JP4848921B2 - Composite welding method and composite welding equipment - Google Patents

Description

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

    Since laser welding is a high energy density heat source, high-speed welding with a narrow heat-affected zone is possible. However, if there is a gap between the workpieces, the laser beam may come out of the gap and the workpiece may not be heated. In order to overcome this problem, approaches from the welding process include a method of employing a filler and a method of combining with arc welding. The former can improve the gap tolerance, but requires a high power laser compared to laser welding alone because it requires sufficient energy to melt the filler. As a result, the cost of the entire apparatus increases. On the other hand, in the latter case, a wide gap tolerance can be obtained by using arc welding in which a consumable electrode type arc is generated at the welding position of the workpiece. As this type of technique, there is a composite welding method of MIG arc welding and laser welding (see, for example, Patent Document 1).

    In such composite welding, how to install laser welding and arc welding is very important. For example, the penetration of the workpiece is different depending on the arrangement of laser welding and arc welding (for example, see Non-Patent Document 1).

    Therefore, there have been many proposals for installation methods of laser welding and arc welding. For example, it is better to install the laser irradiation position and the arc aiming position so as to be separated from each other by 0.5 mm to 5 mm (for example, see Patent Literature 1). In some cases, the distance between the arc discharge and the arc discharge should be set so that the arc does not interfere with the laser (see, for example, Patent Document 2).

    Most of the conventional proposals have been made from the viewpoint of melting or welding speed of an object to be welded, and none has been proposed from the viewpoint of melting of a wire.

    Moreover, since the area of laser irradiation is usually small in laser welding, only a small molten pool can be made from this point. On the other hand, in arc welding, the area of arc discharge is large, thereby increasing the size of the molten pool formed.

    The weld pool for composite welding is rather close to the weld pool for arc welding (see Non-Patent Documents 1 and 2, for example). A large weld pool means that a large amount of heat is input to the weld, and there is a risk that large thermal deformation will occur in the welded joint. As long as construction permits, it is desirable to reduce the size of the molten pool as much as possible. Since the size of the weld pool for arc welding is larger than that for laser welding, it is effective to reduce the size of the weld pool for arc welding in order to reduce the size of the weld pool for composite welding. In order to reduce the size of the weld pool for arc welding, it is necessary to reduce the arc current. However, in consumable electrode arc welding, reducing the arc current means reducing the wire feed rate at the same time. As a result, the amount of weld metal per unit weld line length may decrease, and a predetermined joint strength may not be obtained (see, for example, Non-Patent Document 3).

As described above, the conventional composite welding can increase the gap margin, but it is difficult to reduce the size of the molten pool.
JP 2002-103069 A JP 2002-346777 A Katayama Seiji, Utsumi Rin, Mizutani Masami, Wang Shizunami, Fujii Koji, Penetration characteristics and porosity prevention mechanism in YAG laser / MIG hybrid welding of aluminum alloys, light metal welding, 44, 3 (2006) Noritaka Eguchi, Tsuyoshi Matsumoto, Mitsuhiro Ema, Seiji Isobe, Characteristics of Aluminum Alloy Joints in Laser-Arc Hybrid Welding, Summary of Lectures at National Conference of the Japan Welding Society, Vol. 71, 2002-10 Japan Welding Society, Welding Arc Physics Research Committee, Welding Process Physics, Kuroki Publishing Co., 1996

    In view of the problems of the prior art, the problem to be solved by the present invention is to provide a composite welding method and a composite welding apparatus that reduce the size of a molten pool by arc discharge.

  To achieve the above object, the present invention provides a composite welding method in which a laser beam is irradiated to a welding position of a workpiece, a welding wire is fed to the welding position, and arc welding is performed with the workpiece. The intersection of the optical axis of the laser beam and the workpiece, the central axis of the feeding direction and the intersection of the workpiece are positioned so as not to overlap in the weld pool generated at the welding position, and the optical axis of the laser beam And a welding method for welding the workpiece by arranging the optical axis of the laser beam and the central axis of the feeding direction at a position where the center axis of the feeding direction intersects the laser beam, or a laser at the welding position of the workpiece A condensing optical system for irradiating a beam; a torch for feeding a welding wire to the welding position; and a wire feeding means; and an arc generating means for supplying welding power between the workpiece and the welding wire, Laser beam optical axis and cover The intersection of the object, the central axis in the feeding direction, and the intersection of the workpieces do not overlap in the weld pool generated at the welding position, and the optical axis of the laser beam and the central axis in the feeding direction are In the composite welding apparatus, an optical axis of the laser beam and a central axis in the feeding direction are arranged at a crossing position.

    Thus, the optical axis of the laser beam and the central axis of the wire are arranged so as to irradiate the welding wire supplied to the workpiece to be welded, and the welding wire is directly melted by the laser beam, so that it is necessary for melting the wire. The arc current can be reduced, and the size of the molten pool caused by the arc can be reduced.

    As described above, according to the present invention, the optical axis of the laser beam and the central axis of the wire are arranged so that the laser beam is directly applied to the wire to be welded, and the wire is directly melted by the laser beam. Thus, the arc current required for wire melting can be reduced, and the size of the molten pool caused by the arc can be reduced.

(Embodiment 1)
FIG. 8 is a block diagram showing the configuration of the composite welding apparatus. Reference numeral 1 denotes a laser generating means, which comprises a laser oscillator 2, a laser transmission means 3, and a condensing optical system 4, and irradiates a welding position of a workpiece 6 with a laser beam 5.

  The laser oscillator 2 can freely control its laser output value and laser output timing by the control means 12. The laser transmission means 3 may be an optical fiber or a transmission system combined with a lens. The condensing optical system 4 may be composed of one or a plurality of lenses. A welding wire 7 is fed to the welding position of the workpiece 6 through the torch 9 by the wire feeding means 8. An arc generating means 10 controls the wire feeding means 8 at the start of welding, and feeds the welding wire 7 toward the welding position of the workpiece 6 through the torch 9, The welding arc 11 is controlled to be generated between the workpiece 6 and the workpiece 6. At the end of welding, the welding wire 7 is stopped by the welding wire feeding means 8 and the welding arc 11 is stopped. To do. The arc generating means 10 can freely control its output value and output timing by the control means 12. Although not shown, the control means 12 receives a welding start or welding end command from the outside and controls the laser generating means 1 and the arc generating means 10. The control means 12 controls the irradiation timing of the laser beam 5 generated from the laser generating means 1 and its output, and also controls the discharge timing of the welding arc 11 generated from the arc generating means 10 and its output. . As the control means 12, a computer may be used, but a component, a device, an apparatus having a calculation function such as a computer, or a combination thereof may be used. Further, a robot may be used as the control means 12. Although the detailed description is omitted, when the robot is used, the condensing optical system 4 and the torch 11 can be fixed to the manipulator portion of the robot. The operation of the conventional composite welding apparatus configured in this way is as follows. At the start of welding, the control means 12 that has received a welding start command sends a laser welding start signal to the laser generating means 1 to start laser beam irradiation. Then, an arc welding start signal is sent to the arc generating means 10 to start arc discharge. At the end of welding, the control means 12 that has received the welding end command sends a laser welding end signal to the laser generating means 1 to irradiate the laser beam. At the same time, an arc welding end signal is sent to the arc generating means 10 to end the arc discharge. The welding start or welding end timing of the laser welding and the arc welding and the laser output of the laser welding or the arc output of the arc welding can operate according to a sequence set in the control means 12 in advance.

  FIG. 1 is a schematic diagram showing the correlation between the laser irradiation position and the wire aiming position of the composite welding method or composite welding apparatus in Embodiment 1 of the present invention.

  FIG. 1 shows the vicinity of the workpiece 6, that is, the vicinity of the tip of the torch 9 and the focus of the laser beam 5 in the configuration in FIG. 8, and 9 a is attached to the tip of the torch 9, A power supply chip to be supplied. aa ′ is the optical axis of the laser beam 5, and bb ′ is the central axis of the welding wire 7. cc ′ is a weld line to be welded on the surface of the work piece 6. Reference numeral 13 denotes a molten pool that can be formed on the weld line cc '. A is a laser irradiation position on the weld line cc ′ and indicating the intersection of the optical axis aa ′ and the workpiece 6. B is a wire aiming position which is on the welding line cc ′ and indicates the intersection of the central axis bb ′ of the welding wire 7 and the workpiece 6. C is a laser irradiation tip position that is located on the surface of the welding wire 7 and indicates the position closest to the tip of the power feed tip 9a in the irradiation region that is directly irradiated with the laser beam 5. L1 is a laser-arc distance indicating a distance on the surface of the workpiece 6 between the laser irradiation position A and the wire aiming position B. L2 is a distance between the electrode and the base material indicating the distance from the tip of the power feed tip 9a to the wire aiming position B. L3 is a distance between the wire aiming position B and the laser irradiation tip position C, that is, before the welding wire 7 is supplied from the tip of the power feed tip 9a to the wire aiming position B. This is the laser irradiation length indicating the length of direct irradiation of the beam 5. L4 is a laser non-irradiation length indicating the length of a portion of the welding wire supplied from the tip of the power supply tip 9a that is not directly irradiated with the laser beam 5.

  The operation of the above embodiment will be described. Operations at the start of welding and at the end of welding will be described with reference to FIG. FIG. 2 is a schematic diagram showing operation timings of the arc output and the laser output of the composite welding method or the composite welding apparatus in the first embodiment.

  At the start of welding, the control means 12 sends an arc welding start signal to the arc generating means 10 and starts arc welding at the time t1, but after that, after a period of Δt1, a laser welding start signal is sent to the laser generating means 1 and t2 Welding is started by starting laser welding at the time. As described above, it is a feature that arc welding is started before laser welding. If the arc welding is started after the laser welding is started, the welding wire 7 supplied toward the workpiece 6 is in contact with the workpiece 6 before the arc 11 is generated. This is because the beam 5 may be melted by direct irradiation and the arc welding cannot be started normally.

  On the other hand, at the end of welding, the control means 12 sends a laser welding end signal to the laser generating means 1 and ends the laser welding at the time t3, but thereafter sends an arc welding end signal to the arc generating means 10 after a lapse of Δt2. , The arc welding is terminated at time t4 to terminate the welding. In general, it is necessary to stop the torch 9 when the welding is finished. However, when the laser beam 5 is irradiated longer than the arc 11 in a state where the torch 9 is stopped, the penetration depth in the workpiece 6 is reduced. This is because it increases too much, and there is a possibility that melting may occur. The Δt1 period and the Δt2 period can be adjusted according to the material and plate thickness of the workpiece 6, arc welding welding conditions, and laser welding welding conditions.

  The operation in the main welding period from the start to the end of welding will be described with reference to FIG. FIG. 3 is a schematic diagram showing wire melting and arc form after the start of welding by the composite welding method or composite welding apparatus in the first embodiment. 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 in FIG. 1, detailed description is abbreviate | omitted, and it demonstrates centering on a different part. D is a wire tip indicating the position of the tip of the welding wire 7 after the arc 11 is generated. L5 is an arc length indicating the length of the arc 11. L6 is the distance from the tip of the tip 9a to the wire tip D, that is, the wire protruding length. In the illustrated example, the arc length L5 is drawn shorter than the laser irradiation length L3. In actual composite welding, the arc length L5 shown in FIG. 3 is determined when the arc welding method and the material of the welding wire 7 are determined, the supply speed of the welding wire 7, the output of the laser beam 5, and the arc of the composite welding. It depends on the current and the arc voltage of the composite welding. In order to obtain good composite welding, it is important to control the arc length L5 within a predetermined range.

When the supply speed of the welding wire 7 is constant, the relationship between the arc length L5, the laser output P _LASER of the laser beam 5, and the arc current I _ARC will be described with reference to FIG. FIG. 4 is a schematic diagram showing a correlation among laser output, arc length, and arc current in the first embodiment. L5 is the arc _length, and _{L ARC1} and _{L ARC2} is arc alone when the arc length during arc welding alone. I _ARC is the arc current, and I _ARC1 is the arc current during arc welding alone. In arc welding alone, the arc length L _ARC1 or L _{ARC2 in} arc alone is determined by the arc current I _ARC1 in arc alone and, as will be described later, the arc voltage in arc alone during arc welding. For example, when the arc voltage for arc only L _ARC2 is selected so that the arc length L5 for arc single welding becomes arc length L _ARC2 for arc only, the arc length L _ARC2 for arc only is longer than the laser irradiation length L3. This means that the laser beam 5 does not directly irradiate the welding wire 7 even if the laser beam 5 is irradiated after welding is started. In this case, since the length of the arc 11 is as shown by the curve C1 shown in FIG. 4, it is not affected by the laser output P _LASER . On the other hand, when the arc voltage for arc only is selected so that the arc length L5 at the time of arc independent welding is smaller than the laser irradiation length L3, for example, the arc voltage at the time of arc alone is set so as to be arc length L _ARC1 at the time of arc alone. selected, Note, consider the composite welding when the laser beam 5 of laser output P _a. For the sake of explanation, it is assumed that the arc length L5 is at the arc length operating point E when the arc is alone and the arc current I _ARC is at the arc current operating point E ′ when the arc is alone. Since the arc length L _ARC1 when the arc is alone is shorter than the laser irradiation length L3, after the irradiation of the laser beam 5 starts, the welding wire 7 receives the direct irradiation of the laser beam 5 at a higher speed than when the arc welding is alone. Melt. As a result, the arc length L5 moves from the arc length operating point E at the time of the arc alone to the arc length operating point F at the time of composite welding along the curve C2 in the direction of the arrow G, and becomes the arc length L _ArcA at the time of composite welding. Needless to say, the arc length L _ARCA during composite welding is longer than the arc length L _ARC1 during arc alone. Similarly, the arc current I _ARC is 'hybrid welding Arc current operating point F along the curve C3 from the direction of arrow H' moves into the arc itself during arc current operating point E, the hybrid welding when the arc current I _ARCA Become.

As described above, by irradiating the laser output P _A, it is possible to reduce the actual arc current I _ARC difference current [Delta] I _A min only. As a result, the heat input by the arc 11 can be lowered, and the size of the molten pool by the arc 11 can be reduced.

Like the correlation between the laser output _{P LASER} arc length L5 and arc current _{I ARC} and the laser beam 5 of FIG. 4, the correlation between the arc current _{I ARC} and the arc voltage _{V ARC} and wire feed speed _{V M} There is. The contents will be described with reference to FIG.

FIG. 5 is a schematic diagram showing the correlation among the arc current, arc voltage, and wire supply speed in the first embodiment. 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 in FIG. In FIG. _{5, V ARC} is the arc length, the _{V M} is a wire feed rate. V _ARC1 is arc alone when arc voltage during arc welding alone, V _ARCA is a composite during welding arc voltage during the combined welding. The operation during welding is as follows. J is an arc-only wire supply speed operating point in the curve C4, and J ′ is an arc-only arc voltage operating point in the curve C5 corresponding to the operating point J. As shown in FIG. 4, it is irradiated with the laser beam 5 of laser output P _A to the welding wire 7, the same wire feed speed V _M, by the difference current [Delta] I _A arc current is reduced. As a result, the wire feed speed V _M moves the composite to the welding at the wire feed speed operating point K on the curve 6 from the arc itself when the wire feed speed operating point J in the direction of arrow L. At this time, the arc voltage V _ARC moves not to the arc voltage operating point K ″ for arc welding alone in the curve C5 but to the arc voltage operating point K ′ for combined welding in the curve 7 in the direction of the arrow M. The arc voltage V _ARC at this time becomes the arc voltage V _ARCA during composite welding. This is because, as described above, the wire 7 is directly irradiated with the laser beam 5 and melts faster than arc welding alone. Further, depending on the laser welding or arc welding conditions to be used, the arc voltage V _ARC can be moved to the arc voltage operating point K ′ ″ at the time of composite welding on the curve C8.

The correlation between the curve 2 and the curve 3 in FIG. 4 will be described. In a typical arc welding or hybrid welding, in order to obtain a good weld, it is necessary to control so as to be equal to the wire feed speed V _M and the melting rate of the wire 7. Based on the formula melting rate of the arc welding alone when the wire 7 shown in Non-Patent Document 3, it is possible to obtain the relationship between the wire feed speed V _M and the arc current I _A as shown in equation (1).

However, I _A is the arc itself when the arc current. E _X is the length and wire extension, which is equivalent to L6 shown in Fig. α and β are proportional constants, and according to Non-Patent Document 3, they vary depending on the material and diameter of the wire, shield gas, and the like. In the above (Equation 1), the first term on the right side contributes to the melting of the wire 7 by the arc 11, and the second term melts the wire 7 due to resistance heat generation at the portion of the protruding length L6 of the wire 7. Represents the contribution to

On the other hand, considering the melting behavior of the wire 7 when the wire 7 is directly irradiated with the laser beam 5, the contribution to the melting of the wire 7 due to the irradiation of the laser beam 5 may be considered on the right side of the mathematical formula 1. That is, the relationship between arc current I _AH composite welding wire feed speed V _M of the hybrid welding in the first embodiment of the invention, can be expressed as (Equation 2).

However, _IAH is an arc current at the time of composite welding, _EXH is a wire protrusion length, and P _LASER is a laser output. γ is a proportional constant, and the material and diameter of the wire, the length of the wire 7 directly irradiated with the laser beam 7, the laser irradiation time related to the supply speed of the wire 7, the spread angle of the laser beam 7 and its intensity distribution. , Depending on the installation method shown in FIG. Solve centralized quadratic equations in (Expression 1) and (Equation 2), noted by comparing the two, it is possible to obtain the obtaining the difference currents [Delta] I _A shown in FIG. 4 (Equation 3).

In actual welding, it is desirable to maintain the arc voltage or arc length within a certain range for both arc single welding and composite welding. As shown in FIG. 3, the arc length L5 is much shorter than the wire protrusion length L6. Therefore, the equation (3) no problem even assuming approximately equal to the arc welding alone when the protruding length E _X and protruding length during the combined welding E _XH in. Therefore, by setting E _X = E _XH , a more simplified (Expression 4) can be obtained.

According to equation (4), it is possible to increase the difference current [Delta] I _A by increasing the laser output P _LASER in hybrid welding. However, as shown in FIG. 4, the difference current ΔI _A cannot be increased infinitely, and there is a limit difference current ΔI _ATH . The limit difference current ΔI _ATH will be described. When the laser output P _LASER is increased, the arc length L5 is increased, but since the tip-base material distance L2 is constant, the wire protrusion length L6 is shortened. Since the length that is directly irradiated with the laser beam 5 at the distal end portion of the welding wire 7 is (L6-L5) , the length of the wire 7 that is directly irradiated with the laser beam 5 is shortened when the arc length L5 is increased. This corresponds to a decrease in the γ value in (Equation 3). As a result, the γ value decreases as the laser output P _LASER increases. When the wire protrusion length L6 becomes substantially equal to the laser non-irradiation length L4, the γ value also decreases to almost zero.
Therefore, even if the laser output P _LASER is further increased, the arc current I _ARC is not reduced. The difference current at this time is the limit difference current ΔI _ATH . However, strictly speaking, the wire protrusion length L6 is not completely equal to the laser non-irradiation length L4. This is because it takes time until the welding wire 7 is melted after being irradiated with the laser beam 5.
That is, as shown in FIG. 4, no matter how much the laser output P _LASER is increased, the arc length L5 of the composite welding is always shorter than the laser irradiation length L3 by the laser heating transient length L7.

6, the composite welding between MIG arc welding and laser welding of aluminum alloy, shows the measured values of the measured wire melting rate V _M and the arc current I _ARC when fixing the laser output to 1.8 kW. If it is the same wire melting rate _{V M,} L1 = in the case of 4 mm, L1 = 0 mm or it can be seen that less than MIG arc welding alone arc current _{I ARC.} This is a result of a decrease in arc current due to direct irradiation of the laser beam 5 onto the wire 7 as described above.

    In the present embodiment, as shown in FIGS. 1 to 6, the optical axis of the laser beam and the central axis of the wire are arranged so that the laser beam is directly applied to the welding wire supplied to the workpiece, By directly melting the wire with the laser beam, the arc current required for wire melting can be reduced, and the size of the molten pool by the arc can be reduced.

  In the above embodiment, the laser welding laser irradiation is started after the arc welding arc discharge is started at the start of welding, but the arc welding arc is started after the laser welding laser irradiation is ended at the end of welding. A similar effect can be obtained by terminating the discharge.

    Moreover, in said embodiment, the same effect can be acquired by using the wire which does not have copper plating in the wire used for arc welding in the wire which has iron as a main component. In general, the material used for the plating material of the welding wire mainly composed of iron is copper, but by using the welding wire having no copper plating, the absorption to the laser beam 5 is made higher than the copper on the surface of the plating wire. This is because the welding wire 7 can be more easily melted.

In the above embodiment, if the welding wire used for arc welding is an Al—Mg alloy-based aluminum wire, the amount of Mg is 1.05 to 1.2 times the amount of additive element of a normal arc welding wire. A similar effect can be obtained. This is due to the following causes. As shown in FIG. 1, the tip of the welding wire 7 is not only heated by the arc 11 but also heated by the laser beam 5 during welding. Laser power _{P LASER} is high or the same when the diameter of the laser beam 5 be a laser output _{P LASER} is thin, the surface of the power density (the welding wire 7 of the laser beam 5, the laser output _{P LASER} per unit area, ) Is high. Since Mg contained in the molten metal formed at the tip of the welding wire 7 is heated by the laser beam 5 having a high power density, the evaporation thereof becomes more intense than in the case of ordinary arc welding alone. As a result, the Mg content in the weld metal part of the composite welding is reduced as compared with the ordinary arc single welding, and a predetermined joint performance is obtained.

(Embodiment 2)
FIG. 7 is a schematic diagram showing the correlation between the laser irradiation position and the wire aiming position of the composite welding method or composite welding apparatus in Embodiment 2 of the present invention.

In addition, the same code | symbol is attached | subjected to the place which show | plays the structure, operation | movement, and effect similar to the content shown in FIG. aa ′ is the optical axis of the laser beam 5, and bb ′ is the central axis of the welding wire 7. cc ′ is a weld line to be welded on the surface of the work piece 6. A thick arrow indicates the welding direction. θ _L is an angle formed in the welding direction between the optical axis aa ′ and the welding line cc ′, and a laser beam inclination angle. θ _A is an angle formed in the welding direction between the central axis bb ′ and the welding line cc ′, and a wire inclination angle. Compared with the schematic diagram shown in FIG. 1, the schematic diagram shown in FIG. 7 has the same configuration except for the inclination direction of the laser beam 5. Also by doing so, it is possible to achieve the same effect as the composite welding method or the welding apparatus in the first embodiment. As shown in FIG. 7, since both the laser beam inclination angle θ _L and the wire inclination angle θ _L are acute or obtuse, the angle formed by the optical axis aa ′ and the central axis bb ′ is small and a narrow place It is easy to weld in

In FIG. 7, the laser beam tilt angle θ _L and the wire tilt angle θ _L are written as acute angles, but it goes without saying that they may be obtuse angles. Although wrote direction of thick arrow as welding direction, may be addressed in the opposite direction, it may be obtuse angle with the laser beam inclination angle theta _L and wire inclination angle theta _L even when this.

    In the present embodiment, as shown in FIG. 7, the optical axis of the laser beam and the central axis of the welding wire are arranged so that the laser beam is directly irradiated onto the welding wire supplied to the workpiece, In addition to melting the welding wire directly, the angle formed in the welding direction between the optical axis of the laser beam and the welding line and the angle formed in the welding direction between the central axis of the welding wire and the welding line are both acute or obtuse. Thus, not only can the arc current required for melting the wire be reduced and the size of the molten pool caused by the arc can be reduced, but also welding in a narrow place can be facilitated.

    In the first embodiment or the second embodiment, the welding direction may be preceded by either the laser beam irradiation position or the wire aiming position on the surface of the workpiece.

    As described above, according to the present invention, it is possible to provide a composite welding method and a composite welding apparatus that can reduce the arc current required for wire melting and reduce the size of the molten pool by the arc.

The schematic diagram which shows the correlation with the laser irradiation position and wire aim position of the composite welding method or composite welding apparatus in Embodiment 1 of this invention The schematic diagram which shows the operation timing of the arc output and laser output of the composite welding method or composite welding apparatus in Embodiment 1 The schematic diagram which shows the wire melting and arc form after the welding start of the composite welding method or composite welding apparatus in Embodiment 1 Schematic diagram showing the correlation between laser output, arc length, and arc current in the first embodiment Schematic diagram showing the correlation between arc current, arc voltage, and wire supply speed in the first embodiment Graph showing measured values of wire melting rate and arc current measured when laser output is fixed at 1.8 kW in composite welding of aluminum alloy MIG arc welding and semiconductor laser welding The schematic diagram which shows the correlation with the laser irradiation position and wire aim position of the composite welding method or composite welding apparatus in Embodiment 2 of this invention Block diagram showing the configuration of the composite welding equipment

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Laser generating means 2 Laser oscillator 3 Laser transmission means 4 Condensing optical system 5 Laser beam 6 To-be-welded object 7 Wire 8 Wire feeding means 9 Torch 9a Feeding tip 10 Arc generating means 11 Arc 12 Control means 13 Molten pool outline t1 Time t2 time t3 time t4 time aa ′ optical axis bb ′ wire center axis cc ′ welding line A laser irradiation position B wire aiming position C laser irradiation tip position C1 curve C2 curve C3 curve C4 curve C5 curve C6 curve C7 curve C8 curve D wire Tip E Arc length operating point for arc alone E 'Arc current operating point for arc alone F Arc length operating point for combined welding E' Arc current operating point for combined welding G arrow H arrow J Wire supply speed operating point for arc alone I _ARC arc current I _ARC1 arc alone when the arc current I _ARCA hybrid welding time A Leakage current I _ARCTH limiting the arc current J arc alone when the wire feed speed operating point J 'arc independently Arc voltage operating point K hybrid welding when the wire feed speed operating point K' hybrid welding Arc voltage operating point K '' operating point K ''' Operating point L Arrow L1 Distance between laser and arc L2 Distance between tip and base material L3 Laser irradiation length L4 Laser non-irradiation length L5 Arc length L6 Wire protrusion length L7 Laser heating transient length L Arc at arc of _ARC1 alone The length L _ARC2 arc alone during arc length L _ARCA hybrid welding arc length M arrow P _A laser output P _lASER laser output V _aRC arc voltage V _ARC1 arc alone arc voltage V _ARCA hybrid welding arc voltage theta _L laser beam tilt angle theta _A wire inclination angle [Delta] _ATH threshold difference current [Delta] I _A difference current [Delta] I _ATH threshold difference current Δt1 phase Δt2 period

Claims (11)

    In a composite welding method in which a laser beam is irradiated to a welding position of an object to be welded, a welding wire is fed to the welding position and arc welding is performed with the object to be welded, an optical axis of the laser beam and an object to be welded The intersection point, the central axis in the feeding direction, and the intersection point of the workpieces are positioned so as not to overlap in the weld pool generated at the welding position, and the optical axis of the laser beam and the central axis in the feeding direction intersect. A composite welding method in which an optical axis of the laser beam and a central axis in the feeding direction are arranged at positions to weld an object to be welded.     2. The composite welding according to claim 1, wherein the laser beam is irradiated after the arc discharge of the arc welding is started at the start of welding, and the arc discharge of the arc welding is terminated after the irradiation of the laser beam is completed at the end of welding. Method.   3. The composite welding method according to claim 1, wherein when a wire containing iron as a main component is used as the welding wire, one without copper plating is used. The composite welding according to claim 1 or 2 , wherein when an Al-Mg alloy-based aluminum wire is used as the welding wire, the amount of Mg is 1.05 to 1.2 times the amount of additive elements of a normal arc welding wire. Method.     The angle formed in the welding direction between the optical axis of the laser beam and the welding line and the angle formed in the welding direction between the central axis in the feeding direction and the welding line are both acute angles or obtuse angles. The composite welding method according to claim 1.     6. The composite welding method according to claim 1, wherein either a laser beam irradiation position or a welding wire aiming position on the surface of the workpiece is preceded as a welding direction.     A condensing optical system for irradiating a welding position of the workpiece to be welded, a torch and a wire feeding means for feeding a welding wire to the welding position, and supplying welding power between the workpiece and the welding wire Arc generating means, and the intersection of the optical axis of the laser beam and the workpiece to be welded, the central axis of the feeding direction and the intersection of the workpiece to be welded do not overlap in the weld pool generated at the welding position, and A composite welding apparatus in which the optical axis of the laser beam and the central axis in the feeding direction are arranged at a position where the optical axis of the laser beam and the central axis in the feeding direction intersect.   The composite welding apparatus according to claim 7, wherein when a wire containing iron as a main component is used as the welding wire, an apparatus without copper plating is used. The composite welding apparatus according to claim 7 , wherein when an Al-Mg alloy-based aluminum wire is used as the welding wire, the amount of Mg is 1.05 to 1.2 times the amount of additive elements of a normal arc welding wire.     The angle formed in the welding direction between the optical axis of the laser beam and the welding line and the angle formed in the welding direction between the central axis in the feeding direction and the welding line are both acute angles or obtuse angles. A composite welding apparatus according to claim 1.     The composite welding apparatus according to any one of claims 7 to 10, wherein either a laser beam irradiation position or a welding wire aiming position on the surface of the workpiece is preceded as a welding direction.