JP7473399B2 - Laser-arc hybrid welding equipment - Google Patents

Description

This disclosure relates to a laser-arc hybrid welding device that uses a laser and an arc.

JP 2000-263225 A (Patent Document 1) discloses an arc induction method for inducing an arc using laser light. In this method of inducing an arc using laser light, an arc generated between the arc electrode and the workpiece is induced to occur between the arc electrode and the laser light irradiation position by irradiating a laser light onto the intended processing position on the surface of the workpiece. This allows the arc discharge position to be stably induced by the laser light, stabilizing the arc (see Patent Document 1).

JP 2000-263225 A

In the arc induction method described in Patent Document 1, the base material is spot-irradiated with laser light through a condenser lens. The irradiation width of the laser spot is very small, for example, about 0.2 mm, which is less than 1/10 of the width of the edge of the arc umbrella. Therefore, there is a low tolerance for deviation of the laser irradiation from the target position of the laser spot. If the actual irradiation position deviates from the target position by even 1 mm, for example, the arc and the laser become independent welds, and the effect of guiding the arc by the laser light cannot be obtained, and it may become impossible to stabilize the arc by the laser light.

One way to address this issue is to improve the precision of mechanical parts such as the bracket that secures the laser head, thereby minimizing assembly and dimensional errors, thereby minimizing the positional deviation of the laser spot. However, this approach could increase the cost of mechanical parts such as the bracket, and reduce versatility in manufacturing.

This disclosure has been made to solve the above problems, and the purpose of this disclosure is to increase the tolerance for laser irradiation misalignment and stabilize the arc in a laser-arc hybrid welding device while suppressing cost increases.

The laser-arc hybrid welding device disclosed herein includes an arc welding device and a laser irradiation device. The laser irradiation device is configured to irradiate laser light forward in the welding direction from the arc output from the arc welding device. The laser irradiation device is configured to irradiate the laser light so that the shape of the irradiation area irradiated with the laser light is an arc shape that follows the edge of the arc umbrella.

In this laser-arc hybrid welding device, the laser light is irradiated in front of the arc in the welding direction so that the shape of the laser irradiation area is an arc that follows the edge of the arc umbrella. This increases the tolerance for deviation from the target position of the laser irradiation. For example, even if the laser irradiation area is shifted in the rotation direction of the optical axis from the initial target position, the distance between the laser light and the arc does not change significantly, and the impact on the stability of the arc is small. Therefore, with this laser-arc hybrid welding device, the tolerance for deviation of the laser irradiation can be increased and the arc can be stabilized without increasing the accuracy of mechanical parts such as brackets.

The central angle of the arc-shaped laser irradiation area may be less than 180 degrees.

If the laser irradiation area wraps around to the rear of the arc, the stability of the arc may change, which may affect weldability. Therefore, by making the central angle of the laser irradiation area smaller than 180 degrees, the possibility of the laser irradiation area wrapping around to the rear of the arc can be reduced, even if the laser irradiation area is shifted in the rotation direction of the optical axis from the target position. Therefore, with this laser-arc hybrid welding device, it is possible to suppress changes in arc stability due to deviations in laser irradiation.

The arc-shaped laser irradiation area may be formed outside the edge of the arc umbrella.

If the laser irradiation area interferes with the arc umbrella, the arc can become unstable. With this laser-arc hybrid welding device, the laser irradiation area is formed outside the edge of the arc umbrella, ensuring arc stability.

The arc-shaped laser irradiation area may be formed at a position 1 to 3 mm from the center of the arc.

If the laser irradiation area is formed closer than 1 mm from the center of the arc, there is a high possibility that the laser irradiation area will interfere with the arc umbrella. On the other hand, if the laser irradiation area is formed farther than 3 mm from the center of the arc, there is a possibility that the arc induction effect of the laser light will not be sufficient. With this laser-arc hybrid welding device, the laser irradiation area is formed 1 to 3 mm from the center of the arc, making it possible to stabilize the arc with the laser light.

The arc-shaped laser irradiation area may be formed outside the edge of the molten pool formed by the arc.

If the laser irradiation area interferes with the molten pool formed by the arc, problems such as burn-through due to excessive energy concentration and reduced energy efficiency can occur. With this laser-arc hybrid welding device, the laser irradiation area is formed outside the edge of the molten pool formed by the arc, making it possible to avoid the above problems.

The laser-arc hybrid welding device disclosed herein can increase the tolerance for laser irradiation misalignment and stabilize the arc while minimizing cost increases.

1 is a diagram showing an overall configuration of a laser-arc hybrid welding apparatus according to an embodiment. FIG. FIG. 2 is a perspective view illustrating an image of laser irradiation by the hybrid welding apparatus shown in FIG. 1 . FIG. 2 is a plan view illustrating an image of laser irradiation by the hybrid welding apparatus shown in FIG. 1 . FIG. 13 is a diagram showing an example of the relationship between a laser light irradiation area and an edge of an arc umbrella. FIG. 13 is an image diagram of a reference example in which the irradiation area of the laser light is spot-shaped. FIG. 4 is a diagram for explaining the distance between the center of the arc and the irradiation area of the laser light. 1 is a diagram showing an example of the relationship between a laser beam irradiation area and an edge of a molten pool formed by an arc;

The following describes in detail the embodiments of the present disclosure with reference to the drawings. Note that the same or corresponding parts in the drawings are given the same reference numerals and their description will not be repeated.

Figure 1 is a diagram showing the overall configuration of a laser-arc hybrid welding device according to an embodiment of the present disclosure. With reference to Figure 1, the laser-arc hybrid welding device 1 (hereinafter sometimes simply referred to as "hybrid welding device 1") includes a welding torch 10, a welding wire 20, a welding power supply device 30, a laser head 40, and a laser oscillator device 60.

This hybrid welding device 1 can be used to weld various members and can also be used to weld dissimilar materials. Dissimilar materials are joined together by joining different materials whose main components are different. The hybrid welding device 1 can be used to weld, for example, hot-dip galvanized steel sheets, such as GI steel sheets and GA steel sheets, to aluminum alloy sheets. Not only soft aluminum, but also hard aluminum sheets such as JIS 5000 series (e.g., 5052), 6000 series (e.g., 6063), and 7000 series (e.g., 7075) can be used for the aluminum alloy sheets. The hybrid welding device 1 joins one and the other of the base materials 70 to be joined together, for example, by a lap fillet weld joint or a flare weld joint.

The welding torch 10, the welding wire 20, and the welding power supply 30 constitute an arc welding device that performs welding by generating an arc between the joint of the base material 70. The welding torch 10 supplies the welding wire 20 and a shielding gas (not shown) toward the joint of the base material 70. The welding torch 10 receives a supply of welding current from the welding power supply 30, generates an arc 25 between the tip of the welding wire 20 and the joint of the base material 70, and supplies a shielding gas (argon gas, carbon dioxide gas, etc.) toward the welded portion. A non-consumable electrode (tungsten, etc.) may be used instead of the welding wire 20. In other words, the arc welding using the welding torch 10 may be of a consumable electrode type (MAG welding, MIG welding, etc.) or a non-consumable electrode type (TIG welding, etc.).

The welding power supply 30 generates a welding voltage and a welding current for performing arc welding, and outputs the generated welding voltage and welding current to the welding torch 10. The welding power supply 30 also controls the feed speed of the welding wire 20 in the welding torch 10.

The laser head 40 and the laser oscillator 60 constitute a laser irradiation device that performs welding by irradiating a laser beam 50 toward the joint of the base material 70. The laser head 40 receives a supply of laser beam from the laser oscillator 60 and irradiates the laser beam 50 toward the joint of the base material 70. The laser beam 50 from the laser head 40 is irradiated near the arc 25 generated from the welding torch 10, and in this hybrid welding device 1, the laser beam 50 is irradiated forward in the welding direction of the arc 25 generated from the tip of the welding wire 20.

In the hybrid welding device 1 according to this embodiment, the laser head 40 irradiates the laser light 50 toward the joint of the base material 70 so that the shape of the irradiation area of the laser light 50 irradiated from the laser head 40 (hereinafter also referred to as the "laser irradiation area") is an arc shape that follows the umbrella edge of the arc 25. This increases the tolerance (tolerance) of the deviation of the laser irradiation from the target position of the laser irradiation area, thereby stabilizing the arc 25. This point will be explained in detail below.

In laser welding, the laser light is usually focused by a focusing lens and is often spot-irradiated onto the base material. The irradiation width of the laser spot (laser irradiation area) is small (e.g., about 0.2 mm in diameter), and is often quite small compared to the width of the arc umbrella (e.g., 1/10 or less). The arc umbrella refers to the shape of the arc discharge area that occurs between the welding wire and the base material. The arc umbrella can be seen because the arc discharge area emits a strong light.

As described above, because the irradiation width of the laser spot is small, there is little tolerance for deviation of the laser irradiation from the target position of the laser spot, and if the actual laser irradiation position deviates from the target position by even 1 mm, the interaction between the laser light and the arc may become small. As a result, the arc induction effect of the laser light is reduced, and it may become impossible to stabilize the arc by the laser light.

To address this issue, it is possible to minimize misalignment of the laser spot by improving the precision of mechanical parts such as the bracket that secures the laser head 40, thereby minimizing assembly errors and dimensional errors. However, this approach may increase the cost of mechanical parts such as the bracket, and may result in a loss of versatility in manufacturing.

Therefore, in the hybrid welding device 1 according to this embodiment, the laser head 40 irradiates the laser light 50 toward the joint of the base material 70 so that the shape of the irradiation area of the laser light 50 irradiated from the laser head 40 is an arc shape that follows the edge of the umbrella of the arc 25. This makes it possible to increase the tolerance for misalignment of the laser irradiation without increasing the accuracy of mechanical parts such as the bracket that fixes the laser head 40.

Figures 2 and 3 are conceptual diagrams of laser irradiation by the hybrid welding device 1 shown in Figure 1. Figure 2 is a perspective view of the welded area by the arc 25 and the laser light 50, and Figure 3 is a plan view of the welded area viewed from the z direction (Figure 1). Note that in Figure 1, the axis of the welding wire 20 extending from the welding torch 10 is inclined backward in the welding advance direction, but for ease of explanation, in Figures 2 and 3, the axis of the welding wire 20 is described as being along the z direction. Also, in Figure 2, the welding wire 20 and the laser light 50 above in the z direction are not shown.

Referring to Figures 2 and 3, this example shows a joint in a fillet weld of a lap joint. The base material (material to be welded) 70 consists of a lower plate 71 and an upper plate 72 overlapped on the lower plate 71. A weld bead 73 is formed at the end of the upper plate 72 on the lower plate 71.

The arc 25 generated from the tip of the welding wire 20 spreads out radially as it reaches the base material 70. The shape of the arc 25 is umbrella-shaped, and the edge of the umbrella of the arc 25 on the base material 70 (71, 72) is circular (Figure 3).

The irradiation area 52 of the laser light 50 on the base material 70 is formed in an arc shape along the umbrella edge of the arc 25, ahead of the arc 25 in the welding advance direction. Such a laser irradiation area 52 can be formed, for example, by providing a diffractive optical element (hereinafter referred to as a "DOE (Diffractive Optical Element)") in the laser head 40. In other words, the DOE is configured so that the irradiation area 52 of the laser light 50 irradiated from the laser head 40 is in an arc shape along the expected umbrella edge of the arc 25.

The shape of the edge of the arc 25 can be estimated from the output of the welding torch 10 (output of the welding power supply 30) and the distance between the welding wire 20 and the base material 70. Therefore, it is possible to prepare the DOE in advance so that the laser irradiation area 52 is arc-shaped along the expected edge of the arc 25.

By making the laser irradiation area 52 arc-shaped along the edge of the umbrella of the arc 25, the tolerance for deviation from the target position of the laser irradiation is increased. For example, as shown in FIG. 4, even if the laser irradiation area 52 is shifted in the rotation direction of the optical axis (dotted line) from the target position (solid line), the distance between the laser irradiation area 52 and the arc 25 does not change significantly, and the impact on the stability of the arc 25 is small. In other words, by making the laser irradiation area 52 arc-shaped as shown, the tolerance for deviation from the target position of the laser irradiation can be increased. As a result, the arc 25 can be stabilized by increasing the tolerance for deviation of the laser irradiation without increasing the accuracy of mechanical parts such as the bracket that fixes the laser head 40, i.e., while suppressing the increase in the cost of mechanical parts.

Figure 5 is an image diagram of a reference example in which the laser irradiation area is in the form of a small spot. Referring to Figure 5, the irradiation width of the laser spot 54 is generally small, for example, about 0.2 mm, which is less than 1/10 of the width of the umbrella of the arc 25.

Therefore, there is a low tolerance for deviation of the laser spot 54 from the target position, and if the actual laser spot 54 deviates from the target position (dotted line) by even 1 mm, the interaction between the laser light and the arc may be reduced, or the induction effect of the arc 25 by the laser light may change significantly. As a result, it may not be possible to stabilize the arc 25 by the laser light.

In contrast, in this hybrid welding device 1, as shown in FIG. 4, the laser irradiation area 52 is made arc-shaped, which increases the tolerance for deviation from the target position of the laser irradiation.

Referring again to FIG. 4, in the hybrid welding device 1 according to this embodiment, the central angle θ of the arc-shaped laser irradiation area 52 is smaller than 180 degrees. If the laser irradiation area wraps around to the rear side of the arc 25 (rear side in the welding advance direction), the stability of the arc 25 caused by the laser light may change, which may affect the weldability. Therefore, by making the central angle θ of the laser irradiation area 52 preceding the arc 25 smaller than 180 degrees, the possibility of the laser irradiation area 52 wrapping around to the rear side of the arc 25 can be reduced even if the laser irradiation area 52 is shifted in the rotation direction of the optical axis relative to the target position.

In addition, in the hybrid welding device 1 according to this embodiment, the arc-shaped laser irradiation area 52 is formed outside the edge of the umbrella of the arc 25. If the laser irradiation area directly interferes with the umbrella of the arc 25, the arc 25 may become unstable. In this hybrid welding device 1, the irradiation area 52 is formed outside the edge of the umbrella of the arc 25, so the stability of the arc 25 can be ensured.

As described above, according to this embodiment, the laser light 50 is irradiated so that the shape of the laser irradiation area 52 is an arc shape that follows the edge of the umbrella of the arc 25, so there is a high tolerance for deviation from the target position of the laser irradiation. Therefore, according to this embodiment, it is possible to stabilize the arc by increasing the tolerance for deviation of the laser irradiation without increasing the precision of mechanical parts such as brackets, i.e., while suppressing increases in costs.

In the above embodiment, the shape of the edge of the arc 25 is estimated from the output of the welding torch 10 (output of the welding power supply 30) and the distance between the welding wire 20 and the base material 70, and the DOE is configured so that the laser irradiation area 52 is arc-shaped along the estimated edge of the arc 25. However, as shown in FIG. 6, the arc-shaped laser irradiation area 52 may be formed in advance at a predetermined distance D from the approximate center O of the arc 25.

The specified distance D is preferably, for example, about 1 to 3 mm. If the laser irradiation area 52 is formed at a position closer than 1 mm from the center O of the arc 25, there is a high possibility that the laser irradiation area 52 will interfere with the umbrella of the arc 25. On the other hand, if the laser irradiation area 52 is formed at a position farther than 3 mm from the center O of the arc 25, there is a possibility that the induction effect of the arc 25 by the laser light 50 will not be sufficient.

If within the range of welding conditions, the output of the welding torch 10 may be adjusted by the welding power supply 30 so that the edge of the arc 25 is aligned with the laser irradiation area 52.

In the above embodiment, the arc-shaped laser irradiation area 52 is formed by providing a DOE in the laser head 40, but the method of forming the laser irradiation area 52 is not limited to the method using a DOE. For example, the laser head 40 may be provided with a laser scanning device capable of scanning the laser light 50 on the base material 70, and the arc-shaped laser irradiation area 52 may be formed by scanning the laser light 50 with the laser scanning device. Alternatively, the arc-shaped laser irradiation area 52 may be formed using a laser head capable of changing the profile of the laser irradiation area 52.

In the above embodiment, the laser beam 50 is irradiated so that the shape of the laser irradiation area 52 is an arc shape that follows the edge of the umbrella of the arc 25. However, if the welding speed is slow and the molten pool formed by the arc 25 extends further forward in the welding advance direction than the edge of the umbrella of the arc 25, the laser irradiation area 52 may be formed outside the edge of the molten pool formed by the arc 25.

If the laser irradiation area 52 interferes with the molten pool formed by the arc 25, problems such as burn-through due to excessive energy concentration and reduced energy efficiency can occur. Therefore, in the case of welding conditions in which the molten pool formed by the arc 25 spreads forward in the welding direction beyond the edge of the umbrella of the arc 25, the above problems can be avoided by forming the laser irradiation area 52 outside the edge of the molten pool 75 formed by the arc 25, as shown in Figure 7.

The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is indicated by the claims, not by the description of the embodiments above, and is intended to include all modifications within the meaning and scope of the claims.

1 Laser-arc hybrid welding device, 10 Welding torch, 20 Welding wire, 25 Arc, 30 Welding power supply device, 40 Laser head, 50 Laser light, 52, 54 Laser irradiation area, 60 Laser oscillation device, 70 Base material, 71 Upper plate, 72 Lower plate, 73 Weld bead, 75 Molten pool.

Claims (4)

An arc welding device;
a laser irradiation device configured to irradiate a laser beam forward in a welding direction from the arc output from the arc welding device,
the laser irradiation device is configured to irradiate the laser beam so that the shape of an irradiation area irradiated with the laser beam is an arc shape along an edge of an arc umbrella;
A laser-arc hybrid welding apparatus, wherein the arc-shaped irradiation area is formed outside the edge of the arc umbrella. An arc welding device;
a laser irradiation device configured to irradiate a laser beam forward in a welding direction from the arc output from the arc welding device,
the laser irradiation device is configured to irradiate the laser beam so that the shape of an irradiation area irradiated with the laser beam is an arc shape along an edge of an arc umbrella;
A laser-arc hybrid welding device, wherein the arc-shaped irradiation area is formed at a position 1 to 3 mm from the center of the arc. An arc welding device;
a laser irradiation device configured to irradiate a laser beam forward in a welding direction from the arc output from the arc welding device,
the laser irradiation device is configured to irradiate the laser beam so that the shape of an irradiation area irradiated with the laser beam is an arc shape along an edge of an arc umbrella;
A laser-arc hybrid welding device, in which the arc-shaped irradiation area is formed outside the edge of the molten pool formed by the arc. 4. The laser-arc hybrid welding device according to claim 1 , wherein a central angle of the arc-shaped irradiation area is smaller than 180 degrees.

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