, and the plate material (1) is restrained on its upper and lower surfaces by the upper roll (2) and the lower roll (3) K, while the left and right vertical rolls (4)
By (4), horizontal reduction is applied, and only the heated part (A) is partially compressed and thickened by this K. In such a process, the plate material (1) is locally heated only in the part where the thickness is increased, so even if compression is applied in the width direction, buckling in other parts is appropriately prevented. In this example, the upper and lower rolls (2) and (3) are heated.

A concave portion that restrains the plate material (1) including the portion (A) and thus allows the above-mentioned thickness increase? The upper roll (2) K is formed with a mask. You can also top roll like this (
By forming recesses 9 in 2), the thickness is increased only on the upper surface side of the plate material which should be outside the crests of the angle iron. ) The main purpose of the restraint is to prevent buckling of the material, especially the heating part.For this purpose, the parts on both sides of the heating part (A) may be pressed to be restrained by upper and lower rolls. After processing, the plate material (1) is bent into a section steel shape using upper and lower pulls (5) and (6), i.e.,
As shown in Fig. 2 (c) K, the thickened heating section (A) is rolled by an upper roll (5) and a lower roll (6) having holes corresponding to the ridges of the angle iron. By this rolling, the heated part is bent while reducing the thickness by rolling and formed into a predetermined cross-sectional shape of angle iron.In addition, (7) is a presser roll of To9, both sides of the material during the above bending process. is pressed downward.

This type of bending process is performed by locally heating the part to be processed, so it is possible to perform the process with a small i load, and it is also possible to
It is possible to suppress the deviation of the peak angle due to spring back, and in particular, the thickness of the heated part is increased and the surface is flattened by a pul. It is possible to bend the thick material at a predetermined angle without causing cracks on the outside of the crest, and the radius on the outside of the crest can be kept small.

Figure 3 (A) and (C) show the case in which the present invention is applied to the production of channel steel. In this case, first, as shown in (A), the portions that will become the corners are heated. (A) (A)
L and then (B), while restraining both sides of (A), the vertical roll (A) (A) is thickened. Then, the plate material (1) that has been thickened in this way is bent by rolling and formed into a section steel shape as shown in ()S in the same figure.
In this example, the above-mentioned processing is carried out by the lower roll (6) and the first rolling mill, and the heating part (A) is reduced in thickness by rolling and subjected to the bending process to form a predetermined channel steel. Molded into a cross-sectional shape.

In the above-described embodiments, a multi-stage rolling mill is used to sequentially bend the plate material from a shallow angle to a predetermined angle, thereby making it possible to perform the instant forming shown in each figure (c).

According to the method of the present invention described above, it is possible to perform the processing with high precision without causing distortion due to springback etc. with a small load, and in addition, it is possible to partially thicken the bending part in a heated state, Since this thickened part is bent while reducing the area with a roll, the bending parts such as peaks and corners may become thinner, cracks may occur on the outside of the peaks of thick materials, and even the peaks may become thinner. There is an effect that a section steel of any shape and size can be easily and appropriately manufactured from a plate-like material without causing problems such as an excessively high outer radius.

[Brief explanation of the drawing]

FIGS. 1(A) and 1(B) are explanatory diagrams showing a section steel manufactured by a conventional method. FIGS. 2(a) to 2(c) are explanatory diagrams showing step by step an embodiment in which the present invention is applied to the manufacture of angle iron. FIGS. 3(A) to 3(C) are explanatory diagrams showing step by step an embodiment in which the present invention is applied to the production of channel steel. Patent applicant Nippon Kokan Co., Ltd. Inventor Renma Furukawa Kei Okamoto Shunma Takeshi Hirasawa Patent attorney Sho Yoshihara Dou Mima Takahashi Torama Attorney Hiroko Yoshihara

Claims (1)

[Claims] After locally heating a part of the plate-shaped material in the width direction, compressing the plate-shaped material in the width direction while restraining it with upper and lower rolls K causes the heating part to partially thicken, and then 1. A method of manufacturing a section steel, characterized in that bending is carried out while pressing down a heated part from above and below.