JP4100593B2 - Laser welding equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a laser welding apparatus. Specifically, when a filler wire is fed to a welded portion or an assist gas is supplied, the feeding direction of the filler wire relative to the welding progress direction and the assist gas The present invention relates to a laser welding apparatus that can easily control the supply direction and the like.
[0002]
[Prior art]
The structure around the welding torch in the conventional laser welding apparatus is shown in FIG. In the figure, reference numeral 51 denotes a welding torch. A condensing lens 52 is arranged inside the welding torch 51, and a shield gas inlet 53 is formed on the side thereof. Furthermore, a filler wire feed nozzle holding bracket 54 is attached to the side portion of the welding torch 51, and a filler wire feed nozzle 55 is attached to the bracket 54. In this laser welding apparatus, welding is performed while feeding the filler wire 56 from the filler wire feeding nozzle 55 to the welded portion W irradiated with the laser beam. In the conventional laser welding apparatus, the welding torch 51 is not moved, but welding is performed while moving the member to be welded, as indicated by an arrow in FIG. Further, since the welding torch 51 and the periphery thereof are relatively large, it is normal that the rotating shaft around the laser beam axis L is not provided.
[0003]
[Problems to be solved by the invention]
By the way, in the laser welding apparatus as described above, there is no particular problem when the weld line is a straight line, but when the weld line is a curve as shown in FIG. The following problems occur in relation to the delivery of In the case of welding a curve as shown in the figure, if the position of the member to be welded is moved on the XY plane, the irradiation position of the laser beam can accurately follow the welding line WL. This means that the feeding direction of the filler wire 56 with respect to the portion W remains held in a certain direction, so that it cannot follow the weld line. That is, it is preferable in terms of welding quality that the filler wire 56 is fed to the welded portion W from the rear in the welding progress direction toward the welding progress direction, whereas the welding torch 1 and the filler wire feeding nozzle 55 are relatively Since the filler wire feeding nozzle 55 cannot be rotated and is maintained in a constant state, the feeding direction of the filler wire 56 with respect to the welding progress direction is changed every moment during welding. If the filler wire 56 is fed from the wrong direction with respect to the welding progress direction, a welding defect D may occur as indicated by point B in FIG. In addition, A point in the same figure has shown the state by which the filler wire was correctly fed along the welding progress direction, and favorable welding quality was acquired.
[0004]
In order to solve the above-described problems, a mechanism for rotating the member to be welded may be provided. However, providing such a rotation mechanism is not practical because a large space is required. As shown in FIGS. 12 and 13, a laser welding torch 51 having two rotation axes (α axis and β axis) is also known, but even if such a welding torch 51 is used, the filler wire 56 is used. In order to correctly feed the wire along the welding direction, the rotating mechanism of the member to be welded as described above is indispensable. In FIGS. 12 and 13, 57 indicates a window, 58 indicates a reflecting mirror, and 59 indicates a parabolic mirror, and the same functional parts as those in FIG. ing.
[0005]
In addition, it is known that it is advantageous to use an assist gas in order to perform efficient laser welding (for example, the Journal of Welding Society Vol. 3 (1985) No. 2). The direction of supply greatly affects the quality of laser welding. In other words, the assist gas is used to remove the plasma generated in the laser irradiation part to ensure the penetration depth. By blowing the assist gas, pressure acts directly on the cavity and the molten pool. Depending on the supply direction, welding defects will occur. In vertical upward welding and vertical downward welding, it is said that the weld pool becomes unstable due to the influence of the gravity head acting on the weld pool, making it difficult to perform good welding. In such a case, the supply direction of the assist gas greatly affects the welding quality.
[0006]
The present invention has been made to solve the above-described conventional drawbacks, and an object thereof is to provide a laser welding apparatus capable of easily controlling the filler wire feeding direction, the assist gas feeding direction, and the like. There is to do.
[0007]
[Means and effects for solving the problems]
Accordingly, a laser welding apparatus according to claim 1 is a laser welding apparatus including a welding torch 1 for irradiating a welded portion W with a laser beam, and an attachment including at least a filler wire feeding nozzle 9 and an assist gas supply nozzle 10. The attachment support member 5 that supports the attachment is movably provided, and further, a drive source 6 that moves the attachment support member 5 and a control unit 8 that controls the drive source 6 are provided. By controlling the position of the attachment support member 5 by controlling the drive source 6, the attachment is moved around the axis of the laser beam axis L, the feeding direction of the filler wire 11 with respect to the welded portion W, and The supply direction of the assist gas should be changed around the axis of the laser beam axis L. Made to constitute, by the control unit 8, TatsuMuko or in horizontal welding, weld pool assist gas feed to the feed direction directing to the upper side of the assist gas so as to support the gravity head acting downwardly against the MP The position of the nozzle 10 is controlled.
[0008]
According to the laser welding apparatus of the first aspect, by controlling the drive source 6 by the control unit 8 by controlling the position of the attachment support member 5, the Atatchimen bets about the axis of the laser beam axis L It is possible to change the feeding direction of the filler wire 11 with respect to the welded portion W around the axis of the laser beam axis L. Therefore, the relationship between the welding progress direction and the filler wire 11 feeding direction, the assist gas supply direction, and the like can be easily matched. As a result, stable welding can be achieved even when the welding line WL is a curve. It becomes possible to do. Moreover, according to this laser welding apparatus, the gravity head acts downward on the molten pool, whereas the assist gas force acts in the direction of supporting the molten pool from the lower side to the upper side. The tendency to melt down can be reduced, and stable welding can be performed. And since arrangement | positioning of the filler wire feed nozzle 9 and the assist gas supply nozzle 10 for obtaining such an effect | action can be easily achieved in any case by the movement of the attachment support member 5, the operation | work is carried out. Improves.
[0009]
The laser welding apparatus according to claim 2, said attachment support member 5 is rotatably mounted to the welding torch 1 in the laser beam axis L and substantially coaxially, pivotable above Atatchimen bets are around the laser beam axis L It is characterized by being arranged in.
[0010]
According to the laser welding apparatus of the second aspect, it is possible simplify the configuration for controlling the position of Atatchimen bets, also improves the positioning accuracy of Atatchimen bets.
[0011]
In the laser welding apparatus according to claim 3, the filler support nozzle 5 has a filler wire feed nozzle 9 and an assist gas supply nozzle 10 attached at positions facing each other across the laser beam axis L. The position of the attachment support member 5 is controlled by the control unit 8 so that the wire feed nozzle 9 is positioned forward in the welding progress direction and the assist gas supply nozzle 10 is positioned rearward in the welding progress direction to perform vertical upward welding. It is characterized by performing.
[0012]
According to a fourth aspect of the present invention, in the attachment support member 5, the filler wire feed nozzle 9 and the assist gas supply nozzle 10 are attached to positions opposite to each other across the laser beam axis L, and the assist support member 5 has the assist beam. The position of the attachment support member 5 is controlled by the control unit 8 so that the gas supply nozzle 10 is positioned forward in the welding progress direction and the filler wire feed nozzle 9 is positioned backward in the welding progress direction to perform vertical downward welding. It is characterized by performing.
[0013]
According to the laser welding apparatus of the third and fourth aspects, the gravity head acts downward on the molten pool, whereas the assist gas force acts in a direction to support it from the lower side to the upper side. As a result, the tendency of the molten pool to burn down can be reduced, thereby enabling stable welding. And since arrangement | positioning of the filler wire feed nozzle 9 and the assist gas supply nozzle 10 for obtaining such an effect | action can be easily achieved in any case by the movement of the attachment support member 5, the operation | work is carried out. Improves.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Next, specific embodiments of the laser welding apparatus of the present invention will be described in detail with reference to the drawings. First, in FIG. 1, reference numeral 1 denotes a laser welding torch. A condensing lens 2 is disposed inside the welding torch 1, and a shield gas inlet 3 is formed on the side thereof. An attachment support member 5 is rotatably attached to the outer periphery of the welding torch 1 via a bearing 4. The attachment support member 5 is attached so as to be rotatable coaxially with the laser beam axis L. A motor 6 as a drive source is attached to the outer periphery of the welding torch 1 at a position above the attachment support member 5 so as to face downward. A pinion 7 is attached to the output shaft of the motor 6, and the pinion 7 meshes with a gear formed on the outer peripheral portion of the attachment support member 5, whereby the motor 6 is driven to drive the attachment support member 5. It can be driven to rotate. Reference numeral 8 denotes a control unit for controlling the motor. A filler wire feed nozzle 9 and an assist gas supply nozzle 10 are attached to the attachment support member 5 at positions facing each other across the laser beam axis L. The filler wire feeding nozzle 9 is for feeding the filler wire 11, and is attached to the attachment support member 5 via a holding bracket 12. In this laser welding apparatus, the filler wire 11 and the assist gas are supplied to the welded portion W while irradiating a laser beam from the welding torch 1 toward the welded portion W. The laser welding is performed while moving to (the welding progress direction is the opposite direction).
[0015]
According to the laser welding apparatus, when the motor 6 is controlled by the control unit 8 and the rotation angle of the attachment support member 5 is adjusted, the filler wire feed nozzle 9 and the assist gas supply nozzle 10 are connected to the laser beam axis. It is possible to position the lens at an arbitrary position around L. Therefore, when the welding line WL is a curved line as shown in FIGS. 2 and 3, the filler wire 11 can be controlled by controlling the rotation of the attachment support member 5 in synchronization with the movement of the XY table. Is sent forward along the weld line WL (in the tangential direction) from the rear in the welding progress direction to the weld W, and the assist gas is sent from the front in the welding progress direction to the weld line WL. Along the line (tangentially). As a result, even without providing a rotating mechanism for the member to be welded, the relationship between the welding progress direction and the feeding direction of the filler wire 11 and the supply direction of the assist gas can be easily matched, and the welding line WL is a curve. Even in some cases, stable welding can be performed. Further, as shown in FIG. 4, even when the welding line WL is bent at a right angle in the middle, if the attachment support member 5 is rotated by 90 ° during the welding, a rotating mechanism for the welded member is not provided. Can be dealt with. Furthermore, according to the laser welding apparatus, even when the wire feed welding of the arc welded fillet joint as shown in FIG. 5 is controlled by synchronizing the rotational drive of the attachment support member 5 with the movement of the XY table. This can be handled in the same manner as described above. Furthermore, as shown in FIG. 6, in the case of a joint in which the member to be welded has a difference in plate thickness, it is easier to form a bead shape when the wire is fed from the thin plate side. This is also effective for welded joints in which the feeding direction is limited.
[0016]
Each of the application examples in FIGS. 2 to 6 has been focused on the feeding direction of the filler wire 11, but the laser welding apparatus controls the supply direction of the assist gas in accordance with the welding posture. It is also preferable to improve the welding quality (particularly the bead shape). FIG. 7 shows the welding state of vertical upward welding (FIG. 7 (a)) and vertical downward welding (FIG. 7 (b)). In FIG. (A)), the filler wire feed nozzle 9 is positioned forward (upper) in the welding progress direction, and the assist gas supply nozzle 10 is positioned rearward (lower) in the welding progress direction, while vertical downward welding is performed. When the welding is performed (FIG. 5 (b)), the assist gas supply nozzle 10 is positioned forward (downward) in the welding progress direction, and the filler wire feed nozzle 9 is positioned rearward (upper) in the welding progress direction. Like to do. In this way, the gravity head acts downward on the molten pool MP, whereas the assist gas force acts in a direction to support it from the lower side to the upper side. The tendency can be reduced, and stable welding can be performed. When the assist gas supply nozzle 10 is disposed in the opposite state, the assist gas force acts downward on the molten pool MP in addition to the gravity head acting downward. The tendency of the molten pool MP to burn off is promoted, and stable welding is difficult. Moreover, in such a case, when the molten pool MP melts down, the filler wire 11 fed from the lower side comes into contact with the molten pool MP, making it difficult to smoothly feed the filler wire 11, The feeding position is deviated, and normal convection of the molten pool MP is hindered. As a result, welding defects such as blow holes and bead shape defects are generated. On the other hand, according to the arrangement as described above, good welding results can be obtained. However, the arrangement of the filler wire feed nozzle 9 and the assist gas supply nozzle 10 for obtaining such an action is not Also in this case, since it can be easily achieved by moving the attachment support member 5, the workability is improved. The holding action of the molten pool MP by the assist gas as described above is not limited to the vertical upward welding and the vertical downward welding, and can be expected in the horizontal welding shown in FIG. By controlling the supply direction of the assist gas as described above, the force by the assist gas can be used as the holding force of the molten pool MP, and therefore, welding work in various welding postures can be performed satisfactorily.
[0017]
9 and 10 show modified examples of the laser welding apparatus. These are all provided with two rotating shafts (α-axis, β-axis) on the welding torch 1. In each figure, the same functional parts as those in FIG. is doing. In each figure, 13 indicates a window, 14 indicates a reflecting mirror, and 15 indicates a parabolic mirror. In these laser welding apparatuses, exactly the same operations and effects as the laser welding apparatus of FIG. 1 can be obtained.
[0018]
Although the embodiment of the laser welding apparatus of the present invention has been described above, the laser welding apparatus of the present invention is not limited to the above-described embodiment, and can be implemented with various modifications. For example, in the above, an example of using a filler wire feed nozzle 9 and the assist gas feed nozzle 10 as an attachment, with these, may be used attachments such as weld line detecting sensors. In addition, in the invention of claim 1 of the present application, the attachment support member 5 includes a structure that supports the welding torch 1 and supports it at other appropriate places. Furthermore, the invention of claim 1 and claim 2 includes an embodiment in which the filler wire feed nozzle 9 and the assist gas supply nozzle 10 are attached in the same direction.
[Brief description of the drawings]
FIG. 1 is a schematic view of a central longitudinal section showing an embodiment of a laser welding apparatus of the present invention.
FIG. 2 is an explanatory diagram for explaining an application example of the laser welding apparatus of the embodiment and the conventional example.
FIG. 3 is an explanatory diagram for explaining another application example of the laser welding apparatus of the embodiment and the conventional example.
FIG. 4 is an explanatory diagram for explaining an application example of the laser welding apparatus of the embodiment.
FIG. 5 is an explanatory diagram for explaining another application example of the laser welding apparatus of the embodiment.
FIG. 6 is an explanatory diagram for explaining still another application example of the laser welding apparatus of the embodiment.
FIGS. 7A and 7B are explanatory views showing a state in which vertical welding is performed in the laser welding apparatus of the embodiment, wherein FIG. 7A shows upward welding and FIG. 7B shows downward welding.
FIG. 8 is an explanatory diagram showing a state in which horizontal welding is performed in the laser welding apparatus of the embodiment.
FIG. 9 is a schematic diagram of a central longitudinal section showing another embodiment of the laser welding apparatus of the present invention.
FIG. 10 is a schematic diagram of a central longitudinal section showing another embodiment of the laser welding apparatus of the present invention.
FIG. 11 is a schematic diagram of a central longitudinal section showing a conventional laser welding apparatus.
FIG. 12 is a schematic diagram of a central longitudinal section showing another conventional example.
FIG. 13 is a schematic diagram of a central longitudinal section showing still another conventional example.
[Explanation of symbols]
1 welding torch 5 attachment support member 6 motor (drive source)
8 Control part 9 Filler wire feed nozzle 10 Assist gas supply nozzle 11 Filler wire L Laser beam axis W Weld part MP Weld pool WL Weld line

Claims (4)

In a laser welding apparatus comprising a welding torch (1) for irradiating a welded part (W) with a laser beam, and an attachment comprising at least a filler wire feed nozzle (9) and an assist gas supply nozzle (10), An attachment support member (5) that supports the attachment is movably provided, and further, a drive source (6) that moves the attachment support member (5), and a controller (8) that controls the drive source (6), And by controlling the position of the attachment support member (5) by controlling the drive source (6) by the control unit (8), the attachment is made around the axis of the laser beam axis (L). The direction of feeding the filler wire (11) to the welded portion (W) and the direction of supplying the assist gas are moved to the laser beam axis. It becomes configured to vary about the axis of the L), by the control unit (8), in TatsuMuko or horizontal welding, to support the gravity head acting downwardly against the molten pool (MP) A laser welding apparatus, wherein the position of the assist gas supply nozzle (10) is controlled so that the assist gas supply direction is directed upward. The attachment support member (5) is attached to a rotatable welding torch (1) the laser beam axis (L) and substantially coaxially pivotally disposed above Atatchimen bets are around the laser beam axis (L) The laser welding apparatus according to claim 1, wherein A filler wire feed nozzle (9) and an assist gas supply nozzle (10) are attached to the attachment support member (5) at positions facing each other across the laser beam axis (L). The attachment support is supported by the control unit (8) so that the feed nozzle (9) is positioned forward in the welding progress direction and the assist gas supply nozzle (10) is positioned rearward in the welding progress direction to perform vertical upward welding. member (5) laser welding apparatus according to claim 1 or 2, characterized in that to control the position of the. A filler wire feed nozzle (9) and an assist gas supply nozzle (10) are attached to the attachment support member (5) at positions facing each other across the laser beam axis (L). The attachment support is supported by the control unit (8) so that the supply nozzle (10) is positioned forward in the welding progress direction and the filler wire feed nozzle (9) is positioned backward in the welding progress direction to perform vertical downward welding. member (5) laser welding apparatus according to claim 1 or 2, characterized in that to control the position of the.

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