JP2000246490A - Method and equipment for joining steel strips to each other - Google Patents

Abstract

PROBLEM TO BE SOLVED: To joint a preceding steel strip to a succeeding one in a remarkably well- fitted manner by moving the leading edge of the succeeding strip in the width direction so that its center position is in matched with that of the preceding strip, cutting the leading edge of the succeeding strip so that the shape of its edge is matched with that of the trailing edge of the preceding strip, and then butt-welding both edges together. SOLUTION: With the purpose of aligning the center of a preceding steel strip 1A with that of a succeeding steel strip 1B, side guide rolls 4 are arranged in a few pairs in the advancing direction across the steel strip 1 on both sides of the advancing line of the strips, and are installed with position detectors. The side guide rolls 4 are so designed that they move back and forth in the direction vertical to the advancing direction of the strip 1, and that a succeeding strip 1b is thereby moved so as to be aligned with the preceding strip 1A in the center line. The centering is performed with a space apart between the preceding and the succeeding strips 1A, 1B; the edges of these strips are butted and welded to each other after flare 5 is cut at the leading edge of the succeeding strip 1B. Computation is performed such as the center position, steel strip width and cutting position, by an arithmetic unit.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for joining steel strips, and more particularly, to a method for unwinding a steel strip wound in a coil shape, the rear end of a preceding steel strip and the steel to be moved backward. The present invention relates to a technique of joining a belt end with a welding.

[0002]

2. Description of the Related Art For example, in order to manufacture a so-called "spiral steel pipe", as shown in FIG. 6, a steel strip 1 wound in a coil shape is rewound by an uncoiler, once flattened, and continuously run. The tube 2 is formed by spirally winding.
Then, the butted portions 3 at the ends in the width direction of the steel strip 1 in a spiral shape of the tubular body 2 are welded together and integrated.

In the manufacturing process of such a spiral steel pipe, when the use of one coil of the steel strip 1 which is a raw material nears the end of the spiral processing apparatus, the steel strip (preceding steel strip 1A) is used as shown in FIG. The ends of the steel strip (the following steel strip 1B) newly unwound from the next coil are abutted against the tail end of the coil and welded to each other. Thus, the steel strip 1 can be continuously supplied to the spiral processing device without interruption, and the operation can be performed efficiently. In addition, when the rear end of the preceding steel strip 1A and the front end of the following steel strip 1B are butted, it is desirable to have as little gap as possible for the sake of subsequent welding. The tip of steel strip 1B
They are cut into appropriate shapes in advance.

The above-mentioned butting and welding operations are performed while the steel strip 1 is running. Therefore, in order to correctly connect the steel strips, it is important that the center lines 6 in the width direction (hereinafter, referred to as centers 6) coincide with each other. Normally, a reference position is provided on one side in the width direction of the steel strip (the side called the operation side is used, and the other side is called the drive side), and a side guide having a vertical axis is provided.
A roll 4 is arranged, and a steel strip 1 is attached to the side guide roll 4.
So that the side edge of

[0005]

However, according to the reference position and the method of using the side guide roll 4, for example, the flare 5 shown in FIG.
(When the steel strip is rolled in the preceding step, the width may be expanded in the width direction of the steel strip).
Even if B is moved along the side guide roll 4 on the operation side, the center deviation 7 occurs between the steel strips due to the width defect. In this case, even if the flare 5 is simply cut and the steel strips are welded together, as shown in FIG. 9, the pipe is formed through spiral processing with the slight center deviation 7 occurring. In other words, the center deviation 7 between the preceding steel strip 1A and the following steel strip 1B causes the steel strip 1 to meander, causing a change in the welding gap, which may cause not only poor spiral processing but also poor quality of the product steel pipe. Many were big problems.

[0006] In view of such circumstances, an object of the present invention is to provide a method of connecting steel strips in which the center of the preceding steel strip and the center of the following steel strip are much better matched than before.

[0007]

Means for Solving the Problems In order to achieve the above object, the inventor has made intensive studies with an eye on improving the use of side guide rolls, and has embodied the results in the present invention.

[0008] That is, the present invention relates to a method for joining steel strips in which the front end of a succeeding steel strip is abutted against the rear end of a preceding steel strip running on a spiral steel pipe production line and welded.
The center position of the following steel strip is measured, and the leading end of the following steel strip is moved in the width direction so as to match the center position of the preceding steel strip. This method is characterized in that the steel strips are joined by cutting and abutting the tips so as to match with each other, and then welding them.

Further, the present invention provides a spiral steel pipe manufacturing line, a side guide roll for pressing a side end of a steel strip, a cutting machine for cutting a rear end of a preceding steel strip and a front end of a following steel strip, and a cutting machine. In a joining apparatus for steel strips provided with a welding device for butting against each other and welding, a plurality of the side guide rolls can be moved forward and backward in the width direction of the steel strip, and a plurality of the side guide rolls are provided at both ends sandwiching the steel strip. The center position of the preceding steel strip and the following steel strip measured by moving the guide roll forward and backward, and the longitudinal position of the following steel strip whose band width matches the preceding steel strip are input, and both center positions are made to coincide with each other. Calculates the amount of movement of the succeeding steel strip in the width direction, and calculates the calculated value as the side guide /
The roll is provided with a computing unit that outputs the longitudinal position to a cutting machine. According to the present invention, when the preceding steel strip and the following steel strip are abutted, the center positions of both steel strips coincide with each other, and the cutting position of the following steel strip becomes accurate. It becomes possible. As a result, in the production of the spiral steel pipe, the spiral processing defect of the steel strip and the quality defect of the product steel pipe caused by the fluctuation of the welding gap, which have frequently occurred before, are eliminated.

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

In the conventional connecting device, since the operation side of the side guide roll 4 is always fixed at the reference position (fine adjustment is of course possible), the center deviation 7 between the steel strips shown in FIG. It was inevitable. Therefore, the inventor has corrected the problem as follows.

First, the apparatus for connecting steel strips according to the present invention includes side guide rolls on both sides of a line on which the steel strip 1 travels in order to align the centers 6 of the preceding steel strip 1A and the following steel strip 1B. 4 are provided. The side guide rolls 4 form a pair with the steel strip therebetween and are arranged in pairs in the traveling direction of the steel strip. The side guide rolls 4 sandwich the rear end of the preceding steel strip 1A and the pair of the side guide rolls 1B. Divided into Each side guide roll 4 is provided with a position detector in order to measure the width of the steel strip 1 and the center 6.
As shown in (a), the steel strip 1 moves forward and backward in a direction perpendicular to the traveling direction. A known cylinder mechanism 8 (see FIG. 1) can be used for the forward and backward movement. The side guide roll 4 also functions as a means for moving the steel strip 1B in the width direction by moving the steel strip 1B back and forth. Therefore, when the center 6 of the rear end of the preceding steel strip 1A and the center 6 of the front end of the following steel strip 1B is measured using the side guide rolls 4, the side guide rolls sandwiching the following steel strip 1B are moved in the steel strip traveling direction. And the center 6 of both steel strips can be made to coincide.

However, in order to connect the steel strips, it is not enough to just align the center 6, and it is necessary to properly abut the front and rear ends. Otherwise, inconvenience occurs at the time of welding, and spiral processing becomes difficult. Therefore, as shown in FIG. 5B, in order to align the centers 6 of both steel strips, the leading steel strip 1A and the following steel strip 1B
Are centered with a gap between them, and the flare 5 generated at the tip of the succeeding steel strip 1B is cut and then butted. It is important for the cutting to be perpendicular to the traveling direction of the steel strip and to be as close as possible to the rear end width of the preceding steel strip 1A. In the present invention, in order to correctly detect the cutting position, the side guide roll 4 having the above-described function is used.

Further, in order to perform these operations accurately, in the present invention, a computer 9 (arithmetic unit) is interposed, as shown in FIG.
The calculation of the cutting position and its output (instruction) are performed.

Next, a connection method using the above-described apparatus according to the present invention will be described with reference to the drawings and along the operation procedure. <Work procedure> 1. The rear end of the preceding steel strip 1A is cut perpendicular to the traveling direction. 2. The position of the side guide roll 4 sandwiching the preceding steel strip 1A in the width direction of the steel strip is detected, and the detected value is input to the calculator 9. 2. The leading end of the following steel strip 1B is supplied to the installation position of the side guide roll 4. 3. No. No. 1 side guide roll, No. The following steel strip 1B is sandwiched between the two side guide rolls, and the operation side positions of these side guide rolls are set to the zero point (reference position). , To the computing unit 9. 4. The arithmetic unit 9 calculates the width, the center position, and the cutting position of the following steel strip 1A and the following steel strip 1B. 5. In accordance with the output of the arithmetic unit 9, the side guide roll 4 is moved forward and backward while the succeeding steel strip 1B is sandwiched, and the leading steel strip 1 is moved.
Align A with the center position. 6. The cutting position of the succeeding steel strip 1B is adjusted to the cutting machine, and the flare 5 is cut. 7. The rear end of the preceding steel strip 1A and the front end of the following steel strip 1B are butted and welded to each other. 8. At the end of the welding, the side guide roll 4 sandwiching the succeeding steel strip 1B is opened.

The specific calculation method of the steel strip width and the center position in the calculator 9 is performed as follows. As shown in FIG. 2, the operation side reference position of the side guide roll 4 is set to zero, and the drive side is set to the + direction and the operation side is set to the-direction from that position. Accordingly, the leading steel strip No. In the three-side guide roll 4, the width of the trailing steel strip W ₃ = b ₃ -a _3,
And the center _{S 3 = W 3/2 +} a at the current strip position can be calculated. Here, the subscript numbers indicate the side guide roll numbers. Corresponding to In addition, No. 1 sandwiching the succeeding steel strip 1B. 1
And No. In 2 side guide roll 4, each N
o. Assuming that the center positions at the _first and _second positions are S ₁ and S ₂ , S
_1, the amount X of the center deviation 7 from S ₃ of S ₂ X ₁ = S ₁ -
S ₃ , X ₂ = S ₂ −S ₃ Furthermore, the cutting position of the following steel strip 1B should just find the longitudinal position of the following steel strip 1B which becomes the same as the width | variety of 1 A of preceding steel strips. Therefore, in order to correct the amount X of the center deviation 7, the No. 1 and No. 2 side guide rolls 4 move forward and backward in the width direction of the steel strip with the subsequent steel strip 1 sandwiched therebetween to perform the center alignment. Fig. 3 shows a state in which both steel strips are sandwiched between side guide rolls 4.
FIG. 4 shows the state at the stage when the position detection, calculation, and movement are all completed.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A spiral steel pipe manufacturing line was provided with a steel strip connecting apparatus according to the present invention shown in FIG. 1 on a spiral steel pipe manufacturing line. The steel type of the steel strip is general steel (40
K), having a width of 1700 mm and a thickness of 16 mm. The number of coils of the steel strip used at that time was four, and each connection was performed by the connection method according to the present invention on the upstream side of the spiral machining apparatus. The running speed of the steel strip is
At 2.8 m / min, the cutting machine is a plasma cutting machine,
An automatic submerged arc welding machine was used as the welding machine.

The results are shown in Table 1. Steel strips from any of the coils could be connected smoothly. As a result, the relay operation time of the target coil was reduced by 8.3% on average.

[0019]

[Table 1]

[0020]

As described above, according to the present invention, the center of the preceding steel strip and the center of the succeeding steel strip can be made much better than before, and the ideal joint shape between the steel strips can be easily secured. Now you can. As a result, factors that impair the formability of spiral processing such as meandering of a steel strip were eliminated, and stable pipe making became possible.

[Brief description of the drawings]

FIG. 1 is an overall explanatory view of a connecting device according to the present invention.

FIG. 2 is a diagram showing a calculation basis of a steel strip center and the like.

FIG. 3 is a diagram showing a situation when measuring a steel strip center.

FIG. 4 is a diagram showing a state after the movement of the following steel strip is completed.

FIG. 5 is a diagram illustrating a connection method according to the present invention;
(A) shows the moving direction of the side guide roll, and (b) shows the necessity of cutting the flare.

FIG. 6 is a diagram showing a state of spiral machining of a steel strip.

FIG. 7 is a view showing the necessity of connecting a preceding steel strip and a following steel strip.

FIG. 8 is a view showing the necessity of cutting the flare of the succeeding steel strip.

FIG. 9 is a diagram showing a center shift between steel strips.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Steel strip (coiled steel strip) 1A Leading steel strip 1B Trailing steel strip 2 Pipe 3 Butted part 4 Side guide roll 5 Flare 6 Center (center line) 7 Center shift 8 Cylinder mechanism 9 Computer (computer)

Claims (2)

[Claims] 1. A method for joining steel strips to be welded with a front end of a succeeding steel strip abutting against a rear end of a preceding steel strip running on a spiral steel pipe production line, wherein a center position of the subsequent steel strip is measured. Then, after moving the leading end of the succeeding steel strip in the width direction so as to match the center position of the preceding steel strip, cut the leading end so that the shape of the leading end matches the rear end shape of the preceding steel strip. Butting and then welding. 2. A side guide roll for pressing a side end of a steel strip, a cutting machine for cutting a rear end of a preceding steel strip and a front end of a following steel strip, and a cutting portion are butt against a spiral steel pipe production line. A welding device for welding steel strips with a welding device for welding, wherein the side guide rolls are capable of moving forward and backward in the width direction of the steel strip, and a plurality of side guide rolls are provided at both ends sandwiching the steel strip. Enter the longitudinal position of the following steel strip whose center and width of the leading steel strip and the following steel strip measured by moving forward and backward match the preceding steel strip, and make the two center positions coincide with each other. And a calculating device for calculating the amount of movement of the steel strip in the width direction, outputting the calculated value to a side guide roll, and outputting the longitudinal position to a cutting machine.