JP3399312B2 - Method and apparatus for bending edge of steel plate at the time of forming welded 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 bending an end of a steel plate when producing a welded pipe and an apparatus for carrying out the method.

[0002]

2. Description of the Related Art In the production of welded pipes, in particular, steel pipes according to the UOE method, both side edges of a steel sheet are cut, cut and shaped (end bending) so that a welding groove can be obtained in advance. After U-pressing, O-press forming is performed, both side edges are butted, and seam portions are welded to obtain a steel pipe.

By the way, various methods of forming (end bending) have been proposed. One of them is JP-A-56-1.
It is disclosed in Japanese Patent No. 14530. In this method, both side edges in the longitudinal direction of the steel plate are interposed between an upper die and a lower die having respective predetermined curvatures, the upper die is fixed, and one end of the lower die is a side edge of the steel sheet. Placed on a bed member, which is an operating portion pivotally attached to a shaft support portion inside the end and the other end extending outside the edge of the steel plate side, and the operating portion at the tip of the bed member is directed toward the upper mold. The end is bent by rotating around the support shaft.

[0004]

However, in the above-mentioned end bending method, when the diameter size of the steel pipe changes, the upper die and the lower die must be reassembled to fit the size.

It is an object of the present invention to provide a method and apparatus for which the upper die and the lower die do not have to be replaced for a plurality of steel pipe sizes.

[0006]

The present invention achieves the above objects by the following method and apparatus.

The method is an end bending method for a steel sheet, in which both side edges of a steel sheet cut prior to forming are pressed by an upper die and a lower die when manufacturing a welded pipe, and the method is performed at a plurality of curvatures. By rotating the upper die composed of a series of arcs to select the arc portion with a predetermined curvature freely, it is possible to use one upper die to bend the ends of steel plates with different curvatures. This is the method of bending the edges of the steel sheet.

The first device is composed of a series of arcs having different curvatures and is rotatable, a rotatable upper mold, a means for moving the upper mold up and down, and a rotation driving device for the upper mold. And a rotation stopper device, a lower mold which is vertically movable, a means for moving the lower mold in a direction orthogonal to the end bending line, and a means for vertically moving the lower mold. It is a device for bending the edge of a steel plate.

The second device is composed of a series of arcs having different curvatures and is rotatable, a means for moving the upper mold up and down, and a rotation driving device for the upper mold. A roll lower die that is rotatable and movable back and forth, an elevating table that supports the die so that it can move up and down, and an elevating table.
And a device for moving the lower mold in a direction orthogonal to an end bending line and a device for moving the elevating table up and down, which is an end bending device for a steel plate at the time of pipe making.

[Operation] Since the upper die which is composed of a series of arcs having a plurality of curvatures is used, the upper die is replaced by rotating the upper die so that the arc having a curvature suitable for the size of the steel pipe is located directly below. It is possible to perform end bending without doing so.

Since the lower mold can be moved in a direction orthogonal to the end bending line and can be vertically moved up and down, the lower mold can be moved in a direction perpendicular to the end bending line and vertically in accordance with the bending degree of the steel sheet. By moving in the direction, a predetermined end bending can be performed in cooperation with the upper mold, and one lower mold can handle all sizes of steel pipe.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the apparatus of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic front view of the device of the present invention, and FIG.
1 is a view taken along the line AA of FIG. 1, and FIG. 3 is a schematic left side view of the device of the present invention. Reference numeral 1 denotes an upper die, which is composed of a series of a plurality of arcs having different curvatures. FIG. 6 shows an example of the cross section. In this example, the roll cross sections are R1, R2,
It is composed of a combination of four circular arcs R3 and R4. Reference numeral 2 denotes a pair of left and right bearings that support the upper die 1, and these bearings are suspended and supported by a pair of left and right hydraulic cylinders 6 fixedly mounted on the press body frame 20. The upper die 1 is moved up and down by a hydraulic cylinder 6.

The upper die 1 is rotationally driven via a motor 4 and a pair of miter gears 3. A backup roll 7 of the upper mold 1 is rotatably supported by a bearing box 8 fixed to the main body frame 20. The backup roll 7 is divided into three in this example. Reference numeral 5 is a resolver for measuring the rotation angle, and the arc used by the upper die 1 can be determined by this information.

Reference numeral 9 is a lower mold composed of rolls divided into three pieces. These are supported by the bearing 10. Each bearing 10 is threadedly engaged with a screw shaft 13 that is axially supported at the front and rear ends, and moves in the front-rear direction (direction orthogonal to the end bending line) by the rotation of the screw shaft 13.
Each bearing 10 is attached to a lifting table 11.
A miter gear 16a is attached to the front end of each screw shaft. On the other hand, left and right shafts 14a and 14b are axially supported along the front edge of the lifting table 11, a drive motor 15 is provided in the center between them, and output shafts 15a and 15b extend on both left and right sides thereof. ing. Shaft 14a,
14b, 15a and 15b and the respective screw shafts 13
A miter gear that meshes with each of the miter gears 16a is attached at a position intersecting with.

Therefore, when the drive motor 15 is driven to rotate the output shafts 15a and 15b, the screw shafts 13 are rotated through the miter gears, and the bearings 10 engaged with the screw shafts 13 are moved forward and backward. Move to. That is, the lower mold 9 moves in the front-rear direction.

The elevating table 11 can be vertically moved up and down by three hydraulic cylinders 12 provided therebelow.

In front of the upper and lower molds 1 and 9, the main body frame 2
An upper clamp 17 is fixed to 0, and a lower clamp is provided so as to be vertically movable by a hydraulic cylinder.

FIG. 4 is a perspective view of the above device. FIG. 5 shows an example in which the lower die is replaced with a roll and is of a non-roll type. The lower die 21 is provided below the end of the steel plate P set in the apparatus, and the lower die 21 is provided with a plurality of hydraulic cylinders 22.
It is designed to move up and down.

Next, a method for bending an end using the apparatus of the present invention will be described. (1) The upper die 1 is driven by the motor 4 to set an arc having a predetermined curvature directly below. (2) The steel plate is moved by a transport table roll (not shown), and the edge portion to be bent is taken between the upper mold 1 and the lower mold 9. (3) The lower clamp 18 is raised to clamp the steel plate. (4) Raise the lifting table 11 to move the lower mold 9 or
The steel plate P is pressed by the lower mold 21. (5) After that, while continuing to raise the elevating table 11 while aligning it with the arc of the upper die 1, the screw shafts 1
3 is turned to move the upper die 1 in the forward direction to bend the steel sheet. In the case of the non-roll type lower die 21, this step is not provided. (6) When the end bending is completed, the elevating table 11 and the lower clamp 18 are lowered, and the upper mold 1 is raised until the bent end portion of the steel sheet is avoided. (7) In the above forming operation, when the end bending of the steel plate is not completed, the steel plate is moved forward, and then (2) to (4) are repeated to complete the end bending of the forming end.

When the size of the steel pipe is changed, the upper die 1 is rotated to set a desired arc right below, and the end bending is performed by the above procedure.

When changing the upper die 1 to another one,
The rearrangement is performed according to the following procedure. (1) After lowering the elevating table 11, the upper mold 1 is lowered until a gap necessary for the rearrangement with the backup roll 7 is formed. (2) Replace the upper mold 1 with another upper mold 1 '. (3) The upper die 1'is raised and brought into contact with the backup roll 7.

[0023]

According to the present invention, since the upper die formed of a series of arcs having a plurality of curvatures is used, the upper die can be replaced within the arc range of the upper die used even if the size of the steel pipe changes. It is possible to bend the edge of the steel plate without using it. Therefore, the efficiency of the end bending work can be significantly improved.

[Brief description of drawings]

FIG. 1 is a schematic front view of a device of the present invention.

FIG. 2 is a view on arrow AA of FIG.

FIG. 3 is a schematic left side view of the device of the present invention.

FIG. 4 is a perspective view of the device of the present invention.

FIG. 5 is a schematic left side view of an example in which the lower mold of the device of the present invention is a non-roll mold.

FIG. 6 is a transverse cross-sectional view of a roll mold upper die according to the device of the present invention.

[Explanation of symbols]

1 roll upper mold 2 bearings 3 miter gears 4 motor 6 hydraulic cylinder (for upper mold) 7 backup roll 8 bearing box 9 roll type lower die 10 Bearings (for lower mold) 11 Lifting table 12 Hydraulic cylinder (for lifting table) 13 screw shaft 14a, 14b axes 15 Motor (for screw shaft drive) 16a-16d Miter gear 21 Non-roll type lower die

Claims (3)

(57) [Claims] 1. A method for bending an end of a steel sheet, wherein both side edges of the steel sheet cut prior to forming are pressed by an upper die and a lower die when producing a welded pipe, the arc portion having a plurality of curvatures. A welded pipe characterized by performing end bending of a steel sheet having a different curvature by one upper mold by rotating an upper mold constituted by a series of the above to freely select an arc portion having a predetermined curvature. How to bend the edge of steel sheet during pipe making. 2. An upper mold which is composed of a series of arcs having different curvatures and which is rotatable, a means for moving the upper mold up and down, a rotation driving device and a rotation stopping device for the upper mold. A lower die provided so as to be movable up and down, a means for moving the lower die in a direction orthogonal to an end bending line, and a steel plate at the time of pipe making for welding, comprising means for vertically moving the lower die. Edge bending device. 3. A rotatable upper die, which is composed of a plurality of arcs having different curvatures and is rotatable, means for moving the upper die up and down, and a rotation drive device for the upper die. Further, a lower die of a roll die provided so as to be movable back and forth, an elevating table for supporting the die so as to be vertically movable, and an elevating table provided on the elevating table. An end bending device for a steel plate at the time of producing a welded pipe, which comprises a means for moving in a direction orthogonal to each other and a means for vertically moving the lifting table.