JPS62282793A - Manufacture of thin tubular body - Google Patents

Abstract

PURPOSE:To enable the high speed production of a thin tubular body by spirally winding a thin strip shaped plank and welding by projecting a laser beam on the side edge of each loop abutted each other and the side edge of the adjoining loop. CONSTITUTION:The strip shaped plank 2 wound on a reel 1 is pulled out in the arrow mark direction and wound on the outer periphery of a mandrel 6 by making the prescribed angle for the center shaft of the mandrel 6. The plank 2 is wound with its pressing by a roller 18 and the seam 5 is formed by closely fitting the side edge 9 to the previously wound side edge 9. A laser beam 20 is then arranged on the upper part of the seam 5 and the welding is performed by projecting in on the seam 5. In this way the heat influence is limited, the dimensional accuracy in welding is improved and the work removing the tubular body from the mandrel after welding is facilitated.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention Industrial Application Field The present invention relates to a method for manufacturing a thin-walled tubular body in its entirety. This invention relates to a method for producing a thin-walled tubular body by irradiating and welding the side edges of adjacent loops with a laser beam.

Prior art and its problems Patent No. 3,206.210 discloses that a strip-shaped thin plate drawn from a coil is formed into a tubular shape around a longitudinal center line, and both side edges are opposed to each other in a V-shape. A method is described in which welding is performed by irradiating a laser beam to the middle part of two side edges, and when the fabricated tubular body reaches a predetermined length, the laser beam is used to cut the tubular body one after another. . The welding of the longitudinal edges of the tubular body according to the present invention is neither lap welding nor butt welding, but is a very special type of welding in which the intermediate portions of both side edges arranged in a V-shape are welded. Therefore, the product produced by this method cannot be used as a can body.

A method has also been developed in which a strip blank is formed into a tube shape and the longitudinal edges are abutted or overlapping welded to produce can body material, but when the plate thickness is small, the claws used for feeding Traces remain and cause problems in production.

OBJECTS OF THE INVENTION An object of the present invention is to provide a method for producing a tubular body suitable for a can body at high speed using a medium-sized blank with a thin wall of about 0.2 mm.

The above object of the present invention is to provide a method for winding a thin strip-like blank of a predetermined width around the outer periphery of a mandrel made of a round bar in a spiral manner at a predetermined pitch. This is achieved by the method of manufacturing a thin-walled tubular body of the present invention, which is characterized in that the edges are irradiated with a laser beam and welded.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of the method of the present invention will be described below with reference to embodiments shown in the accompanying drawings.

Referring to FIG. 1, a mandrel 6 made of a round bar is arranged horizontally, and its upper end is rotatably supported by a bearing 7. The mandrel 6 is provided with a toothed ring 8 at the end projecting upward from the bearing 7. The toothed wheel 8 meshes with another toothed wheel (not shown) connected to a suitable drive source. A strip blank 2 wound on a reel 1 is pulled out in the direction of the arrow P, and a driving roller 3, a guiding roller 4, and an edge roller 1 are pulled out.
9, it is wound around the outer periphery of the mandrel 6 at a predetermined angle θ with respect to the central axis YY of the mandrel 6. The mandrel 6 is not only rotated by the gear wheel 8, but also
It is reciprocated in the YY direction by an appropriate drive source (not shown). Rotation axis 18A parallel to central axis YY of mandrel 6
? A roller 18 having a reel 1 is placed in a position opposite to the strip blank 2 led to the upper part of the mandrel 6, and presses the strip blank 2 onto the surface of the mandrel 6. By this pressure contact, the blank 2 is wound with the side edge 9 held at a predetermined angle θ with respect to the central axis YY of the mandrel 6. When the blank 2 is wound onto the simandrel by the rollers 18, the side edges 9 form a seam 5 to be welded in close contact with the side edges 9 of the rolled blank part. Reference numeral 15 indicates a pressure roller disposed perpendicularly to the rotation axis 15A'i seam 5. The pressure roller 15 is 120 around the mandrel 6.
They are arranged in three pieces with a distance of 3 degrees. A laser beam source 21 is placed at the top of the seam 5 and the laser beam 2
0 to seam 5. In operation, the strip blank 2 guided from the reel 1 to the mandrel 6 is guided by the guide rollers 4
The direction is controlled by an edge roller 19, and the seam 5 is pressed against the surface of the mandrel 6 at a predetermined angle θ, thereby forming the entire seam 5. The laser beam 20 is irradiated at a position adjacent to the pressure roller 18 . The alignment between the two side edges of the strip blank forming the seam 5 is effected by the actuation of edge rollers 19.

FIG. 2 shows a modified embodiment of the apparatus shown in FIG. 1, in which when using a specific angle as the pinch angle
Only % of the total surface of mandrel 101 can be used in 360 helical wraps around 10, leaving the remaining % of the total surface area unused. The remaining % unused area also extends in a helical manner around the outer periphery of the mandrel 101 and has the same pitch as the helix of the first blank 101. When the second blank 103'i is wound spirally, the embodiment of FIG. 2 is obtained. In this example it is always 2
Mandrel 1 with different blanks 101, 103i at the same time
10 and each blank, e.g. 103, is simultaneously welded on both side edges to the side edges of the other blank 101, respectively, using separate laser beam sources 10.7A, 107B, thereby increasing productivity. It is the same as in Figure 1 that all welding is done using a laser beam to the butted side edges. Since the product is welded together, the outer surface of the product is smooth and does not look inferior to products made using other methods. Since welding is performed using the entire laser beam, heat effects are localized and dimensional accuracy of welding is improved. This is particularly advantageous when welding printed blanks. In addition, since shallow penetration welding is possible, the blank will not form a fusion layer on the mantle rail due to welding.

To facilitate the work of removing a tubular body from a mandrel after welding. It is advantageous in terms of environmental hygiene because welding can be performed with less contamination.

[Brief explanation of drawings]

FIG. 1 is a plan view showing an embodiment of the present invention. FIG. 2 is a perspective view showing a modified embodiment of the present invention. 1 Reel 2　　　　　　　　Striped blank 3 A pair of driving rollers 4 Pair of guide rollers 5 Seam 6 Mandrel 7 Bearing head 8 Tooth ring 9 Side edge 15 Pressure roller 18 Pressure roller 19 Edge roller

Claims (1)

[Claims] When a thin strip-shaped blank of a predetermined width is wound spirally around the outer circumference of a round bar mandrel at a predetermined pitch, a laser beam is irradiated on the side edges of each loop and the side edges of the adjacent loops that abut each other. A method of manufacturing a thin-walled tubular body, characterized by welding.