JP2012030262A - Laser welding method and laser welding equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laser welding method and laser welding equipment feeding a filler to a welding position and performing welding while heating the filler when arc welding is performed simultaneously by feeding wire while a laser is applied to the welding position of a workpiece to be welded.SOLUTION: The laser welding equipment includes a laser generating means 9, an arc generating means 13, a heating means 20, a wire feeding means 17, a filler feeding means 18, and a control means 23. When the arc welding is performed simultaneously by feeding the wire 3 while a laser beam 2 is applied to the welding position of the workpiece to be welded 1, the control means 23 feeds the filler 7 at the welding position and makes the filler 7 and the workpiece to be welded 1 or a molten pool 6 contacted, and performs welding while heating the filler 7 by passing a current through the filler 7, thereby increasing a welding speed.

Description

  The present invention relates to a laser welding method and a laser welding apparatus for simultaneously performing laser welding and arc welding on a workpiece.

  Laser welding is a method that can be performed at a high speed. However, if there is a gap in the work piece, there is a drawback that the laser beam can escape from the gap and welding cannot be performed. In order to make up for this drawback, a method of supplying a filler and a laser welding method combining laser welding and consumable electrode arc welding have been proposed. In the former, since the laser energy is excessively consumed to melt the filler, improvement in cost is required. On the other hand, in the latter, the welding speed of the wire used for arc welding cannot be adjusted independently of the welding current, and its application range is limited.

  In order to solve the above problem, the inventor of the present invention proposes a method of supplying a filler provided separately from an arc welding wire to the welding position, and independently adjusts the welding speed and the welding current ( For example, see Patent Document 1).

  FIG. 3 is a schematic diagram showing the configuration of a conventional laser welding method proposed by the inventors of the present invention. 1 is a workpiece, 2 is a laser beam, 3 is a wire, 4 is an arc generated between the wire 3 and the workpiece 1, 5 is a droplet formed by melting the wire 3, The molten pool formed by the laser beam 2 and the arc 4 on the workpiece 1, 7 is a filler fed to the welding position of the workpiece 1, and 8 is a bead formed by solidification of the molten pool 6. It is.

  FIG. 4 is a schematic diagram for explaining the principle of independent adjustment of the welding speed and the welding current in the laser welding method proposed by the inventors of the present invention. MRA is a melting curve showing the welding speed of the laser welding method combining laser welding and consumable electrode type arc welding, and is equal to the welding speed when arc welding alone.

  MRH is a melting curve indicating the sum of a melting curve MRF indicating the welding speed of the filler 7 and a melting curve MRA in the laser welding method of FIG. 3 proposed by the inventors of the present invention. Assuming that the target welding speed is VW0, in order to realize VW0 by the laser welding method combining laser welding and consumable electrode type arc welding, a welding current of I0 is necessary, but the laser proposed by the inventors of the present invention. In the welding method, the welding speed follows the melting curve MRH, so that the required welding current is IH lower than I0. If the melting curve MRF of the filler 7 is adjusted, the welding current IH can be adjusted in a wide range regardless of I0.

  In the laser welding method proposed by the inventor of the present invention, the welding speed is adjusted by using a filler. However, the filler is melted by using laser energy or partial energy of an arc. Good. In particular, since the energy of the laser is high, the filler can be melted more efficiently. However, since the filler normally used is in a room temperature state, it is necessary to melt it by heating it to the melting point. That is, if the energy for raising the temperature of the filler from room temperature to the melting point is provided only by the laser, there is a drawback that the cost of the entire apparatus increases.

International Publication No. 2010/021094

  In view of the problems of the prior art, the problem to be solved by the present invention is to perform filler welding at the welding position while simultaneously performing laser welding and arc welding performed by feeding a wire to the welding position of the workpiece. In a laser welding method to be supplied, a laser welding method and a laser welding apparatus for performing welding while heating the filler by bringing the filler into contact with the workpiece or the molten pool and passing an electric current through the filler are provided. It is in.

  In order to achieve the above object, the present invention controls a laser generating means for irradiating a welding position of a workpiece to be welded, a wire feeding means for feeding a wire to the welding position, and the wire feeding means. An arc generating means for supplying electric power for arc welding to the wire and the workpiece, a filler feeding means for feeding a filler to the welding position, a heating means for passing an electric current to the filler, A control means for controlling the laser generating means, the arc generating means and the heating means, and simultaneously performing laser welding and arc welding performed by feeding a wire to the welding position of the work piece; The filler is supplied to the filler, the filler to be welded or the weld pool is brought into contact, and an electric current is passed through the filler to perform welding while heating the filler. It is a device.

  Further, the present invention is a laser welding method and a laser welding apparatus that perform welding by arranging in the order of wire, laser beam, and filler, or in the order of filler, laser beam, and wire from the direction of welding.

  The present invention also provides a laser welding method and a laser welding apparatus in which a distance between a target position on the surface of a workpiece to be welded and a laser beam irradiation position is 1 to 5 times the wire diameter.

  The present invention also relates to a laser welding method and a laser welding apparatus in which the workpiece, the wire, and the filler are steel materials.

  As described above, the present invention provides a laser welding method for supplying a filler to the welding position while simultaneously performing laser welding and arc welding performed by feeding a wire to a welding position of an object to be welded. The welding speed can be further increased by contacting the work piece or the molten pool and performing welding while heating the filler by passing an electric current through the filler.

Schematic diagram showing the configuration of the laser welding apparatus according to Embodiment 1 of the present invention. Schematic diagram when irradiating filler with laser beam and schematic diagram of filler current and welding speed obtained with laser apparatus of the present invention Schematic diagram showing the structure of a conventional laser welding method Graph explaining the principle of independent adjustment of welding speed and welding current in conventional laser welding methods

(Embodiment 1)
FIG. 1 is a schematic diagram showing a configuration of a laser welding apparatus according to Embodiment 1 of the present invention. In addition, the same code | symbol is attached | subjected to the place which show | plays the same structure, operation | movement, and effect as the content shown to FIG. 3 and FIG. 4, detailed description is abbreviate | omitted, and it demonstrates centering on a different part. Reference numeral 9 denotes a laser generating means comprising a laser oscillator 10, a laser transmission means 11, and a condensing optical system 12. 13 is connected to the torch 16 through which the wire 3 is passed by the cable 14, and is connected to the work piece 1 by the cable 15, and power for generating the arc 4 between the wire 3 and the work piece 1. Arc generating means for feeding 17 is a wire feeding means for feeding the wire 3 to the workpiece 1 through the torch 16, and 18 is a filler feeding means for feeding the filler 7 to the welding position of the workpiece 1 through the torch 19. is there. A heating unit 20 is connected to the torch 19 and the workpiece 1 by the cable 21 and the cable 22 and heats the filler 7 by supplying current to the filler 7. Reference numeral 23 denotes control means for controlling the laser generating means 9, the arc generating means 13, the filler feeding means 18, and the heating means 20.

  The laser generating means 9 condenses the laser beam 2 by the condensing optical system 12 and irradiates the work piece 1. The condensing optical system 12 may be composed of one or a plurality of lenses. The laser transmission means 11 may be an optical fiber or a transmission system combined with a lens. Although not shown, the laser oscillator 10 can freely control its output value and output timing by an external control device.

  The arc generating means 13 controls the wire feeding means 17 at the start of welding, and feeds the wire 3 toward the workpiece 1 while the wire 3 and the workpiece 1 are in contact with each other. The arc 4 is controlled to be generated. At the end of welding, the wire feeding means 17 stops feeding the wire 3 and controls the arc 4 to stop.

  The filler feeding device 18 or the wire feeding device 17 can freely control the feeding speed and the start and stop of feeding by an external control device. The heating means 20 can supply a predetermined current, and the current value and supply timing can be controlled by an external control device. The heating unit 20 may be, for example, a power source that supplies a constant direct current or a power source that supplies a pulsed current. Something like a TIG power supply may be used.

  The control means 23 may use a computer, but may use components, devices, apparatuses, or combinations thereof having a calculation function such as a computer. As the control means 23, a robot may be used. In this case, although the detailed description is omitted, the condensing optical system 12, the torch 16, and the torch 19 may be fixed to the manipulator portion of the robot. Although not shown in the drawing, the control means 23 is the timing of welding start (arc start, laser irradiation start), the feed speed of the wire 3 or filler 7 or the timing of changing it, the heating current of the filler 7 or the timing of changing it. Can be controlled.

  The operation of the laser welding apparatus in the first embodiment of the present invention will be described. As shown in FIG. 1, the control means 23 controls the laser generation means 9 and the arc generation means 13 to irradiate the welding position of the workpiece 1 or generate the arc 4 to perform welding simultaneously. The filler 7 is operated to be supplied to the welding position.

  Further, the control means 23 controls the heating means 20 to supply a current for heating the filler 7. The principle of increasing the welding speed of the filler 7 by heating the filler 7 with the heating means 20 will be described with reference to FIG.

  In addition, the same code | symbol is attached | subjected to the place which has the structure, operation | movement, and effect similar to the content shown to FIG.1, FIG.3 and FIG.4, detailed description is abbreviate | omitted, and it demonstrates centering on a different part. FIG. 2A shows a schematic diagram when the laser beam 2 irradiates the filler 7. The basic configuration is the same as that in FIG. 3, but the arc portion is omitted. 7a is a chip in the torch 19 for energizing the filler 7 through this. In order to simplify the description, the power supply to the filler 7 will be described by energizing from the tip of the chip 7a.

  Accordingly, the heating of the filler 7 is determined by the heating current to the filler 7, that is, the resistance of the filler 7 and the protrusion length L 0 of the filler 7 if the feeding speed of the filler 7 is constant. The higher the filler current or the longer the protruding length L0, the greater the heating effect.

  FIG.2 (b) shows the schematic diagram of the welding speed | velocity obtained with a filler current and the laser welding apparatus of this invention. This corresponds to the arc current IH in FIG. In FIG. 4, since there is no filler current, the overall welding speed VW0 corresponds to the welding speed VWF by the filler 7 and the welding speed by the wire 3 (not shown in FIG. 4, but in FIG. 2B, it corresponds to VWA. ).

  In FIG. 2, the description will be made under the condition of the filler current IF. The welding speed VWH in the first embodiment of the present invention corresponding to the filler current IF is composed of three parts. One is VWA and the other is VWF. These two can also be obtained by the conventional laser welding apparatus shown in FIG. The third is VWFH, which is increased by supplying the filler current IF. As shown, since only the filler current IF can be increased regardless of the VWA or VWF, the overall welding speed in the first embodiment of the present invention can be further increased by VWFH.

  According to the configuration and operation of the laser apparatus of the present invention, the overall welding speed of the present invention is further increased by increasing the filler current IF without increasing the arc current (corresponding to IH in FIG. 4). It becomes possible. When the welding speed is increased at a low arc current, the ability to bridge the gap even when there is a gap is increased and a wide allowable gap can be realized.

  As described above, according to the laser welding apparatus in the first embodiment of the present invention, the filler is supplied to the welding position while simultaneously performing the laser welding and the arc welding performed by feeding the wire to the welding position of the workpiece. In the laser welding method, the welding speed can be increased by bringing the filler into contact with the work piece or the molten pool, and performing welding while heating the filler by passing an electric current through the filler. A wide allowable gap can be obtained by welding.

  In the laser welding apparatus according to the first embodiment of the present invention described above, the welding is performed by arranging and welding in the order of the wire, the laser beam, and the filler, or the filler, the laser beam, and the wire in the order of welding. The effect of can be obtained.

  In the laser welding apparatus according to Embodiment 1 of the present invention described above, the distance between the target position of the wire 3 on the surface of the workpiece 1 and the irradiation position of the laser beam 2 is 1 to 5 times the wire diameter. By doing so, the same effect can be obtained.

  This is for the following reason. If the distance between the irradiation position of the laser beam 2 and the target position of the wire 3 is too short, the droplet 5 moving to the molten pool 6 is directly irradiated with the laser beam 2 and is violently evaporated or sputtered. There are things to do. On the other hand, if the distance between the two is too long, the molten pool formed by the laser beam 2 is separated from or separated from the molten pool formed by the arc 4, so that the ability to melt the workpiece 1 is reduced. In actual welding, the distance between the two is preferably 1 to 5 times the wire diameter.

  Moreover, in the laser welding apparatus in Embodiment 1 of this invention shown above, the to-be-welded object, a wire, and a filler can acquire the same effect with steel materials.

  As described above, according to the present invention, in the laser welding method of supplying filler to the welding position while simultaneously performing laser welding and arc welding performed by feeding a wire to the welding position of the work piece, the filler And the welding object or the molten pool are brought into contact with each other and a welding current can be increased by flowing current through the filler while heating the filler, whereby a laser welding method and a laser welding apparatus can be provided.

DESCRIPTION OF SYMBOLS 1 Workpiece 2 Laser beam 3 Wire 4 Arc 5 Droplet 6 Molten pool 7 Filler 8 Bead 9 Laser generating means 10 Laser oscillator 11 Laser transmission means 12 Condensing optical system 13 Arc generating means 14 Cable 15 Cable 16 Torch 17 Wire feed Feeding means 18 Filler feeding means 19 Torch 19a Tip 20 Heating means 21 Cable 22 Cable 23 Control means I0 Welding current IF Filler current IH Welding current L0 Overhang length MRA Melting curve MRA1 Melting curve MRF Melting curve MRF1 Melting curve MRH Melting curve MRH Melting curve VW0 Welding speed VWA Welding speed VWF Welding speed VWFH Welding speed VWH Welding speed

Claims (8)

In the laser welding method of supplying a filler to the welding position while simultaneously performing laser welding and arc welding performed by feeding a wire to the welding position of the workpiece, the filler and the workpiece or the molten pool are A laser welding method in which welding is performed while heating the filler by bringing the filler into contact with each other and passing an electric current through the filler. The laser welding method according to claim 1, wherein welding is performed by arranging in the order of wire, laser beam, filler, or filler, laser beam, and wire in this order from the welding direction. 3. The laser welding method according to claim 1, wherein a distance between a target position on the surface of the workpiece to be welded and a laser beam irradiation position is 1 to 5 times the wire diameter. The laser welding method according to claim 1, wherein the workpiece, the wire, and the filler are steel materials. Laser generating means for irradiating a welding position of a workpiece to be welded, wire feeding means for feeding a wire to the welding position, and an arc on the wire and the workpiece to be welded while controlling the wire feeding means Arc generating means for supplying electric power for welding; filler supplying means for supplying filler to the welding position; heating means for supplying current to the filler; the laser generating means; the arc generating means; Control means for controlling the heating means, and simultaneously performing laser welding and arc welding performed by feeding a wire to the welding position of the workpiece, and supplying filler to the welding position to supply the filler and the filler A laser welding apparatus that performs welding while heating the filler by bringing an object to be welded or a molten pool into contact with each other and passing an electric current through the filler. 6. The laser welding apparatus according to claim 5, wherein welding is performed by arranging in the order of wire, laser beam and filler, or in the order of filler, laser beam and wire in the welding direction. 7. The laser welding apparatus according to claim 5, wherein a distance between a target position on the surface of the workpiece to be welded and a laser beam irradiation position is 1 to 5 times the wire diameter. 8. The laser welding apparatus according to claim 5, wherein the workpiece, the wire, and the filler are steel materials.

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