JPH0569151A - Preparatory lap seam welding equipment - Google Patents

Abstract

PURPOSE:To settle problems caused in preparatory lap seam welding equipment in the past that a notched flaw occurs on a superposed part between a preceding sheet and a succeeding sheet by reversing of a cutting blade of a shearing device of ends of the preceding sheet and the succeeding sheet of a metallic strip and further, the difference in level is generated on a weld zone of the preceding sheet and the succeeding sheet when the thickness of the preceding sheet is different from that of the succeeding sheet. CONSTITUTION:Single trapezoidal swasing rolls 19, 20; 23 and 24 to roll down separately shear cutting parts of the preceding sheet and the succeeding sheet are provided on the preparatory lap seam welding equipment. The ends formed thin by these single trapezoidal swasing rolls are superposed on each other and subjected to seam welding.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a prep lap seam welding device for connecting a trailing end of a leading plate of a metal strip and a leading end of a trailing plate.

[0002]

2. Description of the Related Art Preplap seam welding equipment (pre)
The partition lap seam welder is a device that thinly processes a lap portion of a leading plate and a trailing plate of a metal strip, and superimposes the lap portion and simultaneously seam-welds the lap portion while simultaneously crushing the weld portion.

[0003] Conventionally, a mash seam welding method has been generally known for seam welding of metal strips. In mash seam welding, seam welding is performed by pressing the stacked plate with the upper and lower electrode discs and crushing the welded portion simultaneously with welding. Generally, on the strip running line, the trailing edge of the leading plate and the leading edge of the trailing plate are held by opposing inlet and outlet clamp devices, and the clamp-held strip ends are cut by a shearing device, The clamp device is moved so that the cut ends of the leading plate and the trailing plate are overlapped by the required amount, and the overlapped contact part is sandwiched between the widthwise ends of the strip by the upper and lower electrode wheels, and a strong force is applied. By applying pressure and a large current, the metal part that has been softened by temperature rise is flattened by an electrode wheel and welded, and then the welded part is further crushed by a roll to proceed.

In recent years, it has been generally practiced to reduce the off-gauge portion before and after the welded portion of the strip by a skin pass mill to reduce the welded portion of the strip to improve the productivity. The problem at that time is the finished thickness of the welded portion. If the finished thickness of the welded portion is large, the skin pass roll is dented and the dented portion is transferred to the strip. Therefore, in order to improve this and reduce the finished thickness of the weld, the preplap seam welding method is adopted. That is, as a pre-process of mash seam welding, the overlapping portion of the leading plate and the trailing plate is crushed with a roll in advance to form a sword-like crushed portion, and the crushed overlapping portion has an overlapping amount. The thickness of the overlapped portion of the welded portion is reduced by reducing the thickness of the welded portion, and then the seam welding is performed in the same process as the mash seam welding method to reduce the finished thickness of the welded portion.

A conventional prep lap seam device and its welding process will be described. FIG. 4 shows a schematic side view of a conventional prep lap seam welding device. FIG. 5 shows steps in the case of preplap seam welding using a conventional device. FIG. 6 shows an example in which the conventional prep lap seam welding is performed under the condition that the thicknesses of the leading plate and the trailing plate differ by 140% on the basis of the thin plate.

FIG. 4 shows a movable table 5 of the prep lap seam device mounted on the rail 6. The strip 4 runs in a direction perpendicular to the plane of the drawing in FIG. The moving table 5 is guided on the rail 6 and moves forward and backward in a direction perpendicular to the strip traveling line (direction along the plane of FIG. 4) by a drive source such as a cylinder (not shown). The upper temper color removing brush 8 is supported on the lower side of the upper arm of the moving table 5 and moves up and down by a pressure cylinder 10 mounted on the upper arm of the moving table, and the brush 8 is driven by a hydraulic motor (not shown). The lower temper color removing brush 9 is fixed, the upper temper color brush 8 descends, and the upper and lower temper color brushes 8 and 9 remove the oxide film on the steel plate surface. The upper swaging roll 11 is supported below the upper arm of the moving table 5 and moves up and down by a pressure cylinder 12 mounted on the upper arm of the moving table 5, and cooperates with a lower swaging roll (fixed) 13. Before welding, the plate thickness of the overlapped portion of the strip and the welded portion immediately after welding is finally crushed to a certain thickness. The upper electrode disk 14 moves up and down by a pressure cylinder 15 supported on the lower side of the upper arm, and the pressure cylinder 1
5 gives a strong electrode pressing force necessary for welding.
The lower electrode disk 16 corresponding to the upper electrode disk 14 is fixed to the lower arm of the moving table 5 so as to be vertically adjustable. Shear device 17 for cutting the end of the metal strip,
18 are provided. The shear devices 17 and 18 are composed of a lower shear 17 which moves up and down by a cylinder supported on the upper side of a lower arm, and an upper shear 18 which moves up and down by a corresponding cylinder supported on the lower side of an upper arm. ..

5 and 6 show the operation of this device. Reference numeral 1 indicates a leading board strip, and 2 indicates a trailing board strip. The arrow indicates the strip running direction of the strip running line. Three
Is an input side clamp device, and 4 is an output side clamp device. 5
Is a moving table corresponding to the frame of the welding machine body. The inlet side clamp device 3 and the outlet side clamp device 4 are arranged at positions facing each other on the strip traveling line, and are supported so as to be movable in the strip traveling direction and up and down. Figure 5
The entrance side clamp device 3 shown in (a) is configured to be shiftable in the front-rear direction, and is configured so that the amount of protrusion of the tip of the clamp can be adjusted. By doing so, it is possible to adjust the stock removal amount during swaging and retract during the early period of strip cutting. 5 and 6 show the steps in the case of preplap seam welding. Further, FIG. 7 shows a change in an overlapping portion at the time of preplap seam welding.

(1) The trailing edge of the leading plate 1 and the leading edge of the trailing plate 2 are sandwiched by the in-out side clamps 4 and 3 to set a margin for shear cutting. (FIG. 5 (a)) (2) The lower shear 17 and the upper shear 18 cut the end portions 1a and 2a of the strip. (Fig. 5 (b)), (Fig. 7
(A)) (3) In order to perform the swaging in the first period, the entrance side clamp device 3 moves forward to set the overlap margin. (FIG. 5 (c)), (FIG. 7 (b)) (4) The upper and lower swaging rolls 13 and 17 crush the rear end of the leading plate and the leading end of the trailing plate to reduce the thickness of the overlapped portion during shear cutting. The thickness is 150% of the plate thickness. (Fig. 6
(A)), (FIG. 7 (c)) (5) The entrance side clamp device 3 is retracted by e in the direction of the arrow 3a to reduce the thickness of the overlapping portion. (Fig. 6 (b)),
(FIG. 7D) (6) A large current is applied to the overlapping portions of the upper and lower electrode discs 14 and 16 to seam weld the overlapping portions and soften the temperature by softening. (FIG. 6 (c)), (FIG. 7 (e)) (7) The temperature-softened weld is pressed down by the upper and lower swaging rolls 11 and 13 to finally crush the thickness of the weld to the target thickness. ..

In the above conventional prep lap seam welding, when the welding thickness is 0.8 mm or more, it is possible to reduce it to 110% of the sheet thickness before welding. But,
As shown in FIG. 8, when the leading plate 1 and the trailing plate 2 have different plate thicknesses, the leading plate 1 and the trailing plate 2 are overlapped as shown in FIG. 8A, and at the stage of FIG. 8B. When swaging in the first half of the previous year, the thinner plate will be crushed too much. Therefore, when the trailing plate 2 is retracted and welded as shown in FIG. 8C, the thicker plate does not melt at the end of the welded portion and a large step is formed as shown in FIG. 8D. As a result, the finished thickness of the weld does not reach the target. In such a case, if the electrode pressure is increased to reduce the step, the plate on the thin plate side is excessively crushed, the electrodes hit the leading plate and the trailing plate, and the current flowing in the overlapping portion becomes small. Then, the temperature of the overlapped portion is not sufficiently raised, and the welded portion is peeled off.

[0010]

In the case of the conventional prep lap seam welding, the trailing edge of the leading plate and the leading edge of the trailing plate are superposed and then rolled down by a swaging roll. There is a blade back on the cut part,
Due to the blade return, notch scratches occur in the overlapping part,
The strip may break from the notch. When the leading plate and the trailing plate have different plate thicknesses, the crushed amounts of the leading plate and the trailing plate are different due to the difference in plate thickness, and a large step is generated in the welded portion. It is an object of the present invention to provide a prep lap seam welding device that solves such problems.

[0011]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides a prep wrap provided with a single trapezoidal swaging roll that individually reduces the leading plate and the trailing plate according to the plate thickness. A seam welding device is provided.

[0012]

According to the present invention, the trailing edge of the leading plate and the leading edge of the trailing plate, which are cut by the shear device, are pressed down by different single trapezoidal swaging rolls according to the plate thickness of the leading plate and the trailing plate. As a result, the above problems have been solved. That is, (1) Burrs generated when cutting with a shearing device can be crushed. As a result, the notch flaw caused by the burr does not occur, and the weld portion of the strip does not break from the notch flaw. (2) Even if the leading plate and the trailing plate have different plate thicknesses, they can be crushed to the same thickness. As a result, no step difference occurs in the welded portion due to the difference in plate thickness between the preceding plate and the following plate.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the device of the present invention will be described with reference to the drawings. FIG. 1 is a schematic side view showing an embodiment provided with a single-trapezoidal swaging roll device, and FIG. 2 is a front view of a main part thereof. FIG. 3 shows an embodiment in which welding is performed using a single trapezoidal swaging roll.

The device of the present invention is an improvement of the conventional prep lap seam device shown in FIG. 4, and the same reference numerals as those in FIG. 4 in FIG. 1 are the same as those in FIG.
FIG. 1 is different in that swaging rolls 19, 20, 23, 24 and their reduction cylinders 21, 22 are provided. As shown in FIG. 2, the front view of this swaging roll is such that a single trapezoidal roll 19 and a flat type roll 20 form a set of single trapezoidal swaging rolls.

In the present invention, by using the two pairs of the single trapezoidal swaging rolls 19, 20; 23, 24 in the pre-lap seam welding, the thickness of the leading plate 2 and the trailing plate 1 is changed. Even if they are different, the welded part finish thickness can be reduced without causing a large step in the welded part. Single trapezoidal swaging roll 19, 20; 2
Reference numerals 3 and 24 are provided on the rear end of the leading plate 2 and the front end of the trailing plate 1, respectively, and are constituted by a combination of single trapezoidal rolls 20 and 24 and flat rolls 19 and 23, respectively. Two
Cylinder 2 for each pair of single trapezoidal swaging rolls
1 and 22 are vertically movable and have a structure in which the leading plate and the trailing plate can change the pressing force respectively.

The process of the seam device using the device of the present invention will be described with reference to the embodiment shown in FIG. As shown in FIG. 3A, the leading plate 1 has a plate thickness of 1.2 mm, and the trailing plate 2 has a plate thickness of 0.
It is an example of 8 mm. In the first-stage swaging process, as shown in FIG. 3B, the leading plate 1 (thickness 1.2 mm) is pressed down by 2.5 ton and the trailing plate 2 (thickness 0.8 mm) is pressed down by 0.7 ton. Then, the thick side was crushed first. Next, as shown in FIG. 3 (c), the trailing edge of the leading plate and the leading edge of the trailing plate were wrapped by 1.2 mm, and welding was performed using an electrode disc having an electrode tip shape of R50. As a result,
As shown in (d), the finished thickness of the welded portion is equal to the plate thickness on the thin side, and no step is formed in the welded portion.

[0017]

By using the apparatus of the present invention, in the swaging step of prep lap seam welding, the trailing edge of the leading plate and the leading edge of the trailing plate are applied with respective single trapezoidal swaging rolls according to the plate thickness. By changing the pressure and crushing, the thickness of the welded part can be reduced.
In particular, when the leading plate and the trailing plate have different plate thicknesses, the welded part finish thickness can be made equal to the plate thickness on the thinner side, and the step difference of the welded part that occurs during welding of different thicknesses does not occur. Also, in the conventional swaging process, burrs generated during shear cutting cause notch scratches in the overlapping part, but this burr is also crushed by the single trapezoidal swaging roll to the rear edge of the leading plate and the tip of the trailing plate. Therefore, burr does not occur. Therefore, breakage due to notch scratches can be prevented.

[Brief description of drawings]

FIG. 1 is a side view of an embodiment of a prep lap seam welding device equipped with a single trapezoidal swaging roll device.

FIG. 2 is a front view of a single trapezoidal swaging roll.

FIG. 3 is a process drawing of an example in which welding is performed using a single trapezoidal swaging roll.

FIG. 4 is a schematic side view of a conventional prep lap seam welder.

FIG. 5 shows steps in the case of conventional prep lap seam welding.

FIG. 6 shows steps in the case of conventional prep lap seam welding.

FIG. 7 is a process diagram showing a conventional prep lap seam welding process.

FIG. 8 is a process diagram in the case where conventional prep lap seam welding is performed under the condition that the plate thicknesses of the preceding plate and the following plate differ by 40% on the basis of the thin plate.

[Explanation of symbols]

1 Leading Plate 2 Trailing Plate 3 Inlet Clamping Device 4 Outlet Clamping Device 5 Moving Stand 6 Rail 8 Upper Temper Color Brush 9 Lower Temper Color Brush 10 Temper Color Brush Cylinder 11 Upper Swaging Roll 12 Upper Swaging Roll Cylinder 13 Lower Swaging roll 14 Upper electrode disc 15 Upper electrode disc cylinder 16 Lower electrode disc 17 Lower shear 18 Upper shear 19,23 Flat roll 20,24 Single trapezoidal roll 21 Upper swaging roll cylinder 22 Lower swaging roll cylinder

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Masaru Higashi 1 Kawasaki-cho, Chiba City, Chiba Steel Works, Ltd. (72) Inventor Michio Kondo 1 Kawasaki-cho, Chiba City, Chiba Steel Works ( 72) Inventor Hiroshi Tsunekawa 1st Kawasaki-machi, Chiba City Kawasaki Steel Co., Ltd. Chiba Steel Works

Claims (1)

[Claims] 1. A preplap seam welding device, comprising: a single trapezoidal swaging roll for pressing down a rear end of a leading plate and a front end of a trailing plate.