JPS6397372A - Torsion straightening method for weld zone of resistance welded pipe - Google Patents

Abstract

PURPOSE:To straighten torsion without stopping a line by horizontally moving the side guide roller just before the final roll of fin pass according to the torsion amount of the seam welding of a resistance welded pipe detected just after a squeezing roll. CONSTITUTION:A forming material 1 is formed in circular shape in order in breakdown zone, intermediate forming zone and fin pass forming zone and after seam welding subjected to squeeze forming and attained to a round resistance welded pipe, but due to unequal quality in the forming material 1, the unconformity of the gap and position of forming roll, etc., torsion is caused on weld zone causing quality deterioration and line stoppage correction. The torsion amount of seam weld part is detected by a reflection light detector 20 at the position immediately after discharging of a squeezing stand 5, the side guide rollers 2, 3 arranged just before the final stand 6 of the fin pass are moved in the horizontal direction according to the amount thereof and the reverse rotation moment in the torsion direction is given to the forming material 1 to correct the torsion. Consequently the quality deterioration due to the torsion is eliminated on the resistance welded pipe and the line stoppage due to the correction is eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for correcting torsion of an electric resistance weld seam in the manufacture of electric resistance welded pipes.

(Prior art) In general, the forming and bath welding of electric resistance welded pipes are performed by breakdown forming (A), intermediate forming (B), fin/guss forming (0, welding ρ), and squeeze forming ( 6) etc.

Figures 9 to 12 show each forming process in breakdown forming, Figure 3 shows intermediate forming, and Figure 2 shows fin and gas forming. Then, the squeeze molding shown in FIG. 4 is performed.

(Problems to be solved by the invention) In the process of manufacturing electric resistance welded pipes, changes in the thickness of the camper 1 of the molding material in the board width direction, roll gears in each molding zone, asymmetry of the gears, occurrence of walking in the breakdown molding stand, etc. As shown in FIG. 5, a phenomenon occurs in which the seam welded portion a is twisted after squeeze forming. For this reason, although a device for completely annealing the seam weld is disposed at the rear surface of the squeeze molding, this device may not be able to cope with the amount of twist of the comb. Conventionally, this has been dealt with by changing the roll gap for squeeze molding and fin/volume molding, but this has the problem of destroying the original molding hole shape and reducing quality and productivity as the line is stopped due to the roll gap. there were.

(Means for Solving the Problems) The present invention solves the above-mentioned problems, and the gist thereof is to detect twisting of the seam weld after welding an ERW tube by using a detector installed on the rear surface of the squeeze stand. Detects the pressure on the front side of the final stand in the fin pass forming zone, and causes the side guide rollers placed in the fin pass forming zone to move the idle roller in the horizontal direction to correct the torsion of the ERW pipe welding part. This is a twist correction method.

(Function) The method for correcting the torsion of a welded portion of an ERW pipe according to the present invention is a method for correcting torsion of a seam welded portion, which is detected by a detector placed on the back surface of the squeeze forming zone, using a horizontally movable device placed in front of the final stand in the fin pass forming zone. The side is Hydrora and Fidopa,
The side moves the idle roller horizontally to prevent and correct twisting of the seam weld.

(Example) Hereinafter, the present invention will be described in detail based on embodiments shown in FIGS. 1 to 8.

As shown in FIG.
Intermediate forming (B), fin pass forming (C), welding ■)
In the squeeze molding (6) that follows, as shown in FIG.
It is set up. Detection of torsion by the detector 20 utilizes, for example, the characteristic that the gloss of the surface of the seam weld is different from that of surfaces other than the weld. Alternatively, it is possible to employ an optical detector, such as marking the surface of the ERW tube immediately after the squeeze molding, detecting the mark at a successor point a certain distance away, and calculating the twist.

As shown in FIG. 8, the torsion detected in this manner is shown in FIG. 8
When the molded material 1 is moved to the right in the figure, that is, in the horizontal direction, it rotates in the direction of clockwise rotation. In this mechanism, as shown in FIG. 1, a force is applied to the molded material 1 by side guide rollers 2. This is then applied as a reaction force to the fin 4 of the final fin nona standro through the molding material 1 (
) is in effect. The reaction forces of these pushing forces 2 act on the molded material 1 as a moment in the clockwise rotation direction, thereby preventing and correcting twisting. In other words, all traces of the seam weld are detected on the rear surface of the squeeze molding, and the final fin 1 is detected accordingly. The front side of the seam forming stand moves the idle roller left and right to prevent and correct twisting of the seam weld.

(Effect of the invention) Conventionally, when there is a θ degree twist as shown in FIG.
The present invention enables continuous production without stopping the line due to roll gaps, and has the remarkable effect of dramatically improving quality and productivity.

[Brief explanation of the drawing]

Fig. 1 is a front view of the side-id roller according to an embodiment of the present invention, Fig. 2 is a front view of the same fin/4-seat molding, Fig. 3 is a front view of the same intermediate forming, and Fig. 4 is a front view of the same squeeze forming. 5 is a front view showing the normal position of the seam weld, FIG. 6 is a front view showing the twisted state of the seam weld, and FIG. 7 is a plan view showing an example of an apparatus for implementing the present invention. Figure 8 is a front view showing the entire operation of the side idle roller in the present invention, Figures 9, 10, 1I, and 12 are front views showing each breakdown molding unit, and Figure 13 is a front view of the conventional equipment. It is a top view for explanation. 1... Molding material 2.3... Side guide roller 4... Fin/mother stand fin 5... Forming stand 6... Final fin A stand 20... Detector] Shore 1) Positive Line ) ・, −+ ,, l Figure 1 2.3 Sight guide roller

Claims (1)

[Claims] After welding the ERW pipe, the amount of twist in the seam weld is detected by a detector placed on the back of the squeeze stand, and the feedback is fed back to the movable side guide roller placed in front of the final stand in the fin pass forming zone to level the guide roller by the amount of twist. A method for correcting kinks in a welded portion of an ERW tube, the method comprising correcting kinks in a welded portion of an ERW tube by moving the ERW tube in a direction.