JP3126789B2 - Laser welding equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser welding apparatus for performing laser welding on a butt portion of a sheet material.

[0002]

2. Description of the Related Art Conventionally, it is generally well known to irradiate a laser beam from a laser processing head to an abutting portion of a sheet material to perform laser welding on the sheet material.

Further, it has been known that when a laser beam from a laser head is applied to a butt portion of a plate-shaped workpiece and laser welding is appropriately performed, a bulge occurs on the front and back surfaces of the welding surface. I have.

[0004]

By the way, in particular, the shape and size of the bulge of the meat generated on the back surface of the welding surface due to laser welding vary, so that the welding surface on the back surface is not clean and the shape is not good. . That is, there is a problem that the quality of the welded portion is poor.

[0005] An object of the present invention is to improve the above problem by reducing the thermal effect on the back surface of the welded surface of the plate material when laser welding is performed, making the welded surface clean and having a good shape. It is an object of the present invention to provide a laser welding apparatus capable of obtaining a high-quality welding surface.

[0006]

SUMMARY OF THE INVENTION In view of the above-mentioned conventional problems, the present invention provides a jig for supporting a work to be laser-welded, and a jig provided on the jig and welded to the work. A heat sink having an injection opening for injecting a back shield gas to a lower surface, a laser processing head for irradiating a laser beam to a butt line to be welded on the work, and a laser processing head positioned in front of the laser processing head in a traveling direction. A plasma removing nozzle for injecting a shielding gas into a laser welded portion to remove plasma generated during laser welding, wherein the plasma removing nozzle is used for uniformizing a shielding gas supplied from a gas supply pipe. A slit having a large width for injecting the shielding gas with a width larger than the width of the heat-affected zone of the welded portion in the work is provided. Is a configuration that includes communicating with the serial chamber.

[0007]

An embodiment of the present invention will be described in detail with reference to the drawings.

Referring to FIG. 1, a laser welding apparatus 1 includes a rectangular jig 3 on which a plate-shaped work W is positioned and fixed by a plate material fixing arm (not shown). You.

Above the jig 3, a laser processing head 5 movable in, for example, the Y-axis direction (the front-back direction in FIG. 1).
A nozzle 7 is provided at the tip (lower end) of the laser processing head 5. Since the structures of the laser processing head 5 and the nozzle 7 are already known, the description thereof is omitted, and the movement of the laser processing head 5 in the Y-axis direction is performed by driving means such as a driving motor and a ball screw. is there.

With the above structure, the laser beam LB is irradiated from the nozzle 7 of the laser processing head 5 to the butting portion WT of the plate material W positioned and fixed on the jig 3, and the laser processing head 5 is moved in the Y-axis direction, that is, the butting line WL. The laser welding is carried out by moving along.

A nozzle 11 for plasma removal is mounted adjacent to the laser processing head 5 with a mounting bracket 9. The state of attachment of the plasma removing nozzle 11 is, for example, argon,
A shield gas G such as nitrogen is attached so as to be directed in a curtain shape from, for example, 40 to 60 degrees to the plasma P. In addition, the plasma removing nozzle 11 is mounted on the front side in the traveling direction in which the laser processing head 5 moves.

As an example of the plasma removing nozzle 11, as shown in FIGS. 5, 6 and 7, a gas passage 13 for supplying a shielding gas G is formed and one end of the gas passage 13 is provided. The gas supply pipe 15 is screwed. Further, a chamber 17 is formed in the other end of the gas passage 13 and in the plasma removing nozzle 11.

A lower plate 23 is provided with a plurality of screws 2 at the lower end of the plasma removing nozzle 11 via a sealing member 21 made of rubber or the like having a substantially V-shaped groove 19, for example.
5 attached. The groove 19 formed in the seal member 21 communicates with the chamber 17. Since a sealing member 21 having a substantially V-shaped groove 19 is interposed between the lower portion of the plasma removing nozzle 11 and the lower plate 23, as shown in FIG. A slit 27 is formed at the tip of the nozzle 11 by the thickness of the groove 19.

With the above configuration, the shielding gas G is supplied from a shielding gas supply source (not shown),
After that, it is sent to the chamber 17. The shield gas G sent to the chamber 17 is ejected from the slit 27 and plasma P generated at the time of laser welding is removed. Due to the presence of the chamber 17, the shield gas G ejected from the slit 27 is made laminar and uniform.

The plasma P is removed by the shielding gas G, and the surface of the heat affected WB formed around the molten portion WA is cooled by the shielding gas G as shown in FIG. Welding can be eliminated and uniform laser welding can be performed to form an I-shaped welding surface with a narrow welding width.
Further, as shown in FIG. 8, the surface of the bulge WC formed on the surface of the welding surface becomes clean and the shape becomes good.

When the width of the slit 27 is L as shown in FIG. 7 and the width of the heat affected zone WB is H as shown in FIG. 8, the width L of the slit 27 is set so that L / H ≧ 2. If it is large, the cooling effect is greatly enhanced, which is desirable. The plasma removal nozzle 11 may be attached to the laser processing head 5 at any position on the outer periphery adjacent to the laser processing head 15, but the laser processing head 5 is provided in front of the butting portion in the welding direction. Is desirable.

Referring again to FIGS. 1, 2, 3 and 4, the jig 3 is formed with a U-shaped cutout groove 29 extending in the Y-axis direction. This notch groove 2
Reference numeral 9 denotes an opening on the upper surface and the left side surface. In addition, a heat sink 31 as shown in FIG. 3 is detachably engaged with the notch groove 29.

An injection opening 33 extending in the Y-axis direction is formed on the upper surface of the heat sink 31, and a back shield gas passage 37 is formed below the injection opening 33 through a communication passage 35 through the heat sink. 31. The left ends of the injection opening 33, the communication passage 35, and the back shield gas passage 37 are open.

A female screw is formed on the left inner peripheral surface of the back shield gas passage 37, and a male screw 41 attached to the tip of the shield gas hose 39 shown in FIGS. The female screw of the passage 37 is screwed. Further, a gas leakage prevention plate 43 is provided on the upper surface on the left side of the heat sink 31 engaged with the notch groove 29 of the jig 3 so as to be in close contact with the left end of the plate material W as shown in FIGS. Have been.

With the above structure, the abutting portion WT of the plate material W is formed by the X of the injection opening 33 formed on the upper surface of the heat sink 31.
The plate W is positioned and fixed on the jig 3 so as to fall within the width in the axial direction. In this state, when the laser beam LB is irradiated from the nozzle 7 of the laser processing head 5 to the butting portion WT of the plate W and the laser processing head 5 is moved along the butting line WL of the plate W to perform laser welding,
A shield gas G such as argon or nitrogen is supplied from a shield gas supply source (not shown) to a back shield gas passage 37 provided in the heat sink 31 via a shield gas hose 39. This back shield gas passage 3
The shield gas G supplied to 7 is blown from the injection opening 33 to the back surface of the welding surface of the plate W through the communication passage 35.

Therefore, as shown in FIG.
The surface of the bulge WD of the meat formed on the back surface of the welding surface becomes clean and the shape becomes good, so that a high quality welding surface can be obtained.

As shown in FIG. 3, the opening width ΔW of the injection opening 33 formed on the upper surface of the heat sink 31 is desirably, for example, 0.5 to 6 mm, and moreover, every 0.5 mm. A plurality of heat sinks 31 provided with the injection openings 33 having the opening widths described above are prepared in advance, and a jig 3 is selected by appropriately selecting one that matches the laser welding conditions such as the thickness and type of the plate material W to be welded. A high-quality welded surface can be obtained by engaging and using the notch groove 29 formed in the groove.

The present invention is not limited to the embodiment described above, but can be embodied in other modes by making appropriate changes. In this embodiment, a nozzle 11 for removing a shielding gas is provided adjacent to the laser processing head 5.
However, it is also possible to cope with a case where laser welding is performed without providing the shielding gas removing nozzle 11. Further, for example, the shape of the slit 27 formed at the tip of the plasma removing nozzle 11 is an elliptical shape,
It is also possible to adopt a shape in which a plurality of small holes or the like are provided in series.

[0024]

As can be understood from the above description of the embodiment, in short, the present invention provides a jig (3) for supporting a work (W) to be laser-welded, and the jig (3).
A heat sink (31) provided with an injection opening (33) for injecting a back shield gas to a lower surface of a welded portion of the work (W); A laser processing head (5) for irradiating a laser beam (LB) onto the laser beam (W _L ); and a laser welding for removing a plasma (P) generated at the time of laser welding, which is located in front of the laser processing head (5) in the traveling direction. And a plasma removing nozzle (11) for injecting a shielding gas (G) to the section, wherein the plasma removing nozzle (11) is used to make the shielding gas supplied from the gas supply pipe (15) uniform. comprises a chamber (17), and large of the workpiece HAZ of the welded portion in the (W) (W _B) of the width (H) with a large width than (L) width so as to inject a shielding gas (L) A slit (27) is provided in communication with the chamber (7).

As is apparent from the above configuration, the present invention is provided with the heat sink 31 for injecting the back shield gas to the lower surface of the welded portion of the work W during the laser welding. In addition to being able to effectively prevent oxidation of the welded surface and effectively maintain the welded surface, the present invention provides a plasma removing nozzle for removing plasma generated during welding in the chamber 17. by the heat-affected zone W slit 27 of greater width L than the width H of _B preparedness and the workpiece W is configured to include communicates with the chamber 17, the shield gas supplied from the gas supply pipe 15 the chamber The air is uniformized in the inside 17 and is ejected from the slit 27 as a laminar flow.

Therefore, not only plasma generated during welding of the work W can be effectively removed, but also the upper surface of the work can be effectively cooled. In addition, since the shield gas has a laminar flow, it is possible to perform good welding without disturbing the molten metal at the welded portion.

[Brief description of the drawings]

FIG. 1 is a schematic view of a laser welding apparatus according to one embodiment for explaining the present invention.

FIG. 2 is a perspective view showing a notch groove formed in the jig.

FIG. 3 is a perspective view of a sheet sink engaged with a notch groove formed in a jig.

FIG. 4 is a sectional view taken along the line IV-IV in FIG.

FIG. 5 is an exploded perspective view of a plasma removal nozzle.

FIG. 6 is a front sectional view of a plasma removal nozzle.

FIG. 7 is a sectional view taken along the line VII-VII in FIG. 6;

FIG. 8 is a welding state diagram of a sheet material obtained by laser welding according to the present invention.

[Description of Signs] 1 Laser welding device 3 Jig 5 Laser processing head 7 Nozzle 11 Plasma removal nozzle 27 Slit 29 Notch groove 31 Heat sink 33 Injection opening 37 Back gas passage

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B23K 26/00-26/14 B23K 37/06

Claims (1)

(57) [Claims] 1. A jig (3) for supporting a work (W) to be laser-welded, and a back shield gas provided on the jig (3) and to a lower surface of a welded portion of the work (W). A heat sink (31) having an injection opening (33) for injection, and a laser processing head (5) for irradiating a laser beam (LB) to a butt line (W _L ) of the work (W) to be welded. A shielding gas (G) which is located in front of the laser processing head (5) in the advancing direction of the laser processing head to remove a plasma (P) generated during laser welding;
And a plasma removal nozzle (11) for injecting gas. The plasma removal nozzle (11) is provided with a gas supply pipe (1).
5) comprising a chamber (17) for achieving the uniformity of the supplied shielding gas from, and the heat-affected zone of the weld in the workpiece (W) (W _B) of the width (H) greater width than (L A) a slit (27) having a large width (L) communicated with the chamber (7) so as to inject the shielding gas.