JP2878992B2 - Seam welding method for thin steel sheet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lap welding method for steel sheets, and more particularly, to connect a preceding steel sheet and a succeeding steel sheet by welding using a welding machine in a steel sheet processing equipment such as a continuous annealing pickling equipment. Related to technology.

[0002]

2. Description of the Related Art In order to treat a steel sheet in a continuous annealing pickling facility or the like, a preceding steel sheet and a succeeding steel sheet are overlapped and welded at the entry side of the equipment to be unified and continuously passed. Is common. Then, in such equipment, in order to prevent the surface of the rolling roll arranged in the subsequent line from being damaged, the welding electrode roll is run and welded, and then immediately to the overlap welding portion (hereinafter, simply referred to as a welding portion). A so-called overlap seam welding is performed in which a separately provided reduction roll (arranged and suspended on the same gantry as the welding electrode roll) is driven to follow and pressurize and smooth the weld. For example,
JP-A-2-11278). That is, as shown in FIG. 2, the apparatus for performing the seam welding includes entrance clamps 8, 8 ′ and exit clamps 7 for respectively fixing the rear end of the preceding steel plate 3 and the rear end of the following steel plate 4. , 7 ′, a pair of welding electrode rolls 2, 2 ′, and rolling rolls 1, 1 ′. The overlap between the steel plates is appropriately clamped by the rolling rolls 1, 1 ′ after welding. As a result, the surface of the roll becomes smooth and slightly raised, so that the above-mentioned generation of the flaw on the roll surface can be prevented.

[0003] By the way, when the welding roll 9 is lowered by the rolling rolls 1 and 1 ', when the peripheral speed of the rolling rolls 1 and 1' is lower than the traveling speed of the gantry 5, 5 ', the welding zone 9 is reduced. It tends to be torn, and there is a tendency that steel plates cannot be connected to each other. This problem occurs when the thickness of one of the steel plates 3 and 4 is as thin as 0.2 to 1.0 mm, or when the reduction rolls 1 and 1 ′ This is likely to occur when the peripheral speed of 1 'is unstable. For this reason, conventionally, the driving devices 6, 6 'for rotation are installed on the rolling rolls 1, 1', and when welding is performed with the welding electrode rolls 2, 2 ', when the gantry 5, 5' travels, the vertical rolling reduction is performed. The rolls 1 and 1 'are brought into contact with each other so that the peripheral speed of the rolls 1 and 1' is synchronized with the traveling speed of the gantry 5 and 5 '(see JP-A-2-11278).

[0004]

However, the method of installing a driving device on the reduction roll and synchronizing the rotation speed of the reduction roll with the traveling speed of the carriage is not effective in stabilizing the rotation speed of the reduction roll. However, when the thickness of the steel sheet was as thin as 0.2 to 1.0 mm, there was still a tendency for cracks in the welded portion to occur.

[0005] In view of such circumstances, the present invention has a thickness of 0.
It is an object of the present invention to provide a seam welding method for a thin steel sheet which does not cause a break in a weld even if the steel sheet is as thin as 2 to 1.0 mm.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention relates to a welding method in which a rear end of a preceding steel plate and a front end of a succeeding steel plate are overlapped on a steel sheet processing line, and the portion runs in the width direction of the steel plate. Immediately after welding with the electrode roll, the welded portion is arranged in the same base as the welding electrode roll, followed by a suspended rotating rolling roll, pressed, and pressed to form the steel plate into a single piece. This is a seam welding method for a thin steel plate, wherein a ratio between a peripheral speed S of an expression reduction roll and a traveling speed R of a gantry is adjusted according to a total thickness of a succeeding steel plate.

Further, according to the present invention, the ratio of the peripheral speed S of the rotary rolling down roll to the traveling speed R of the gantry satisfies the following expression: It is preferred that When 0.4 mm ≦ (t ₁ + t ₂ ) ≦ 2.0 mm, (S
/R)≧1.1 2.0 mm <(t ₁ + t ₂ ), 0.9 ≦ (S /
R) <1.1 Here, (t ₁ + t ₂ ) is the total thickness of the succeeding steel sheet.

According to the present invention, a driving device for rotating the roll is provided on the reduction roll for clamping the welded portion, and the peripheral speed of the reduction roll is set to a multiple of the traveling speed of the gantry according to the total thickness of the leading and trailing ends. The welding speed is set at that peripheral speed and the welded portion is pinched and welded, so that no shearing force is generated in the welded portion and the problem of the welded portion being torn off by the rolling roll can be prevented. became. In addition, the total value of both plate thickness is 0.
In the range of 4 mm or more and 2.0 mm or less, the rolling roll peripheral speed is preferably 1.1 times or more of the gantry traveling speed, and in the range of more than 2.0 mm, 0.9 times or more and less than 1.1 times is preferable. The reason for this is that no tearing of the weld occurs in this region.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a state in which a seam welding method for a thin steel sheet according to the present invention is carried out. FIG. 1 shows a superposed portion 9 of a preceding steel plate 3 and a following steel plate 4, that is, a welded portion 9.
The steel plates 3 and 4 move in a direction perpendicular to the plane of the drawing when viewed from the vertical section of FIG. Welding electrode rolls 2 and 2 'and pressing rolls 1 and 1' are paired up and down on steel plates 3 and 4.
Are arranged and suspended on the same gantry 5, 5 '. Therefore, the welding electrode roll 2,
When 2 'advances and welds the overlapping portion 9 in the plate width direction, the pressing rolls 1 and 1' crush the welded portion 9 following the welding. In the present invention, this reduction roll 1
The welding is performed while adjusting the peripheral speed of 1 'by limiting the traveling speed of the gantry 5, 5' and the thickness of the steel plate overlapping portion 9.

For example, two steel plates 3 having a thickness of 0.2 mm,
In the case of welding 4, assuming that the gantry 5, 5 'is advanced at a speed of 10 m / min, the total thickness is 0.4 mm. Therefore, the peripheral speed of the rolling rolls 1 and 1 ′ is 1.1 ×
The rolling roll 1, so as to be about 10 m / min,
The drive devices 6 and 6 'of 1' were adjusted. FIG. 3 shows one embodiment of the present invention. In welding stainless steel plates having a thickness of 0.2 mm, welding is performed between a case where the peripheral speed of the pressing rolls 1 and 1 ′ is equal to the traveling speed of the gantry 5 and 5 ′ and a case where the peripheral speed of the gantry is 1.1 times the traveling speed of the gantry. The occurrence rate of partial tearing is shown in comparison. At this time, the traveling speed of the gantry is 10 m /
The welding test was performed 10 times each under two conditions of min and 15 m / min. As is apparent from FIG. 3, when the peripheral speed of the rolls 1, 1 'is 1.1 times the traveling speed of the gantry 5, 5' as compared to when the peripheral speed of the gantry 5, 5 'is equal to the traveling speed, the welding portion is formed. The tearing rate at 9 was greatly reduced,
The tearing rate was zero.

[0011]

As described above, according to the present invention, when seam welding is performed on a line where thin steel sheets are overlapped on a line, the peripheral speed of the rolling roll is determined by the total thickness of the steel sheets to be overlapped. By setting it to twice, the tearing of the welded portion by the reduction roll can be prevented.

[Brief description of the drawings]

FIG. 1 is a front view in which seam welding of a thin steel sheet according to the present invention is performed.

FIG. 2 is a longitudinal sectional view showing a state where seam welding of a conventional thin steel plate is performed.

FIG. 3 is a diagram comparing the tearing occurrence rate of a welded portion between the method of the present invention and the conventional method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Roll-down roll (upper) 1 'Roll-down roll (lower) 2 Welding electrode roll (upper) 2' Welding electrode roll (lower) 3 Leading steel plate 4 Trailing steel plate 5 Mount (upper) 5 'Mount (lower) 6 Roll-down roll Driving device (upper) 6 'Driving device for lowering roll (lower) 7 Outgoing side clamp 8 Inlet side clamp 9 Overlapping part (welding part) 10 Mount traveling direction 11 Steel plate traveling direction

Claims (2)

(57) [Claims] The present invention is characterized in that a rear end of a preceding steel plate and a front end of a following steel plate are overlapped on a steel sheet processing line, and that portion is welded with a welding electrode roll running in the width direction of the steel plate. In seam welding of a thin steel sheet, which is arranged in the same mount as the welding electrode roll, is followed and pinched by a suspended rolling reduction roll, and unifies the steel sheet, the peripheral speed S of the rotation reduction roll and the traveling speed R of the mount are used. A seam welding method for a thin steel sheet, wherein the ratio of the steel sheet is adjusted according to the total thickness of the succeeding steel sheet. 2. The method according to claim 1, wherein the ratio of the peripheral speed S of the self-rotating pressing roll to the traveling speed R of the gantry satisfies the following expression. When 0.4 mm ≦ (t ₁ + t ₂ ) ≦ 2.0 mm, (S
/R)≧1.1 2.0 mm <(t ₁ + t ₂ ), 0.9 ≦ (S /
R) <1.1 Here, (t ₁ + t ₂ ) is the total thickness of the succeeding steel sheet.