SU1699680A1 - Method for making curved sections - Google Patents

Abstract

The invention relates to the processing of metals by pressure, in particular, to the technology for the manufacture of rolled sections from sheet metal. The purpose of the invention is to improve the quality by eliminating the distortion of the profile during cross-cutting to dimensional lengths and saving the metal by reducing the length tolerance. Before profiling, the strip is perforated in places of future divisions into dimensional lengths. The perforations are carried out in the areas to be profiled in a direction perpendicular to the direction of the profiling, in the form of rectangular grooves arranged in rows along lines coinciding with the cutting lines. The width of the grooves is chosen equal to 1.5-2 width of the cut line. 4 Il.

Description

The invention relates to the processing of metals by pressure, in particular, to the technology of making curved profiles of strip or sheet.

The purpose of the invention is to improve the quality by eliminating profile distortion during cutting and saving metal by reducing the tolerance for length.

Figure 1 shows a smooth perforated sheet before profiling, top view; figure 2 - section aa in figure 1; on fig.Z - profiled sheet, a cut along the cutting line; figure 4 - profiled sheet with perforation, General view.

The method of making curved profiles is as follows.

Before the beginning of the profiling, the smooth sheet is perforated (for example, with the help of punching rolls) in places of future divisions of the profiled sheet into measured lengths (Fig. 1). After perforation, smooth rolls align the perforated edges and feed the sheet into a roll forming mill. The profiled sheet (figure 4) is fed to the cutting device for measuring lengths. There, the profiled sheet is rigidly fixed with the location of the pre-perforation along the line of movement of the circular saw. This method of fixation significantly reduces the length tolerance.

After fixing the profiled sheet using a circular saw, the sheet is cut by preliminary perforation. The width of the perforation lies in the range of 1.5-2.0 from the thickness of the saw in order to avoid rubbing the side surfaces of the saw against the edges of the perforated sections, since this contact, like cutting the non-perforated profile with a saw, can cause its distortion.

Example. The method was tested on a 1-4x50-300 roll-bending unit, in which before the first formO Yu Yu Os 00

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A perforation pair of rolls was installed in the cage, and the flying saw was equipped with a mechanism for fixing the perforation of the profile relative to the saw. A cutting disc was installed with a diameter of 300 mm, 2 mm thick, made of 65G steel. The rolled profile - channel 60x32x1. Material Art. Weight per meter 0.89 kg. The length of the profile is 6 m. The length tolerance is 40 mm. The actual length of the resulting profile is 6005 mm. The tolerance is 5 mm for vils due to inaccuracy when punching. Loss of geometric characteristics of the profile did not occur. Due to the axial beating of the saw blade, the actual width of the cutting line was 3 mm.

With a perforation width of 4.2 mm (1.4x3 mm), greater than the width of the cutting line, the profile warped due to cutting also of perforated sections, the cutting line is even. The yield of products of 72%.

With a perforation width of 4.5 mm (1.5x3 mm), greater than the width of the cutting line, a distortion of the profile was observed in some cases, the cutting line was even. The yield of products 98%.

With a perforation width of 5 mm (1.66x3 mm), greater than the cutting line, the profile did not warp, the cutting line is smooth, the yield of the product is 100%.

With a perforation width of 6 mm (2x3 mm), greater than the width of the cutting line, no distortion of the profile occurred, in a number of cases there was a bend in the corners of the sheet at the points where the perforation passes into the cut part of the profile. Yield of products 95%,

With a perforation width of 6.3 mm (2.1x3 mm), greater than the width of the cutting line, no distortion of the profile was observed, a sheet bend was folded over a significant part of the profiles. The yield of products of 76%.

Based on the foregoing, an interval of 1.5-2 was chosen from the saw blade thickness and, in the ideal case (when there is no disc beat), from the width of the cutting line, ensuring an optimal course of the process.

The use of the proposed method of making curved profiles, as compared with the known, improves the quality of the profiles by eliminating the distortion of the profile during cutting, as well as saving the metal in the range of 0.6-1.0% by reducing the length tolerance.

Claims (1)

The invention The method of making curved profiles including pre-perforation of the strip in the form of rectangular grooves, alignment of the perforated edges, forming a periodic profile with flat sections between them, and dimensional cutting with a circular knife over the perforated sections, characterized by the the length and economy of the metal by reducing the length tolerance, the perforations are made in the direction perpendicular to the direction of the profiling in the sections to be profiled vania, with width, equal to 1.5-2.0 of the width of the circular knife, and before cutting to measured lengths, the circular knife is aligned with the groove until it touches the plane of the non-profiled sections. AT L Fig1 Aa VSSSlVSSS YSmYSfA FIG. 2 figl Fig.Z