JPH0344387Y2 - - Google Patents

Description

[Detailed explanation of the invention] [Industrial application field] This invention is for manufacturing can bodies of metal cans.
The present invention relates to a device for welding circumferential edges of can bodies together using a laser welding method.

[Conventional technology]

The edges of the can body are generally welded by a resistance welding method that utilizes electrical resistance heat. In the resistance welding method, pretreatment work is essential to remove oil, moisture, rust, or printed layers adhering to the welding area.

In order to omit such pre-treatment work and improve welding speed, it has been proposed to perform edge welding of can bodies by laser welding. For example, Japanese Patent Application Laid-open No. 76690/1983 by the present applicant is one of them.

The present inventor has been researching the practical application of can body edge welding using a carbon dioxide gas laser for several years, and has attempted to put edge welding to practical use under mass production conditions using a welding device with an output of 1KW as shown in Figure 4. This device is used for can body material 1.
and a pair of rollers 4 that press and hold the edges 1a and 1b of the can body against the table 2.
0, and while the can body material 1 is held in a welding position by rollers 40 and fed and moved in the direction of arrow A, welding is performed by irradiating a laser beam from a processing head 3 facing the table 2. A condensing lens 5 is arranged inside the processing head 3, and a nozzle 7 for blowing out assist gas is provided at the lower end of the condensing lens 5. 8 is the air outlet.

[Problem that the invention attempts to solve]

Laser welding differs fundamentally from conventional resistance welding in that the welded area is heated in a non-contact manner.
Therefore, in either case of lap joints or butt joints, the success or failure of welding and the quality of welding depend on how accurately the can body edges are held in position at the welding site.

Conventionally, to maintain the posture of the can body material 1, rollers 40, 40 are used to hold the can body material 1 at two locations, front and rear, in the material feeding direction A, with the nozzle 7 in between. For this reason, even if the diameter of the roller 40 is set as small as possible, there is a problem in that the material pressing position cannot be brought sufficiently close to the welding position, and the posture cannot be maintained reliably. More specifically, since the lower roller 40 in the feeding direction holds the can body material 1 after welding, the upper roller 4 is used from the start of welding until the can body material 1 reaches the lower roller 40.
0 and the auxiliary guide frame (not shown) are used to maintain the posture, and from this point as well, the posture at the welding site cannot be accurately maintained. Incidentally, if the pressing force of the roller 40 is increased, the displacement of the can body material 1 can be prevented to some extent, but since most of the can body material 1 has already been printed or coated, if the pressing force is large, feeding scratches may occur. So it's not practical.

In the laser welding method, spatter is easily scattered around the welding point, and the printed surface and coating of the can body are easily damaged or soiled by the spatter. especially,
When welding can body material 1 printed with inorganic paint containing pigments such as titanium and lead, spatter is likely to fly off.

In order to eliminate such spatter, nozzle 7
The idea of arranging a vacuum-pressured dust exhaust pipe near the dust pipe to suck out spatter is known in other business fields (Japanese Patent Laid-Open No. 46-6065). but,
As mentioned above, there are presser rollers 40 in front and behind the nozzle 7,
40, the rollers 40 will get in the way, making it impossible to arrange the dust exhaust pipe, and the rollers 40 cannot be omitted because it is necessary to maintain the welding posture of the can body edges 1a, 1b.

The present invention has been proposed to solve the above problems.

An object of the present invention is to accurately maintain the posture of the can body material at the welding site and to weld the edge of the can body reliably and with high quality.

Another object of the present invention is to prevent spatter from scattering around the can body and to easily eliminate stains and scratches on the can body.

[Means for solving problems]

In the present invention, the rotating presser member 1
3 to hold the welding position accurately.

Specifically, as shown in FIG. 1, a table 2 supports a can body material 1 bent into a ring shape so as to move it in one of the forward and rearward material feeding directions A;
In a can body manufacturing apparatus in which a processing head 3 for welding the edges 1a and 1b of a moving can body material 1 by irradiating a laser beam with each other is arranged vertically opposite to each other, a condensing lens 5 for the laser beam is used. A nozzle 7 is fixed to the lower end of the built-in processing head 3 to blow out the assist gas supplied inside toward the welded part W of the can body material 1. , a pair of workpiece pressing means 12, 12 for holding the can body material 1 in a welding position on the table 2;
are arranged, and each workpiece pressing means 12 has a flat inverted mortar shape, and the lower periphery is close to the can body material 1.
A rotating presser member 13 formed on a pressing surface 16 that presses the rotary presser member 13 against the table 2, a vertical shaft 14 that rotatably supports the rotary presser member 13, and a pressing posture of the rotary presser member 13 via the shaft 14. and the rotational center axes S, S of the pair of left and right rotating presser members 13, 13.
is required to be inclined in an upwardly tapered shape toward the vertical central axis V of the nozzle 7.

[Effect]

While the can body material 1 is being fed in one of the front and rear material feeding directions A on the table 2, the edge 1 of the can body material 1
When a and 1b are welded together using a laser beam, each of the left and right rotary holding members 13 rotates around the shaft 14, and the pressing surface 16 at the lower peripheral edge of each rotating holding member 13 presses the can body material 1 from the outside onto the table 2. to press.

At this time, since the rotary presser member 13 as a whole has an inverted mortar shape, even if the shaft 14 that supports it is away from the nozzle 7, the rotary presser member 13
The circumferential edge of the can body material 1 is directly below the nozzle 7 without the upper surface contacting the nozzle 7 and interfering with the can body material 1.
can be placed as close as possible to the vicinity of the welded portion W.

Moreover, unlike the configuration in which the left and right rotary press members 13, 13 rotate horizontally around vertical axes 14, 14, the rotation center axes S, S of each rotary press members 13, 13 are aligned with the vertical center axis V of the nozzle 7. Since it is inclined in an upwardly tapered shape, when the pressing point P of each rotating presser member 13 against the can body material 1 is brought close to the welding part W, the pressing surface of the lower peripheral edge of each rotary presser member 13 16, the can body material 1 can be locally and firmly pressed against the table 2 without being lifted up.

[Effect of idea]

Therefore, according to the present invention, since the pair of left and right rotary holding members 13, 13 can locally and firmly press the area close to the weld W of the can body material 1 on the table 2, the can body material 1 Both end edges 1a and 1b can be satisfactorily welded over the entire length without misalignment, and the welding quality can be improved.

The pressing point P of the rotary presser member 13 is set in the material feeding direction A.
By setting the dust suction member 25 on both the left and right sides of the welding part W, which is almost perpendicular to
The suction removal in step 5 prevents spatter from adhering to the surface of the can body and damaging the printed layer and coating layer, and also eliminates the deterioration of the quality of the can body caused by scattered spatter.

[First Embodiment] FIGS. 1 to 3 show a first embodiment of the present invention.

In FIG. 2, a table 2 that supports a can body material 1 and a processing head 3 that irradiates a laser beam are arranged to face each other vertically.

The can body material 1 is made of a steel plate with a thickness of 0.1 to 0.4 mm, usually 0.2 mm, and is bent into a ring shape in the previous process.
The circumferential edges 1a and 1b are guided by a jig (not shown), overlapped, and sent in the direction of arrow A. The can body material 1 sent out from the jig is supported by a table 2 and held in a welding position by a pair of workpiece pressing means 12, which will be described later.

The processing head 3 has a condenser lens 5 supported through a cylindrical holder 4 inside the processing head 3 . The periphery of the holder 4 and the area below the condensing lens 5 are covered with a cylindrical nozzle holder 6 and a nozzle 7 fixed to the lower end opening of the holder. When an inert assist gas such as argon or helium is supplied into the space defined by the nozzle holder 6, the assist gas is blown out from the outlet 8 at the tip of the nozzle 7 toward the welding location. A sub-nozzle 9 is provided in a double cylinder shape on the outer surface of the nozzle 7, and assist gas is also blown out from a blow-off port 10 at the tip thereof. A laser beam generated by a laser oscillation source (not shown) is guided to a processing head 3, condensed by a condenser lens 5, and focused on the workpiece surface facing the air outlet 8 to heat and melt the weld W.

In FIG. 1, the workpiece pressing means 12 includes a rotating holding member 13 that presses the can body material 1 and holds it in a welding position, and a vertical shaft 1 that rotatably supports the holding member 13.
4, and an attitude changing member 15 that adjusts and changes the pressing attitude of the rotary holding member 13 via a shaft 14.

The rotary pressing member 13 is formed into a flat inverted mortar shape, and presses the can body material 1 with a pressing surface 16 on the periphery of its lower surface.
Press. In order to bring the contact position of the pressing surface 16 with the can body material 1, that is, the pressing point P, as close to the welding part W as possible, the rotation center axis S of the rotary holding member 13 is set as shown in FIG. 3 in a plan view. The nozzle 7 is disposed substantially orthogonally to the material feeding direction A, and the central axis S facing each other on the left and right sides is inclined upwardly toward the vertical central axis V of the nozzle 7.

In FIG. 1, the attitude changing member 15 consists of a first arm 18 that supports the shaft 14 orthogonally, and a second arm 19 that supports this arm 18. 1st
The arm 18 is vertically slidably supported in a dovetail-shaped slide groove 20 provided in the second arm 19,
It is fixed with bolts 21 at any sliding position.
The second arm 19 is supported around a bolt 23 screwed into the fixed wall 22 so as to be able to swing up and down. By adjusting the postures of both arms 18 and 19, the pressing posture of the rotary pressing member 13 against the can body material 1 can be changed.

A dust suction member 25 is disposed adjacent to the lower side of the nozzles 7 and 9 in the material feeding direction A. This dust suction member 25
As shown in FIG. 2, a box-shaped dust inlet 26 and a vacuum source 2 are arranged as close as possible to the weld W
7, and a vacuum passage 2 connecting both 26 and 27.
It consists of 8. Due to the laser beam irradiation during welding, spatters are scattered in an inverted conical shape around the weld W, but since the can body material 1 is being fed at a constant speed, the spatter is scattered from the weld W in the feed direction. It tends to scatter more on the lower side. Therefore, by arranging the dust suction port 26 on the downstream side of the nozzle 7 in the feeding direction to suction and remove spatter, most of the scattered spatter can be sucked in.

[Another embodiment example]

In the above embodiment, the rotation presser member 13 is attached to the shaft 14.
Although it is assumed that the rotary presser member 13 is freely rotatably supported, this is not necessarily necessary, and for example, the rotary presser member 13 can be driven to rotate at a circumferential speed that is the same as the material feeding speed or slightly faster than this.

The rotation center axis S of the rotation presser member 13 does not necessarily need to be orthogonal to the material feeding direction A in plan view. For example, when welding the can body edges 1a, 1b in a butt state,
The rotation center axis S may be tilted upward in the material feeding direction A so that the parts b press against each other.

The outer nozzle 9 can also be omitted.

[Brief explanation of the drawing]

1 to 3 show a first embodiment of the welding device according to the present invention, in which FIG. 1 is a front view of the processing head, FIG. 2 is a longitudinal sectional side view of the processing head, and FIG.
The figure is a plan view. FIG. 4 is a longitudinal sectional side view of a processing head showing a conventional example. DESCRIPTION OF SYMBOLS 1... Can body material, 5... Condensing lens, 7... Nozzle, 12... Work pressing means, 13... Rotating presser member, 14... Shaft, 15... Attitude changing member, 2
5...Dust suction member, S...Rotation center axis of rotary holding member, V...Vertical center axis of nozzle, W...Welded portion, P...Press point.

Claims (1)

[Claims for Utility Model Registration] A table 2 that supports a can body material 1 bent into a ring shape so as to be moved in one of the front and rear material feeding directions A, an edge 1a of the can body material 1 during movement,
In a can body manufacturing apparatus in which a processing head 3 for welding parts 1b by irradiating them with a laser beam is arranged vertically facing each other, (a) at the lower end of the processing head 3 containing a built-in condensing lens 5 for the laser beam, A nozzle 7 is fixed that blows out the assist gas fed inside toward the welded part W of the can body material 1. A pair of workpiece pressing means 12, 12 are arranged to hold the can body material 1 in a welding position, and (c) each workpiece pressing means 12 has a flat inverted mortar shape, and the lower peripheral edge holds the can body material 1 in a welding position. A rotary presser member 13 formed on a pressing surface 16 that presses the rotary presser member 13; A vertical shaft 14 that rotatably supports the rotary presser member 13; A pressing posture of the rotary presser member 13 is changed and adjusted via the shaft 14. (d) The rotation center axes S, S of the pair of left and right rotation holding members 13, 13 are inclined upwardly toward the vertical center axis V of the nozzle 7. Can body manufacturing equipment featuring: