JP2002066775A - Method and device for butt welding of steel plates or steel strips - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and a device for welding of steel plates or steel strips which are very advantageous to have a good weld quality and productivity of steel plate or steel strip produced by butt welding of plural steel plates or steel strips. SOLUTION: For continuous butt welding of plural steel plates or steel strips 2 at the edge part using a laser beam 9, plural steel plates or steel strips 2 pass on the welding roll 3 which has a longer roll length than a total width of plates or strips and is installed inclining in the direction at a right angle to the direction the roll is moving, and are butt welded on the circumference of welding roll 3 by laser beam 9.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a joining method and apparatus for joining a plurality of steel plates or steel strips having different thicknesses, strengths or properties with laser beams at their longitudinal ends. is there

[0002]

2. Description of the Related Art As a method of butt-joining steel sheets, a method is known in which steel sheets are butted and fixed on a jig, and welding is performed by moving a laser beam torch along a butt seam. I have. However, in this case, since the length of the welding seam is limited by the torch movement stroke on the equipment, there has been a problem that a steel sheet having a long seam or a steel strip cannot be continuously welded.

In order to solve this problem, there has been proposed a method in which a torch is fixed, a steel plate or a steel strip is conveyed while continuously contacting, and continuous welding is performed. In order to butt and join steel plates or steel strips continuously in the longitudinal direction using a laser beam, these plate ends are butted together without any gap, and the butt seam position is guided within a certain allowable range with respect to the laser beam irradiation position. There is a need to.

As a technique for realizing this, for example, in Japanese Patent Publication No. Hei 6-13153, a welding roller is provided in which welding end faces of steel strips are adjacent to each other, and each of the steel strips to be transported while being vertically separated is inclined. It is conveyed while being pressed with a vertical roller and bringing the welding side end surfaces into contact with the guide surface of the guide member on the same vertical plane, constrained on the same plane by the grip roller, and then welded by laser. is there. In this configuration, the ends may not be straight, and instead the gap may widen when converging with the grip roller, or the ends may protrude, making it impossible to stably hold the path. When the parts are welded, there may be a problem that stable welding accuracy cannot be ensured and the properties of the welded parts obtained by welding are reduced. This phenomenon is particularly remarkable when a steel strip of a thin steel plate is to be welded.

[0005] On the other hand, in Japanese Patent Application Laid-Open No. 2000-158163, a plurality of steel strips are passed between a welding roller and a plurality of holding rollers arranged obliquely to apply a force in the width direction to the steel strip. Accordingly, a welding method has been proposed in which laser welding is performed while applying a pressing force to the end face of an edge portion of a different steel strip. However, in this method, there are a plurality of inclined holding rollers, and since the diameter is smaller than the welding roll having a large diameter, the holding roller and the steel strip are almost in line contact, and the force in the width direction is close to the line. Since the force is transmitted only through the small contact surface, a sufficient force is not generated depending on the surface roughness of the steel strip or the state of lubrication, and there is a problem that the welding quality becomes unstable in rare cases.

[0006]

SUMMARY OF THE INVENTION The present invention is advantageous in that a plurality of steel sheets or steel strips having different thicknesses, strengths, or properties are subjected to butt welding by laser beams at their ends. By welding the plate edges on the weld side without gaps and by welding with more reliable path restraint, producing a welded steel plate or strip with stable weld quality at low cost and high productivity. It provides a method and apparatus that can be used.

[0007]

The gist of the present invention is as follows: (1) In a method of joining edges of a plurality of steel plates or strips by a laser beam, the plurality of steel plates or strips are joined together. The roll body length is longer than its full width, and it is passed so as to wind around a welding roller installed at an angle to the direction perpendicular to the traveling direction, and welding is performed with a laser beam on the circumference of the welding roller. Characteristic butt joining method of steel plate or steel strip. (2) The above-mentioned (1), wherein the welding is performed while guiding the edge of one of the steel plates or strips to be welded, on the side opposite to the butt seam, on the side where the pressing force is exerted by the welding roller, before and after the welding roller. The butt-joining method of the steel plate or the steel strip described in the above). (3) The butting of the steel sheet or the steel strip according to the above (1) or (2), wherein the welding is performed while pressing the steel sheet or the steel strip before and after the welding position from the opposite side of the steel sheet or the steel strip in contact with the welding roller. Joining method. (4) An apparatus for butt-joining the edges of a plurality of steel plates or strips by a laser beam, comprising a welding roller for winding a plurality of steel plates or steel strips, and a laser beam welding machine on the circumference of the welding roller. Wherein the welding roller has a roll body length longer than the entire width of the plurality of steel sheets or steel strips, and is installed inclined with respect to a direction perpendicular to the traveling direction of the steel sheet or steel strip. . (5) A side guide, which guides an edge portion of one of the steel plates or strips to be welded on the side opposite to the butt seam and on which the pressing force is exerted by the welding roller, is provided before and after the welding roller. (4) A butt-joining apparatus for a steel plate or a steel strip according to (4). (6) The butt-joining apparatus for a steel plate or a steel strip according to the above (5) or (6), wherein a holding roll is provided before and after the welding position on a surface opposite to the steel plate or the steel strip in contact with the welding roller. . It is in.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention relates to a method and an apparatus for joining steel sheets or steel strips having different materials, sheet thicknesses, etc. as described above, in which the edges of the steel sheets or strips are continuously and advantageously welded. However, when performing welding with a laser beam on a circumference around which a steel plate or a steel strip is wound around a welding roller having a roll body length longer than the entire width of the steel plate or the steel strip, when the welding roller is used, By being installed at an angle to the direction perpendicular to the traveling direction of the steel strip, it applies a force in the width direction of the steel strip so that the pressing force acts between the edges of the steel plate or steel strip to be joined, improving productivity and The point is that welding enabling good joining quality has been enabled.

[0009] When laser welding is performed by butt-joining the edges of steel plates or steel strips, if a gap is formed in the butt-welded seam portion, poor quality such as undercut tends to occur after welding. However, when manufacturing a steel sheet or steel strip, shearing such as slitting, trimming or shearing may be performed to secure the width accuracy and the shape quality of the edge part. Since a slight unevenness remains in the part, a slight gap occurs when these end faces are butted, and further, at the time of laser welding, a force acting to further open the butted part due to welding thermal deformation acts. Further, the gap at the weld seam is enlarged. Accordingly, in the present invention, the welding roller is inclined with respect to the direction perpendicular to the traveling direction of the steel plate or the steel strip, and by applying a mating force to the edge of the steel plate or the steel strip, the gap created by the thermal deformation is pressed, and the edge of the edge part is further pressed. By reducing the gap due to the unevenness, the gap between the welding seams can be reduced, and stable welding quality can be ensured.

At this time, in order to apply a force in the width direction to the steel sheet or the steel strip, it is generally considered to apply a force from the non-welded side edge of the steel strip such as a side guide roller. For thin steel sheets or steel strips such as those used for slabs, these methods cannot apply sufficient force because a large force will cause buckling of edges and rough ears, etc. There was a problem that the gap between the weld seams could not be reduced. Therefore, in the present invention, a method is adopted in which a steel sheet or a steel strip is wound around an inclined welding roller to apply a force in the width direction to the steel sheet or the steel strip. A sufficient pressing force can be applied to a thin steel plate used for an automobile part without causing roughness.

The welding roller is preferably installed at an angle of 0.1 ° to 0.8 ° with respect to the direction perpendicular to the traveling direction of the steel sheet or the steel strip. As a result of the experiment, the inclination angle α (see FIG. 1 and FIG. 2) is such that if this angle is too small, the pressing force between the steel plates or the steel strips is insufficient, and if there is a side guide, it is pressed against the side guide. It is not preferable because the behavior of the steel strip is not stable due to insufficient force and the steel strip may meander in units of several millimeters in some cases. On the other hand, if the inclination angle α is excessively large, the steel strip is pressed against the side guide by an excessive force.

[0012] In addition, quality problems also occur when the joints between the steel plates or the steel strips are welded so as to be shifted in the thickness direction. By welding a steel sheet or a steel strip in a state wound around the above-mentioned welding roller as in the present invention, it is also possible to prevent misalignment of the welded portion in the thickness direction. By winding around the welding roller, the steel plate or the steel strip is constrained by the surface of the welding roller in the thickness direction, so that there is no misalignment in the thickness direction and stable welding is possible.

In the present invention, the edge of the steel strip or the steel plate on which the steel sheet is not welded, on which the pressing force is applied by the welding roller, is guided before and after the welding roller for edge positioning. The roller imparts an inclination to each steel strip such that a force acts in the direction of the edge positioning position. That is, generally, as shown in Japanese Patent Publication No. 6-13153, a joint is made by applying a pressing force from both sides toward a joint surface of a steel plate or a steel strip. In order to apply the pressing force from both sides, it is necessary to balance the pressing force from both sides so that the joint surface does not always fluctuate.However, differences in surface roughness due to differences in oiling conditions, surface treatment and manufacturing processes, etc. Surface friction is not constant and difficult to adjust. On the other hand, as in the present invention, first, the non-welded edge of one steel sheet or steel strip is pressed against the side guide to determine the width direction, and the other steel sheet or steel strip is pressed against the positioned steel sheet or steel strip. Therefore, the welding position can be stabilized very easily.

In Japanese Patent Application Laid-Open No. 2000-158163, instead of inclining the large-diameter welding roller,
By inclining a plurality of holding rollers provided on the steel strip wound around the welding roller, a force in the width direction is applied to the steel strip. Even when this method was adopted, it was confirmed that the welding quality was extremely easily stabilized as in the present invention.
The press roller and steel strip are almost in line contact,
Since the force in the width direction is transmitted only through this small contact surface close to the line, sufficient force is not generated depending on the surface roughness of the steel strip and the state of oiling, and in rare cases the welding quality becomes unstable. There is. This can be improved by increasing the pressing force of the pressing roller, but even in this case, the contact area is small, and the local surface pressure becomes excessive, which may lead to problems such as rapid surface wear of the pressing roller. But,
If the welding roller having a roll body length longer than the entire width of the steel sheet or the steel strip is inclined in the direction perpendicular to the traveling direction of the steel sheet or the steel strip as in the present invention, a sufficiently large area where the wound welding roller comes into contact with the steel sheet or the steel strip is obtained. Since a force for pressing the steel plate or the steel strip in the width direction acts, a sufficient pressing force in the width direction can be stably secured without the above-described problem.

As a means for guiding the edge portion (side), a side guide constituted by a roll, a shoe, or the like can be used. In addition, by holding the steel plate or the steel strip from the opposite side of the steel plate or the steel strip in contact with the welding roller before and after the welding position and welding, the lifting of the steel plate or the steel strip is suppressed, and the height of the steel sheet or the steel strip at the joint surface is reduced. It is possible to prevent misalignment in the vertical direction. As means for suppressing the steel plate or the steel strip, a holding roll or the like can be used.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. In this embodiment, the apparatus is used to join two steel strips 1 and 2. However, in some cases, the present invention is also effective when three or more steel strips 1, 2, and 10 are joined at a time as shown in FIG. It is. Steel strips 1 and 2 each have a thickness x width of 0.7 mm
X 500 mm, 1.4 mm X 500 mm. The steel strips 1 and 2 were wound around and transported by the welding roller 3, and the welding rollers were installed at an angle of 0.3 degrees with respect to the traveling direction of the steel strip. The side guides 4 and 5 are shoe guides. When the plates are passed at a speed of 2 to 10 mpm, the butt opening is controlled to 0.1 mm or less and the displacement of the butt seam is controlled to ± 0.2 mm or less. And the usefulness of the present invention was confirmed. Then, at the welding point 8 on the welding roller circumference on the joining surface 6, the laser beam 9 was irradiated to perform welding. Further, in the present embodiment, a plurality of pressing rollers 7 may be arranged on the welding roller 3 so as to sandwich the steel strips 1 and 2. 1 and 2 can be effectively prevented from being misaligned in the height direction.
As described in JP-A-158163, by adjusting the pressing force and the inclination angle of the holding roller 7, the steel strip 1 and the steel sheet 1 can be combined with the effect of the inclination of the welding roller, which is the purpose of the present invention.
Two subtle positioning adjustments are possible.

[0017]

According to the method and apparatus of the present invention, it is possible to perform continuous welding of a steel plate or a steel strip having good weld properties and good quality, and to produce such a steel plate or a steel strip inexpensively and with high productivity. It is possible to manufacture with the nature.

[Brief description of the drawings]

FIG. 1 is a plan view of the device of the present invention.

FIG. 2 is a side view of the apparatus of the present invention shown in FIG.

FIG. 3 is a plan view of a case where the present invention is applied to a case where three steel plates or steel strips are simultaneously welded.

[Explanation of symbols]

 1, 2, 10 Steel strip 3 Welding roller 4 Side guide 5 Side guide 6 Joining surface 7 Holding roller 8 Welding point 9 Laser beam

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Shigehiko Nomura 20-1 Shintomi, Futtsu-shi, Chiba F-term in the Technology Development Division, Nippon Steel Corporation (reference) 4E068 BE00 BE02 CA14 DA14 DB01

Claims (6)

[Claims] 1. A method of butt-joining a plurality of steel plates or steel strip edges by a laser beam,
A plurality of steel sheets or steel strips are passed so that the roll body length is longer than the entire width thereof and wound around a welding roller which is installed at an angle to a direction perpendicular to the traveling direction, and a laser beam is formed on the circumference of the welding roller. A butt-joining method of a steel plate or a steel strip, characterized in that the welding is performed in the step (1). 2. The method according to claim 1, wherein an edge of one of the steel plates or strips to be welded on a side opposite to the butt seam and on which a pressing force is exerted by a welding roller is guided by the welding roller before and after the welding. Item 7. The butt joining method of a steel sheet or a steel strip according to Item 1. 3. The butt joint of a steel sheet or a steel strip according to claim 1 or 2, wherein the welding is performed while pressing the steel sheet or the steel strip before and after the welding position from the opposite side of the steel sheet or the steel strip in contact with the welding roller. Method. 4. An apparatus for butt-joining a plurality of steel plates or steel strip edges by a laser beam,
A welding roller for winding a plurality of steel plates or steel strips, and having a laser beam welding machine on the circumference of the welding roller,
The butt-joining apparatus for a steel plate or a steel strip, wherein the welding roller has a roll body length longer than a total width of the plurality of steel plates or the steel strips, and is installed to be inclined with respect to a direction perpendicular to a traveling direction of the steel plate or the steel strip. 5. A side guide for guiding an edge of one of a steel plate or a steel strip to be welded on a side opposite to a butt seam and on which a pressing force is exerted by a welding roller is provided before and after the welding roller. The butt-joining device for a steel plate or a steel strip according to claim 4. 6. The butt-joining apparatus for a steel sheet or a steel strip according to claim 5, wherein a holding roller is provided before and after the welding position on a surface opposite to the steel sheet or the steel strip in contact with the welding roller.