JPH03270811A - Edge preparation control method by means of milling cutter for large diametered welded steel pipe - Google Patents

Abstract

PURPOSE:To obtain excellent butting shapes after formation, by setting the height position of each of upper copying rollers in accordance with the actual plate thicknesses of steel plate edge sides, at the time of controlling the edge preparation by means of milling cutters for a large diametered welded steel pipe. CONSTITUTION:In a case in which the edge preparation of a UOE large diametered welded steel pipe longitudinal joint is conducted for this steel plate X by using milling cutters 2a, 2b, as the upper surface of the steel plate X is being copied by means of copying rollers 1a, 1b, the plate thicknesses of both edge sides of the steel plate X are measured beforehand. And, the height position regulation of the upper copying rollers 1a, 1b is conducted on the basis of these measured data so that outside groove sizes r, s at both edge portions may become equal. For example, if such an operation as the one in which the thinner plate thickness edge side, on the basis of the plate thickness measurement data, is shifted to the lower part than the copying surface of the other roller by as much as the plate thickness difference by means of copying rollers 1a, 1b, is conducted, the groove sizes r, s on the outer surface side which becomes a reference surface after an O press become equal, and the difference of route surfaces almost disappears.

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a method for controlling beveling of a large-diameter welded steel pipe using a milling cutter.

[Conventional technology]

When manufacturing large-diameter welded steel pipes using the UOE method using copper strips, the groove dimensions of the joint in the longitudinal direction are determined by the inner groove dimension U based on the design plate thickness T, as shown in Figure 2. , the root dimension V and the outer surface groove dimension W are designed. On the other hand, when using a milling force vine to create a bevel in the longitudinal joint of a large-diameter welded steel pipe using the UOE method,
Generally, as shown in Fig. 1, the upper copying roller (Ia) (
Copy the top surface of steel plate X using Ib). Both edges of the steel plate X are beveled using milling cutters (2a) and (2b). [Problems to be solved by the invention] The above milling cutters (2a) and (2b) cut so that the designed root dimension V and the measured root dimensions p and q of both edge portions of the steel plate X match. Equipped with a cutter surface that can On the other hand, the position adjustment of the upper copying rollers (la) and (lb) is carried out in order to obtain the designed groove dimensions shown in Fig. 2. m
and n are set to be approximately the same height so that they match. Even when the cutter surfaces of the milling cutters (2a) (2b) and the upper copying rollers (la) (lb) are adjusted as described above, the actual thickness of the steel plate X), the resulting groove dimensions are P"Fq":V and m":n
:u, but on the other hand, the outer surface groove dimension r on the edge side
The other edge side outer surface groove dimension S and the designed outer surface groove dimension W will differ greatly depending on the difference in plate thickness. For large diameter welded steel pipes using the UOE method, the butt shape is determined after they are formed using a press. In this case, as shown in Figure 3, the outer surface side (the lower surface side of the steel plate X in Figure 1) is the reference point. To become a surface. If the outer groove dimension r and the same dimension S are different (r≠S), a discrepancy will occur in the root surface. The present invention was made in view of the above-mentioned problems in the prior art, and it provides a bevel that allows a forming machine to obtain a good butt shape in beveling a large-diameter welded steel pipe using the UOE method using two milling cutters. The purpose is to provide a method for controlling processing. [Means for solving the problem] Therefore, the beveling control method of the present invention uses a milling cutter to open a longitudinal joint for a UOE large-diameter welded steel pipe while tracing the top surface of a steel plate with an upper copying roller. When preforming is performed on the steel plate, the thickness of both edges of the steel plate is measured in advance, and the height of the upper copying roller is adjusted based on the measured data so that the outer surface groove dimensions of both edges are equal. The basic feature is that the position can be adjusted. For example, based on the sheet thickness measurement data, if you perform an operation such as shifting the thinner edge side of the sheet by an upper copying roller pressed against the upper surface side by the thickness difference below the scanning surface of the other roller, the ○press The groove dimensions r and S on the outer surface side, which is the rear reference surface, are equal at both edge portions as shown in FIG. 4, and problems such as the root surfaces becoming misaligned are almost eliminated. [Example] When the present inventors performed beveling of a longitudinal joint for a UOE large-diameter welded steel pipe using a top-copy beveling device using a milling cutter, the present inventors achieved the following results as in the present invention. The discrepancy in the root surface after O-pressing was investigated between a case where the height position adjustment of the upper copying roller was carried out (an example of the present invention) and a case where such adjustment was not made as in the past (a conventional example). That is, the present inventors used a beveling device having a configuration similar to that shown in FIG.
, a beveling process was performed on a steel plate X having a nominal thickness of 19.05 m. At this time, just before the steel plate X enters the beveling device, the thickness of the drive side (milling cutter (2a) side) and work side (milling cutter (2b) side) of the steel plate X is actually measured at three points on each side. and calculate each average value by CPU
(3) (The actual measured average value was 19.35 mw on the drive side and 19.05 mw on the work side). On the other hand, the milling cutter (2
a) and (2b) are provided with a cutter surface that can cut so that the designed root dimension V matches the measured root dimension p of the drive side and the measured root dimension q of the work side. Then, cP U (3) gives a height position control command to the upper copying rollers (la) and (Ib), respectively, based on the above-mentioned actually measured plate thickness data, and adjusts the outer surface groove dimension r of the drive side and the work side. These rollers (la) are adjusted so that the outer surface groove dimension S matches the designed outer surface groove dimension W.
(lb) height position was set. The table below shows the actual values when measuring the discrepancy of the root surface after pressing. As shown in the line table, in the case of the present invention, the O
The discrepancy in the route surface after pressing has become extremely small. [Effects of the Invention] As detailed above, according to the beveling control method of the present invention, the height position of each of the upper copying rollers is set according to the actual plate thickness on both edge sides of the steel plate. Therefore, it is possible to minimize the discrepancy in the root surface of the grooved portion in the butt shape after zero pressing.

[Brief explanation of drawings]

Figure 1 is a schematic diagram showing an example of a device that uses a milling cutter to create a bevel for a longitudinal joint for UOE large-diameter welded steel pipes. A cross-sectional view showing the groove shape. Figure 3 is a cross-sectional view showing the butt shape of the joint groove after O-pressing when there is a difference in thickness between both edges of the steel plate. Figure 4 is a cross-sectional view showing the difference in thickness between both edges of the steel plate. FIG. 3 is a cross-sectional view showing the butt shape of the joint groove after O-pressing when the method of the present invention is applied in a case where there is a problem. In the figure, (la) and (lb) are the upper copying rollers, (2a)
(2b) shows a milling cutter, and (3) shows a CPU. 2 External surface Diagram external surface Diagram external surface

Claims (1)

[Claims] When beveling a longitudinal joint for UOE large-diameter welded steel pipe using a milling cutter while tracing the top surface of a steel plate with an upper copying roller, the thickness of both edges of the steel plate must be determined in advance. Beveling processing using a milling cutter for a large diameter welded steel pipe, characterized in that the height position of the upper copying roller is adjusted based on the measurement data so that the outer surface bevel dimensions of both edges are equal. control method.