JPH0311878B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method for manufacturing a laser-welded can body using a laser as a means for welding the can body, and particularly to a laser-welded can body that improves welding speed and reliability. This invention relates to a method of manufacturing a body.

Conventional technology Generally used for beverage cans and food cans3
The can body of a piece can is manufactured by cutting a metal plate into a cylindrical shape and welding both side edges of the metal plate. Recently, laser welding has begun to be used as a means for welding can bodies.

Conventionally, methods for welding can bodies using a laser include a method in which both side edges 1a and 1b of a can body 1 are abutted against each other as shown in FIG. 7
As shown in the figure, both side edges 3a and 3b of the can body 3
Generally, a method was used in which a slight amount of overlapped portions were overlapped and the overlapping portion was welded using the laser irradiation device 2.

Problems to be Solved by the Invention However, in the above method, the side edges 1a, 1b
The mating surfaces must be finished flat with high precision. If the abutting surfaces of the side edge portions 1a and 1b are uneven, a gap will be created in the abutting portion, and the laser beam will pass through this gap, so there is a possibility that a hole will be formed after welding. Therefore, in the method (2), machining of the side edges 1a and 1b is troublesome, and there is a possibility that holes may be formed in the welded portion, resulting in a problem of poor workability and reliability.

On the other hand, in the above method, the surface to be welded is the contact position of the side edges 3a, 3b, but the laser irradiation is performed on the surface of the side edge 3a.
There was a problem in that the surface portion of the side edge portion 3a was considerably evaporated before the abutting portion was melted. In addition, with this method, the laser irradiation efficiency is poor because the laser is not directly irradiated onto the surface to be welded.
Another problem was that the welding speed was slow.

The present invention was created in view of the above points, and an object of the present invention is to provide a method for manufacturing a laser welded can body that improves welding speed and reliability.

Means for Solving the Problems In order to solve the above problems, in the present invention, the metal plate-like body is run in a cylinder so that both side edges of the metal plate-like body have meeting parts that overlap slightly. A method for manufacturing a laser welded can body was constructed as follows, in which the can body is manufactured by forming a can body into a shape, and by irradiating the meeting portion with a laser beam and welding the side edge portions.

That is, after pressing the side edge portions with a first pair of rolls for position regulation whose roll surfaces are not parallel to each other and forming the meeting portions into a meeting state suitable for laser beam irradiation, the metal plate is moved. A laser beam is irradiated to the meeting part from a direction substantially perpendicular to the direction to melt each inner side edge of the meeting part, and then a second pair of welding rollers disposed forward in the traveling direction is used.
A can body was manufactured by welding the meeting portion while pressing the metal plate as it traveled.

Effect By configuring the method for manufacturing a laser welded can body as described above, even if the can body is cylindrical, the laser beam can be irradiated to the inside of the joint portion to be welded.

In addition, since the meeting state of the meeting part is maintained in an appropriate state by the first roll pair, the laser beam is always irradiated to a predetermined location on the side edge, the welding conditions are constant, and the reliability of the can body is improved. can be achieved.

Furthermore, regulation of the meeting portion by the first pair of rolls and welding by the second pair of rolls can be performed while the metal plate is traveling, and high-speed welding processing can be performed.

Embodiment Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of a can body welding device 4 for carrying out the present invention. The can body welding device 4 shown in the figure roughly consists of a pair of position regulating rolls 5, 6,
A pair of rolls 7 and 8 for welding, a laser irradiation device 9
It is arranged next to the can body forming device (not shown) in a series of can body manufacturing lines.

The can body is made by forming a metal plate-like body 10 obtained by cutting a metal substrate into a size corresponding to one can body into a cylindrical shape using a can body forming device, and then forming the side edges 10a and 10b into a cylindrical shape using a can body welding device 4. Manufactured by welding.
In addition, the can body forming device, the can body welding device 4, etc. are arranged on a line, and the metal plate 10 is sequentially processed and formed by running on this line, so that the can body can be manufactured at high productivity. Well manufactured.

A metal plate 10 that has been formed into a cylindrical shape by a can body forming device is fed into the can body welding device 4 . FIG. 1 shows a state in which a cylindrical metal plate 10 has been fed. In this state, the side edges 10a, 10b of the metal plate-like body 10 have a slight amount (for example,
0.5mm).
The portion where the side edges 10a and 10b overlap is hereinafter referred to as a meeting portion 11.

The rolls 5 and 6 are arranged opposite to each other, and the roll 5
is located outside the metal plate 10, and the roll 6
is arranged so as to be located inside the cylindrical metal plate-like body 10. Among these, the roll 5 has a pressing surface 5a that is an inclined surface, as shown in FIG.
Therefore, the pressing surface 6a of the roll 6 and the pressing surface 5a of the roll 5 are not parallel but have a predetermined angle (indicated by arrow α in the figure). The pair of rolls 5 and 6 regulate the position of the metal plate in the meeting portion 11. Further, by adjusting the inclination angle α, the meeting state of the side edge portions 10a and 10b in the meeting portion 11 can be adjusted.

Incidentally, in order to achieve an appropriate meeting state, the pressing surfaces of each roll may be configured to have a predetermined angle. Therefore, instead of providing an inclination to the pressing surfaces, the axes of the rolls are tilted by β (second (as shown in the figure), the pressing surface may have an angle.

The rolls 7 and 8 are disposed in front of the position of the rolls 5 and 6 in the running direction of the metal plate 10 (in the direction indicated by arrow A in FIG. 1), and
is disposed on the outside of the metal plate-like body 10, and the roll 8 is disposed on the inside. Pressing surfaces 7a and 8a of the rolls 7 and 8 are configured to be parallel to each other. Then, as will be described later, by pressing the side edges 10a and 10b melted by the laser beam, the function of welding the two is performed.

The laser irradiation device 9 is, for example, a Co ₂ gas laser with an output of 1 kW. This laser irradiation device 9 irradiates a laser beam (indicated by a chain line in the figure) from a direction perpendicular to the running direction A of the metal plate 10 toward a meeting portion 11 positioned between the rolls 5 and 6. It is configured so that Therefore, the laser beam enters the inside of the meeting part 11, specifically, the side edge part 1.
The inner surface of 0a and the surface of side edge 10b are irradiated (details are shown in FIG. 3).

Next, according to the present invention, the side edge 1 of the metal plate-like body 10 is
The procedure for manufacturing a can body by welding 0a and 10b will be explained using mainly FIGS. 1 and 2.
When the metal plate 10 formed into a cylindrical shape by the can body forming device enters the can body welding device 4, the position of the meeting portion 11 where the rolls 5 and 6 engage with the side edges 10a and 10b is first regulated. It will be done.

A metal plate 1 is formed by the spot light of the laser beam.
In the case of laser welding in which welding is performed by melting 0, it is necessary to position the meeting portion 11 with high precision. For example, if the positioning is inaccurate and a gap is created between the side edges 10a and 10b in the deep part of the meeting part 11, the laser beam passes through this gap and is irradiated inside the metal plate 10, It may destroy the paint coated on the inner surface, or in the worst case, it may damage the metal plate 1.
A hole may appear at 0.

In this way, the side edge portion 10a in the meeting portion 11,
Although the positioning of the meeting part 10b is important, the meeting part 11 can be easily and accurately positioned by using a pair of rolls 5 and 6 including the roll 5 having the inclined pressing surface 5a. I was able to do that. That is, in the deep part of the meeting part 11, the side edges 10a and 10b are pressed so that no gap is created between them, and in the vicinity of the opening of the meeting part 11, the side edge 10a located on the upper side is It is guided by an inclined pressing surface 5a. Therefore, the meeting state of the meeting section 11 is always constant.

Meeting portion 11 whose position is regulated by these rollers 5 and 6
In this step, the laser irradiation device 9 is irradiated with a laser beam. As described above, since the meeting portion 11 is positioned with high precision, the laser beam is irradiated to a predetermined irradiation position. This laser beam
1 is irradiated to the inner part of the meeting part 11 where the parts 1 can be welded most efficiently. That is, the laser beam is applied to the inner surface of the side edge 10a and the side edge 10b, which are the surfaces to be joined.
is irradiated onto the front side of the This has been made possible by configuring the laser irradiation device 9 to irradiate the laser beam from a direction substantially perpendicular to the traveling direction A of the metal plate 10.

Note that the irradiation direction of the laser beam is set to the metal plate 10.
A configuration in which the metal plate 10 is arranged parallel or close to parallel to the traveling direction A is conceivable, but this is less practical due to the peculiarity of can body manufacturing in which the metal plate 10 is formed into a cylindrical shape and then welded. .

As described above, the laser beam is irradiated to the inner portion of the meeting portion 11, and at this time, the laser beam is configured to weld particularly strongly the portion shown in FIG. 3 with a satin finish. This can be achieved relatively easily by appropriately selecting the irradiation position of the laser beam, the spot diameter of the laser beam, the inclination angle α of the roll 5, etc. because the positioning of the meeting part 11 is performed with high precision. Can be done. This makes it possible to perform strong welding at the tip portions of the side edges 10a, 10b, improving the sealing performance at the welded portions and increasing the reliability of the can body. In addition, since the joint surface is directly melted, the laser beam irradiation time can be shortened (energy can be saved).

Returning to FIG. 1 again, the metal plate 10 whose inside of the joining part 11 has been melted by the laser beam is transferred to the welding roll 7, which is located in the front in the traveling direction.
8 presses the meeting part 11 (FIG. 4 shows how the meeting part 11 is pressed). As a result, the side edges 10a and 10b are reliably welded to form a can body. At this time, since the meeting portion 11 is press-welded, the thickness T of the metal plate 10 at the welded portion is smaller than the thickness t of the metal plate 10 itself, as shown in FIG. T=t<2t, for example T=
Since the weight is approximately 1.3t, it is possible to improve the sealing performance after attaching the can lid.

As described above, positioning and welding of the meeting portion 11 are performed using the rolls 5 to 8. For this reason,
Since positioning and welding can be performed while the metal plate 10 is traveling, the welding speed can be increased and can bodies can be manufactured with high productivity. The traveling speed of the metal plate 10 is determined by the distance between the roll pairs 5, 6 and 7, 8, the material and thickness of the metal plate 10, the output of the laser irradiation device 9, etc.

Effects of the Invention As described above, according to the present invention, since the meeting part is positioned with high precision by the first pair of rolls, there is no gap in the meeting part, and the laser beam is appropriately irradiated to a predetermined position. In addition, since this irradiation position is on the inside of the joining part to be directly joined, it is possible to perform strong and reliable welding, shorten the laser beam irradiation time (save energy), and furthermore, the laser beam irradiation The welded joining part is press welded by the second pair of rolls, so the thickness of the welded part can be made small. In addition, the positioning and press welding of the joining part are performed by the first and second roll pairs. Since the process can be carried out while the metal plate is traveling, it has the advantage of being able to manufacture can bodies with high productivity.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing a can body welding device for explaining one embodiment of the present invention, FIG. 2 is a side view of the can body welding device, FIG. 3 is an enlarged view of a meeting part, and FIG. Figure 4 is a diagram showing the state in which the meeting part is pressed by the roll 7, Figure 5 is a diagram for explaining the thickness of the welded part, and Figures 6 and 7 are diagrams showing the conventional welding method using a laser. FIG. 2 is a configuration diagram showing an example. 4...Can body welding device, 5-8...Roll, 5
a, 6a...pressing surface, 9...laser irradiation device, 1
0...Metal plate-shaped body, 10a, 10b...Side edge portion,
11...Meeting department.

Claims (1)

[Scope of Claims] 1. A metal plate is formed into a cylindrical shape while traveling so that both side edges of the metal plate have a meeting part where they overlap by a slight amount, and a laser beam is irradiated to the meeting part. A method for manufacturing a can body by laser welding the side edges by welding the side edges together, the method comprising
After pressing the side edge portions with a pair of rolls to form the meeting portion into a meeting state suitable for irradiation with the laser beam, the meeting portion is pressed from a direction substantially perpendicular to the traveling direction of the metal plate. A laser beam is irradiated to melt the inner side edges of the meeting portion, and a second pair of welding rollers disposed forward in the traveling direction is used to melt the meeting portion into the metal plate. A method for manufacturing a laser-welded can body, characterized in that the can body is manufactured by welding while pressing as the can body travels.