JPS5858937A - Method and device for on-line adjusting edge bending of band steel - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for on-line adjustment of the bending of a steel strip edge during the production of spirally jointed pipes, as well as an apparatus for carrying out this method.

As is well known, hot-rolled wide steel strips manufactured by continuous rolling may be curved in the horizontal direction due to the properties of the semi-finished product, so-called slab, or due to obstacles in the rolling process. Such strip bulges appear especially at the front and/or rear ends of the strip and are commonly referred to as cambers.

If such a steel strip is processed into, for example, a spirally jointed pipe, it will be tapered and a pipe piece will result, or as a result of the usual sizing operation, a cylindrical pipe piece with stepped weld edges will result. At this time, the edge belonging to the longer side of the curvature protrudes outward, making the curvature more noticeable.

Two phenomena, namely the discrepancy of the taber and the edge, are in the case of tubes.
This is undesirable and manufacturing standards dictate strict tolerances.

Exceeding the allowable limit will result in tedious correction work or disposal of the finished product. The large curvature of the curved steel strip necessitates the use of a rolled steel strip in a wound coil.

When forming the strip into a spirally seamed tube, the peripheral band of the strip behaves differently than the remaining area of the strip width, with the edges protruding outwards after shaping. This phenomenon, called the bulge or bamboo effect, varies in degree depending on the pipe diameter, wall thickness, width and quality of the steel strip, and in modern pipe making equipment, the peripheral zone of the steel strip is still flat before forming. A measure is taken to pre-bend the strip in the opposite direction to the bulge, that is, toward the surface of the steel strip that forms the inside of the tube.

It is an object of the present invention to manufacture spirally jointed pipes that identify the direction and magnitude of recoil in a steel strip and correct the bending according to this information so that edge deviations are kept within acceptable limits. It is an object of the present invention to provide an on-line 1i4u method for bending the edge of a steel strip during the process, as well as an apparatus for implementing this method.

To achieve this objective, we propose the method and device as defined in the claims.

By the method of the present invention, shape errors (curvature) existing in the strip material
can be identified online, the edge lengths can be compared, and different bends can be applied to the strip edges to compensate and avoid manufacturing errors that previously appeared.

When carrying out this method, it is not possible to use the known method of determining approximately the curvature of the arc by the length and height of the string. The only requirement is that the measuring length be long enough to hold it.With existing equipment, this prerequisite can only be achieved at extremely high cost.In the method according to the invention, the curvature of the arc of the steel strip is adjusted to the inner edge of the steel strip. and the arc length of the outer edge.

The accompanying drawings schematically show possible embodiments of the device according to the invention.

Measuring rolls 1 and 2, which can be adjusted to the width of the strip in FIG. 1, are operated by adjusting elements 3, 4;
Acts perpendicular to the edge of the strip.

The steel strip is guided vertically by height guide wheels 5, 6, as shown in FIG. Measuring rolls 1 and 2;
A pulse generator known per se is connected via a calculator and a regulating device for the modification of the edge bending device known per se as shown in FIG. This edge bending device consists of a back roll 7 and bending rolls 8,9.

Figures 4 and 5 show the situation of edge deviation and bulge.

According to the present invention, the curvature of the steel strip is measured by comparing the edge length L1 through which the measuring roll 1 passes and the edge length L2 through which the measuring roll 2 passes for each section using a relational expression. here 8
is the edge width of the steel band, and R is the middle diameter of the curvature. The horizontal movement of the strip is controlled or prevented by means of so-called lateral guides arranged at least immediately after the unwinding table and immediately before the forming part of the equipment, so that the warping of the measuring region can be avoided by moving the measuring roll to 1111.
It becomes clear because it is displaced in the direction of action of the m element 3.4.

By detecting the position of the measuring roll, the computer can subject the radius of curvature measurement to program control. Taking into account the relationship between the magnitude of the curvature of the steel strip and the magnitude of the deviation, which has emerged from experience and theoretical considerations, it is possible to determine the subsequent edge bending of the strip according to the curvature results of the warpage measurements. It is corrected. In that case, pay attention to the distance between the measurement line and the bending line and the strip speed.

[Brief explanation of the drawing]

FIG. 1 is a schematic plan view of the configuration of the device, FIG. 2 is a front view of the device, FIG. 3 is a schematic diagram of the device known per se,
The figure shows a diagram of two abutting edges of a steel strip with edge offset, and FIG. 5 shows a diagram of a peripheral band of a steel strip with a raised or bamboo effect. Measuring roll, 3.4... Adjustment element, 5.6... Height guide wheel. Fig, 4 Fjg, 5

Claims (1)

[Claims] l) A method for on-twin adjustment of the edge bending of a steel strip during the manufacture of helical A9 pipes, in which the curvature of the steel strip in the horizontal direction is adjusted when the steel strip is unwound from the coil. The edge O-bend is corrected by constantly mechanically detecting the arc length of the inner and outer edges of the strip and comparing the target and actual values at adjustable intervals. , a method characterized in that the short r end fine O local marginal zone is pre-bent a little. 2) Height guides acting on the edge Kfli of the strip, which can be adjusted to the width of the strip and are fixed above and below the strip in the area of the strip edge with adjusting elements 3 The single wheel 5 is connected to the machining roll 6 and the measuring rolls l and 2, and is responsive to the rotation thereof, and is connected to the back roll 7 and the bending roll 8 and the measuring roll 9.
Claim 1, characterized in that there is an adjustment device for modifying an edge bending device consisting of triple rolls with adjustable mutual spacing = 3J, and a pulse generator connected via a computer. Apparatus for the implementation of the method. 3I Claims characterized in that the widths of the measuring rolls l and 2 are configured so that any copper thickness can be detected! The device according to item 2. 4) Device according to claims 2 and 3, characterized in that the measuring rolls 1, 2 can be moved on a line 12 perpendicular to the edge of the strip.