JP3436873B2 - Method and apparatus for producing backing metal with projection for welding square pipe - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a backing metal having a projection for welding a square pipe, which is used to secure a welding root gap when a flat plate material such as a flange joint is welded to an end portion of the square pipe. And equipment.

[0002]

2. Description of the Related Art When a square pipe is butt-welded or a flange joint is welded to the end of the square pipe, a frame-shaped ridged back is attached to the end of the square pipe to prevent molten weld metal from flowing into the square pipe. The metal fitting is fitted and the back metal with projection is supported by the projection on the end of the square pipe, and the welding root gap is secured by the gap formed by the thickness of the projection protruding from the end of the square pipe. .

Conventionally, various backing metals with projections for welding square pipes have been proposed. For example, as shown in FIG. 4, the backing metal 1 with a protrusion for welding a square pipe disclosed in Japanese Utility Model Laid-Open No. 1-172493 is such that a tool is pressed along the outer peripheral side surface of the L-shaped backing metal 1. The depression 2 is formed and the volume of the depression 11 is raised to form the protrusion 2.

Further, in Japanese Examined Patent Publication No. 7-110434, the protrusion of the backing metal described in Japanese Utility Model Laid-Open No. 1-172493 described above fits within the gap between the base materials, and the welded meat is reduced in the portion with the protrusion. Therefore, as shown in FIG. 5, the surface corner portion of the width direction one side edge surface of the backing metal 1 used when the flange 13 is welded to the square pipe 12 may be different from the width direction. The tongue-shaped projections 2 thinner than the gap between the base materials are formed by pressing with a punch that advances toward the side to expand the corners. A backing metal is described in which a recess formed in a corner portion of the metal backing is formed to extend from one edge surface in the width direction of the backing metal to the root of the protrusion. Special fair 7 mentioned above
The projection described in Japanese Patent Laid-Open No. 110434 is formed by pressing the surface corner portion of the one side edge surface in the width direction of the backing metal with a punch moving toward the other side in the width direction to extend the corner and form the projection. Therefore, since the amount of metal raised by the press is different between the case where the backing metal has a rectangular cross-sectional shape and the case where the backing metal has a pentagonal cross-sectional shape with a corner, a certain protrusion is not formed, and , If the backing metal type is different, or if the position where the protrusion is provided is different, prepare a press device for each type of backing metal,
Alternatively, there is a drawback that the upper mold and the lower mold need to be replaced or adjusted. Furthermore, since the surface corners of one side edge in the width direction of the backing metal are pressed toward the other side in the width direction, the thin metal backing metal has a small amount of metal heap, so a protrusion is formed at a predetermined position. Becomes difficult to do.

[0005] Therefore, the applicant of the present invention, the cross-sectional shape of the backing metal,
We have developed and applied for a patent for a backing metal with a protrusion for square pipe welding, which can easily form a protrusion at a predetermined position regardless of its thickness or type, and its manufacturing method (Japanese Patent Application No. 8-
316416). In this manufacturing method, the upper die 14 and the lower die 15 are moved diagonally toward the backing die 1 on the outer surface of the backing die 1 to push the backing die 1, and the upper recess 16 and While forming the lower recess 17,
The metal is raised between the upper die 14 and the lower die 15, and the raised metal is pressed between the upper die 14 and the lower die 15 to form the protrusion 2.

[0006]

However, in both cases, since the projection of the backing metal is formed by pressing using a special mold, the processing takes time and is not suitable for mass production. Also, because the position of the protrusion of the backing metal must be changed each time depending on the size of the square pipe, setup time at the time of press processing is required, and many dies corresponding to the size of the square pipe are required. The cost has increased.

Therefore, the present invention provides a method and an apparatus for manufacturing a backing metal with a projection for welding a square pipe, which can be mass-produced in a short processing time and can be mass-produced regardless of the size of the backing metal. Is.

[0008]

A method for manufacturing a backing metal having protrusions for welding square pipes according to the present invention comprises: an upper rolling roll for roughing having a groove continuous in the circumferential direction on its surface; After forming a continuous ridge on the steel plate by rolling a long steel plate by a roughing rolling machine consisting of a surface-shaped lower rolling roll and the surface provided facing the upper rolling roll, A finishing upper rolling roll having a plurality of projection forming concave portions formed at positions corresponding to the convex stripes at a predetermined pitch in the circumferential direction on the surface, and a surface provided facing the finishing upper rolling roll has a planar shape. A finishing rolling machine consisting of a finishing lower rolling roll is used to roll a steel sheet on which continuous ridges are formed in the longitudinal direction to form projections of a predetermined pitch, and a steel sheet on which projections of a predetermined pitch are formed is square pipe welded. Characterized by being molded into a backing metal with protrusions for .

The steel sheet formed on the exit side of the roughing rolling mill and the finishing rolling mill may be sandwiched by side rolls and rolled to be shaped.

Further, the rolling mill for producing the backing metal with projections for welding square pipes of the present invention comprises a rolling mill for roughing forming continuous ridges in the longitudinal direction on a steel plate, and the continuous ridges. It is composed of a finishing rolling machine that forms projections of a predetermined pitch on the formed steel sheet, and the roughing rolling machine is an upper rolling roll for roughing processing with grooves continuous in the circumferential direction on the surface and the roughing processing machine. The surface provided so as to face the upper rolling roll is composed of a lower rolling roll having a planar shape, and the finishing rolling mill has a plurality of concave portions for forming protrusions on the surface at a predetermined pitch in the circumferential direction at positions corresponding to the convex stripes. And a finishing lower rolling roll having a flat surface, the surface being provided so as to face the finishing upper rolling roll. Side rolls can be arranged on the exit side of the roughing rolling mill and the finishing rolling mill.

[0011]

1 is a perspective view of an example of a backing metal with a projection for welding a square pipe obtained by a manufacturing method of the present invention, FIG.
FIG. 2A is a schematic view of a roughing rolling mill used for manufacturing a backing metal having protrusions for welding square pipes according to the present invention, and FIG. 2B is a perspective view showing a roughened steel plate.

The backing metal 1 having projections for welding square pipes manufactured by the present invention shown in FIG. 1 has a plurality of projections 2 formed on the periphery thereof.

The roughing rolling machine shown in FIG. 2 (a) comprises an upper rolling roll 3 for roughing and a lower rolling roll 4 for roughing provided opposite to the upper rolling roll 3 for roughing. A groove 5 continuous in the circumferential direction is formed on the surface of the roll 3, and the surface of the roughing lower rolling roll 4 is formed in a planar shape.

In the roughing rolling mill, a long steel plate 6 is sandwiched between the roughing upper rolling roll 3 and the roughing lower rolling roll 4 and pressed down to move the upper and lower rolls 3 and 4 in opposite directions. When rolled and rolled, the steel sheet 6 is plastically worked, rises in the continuous groove 5 of the roughing upper rolling roll 3, and a continuous ridge 7 is formed on the surface of the steel sheet as shown in FIG. 2B. To be done.

Incidentally, in order to adjust the shape of the steel plate 6 of the steel plate 6 discharged from the roughing mill, side rolls for rolling both side surfaces of the steel plate may be arranged on the exit side of the roughing mill.

FIG. 3 (a) is a schematic view of a rolling mill for finish processing according to the present invention, and FIG. 3 (b) is a perspective view showing a steel sheet subjected to finish processing.

The finishing rolling mill is composed of finishing finishing rolls 8
And a finishing lower rolling roll 9 provided opposite thereto, and the finishing upper rolling roll 8 is circumferentially spaced on the surface of the finishing upper rolling roll 8 as shown in FIG. A plurality of protrusion forming recesses 10 are formed at a predetermined pitch at positions corresponding to the ridges 7 of the steel plate 6 shown in FIG.

A steel plate 6 having a ridge 7 shown in FIG. 2 (b), which is obtained by roughing, is sandwiched between a finishing upper rolling roll 8 and a finishing lower rolling roll 9 and is pressed down. When the rolls 8 and 9 are rolled in opposite directions to each other and rolled, the steel sheet is plastically worked, and the projections 2 having a predetermined pitch are formed by the projection forming recesses 10 of the finishing top rolling roll 8.

The steel sheet 6 from the finishing rolling mill 6
In order to adjust the shape of the steel sheet, side rolls for rolling both side surfaces of the steel sheet may be arranged at the exit side of the finishing rolling mill. The steel plate 6 on which the projections 2 having a predetermined pitch are formed is L-shaped,
Bend into a U-shape or a square to finish the back metal with a projection for pipe welding.

[0020]

The effects of the present invention are as follows.

(1) Since a plurality of protrusions are formed at the same time when the steel material for the backing metal is formed, the pressing step by the conventional press die is not required, the forming step is simplified and mass production is possible. Becomes

(2) Since a plurality of protrusions are formed on the steel plate at a predetermined pitch, the same steel for backing metal can be used regardless of the size of the square pipe.

(3) Since a plurality of protrusions are formed, the position is stable when the backing plate is attached to the end of the square pipe. Also, since the thickness of the protrusion can be made thin and the volume is small,
Fewer defects after welding.

[Brief description of drawings]

FIG. 1 is a perspective view of a backing metal having protrusions for welding a square pipe obtained by a manufacturing method of the present invention.

FIG. 2 (a) is a schematic view of a rolling mill for roughing used for manufacturing a backing metal having protrusions for welding square pipes according to the present invention, FIG.
(B) is a perspective view showing a rough-processed steel plate.

FIG. 3 (a) is a schematic view of a rolling mill for finishing according to the present invention, and FIG. 3 (b) is a perspective view showing a steel sheet subjected to finishing.

FIG. 4 is a perspective view of a conventional L-shaped backing plate.

FIG. 5 is a perspective view showing an example of a backing plate manufactured by a conventional press.

FIG. 6 is a schematic sectional view of a backing metal manufactured by a conventional press.

[Explanation of symbols]

1: Backing metal with protrusion for welding square pipe 2: Protrusion 3: Upper rolling roll for roughing 4: Lower rolling roll for roughing 5: Groove 6: Steel plate 7: Convex strip 8: Upper rolling roll for finishing 9: Finishing Lower rolling roll for use 10: projection forming recess 11: recess 12: square pipe 13: flange 14: upper mold 15: lower mold 16: upper recess 17: lower recess

─────────────────────────────────────────────────── --- Continuation of the front page (56) References JP-A-6-315701 (JP, A) JP-A-5-269537 (JP, A) JP-A-5-123807 (JP, A) JP-A-61- 195701 (JP, A) JP-A-6-226498 (JP, A) Actual development: 2-53830 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) B21B 1/08 B23K 9 / 028 B23K 37/06

Claims (4)

(57) [Claims] 1. A roughing upper rolling roll having grooves formed on the surface thereof that are continuous in the circumferential direction, and a surface-provided lower rolling roll provided facing the roughing upper rolling roll. After rolling a long steel plate with a roughing rolling machine to form continuous ridges on the steel plate in the longitudinal direction, a plurality of protrusions are formed on the surface at a predetermined pitch in the circumferential direction at positions corresponding to the ridges. Ridges continuous in the longitudinal direction by a finishing rolling mill comprising a finishing upper rolling roll having a concave portion for forming and a finishing lower rolling roll having a flat surface provided so as to face the finishing upper rolling roll. The steel plate on which the projections having a predetermined pitch are formed by rolling the formed steel plate, and the steel plate on which the projections having a predetermined pitch are formed is formed into a backing metal having projections for welding square pipes. How to make the money. 2. The projection for welding a square pipe according to claim 1, wherein the steel plate formed on the exit side of the roughing rolling mill and the finishing rolling mill is sandwiched by side rolls and rolled to be shaped. Method of manufacturing back metal. 3. A rolling mill for roughing forming a continuous ridge on a steel plate in the longitudinal direction, and a finishing rolling mill for forming protrusions of a predetermined pitch on the continuous ridge-formed steel plate. The roughing rolling mill is a roughing upper rolling roll having grooves formed on the surface in a circumferential direction and a lower rolling roll having a flat surface provided opposite to the roughing upper rolling roll. Comprising a finishing rolling mill, facing the finishing top rolling roll and the finishing top rolling roll in which a plurality of projection forming recesses are formed on the surface at a predetermined pitch in the circumferential direction at positions corresponding to the ridges. A rolling mill for manufacturing a backing metal with a projection for welding a square pipe, characterized in that the surface provided is composed of a finishing lower rolling roll having a planar shape. 4. The rolling mill for manufacturing a backing metal having projections for welding a square pipe according to claim 3, wherein side rolls are arranged on the exit side of the roughing rolling mill and the finishing rolling mill.