Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
  • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
  • B23K26/14—Working by laser beam, e.g. welding, cutting or boring using a fluid stream, e.g. a jet of gas, in conjunction with the laser beam; Nozzles therefor
  • B23K26/1435—Working by laser beam, e.g. welding, cutting or boring using a fluid stream, e.g. a jet of gas, in conjunction with the laser beam; Nozzles therefor involving specially adapted flow-control means
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
  • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
  • B23K26/14—Working by laser beam, e.g. welding, cutting or boring using a fluid stream, e.g. a jet of gas, in conjunction with the laser beam; Nozzles therefor
  • B23K26/1462—Nozzles; Features related to nozzles
  • B23K26/1464—Supply to, or discharge from, nozzles of media, e.g. gas, powder, wire
  • B23K26/147—Features outside the nozzle for feeding the fluid stream towards the workpiece

Definitions

• the subject of this invention is a high power laser welding installation.
• This type of welding requires the supply of a protective gas to the welding region in order to facilitate the formation of an interaction plasma, in particular to suppress a breakdown phenomenon, or to protect the liquid bath by preventing it. to oxidize or undergo another chemical alteration.
• a conventional solution consists in placing a tube leading to a supply source of gas to be supplied and the end of which is directed towards the welding region. In general, the axis of this tube is placed in the plane defined by the axis of the laser beam and the direction of the weld bead, at an angle which can be about 45 ° relative to the axis of the beam. If this arrangement is interesting for welding a straight bead, it is no longer interesting for welding in a curved line or in three-dimensional space.
• the quality of the gas blanket is no longer constant along the bead. It is to avoid these drawbacks that it has also been proposed to use protective boxes, drilled to let the ray pass, which cover a large region around the welding zone and into which a protective gas is injected. Such boxes are generally supported on the surface to be protected and do not can not move, not being integral with the welding head. Such an installation is awkward to use and hardly suitable for horizontal surfaces.
• the object of the invention is to guarantee the formation of the gaseous medium of the desired composition on the welding zone.
• the invention relates, in its most general form, to a high-power welding installation comprising a beam of a laser and a means for blowing a gas onto a welding region, characterized in that said means comprises an annular nozzle, integral with the laser and designed so that it generates a laminar flow of the gas such that part of the gas is evacuated by a base of the nozzle, radially around a focusing area of the laser beam and towards the outside, and that another part of the gas flows back inside a region surrounded by the nozzle, and escapes towards the outside by an open face of entry of the laser beam.
• FIG. 1 is a general view of the invention
• the welding installation of FIG. 1 comprises a laser 1 which emits a ray or beam 2 towards a welding joint 3 defined between two parts 4 and 5 which may or may not be planar.
• the welding installation also comprises a nozzle 6 linked to the laser 1 by a support head 7.
• the nozzle 6 is composed of an inner tube 8 and an outer tube 9 concentric which therefore define an annular chamber 10 between them and both of which are parallel to the beam.
• a gas pipe 11 originating from a source 12 opens into the chamber 10, which is closed at the rear by a wall 13 but open at the base, towards the parts 4 and 5, so that the gas which is blown s 'escapes at this point according to a laminar flow.
• the parts 4 and 5 becomes a portion flowing toward- one outside and one inside to 1, in particular towards the region 14 for focusing the beam welding where the responsible plasma is formed. Then, the gas animated by the centripetal movement rises in the internal tube 8 and escapes from the nozzle 6 against the current of the beam 2. This exit movement completely sweeps the interior of the nozzle 6 of the ambient gas; it is made possible by the absence of a focusing lens for the beam 2, which can come from a laser 1 at carbon dioxide which has the property of emitting light at a wavelength for which the constituent materials of the lenses are fairly absorbent. As the power must be high (10 kw for example), the lenses could be destroyed, which explains why we usually do without for such applications.
• FIG. 2 shows however that the opening section of the nozzle 6 upwards can be reduced by adding an annular collar 15 which leaves a section corresponding to that of the bundle 2 free, without compromising the evacuation of the gas or disturbing the design of the diverging flow at the outlet of the nozzle 6.
• FIGS. 3 and 4 show however that this flow can be modified by making the internal tube 8 either longer or shorter than the external tube 9 (on the left halves and on the right of FIG . 3 respectively), which deflects the median flow of the gas at the outlet of the nozzle 6 obliquely and makes the proportions of the gases deflected inwards and outwards unequal.
• Another arrangement, represented in FIG. 4 would consist in operating holes at the bottom of one of the tubes, and in particular of the internal tube 8, in order to facilitate the flow of gas inside this tube and therefore d '' increase the protection of the welding area.
• FIGS. 5, and 6 thus show that the nozzle 6 can be cooled by having heat exchange circuits 17 or 18 presented under the form of coils running along tubes 8 or 9 or of channels operated within these tubes; that a diffusing medium 19 can be placed in the chamber 10 to homogenize the flow in the two tubes 8 and 9. All these modifications and additions are, of course, cumulative at will.

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• Physics & Mathematics (AREA)
• Optics & Photonics (AREA)
• Engineering & Computer Science (AREA)
• Plasma & Fusion (AREA)
• Mechanical Engineering (AREA)
• Laser Beam Processing (AREA)

Applications Claiming Priority (3)

Publications (1)

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ID=8861532

Family Applications (1)

Country Status (4)

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Family Cites Families (8)

• 2001
  • 2001-03-26 FR FR0104030A patent/FR2822399B1/fr not_active Expired - Fee Related
• 2002
  • 2002-03-22 EP EP02724378A patent/EP1372902A1/de not_active Withdrawn
  • 2002-03-22 US US10/471,288 patent/US20040099643A1/en not_active Abandoned
  • 2002-03-22 WO PCT/FR2002/001009 patent/WO2002076667A1/fr not_active Ceased

Non-Patent Citations (1)

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