JP2601976B2 - ERW pipe manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an electric resistance welded tube for continuously and continuously forming a strip of azurol material.

[0002]

2. Description of the Related Art Conventionally, a strip plate is sheared in a predetermined width direction by a slitter before entering an uncoiler, so that side trimming on the rear surface of the uncoiler is unnecessary. However, in recent years, a method of directly forming a roll of an as-rolled material (a strip as-rolled) without a slitter has been performed by increasing the width accuracy by automatic tentering control (AWC) of a rolling line.

[0003] However, this as-rolled material has a wide portion at the leading end and the tail end of the strip, and this wide portion is too wide at the time of pipe making, which has an adverse effect on the forming and welding of the steel pipe, or the pipe diameter of the steel pipe is reduced. There was a problem such as too large, and it could not be used.
For this reason, the wide portions before and after the splicing portion of the strip corresponding to the leading end and the tail end of the as-rolled material have no influence on the pipe making.
It was cut off at position b as a crop. And when you cut it off as a crop, the wide part is quite long,
Three to four cuts were required. In addition, as shown in FIG. 5, many of the plate joint materials have a stepped joint in the middle joint C, which causes inconvenience in forming and welding the steel pipe.

[0004]

As described above,
In the case of forming a steel pipe with an as-roll material, the crop length was long and the product yield was poor. In addition, since the crop length is long, only one end of the strip requires three to four cuts, and if the leading end and the tail end of the strip are combined, six to eight cuts are required. For this reason, the number of times of cutting becomes extremely large, and the cutting time becomes long. As a result, the operating rate of the ERW pipe production line is greatly reduced due to the extension of the time required for joining the strips. Further, a stepped portion C is formed at the joint portion of the strip as shown in FIG. 5, and when the copying roll of the cutter gets over the stepped portion, the cutter surface also moves in the width direction, so that a defective cutting shape occurs.

[0005] The present invention has been devised in order to solve such disadvantages of the prior art.
An object of the present invention is to provide a method for manufacturing an electric resistance welded pipe capable of shortening a crop length and improving a product yield, reducing the number of times of crop cutting, and improving an operation rate of an electric resistance welded pipe production line.

[0006]

SUMMARY OF THE INVENTION According to the present invention, there is provided a method for manufacturing an electric resistance welded tube in which a strip of azurol material is continuously formed directly, according to the present invention. This is achieved by cutting only the end face of the strip within the maximum strippable width.

[0007] Then, a shape measuring device for measuring the width of the strip is arranged on the entry side of the milling cutter for cutting the end face of the strip, and the width before and after the splicing portion is measured by the shape measuring device. The cutting start position and the cutting end position in the line direction are set based on this, and the band plate end face of the band joint is cut by the milling cutter within the maximum pipe-forming possible plate width.

[0008] Further, a copying roll that follows the end face of the strip is disposed immediately before the milling cutter.
The milling cutter was fixed only when the milling cutter reached the vicinity of the maximum pipe-forming possible plate width, and the copying roll was not linked with the milling cutter.

[0009] The above-mentioned maximum plate width that can be pipe-formed is too wide at the time of pipe-forming to adversely affect forming and welding of a steel pipe,
It is a plate width that does not cause a problem such as an excessively large diameter of the steel pipe.

[0010]

According to the present invention, by adopting the above-described method for manufacturing an electric resistance welded tube, the length of the crop can be shortened, and the front and rear ends of the coil (strip) conventionally used as scrap can be commercialized, and the yield can be reduced. improves. In addition, since the length of the crop is shortened, the number of times that the crop must be cut is required to be 6 to 8 times. However, the number of times to cut the crop can be reduced to 2 times, the joining time can be shortened, and the operation rate of the ERW pipe production line is greatly improved. did it.

Further, a shape measuring device for measuring the plate width is arranged on the entry side of the milling cutter, and the width before and after the joint is measured by the shape measuring device, and the cutting start position in the line direction is determined based on the measured data. And since the cutting end position was set, it became possible to automate the cutting of the joint part.

[0012] Then, at the cutting position of the normal plate width, the milling cutter is interlocked with the copying roll, and the milling cutter is fixed only when the milling cutter reaches near the maximum plate width capable of forming a pipe. Because it is not linked with, for example, when there is a stepped portion C as shown in FIG. 5 at the joint of the strip, this stepped joint can be cut with a cutter regardless of the copying roll,
No cutting defects as in the prior art occur.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the manufacture of an electric resistance welded tube, there is a range of plate widths at which a tube can be formed when continuously formed with rolls set in a combination of tube diameter and plate thickness. The present invention relates to a tube made of hot rolled as-rolled material whose rolling accuracy has been improved in recent years, and cuts only both ends of a wide portion at a tip end and a tail end of a strip to improve product yield. Hereinafter, embodiments of the present invention will be described with reference to the drawings.

The strip unwound from the uncoiler is passed from a pinch roll leveler through a looper to a pipe making facility. FIG. 1 shows the respective devices arranged in a plane.
The pinch roll leveler 3 is disposed on the rear surface of the uncoiler (not shown), and the shape measuring device 4 is disposed between the pinch roll leveler 3 and the shear 5. The joining material is welded by the welding machine 6 to the leading and trailing members of the strip that has been sheared by the shear 5 (there is also a case where the shear 5 and the welding machine 6 are one body). Milling cutter on the back surface (hereinafter called cutter)
10 are arranged.

The copying roll 7 is arranged on the front side of the cutter 10, and the cutter 10 and the copying roll 7 are mounted on a base 11. The base 11 is shifted by the cylinder 12 in the width direction of the strip.
The copying roll 7 is shifted in the sheet width direction by an electric motor 9 via a jack 8, and controls the position of the copying roll surface with respect to the end face of the strip.

In FIG. 1, the data of the strip width of the strip measured by the shape measuring device 4 is sent to the pulse generator 13, and the line speed V and the distance L (the shape measuring device 4 and the cutter 8) are used.
3 shows a state in which the calculation is performed from (between) and the position of the copying roll 7 is controlled. FIG. 2 shows the tail end 1 of the preceding material of the strip and the tip 2 of the following material. Lines a and b indicate the positions to be cut by the conventional method, and lines c and d are the positions to be cut in the case of the present invention.
In the present invention, when the pipe-forming possible width is W, the hatched portion in the figure remains, and the hatched portion is cut. After cutting, as shown in FIG. 3, the lines c and d shown in FIG. 2 are welded,
It becomes the relay part C.

The hatched portion in FIG. 4 shows one embodiment of the cutting shape, and point A is the cutting start position. Points B and D indicate the limit positions of the pipe-forming possible width W. Point C is a relay position. Point E is a cutting end position. FIG. 6 shows a cutting procedure for obtaining the cutting shape of FIG. This figure 6
In the following, the operation and role of the scanning roll and the cutter according to the measurement values of the respective measurement points A to E and the passing position thereof will be described.

In I, the roll surface of the copying roll 7 and the surface of the cutter 10 are brought into contact with the end surface of the band plate in a state in which the roll surface and the surface of the cutter 10 are parallel to the end surface of the band plate before the front and rear splicing are passed through the position of the cutter 10. It is in a state where copying has begun. In point II, when point A of the strip is passed through the center position of the copying roll 7, the copying roll 7 retreats by a necessary amount of cutting, and as shown in III, the copying is cut by the amount of retreating the cutting roll 7 (shaded portion). )Begin to. B in IV
Point roll 7 copying from the center or the center of the relay portion C copying rolls 7 at a position before L ₁ of the cutter 10 is retracted in a direction away from the strip. At this time, the shift of the base 11 on which the copying roll 7 and the cutter 10 are mounted is fixed. Next, at V, cutting is performed up to point D while maintaining the state of IV. In the case of VI, when the point D comes to the center of the cutter 10, the fixing of the shift of the base 11 is released and the copying roll 7 moves forward until it comes into contact with the end face of the strip. VII shows a state in which the copying roll 7 cuts while following the end face of the strip, and when the point E comes to the center of the cutter 10, the face of the copying roll 7 and the face of the cutter 10 The position of the copying roll 7 is controlled so that the copying roll 7 becomes the same, and cutting is performed.

In addition, as shown in FIG. 5, the intermediate joint C generally has a width difference or a width difference between the preceding material and the following material. In the present method, as shown by IV in FIG. 6, since the copying roll 7 is controlled so as to be separated from the end face of the strip before the point C, it is possible to cope with a width difference or a width deviation of the intermediate joint C.

By controlling the copying roll, cutting can be performed at a width in the vicinity of the pipe forming width W as shown in FIG.
Further, as shown in FIG. 8, it is also possible to cut straight from the copying position.

[0021]

According to the method for manufacturing an electric resistance welded pipe of the present invention in which a strip of as roll material is continuously formed directly, the amount of scrap cut in the length direction of the strip can be reduced, thereby improving the yield. Further, since the amount of scrap cutting in the length direction of the strip can be reduced, the number of times of scrap cutting can be reduced, and the operating rate of the ERW pipe production line can be improved by shortening the scrap cutting time. Furthermore, since it is possible to obtain an appropriate width accuracy capable of forming a pipe without performing full length trimming, it is possible to significantly improve welding quality and dimensional accuracy of a pipe. A desired cutting accuracy can be obtained by controlling the copying roll and the milling. (A board walk is also available.)

[Brief description of the drawings]

FIG. 1 shows a state in which each machine between a pinch roll leveler and a milling cutter 10 is arranged in a plane.

FIG. 2 shows a leading end and a tail end of a strip before cutting by a shear 5;

FIG. 3 shows a state in which the tip end and the tail end are connected by cutting with a shear 5 and then welding with a welding machine 6;

FIG. 4 shows a state in which a cutting edge is cut by a milling cutter while copying the end face of the strip with a copying roll 7, and a hatched portion is a cutting range. In this figure, the hatched portion is enlarged to clarify the cutting range.

FIG. 5 shows a state in which the width of the joint portion C in FIG. 4 is different or shifted.

FIG. 6 is a diagram illustrating a process of copying and cutting by time system.

FIG. 7 is a view showing another cutting shape of the present invention.

FIG. 8 is a view showing another cutting shape of the present invention.

[Explanation of symbols]

Reference Signs List 1 tail end of preceding material 2 tip of trailing material 3 pinch roll leveler 4 shape measuring device 5 shear 6 welding machine 7 copying roll 8 jack 9 motor 10 milling cutter (cutter) 11 base 12 cylinder 13 pulse generator A cutting start point B Possible pipe forming width point C Pipe joint width D Possible pipe forming width point E Cutting end point V Speed and direction of line L Distance between shape measuring device and cutter center W Possible pipe forming width L _{1 From the} joint part where the copying roll retreats at high speed Center distance of copying roll a, b Conventional cutting position c, d Cutting position of the present invention

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Ryoichi Habu 46-59, Ohara Nakahara, Tobata-ku, Kitakyushu-shi, Fukuoka Nippon Steel Corporation Machinery & Plant Business Department (72) Inventor Eizo Uchiyama Tobata, Kitakyushu-shi, Fukuoka Nippon Steel Plant Design Co., Ltd. (72) The inventor Yoji Hashima Inventor, Yoji Hajima 46-59 Nippon Steel Plant Design Co., Ltd., Tobata-ku, Kitakyushu, Fukuoka Prefecture (56) References JP-A-61-126924 (JP, A)

Claims (1)

(57) [Claims] 1. After cutting and joining a strip of as roll material,
In the method of manufacturing an electric resistance welded tube for directly forming a continuous pipe, only the both end faces of a wide portion of a wide portion located before and after the intermediate portion of the strip are cut into an input side of a milling cutter for cutting within a maximum plate width capable of forming a pipe. , A shape measuring device for measuring the width of the plate is provided, and the width of the plate before and after the splicing portion is measured by the shape measuring device. Is set, and a copying roll that follows the end face of the strip is disposed immediately before the milling cutter, and the joining portion is cut from the line-direction cutting start position in the range from the preset line-direction cutting start position to the cutting end position. In the range up to and including the maximum pipe-forming possible plate width, the milling cutter is moved in conjunction with the copying roll in the plate width direction of the strip plate with respect to the copying roll. The milling cutter is fixed without interlocking with the milling cutter.In addition, the milling cutter is moved in the width direction of the strip with respect to the copying roll in the range from the vicinity of the maximum pipe-forming width to the end position in the line direction. A method for manufacturing an electric resistance welded pipe, characterized in that only the both end faces of the wide strip located before and after the middle part of the strip are cut within the maximum strippable width.