JP2536654B2 - Control method of groove processing by milling cutter of large diameter welded steel pipe - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for controlling groove processing of a large diameter welded steel pipe by a milling cutter.

[Conventional technology]

When a large diameter welded steel pipe is manufactured by the UOE method using a steel strip, the groove dimension of the joint in the longitudinal direction is, as shown in FIG. , The root dimension v and the outer surface groove dimension w are designed.

On the other hand, when using the milling cutter to groove the joint in the longitudinal direction of this UOE type large diameter welded steel pipe,
Generally, as shown in FIG. 1, the upper copying rollers (1a) (1b)
The steel plate x upper surface is copied by the milling cutter (2a) (2
According to b), the groove of both edges of the steel sheet x is machined.

[Problems to be solved by the invention]

The milling cutters (2a) and (2b) are provided with cutter surfaces that can be cut so that the designed route dimension v and the actually measured route dimensions p and q of the steel sheet x both edge portions match.

On the other hand, the position adjustment of the upper copying rollers (1a) (1b) is
In order to obtain the designed groove dimension shown in FIG. 2, the designed inner surface groove dimension u and the steel sheet x are set to substantially the same height so that the inner surface groove dimensions m and n of both edge portions match. .

Even when the positions of the milling cutters (2a) (2b) and the upper copying rollers (1a) (1b) are adjusted as described above, the actually measured thicknesses of the steel plate x are the work side and the drive side (that is, the steel plate x). x both edge portions), the obtained groove dimensions are p≈q≈v and m≈n≈u, but the outer surface groove dimension r on one edge side and the outer surface groove on the other edge side The dimension s and the designed outer surface groove dimension w greatly differ depending on the difference in the plate thickness.

UOE type large-diameter welded steel pipe has a butt shape that is determined after being formed by O-pressing. In that case, the outer surface side (steel plate x lower surface side in FIG. 1) is the reference as shown in FIG. Since it is a surface, when the outer surface groove dimension r and the same dimension s are different (r ≠ s), a discrepancy occurs in the root surface.

The present invention has been made in view of the above problems of the prior art, in the groove processing of the UOE method large diameter welded steel pipe using a milling cutter, it is possible to obtain a good butt shape after forming It is intended to provide a control method.

[Means for solving problems]

Therefore, the groove control method of the present invention, when the upper surface of the steel plate is traced by the upper copying roller, when the groove of the longitudinal joint for UOE large diameter welded steel pipe is performed on the steel plate by using a milling cutter. In addition, the basic feature is that the plate thickness on both edges of the steel sheet is measured in advance, and the height position of the upper copying roller is adjusted based on the measured data so that the outer surface groove dimensions of both edge portions become equal. I am trying.

For example, on the basis of the plate thickness measurement data, if an operation such as shifting the edge side having the thin plate thickness downward from the copying surface of the other roller by the upper copying roller pressed against the upper surface side is performed, the O press As shown in FIG. 4, the groove dimensions r and s on the outer surface side, which is the rear reference surface, become the same at both edge portions, and there is almost no problem such as the root surfaces being inconsistent.

〔Example〕

The present inventors, when performing the groove processing of the longitudinal joint for UOE large diameter welded steel pipe using the upper profile type groove processing device using the milling cutter, as in the present invention, The discrepancy of the root surface after O-pressing was examined between the case where the height position adjustment was performed (example of the present invention) and the case where such adjustment was not performed conventionally (conventional example).

That is, the inventors of the present invention groove-processed a steel plate x having a nominal plate width of 1844 mm and a nominal plate thickness of 19.05 mm by using a groove-machining device having the same structure as that shown in FIG. At this time, immediately before the steel plate x enters the groove processing device, the plate thicknesses of the steel plate x drive side (milling cutter (2a) side) and work side (milling cutter (2b) side) are measured at three points on each side. Then, each average value was read by the CPU (3) (the measured average value was 19.35 mm on the drive side and 19.05 mm on the work side.) On the other hand, the milling cutter (2a used for the groove machining was used. (2b) is provided with a cutter surface that can be cut so that the designed route dimension v matches the measured route dimension p on the drive side and the measured route dimension q on the work side.

Then, the CPU (3) gives a height position control command to each of the upper copying rollers (1a), (1b) on the basis of the above-mentioned actually measured plate thickness data, and the outer surface groove dimension r of the drive side and the outer surface opening of the work side are opened. The height positions of these rollers (1a) and (1b) were set so that the tip dimension s coincides with the designed outer surface groove dimension w.

The table below shows the measured values when the discrepancy of the root surface after O-pressing was measured.

As shown in the table, in the case of the present invention, as compared with the conventional case in which the height position of the upper copying roller is not adjusted,
The discrepancy on the root surface after O-pressing was further reduced.

〔The invention's effect〕

As described above in detail, according to the groove control method of the present invention, the height positions of the upper copying rollers are set according to the actual plate thicknesses on both edges of the steel plate. With the butt shape, it becomes possible to reduce the discrepancy between the root surfaces of the groove processing portion.

[Brief description of drawings]

FIG. 1 is a schematic view showing an example of an apparatus for performing a groove processing of a longitudinal joint for a UOE large diameter welded steel pipe using a milling cutter, and FIG. 2 is an ideal design of a UOE type longitudinal groove. FIG. 3 is a cross-sectional view showing the groove shape, FIG. 3 is a cross-sectional view showing the joint groove butt shape after O-pressing when there is a difference in plate thickness between both edges of the steel plate, and FIG. 4 is a plate thickness difference between both edges. FIG. 6 is a cross-sectional view showing a joint groove butt shape after O-pressing when the method of the present invention is applied in the case where there is a gap. In the figure, (1a) and (1b) are upper copying rollers, (2a) and (2b) are milling cutters, and (3) is a CPU.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshiki Takizawa 1-2-2 Marunouchi, Chiyoda-ku, Tokyo Inside Nippon Steel Tube Co., Ltd. Japan Steel Pipe Co., Ltd. (72) Inventor Shuichi Kusaka 1-2-2 Marunouchi, Chiyoda-ku, Tokyo Japan Steel Pipe Co., Ltd. (56) Reference JP 61-8216 (JP, A) JP 51- 147089 (JP, A)

Claims (1)

(57) [Claims] 1. When the groove of a longitudinal joint for a UOE large-diameter welded steel pipe is to be grooved to a steel sheet using a milling cutter while copying the upper surface of the steel sheet with an upper tracing roller, both edges of the steel sheet are previously prepared. Side plate thickness is measured, and based on the measured data, the height position of the upper copying roller is adjusted so that the outer surface groove dimensions of both edge parts are equalized, and the large diameter welded steel pipe milling is characterized. Control method of groove processing by cutter.