JPS638855B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a method for roll forming lightweight section steel.

As is well known, lightweight sections are made by passing strips or cut plates of strips (referred to as strips in this specification) between upper and lower caliber rolls built into a stand of about 6 stages arranged in tandem to adjust the bending angle sequentially. It is customary to manufacture the product by enlarging it and forming it into the desired cross-sectional shape.This roll-forming method requires many stands to be installed in tandem, which increases the length of the building, and also increases the product variety. There are problems such as having to prepare a large number of rolls depending on the case and requiring a considerable amount of capital, so there is a strong demand for a compact molding apparatus.

Further, while the material reaches from one roll stand to the next, the edge spacing may widen due to the spring bag, or deformation such as twisting may occur, making it difficult to control the shape.

The purpose of the present invention is to provide a method for roll forming lightweight section steel that solves the above-mentioned problems.
A single upper roll carries a steel strip of the required width, a plurality of lower rolls arranged in a circular arc facing the upper roll and concentric with the upper roll, and lower rolls installed on both sides of the lower roll. The present invention relates to a roll forming method for lightweight section steel, which is characterized in that it is formed into a desired cross-sectional shape in one pass through a forming device consisting of a shoe in which the bending angle of the subsequent bending surface gradually increases.

The method of the invention will now be described with reference to the accompanying drawings.

FIG. 6 is a side view of a forming apparatus suitable for implementing the method of the present invention, and FIGS. 1 and 2 similarly illustrate the main parts of a forming apparatus for light channel steel. A roll 2 is installed so as to be vertically adjustable as usual, and a roll shaft 3 is connected to a roll drive.

Below the upper roll 2, a plurality of lower rolls 5 are arranged on left and right roll axes on an arc 4 concentric with the upper roll, facing the upper roll 2 over a range of approximately 45° from a vertical line passing through the center of the upper roll. 6 is supported by a shoe 7, and the upper roll and lower roll of both flat rolls can be spaced apart by the thickness of the material strip steel plate 8. Although not shown, the shoes 7 on the left and right sides of the lower roll are divided according to the number of lower rolls, and the shoes mounting stands 7
It is removably fixed to a, and on the inside of each divided part, in other words, on the upper and lower roll sides, there is a bent surface 9 following both ends of the flat surface of the lower roll 5, and each lower roll 5 and the bent surface 9 constitute a caliber for each forming stage, and as the introduced steel strip 8 advances, both ends of the steel strip gradually rise to form a flange portion 10 of the channel steel.

The bending angle θ of the bending surface 9 is the OX cross section in Fig. 2,
An example of the OY cross section is shown in Figures 3 and 4, and the angle θ of the bending surface 9 on the inside of the shoe that bends the flange is, for example, in the OX cross section (Figure 3).
If the angle is 20 degrees, the angle will be 40 degrees in the next OY section (Fig. 4), and during this time the bent surfaces 9 are gently connected by flat or curved surfaces so that the angle changes gradually. In this way, the angle θ of the bending surface 9 of the shoe is gradually changed from 0° for the left and right shoes of the first lower roll to 90° for the left and right shoes of the final lower roll. In the present invention, the number of lower rolls and the bending angle θ of the shoe are set to appropriate numbers and angles, respectively, so that molding can proceed smoothly.
Further, the center angle φ of the upper roll encompassing the lower roll group is determined in relation to the flange height H and the upper roll radius R so that the locus lengths of the corner portion 11 of the product and the flange end 12 are the same.

Note that the material strip steel plate will slide on the bending surface 9 of the shoe during forming, and if there is a flaw on the shoe bending surface 9, the product will also be damaged, so the shoe should be made of a hard material such as tungsten carbide. Alternatively, a roller bearing may be incorporated into the bent surface of the shoe to prevent scratches from occurring.

To illustrate the forming process when a material strip steel plate is passed through such a forming device, as shown in Fig. 5, the strip passes from the first lower roll in (a) to the sixth lower roll in (f). The steel plate is rolled down by the upper roll into a caliber consisting of the bending surface of the shoe and the lower roll, and the bending angle of the flange part increases continuously, and the flange part is bent at a right angle in the caliber of the final lower roll. Becomes light channel steel. The material strip steel plate moves forward between each lower roll while being restrained by the bending surface of the shoe.

In the above explanation, the forming of light channel steel was explained, but it will be easily understood that light mountain section steel can be formed in the same way.

As explained above, according to the method of the present invention, light weight can be achieved by passing a steel strip through a caliber formed by one upper roll, a plurality of lower rolls, and a shoe whose bending angle changes continuously. It is possible to form shaped steel, and during forming until the final shape is reached, the steel strip is rolled down by the upper roll and slides against the shoe bending surface, so the shape of the flange part is always regulated. Unlike conventional methods, there is no deformation during transfer from one roll to the next, and variations during molding can be reduced. In addition, the molding apparatus that implements the method of the present invention requires fewer roll stands than the molding apparatus of the conventional method, and since the rolls are flat rolls, they can be used for different types of molds, and have extremely great practical effects.

[Brief explanation of the drawing]

FIG. 1 is a front view of essential parts of a molding apparatus suitable for implementing the method of the present invention, FIG. 2 is a sectional view taken from FIG. 1, FIG. 3 is a sectional view taken from FIG. FIG. 2 is an OY sectional view, FIG. 5 is a process diagram for explaining the molding process of the method of the present invention, and FIG. 6 is a side view of a molding apparatus suitable for carrying out the method of the present invention. 1...Roll stand, 2...Top roll, 4...
...Circular arc concentric with the upper roll, 5...Lower roll, 6...
... Lower roll shaft, 7... Shew, 8... Steel strip plate, 9
...Show bending surface, 10...Flange, 11...
Corner part, 12...flange end.

Claims (1)

[Claims] 1. In a roll forming method for lightweight section steel, a steel strip of a required width is formed by a single upper roll and a plurality of lower rolls arranged in a row on one arc concentric with the upper roll, facing the upper roll. , a lightweight section steel roll that is formed into a desired cross-sectional shape in one pass through a forming device consisting of shoes that are provided on both sides of the lower roll and gradually increase the bending angle of the bending surface following the lower roll. Molding method.