Laser-arc hybrid welding device

Abstract

To provide a laser-arc hybrid welding device capable of reducing formation of a blow hole to provide sound welding quality.SOLUTION: A laser-arc hybrid welding device 1 comprises: a laser head 2 that irradiates a welding part P with a laser beam L; a welding torch 3 that supplies a filler material W to the welding part P; a trailer house 4 that surrounds the welding part P in a state where the laser beam L applied from the laser head 2 can be projected to the welding part P and a tip of the welding torch 3 can be inserted; a current plate 5 provided with a bottom plate 51 and a pair of side walls 52 and disposed between the laser head 2 and the trailer house 4 to extend in a welding direction; a first air knife 6 that supplies compressed air in a longitudinal direction of the current plate 5; a seconde air knife 7 disposed between the first air knife 6 and the laser head 2 to supply the compressed air in the longitudinal direction of the current plate 5; and an inactive gas supply unit 8 that supplies an inactive gas into the trailer house 4.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a hybrid welding apparatus, and more particularly to a laser-arc hybrid welding apparatus that combines laser welding and arc welding. [Background technology]

[0002] Aluminum alloys are lighter than steel and have excellent corrosion resistance, so they are used in a wide range of fields, including transportation equipment (automobiles, railway cars, etc.) and building materials. On the other hand, although aluminum alloys are suitable for plastic processing and casting, they have the problem of being difficult to weld. If aluminum alloys could be welded efficiently and with high quality, not only could the fields of application be expanded, but it would also eliminate the need for mold management for casting, reducing manufacturing costs.

[0003] Laser-arc hybrid welding equipment that combines laser welding and arc welding has already been proposed as a welding technology that realizes highly efficient and high-quality welding (see, for example, Patent Document 1, etc.). Laser-arc hybrid welding combines the advantages of both arc welding and laser welding, such as the ability to achieve deep penetration depth, high speed, and low heat input that allows for suppression of welding deformation, making it suitable for welding large structures.

[0004] For example, Patent Document 1 discloses a laser-arc hybrid welding apparatus having a laser head (laser welding torch) that irradiates a laser, an arc welding torch that discharges an arc, a first gas supply device that supplies gas from the arc welding torch, a second gas supply device that supplies gas into a trailer (enclosure) that surrounds the welding site, and a control device that controls the amount of gas supplied by the first gas supply device 4 and the second gas supply device 5.

[0005] Patent Document 2 discloses a hybrid welding device having a laser head equipped with a laser nozzle that forms an optical path for the laser light, a first straightening plate that is positioned at the tip side of the laser nozzle so as not to interfere with the laser light, a first air knife that injects compressed air along the first straightening plate, a second straightening plate that is positioned between the first straightening plate and the welded portion so as not to interfere with the laser light, and a second air knife that injects compressed air along the second straightening plate. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent Publication No. 2011-098371 [Patent Document 2] Patent Publication No. 2019-198885 Summary of the Invention [Problem to be solved by the invention]

[0007] Aluminum is prone to blowholes (air bubbles in the weld metal). The main cause of blowholes is hydrogen. Hydrogen is generated when moisture mixed into the weld reacts with aluminum due to the heat of welding. Compared to when aluminum is molten, the solubility of hydrogen gas drops significantly when aluminum solidifies. As a result, blowholes are caused by the hydrogen gas that is generated.

[0008] Possible sources of hydrogen include moisture in the air entrained in the arc atmosphere, moisture adhering to the shielding gas supply hose or nozzle, moisture in the shielding gas, dissolved hydrogen in the base metal or filler metal, moisture or organic matter adhering to the surface of the base metal or filler metal, etc. Of these, the effect of moisture entrained in air is the greatest.

[0009] In addition, because aluminum has a low specific gravity, blowholes that occur during welding are difficult to remove, and rapid solidification due to its high thermal conductivity also prevents the release of blowholes.

[0010] As in the invention described in Patent Document 1 mentioned above, it is possible to enclose the welding area with a trailer and shield the welding gas atmosphere, but there is a problem in that if the welding area is long, the enclosure becomes too large.

[0011] Furthermore, when an air knife and a baffle plate are installed as in the invention described in Patent Document 2 mentioned above, there is a problem that the discharged compressed air attracts surrounding air, generating an air current around the molten metal, disrupting the flow of the shielding gas, and making it difficult to completely isolate the molten metal from the air.

[0012] The present invention has been devised in consideration of such problems, and aims to provide a laser-arc hybrid welding device that can reduce the occurrence of blowholes and obtain sound welding quality. [Means for solving the problem]

[0013] According to the present invention, there is provided a laser-arc hybrid welding apparatus for welding aluminum alloys by combining laser welding and arc welding, comprising: a laser head for irradiating a laser beam to a weld portion; a welding torch for supplying a filler metal to the weld portion; a trailer house for enclosing the weld portion in a state in which the laser beam irradiated from the laser head can be projected onto the weld portion and the tip of the welding torch can be inserted; a straightening plate disposed between the laser head and the trailer house and having a bottom plate and a pair of side walls extending in the welding direction; a first air knife for supplying compressed air along the longitudinal direction of the straightening plate; a second air knife disposed between the first air knife and the laser head for supplying compressed air along the longitudinal direction of the straightening plate; and an inert gas supply device for supplying an inert gas into the trailer house.

[0014] The air straightening plate may include a thrust amplifying plate that is disposed only forward in the injection direction of the compressed air supplied from the first air knife and that amplifies the thrust of the compressed air.

[0015] The thrust amplifier plate may have a pointed end formed so as to narrow a cross-sectional area of ​​a flow passage of the compressed air from the upstream side toward the downstream side.

[0016] The thrust amplifier plate may have a partition portion disposed downstream of the pointed end portion and configured to maintain a state in which the compressed air flow path is divided into left and right portions.

[0017] The flow straightening plate may have an orifice formed in a region including the pointed end.

[0018] The airflow straightening plate may have a backflow prevention plate disposed on an outer surface of the bottom plate and configured to suppress a backflow of air between the trailer house and the airflow straightening plate.

[0019] The backflow prevention plate may have a pyramidal shape formed so that the cross-sectional area gradually increases from the upstream to the downstream.

[0020] The airflow straightening plate may have a plurality of exhaust ports formed on the side wall closer to the laser head than an injection position of the compressed air supplied from the second air knife.

[0021] The trailer house may have a heat-resistant skirt portion that contacts the surface of the workpiece to be welded.

[0022] The laser-arc hybrid welding apparatus may include a drive device that moves the laser head, the welding torch, the trailer house, the baffle plate, the first air knife, and the second air knife along a welding direction. Effect of the Invention

[0023] According to the laser-arc hybrid welding apparatus of the present invention described above, the trailer house, the baffle plate, the first air knife and the second air knife can separate the molten metal from the air, thereby reducing the occurrence of blowholes and achieving sound welding quality. [Brief description of the drawings]

[0024] [Figure 1] 1 is an overall configuration diagram showing an overview of a laser-arc hybrid welding apparatus according to one embodiment of the present invention. [Diagram 2] FIG. 2 is a side view of the device in the vicinity of a weld. [Diagram 3] FIG. 3 is a front view of the portion shown in FIG. 2. [Figure 4] FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] Hereinafter, an embodiment of the present invention will be described with reference to Figs. 1 to 4. Fig. 1 is an overall configuration diagram showing an overview of a laser-arc hybrid welding device according to an embodiment of the present invention. Fig. 2 is a side view of the device in the vicinity of a welded portion. Fig. 3 is a front view of the portion shown in Fig. 2. Fig. 4 is a plan view of a straightening plate. For convenience of explanation, the laser head is omitted in Fig. 3.

[0026] As shown in, for example, FIGS. 1 to 3 , a laser-arc hybrid welding apparatus 1 according to an embodiment of the present invention includes a laser head 2 that irradiates a laser beam L onto a welded portion P, a welding torch 3 that supplies a filler metal W to the welded portion P, a trailer house 4 that surrounds the welded portion P in a state in which the laser beam L irradiated from the laser head 2 can be projected onto the welded portion P and the tip of the welding torch 3 can be inserted therethrough, a straightening plate 5 that is disposed between the laser head 2 and the trailer house 4 and has a bottom plate 51 and a pair of side walls 52 extending in the welding direction, a first air knife 6 that supplies compressed air along the longitudinal direction of the straightening plate 5, a second air knife 7 that is disposed between the first air knife 6 and the laser head 2 and supplies compressed air along the longitudinal direction of the straightening plate 5, and an inert gas supply device 8 that supplies an inert gas into the trailer house 4.

[0027] The laser-arc hybrid welding device 1 is a welding device that combines laser welding and arc welding, and combines the advantages of both arc welding and laser welding, such as the ability to achieve deep penetration depth, high speeds, and low heat input that suppresses welding deformation.

[0028] The laser-arc hybrid welding apparatus 1 is a welding apparatus for welding aluminum alloys. The welded portion P is, for example, a groove portion where aluminum alloy plate materials (workpieces 10) are butted together. Although the present embodiment describes butt welding, the laser-arc hybrid welding apparatus 1 can also be applied to fillet welding by changing the shape of the trailer house 4, etc. The workpieces 10 are fixed to a fixing table 11, for example.

[0029] The laser welding section, which performs the function of laser welding, includes, for example, a laser head 2 that irradiates laser light L onto the welded section P, a laser oscillator 21 that outputs a laser beam, and an optical path 22 (such as an optical fiber) that transmits the laser beam output by the laser oscillator 21 to the laser head 2. For example, various existing devices such as a CO2 laser, a YAG laser, or a fiber laser can be applied to the laser welding section.

[0030] Although not shown, the laser head 2 includes components such as a reflecting mirror that deflects the traveling direction of the laser beam and a condenser lens that adjusts the beam diameter and focus of the laser light L. The configuration of the laser head 2 is similar to that of a conventional laser welding device.

[0031] The arc welding section, which performs the function of arc welding, includes, for example, a welding torch 3 that supplies a filler material W to the welded portion P, a filler material supply device 31 that supplies the filler material W to the welding torch 3, and an arc welding power source 32 that generates an electric discharge between the welding torch 3 and the welded portion P. The arc welding section is, for example, a TIG welding device, but may be another type of arc welding device.

[0032] The trailer house 4 is an enclosure that covers an area including the welded portion P. The trailer house 4 has a function of blocking air that is drawn into the arc atmosphere. The trailer house 4 has, for example, a box shape with an open bottom, and is provided with a first opening 41 for projecting the laser light L on the ceiling, and a second opening 42 for inserting the welding torch 3. The trailer house 4 may have a heat-resistant skirt portion 43 at the bottom that comes into contact with the surface of the workpiece 10.

[0033] A nozzle 81 for supplying an inert gas from an inert gas supply device 8 to the inside of the trailer house 4 is connected to the trailer house 4. When the inert gas is supplied to the internal space of the trailer house 4, the air inside the trailer house 4 is replaced with the inert gas, and the internal space during welding is maintained in an inert gas atmosphere.

[0034] The straightening plate 5 is a groove-shaped plate material disposed above the trailer house 4. As shown in Fig. 4, the straightening plate 5 is composed of a bottom plate 51 disposed between the laser head 2 and the trailer house 4 and extending in the welding direction, and a pair of side walls 52 disposed on both sides of the bottom plate 51. The bottom plate 51 has a first opening 53 for projecting the laser light L and a second opening 54 for inserting the welding torch 3. For convenience of explanation, an air knife is omitted in Fig. 4.

[0035] Since the trailer house 4 and the straightening plate 5 have openings (first openings 41, 53) through which the laser light L is projected, by-products such as spatter, plasma, plume, and fume generated during welding may contaminate the laser optical system. The first air knife 6 has a function of blowing off by-products that pass through the openings (first openings 41, 53) and rise up. The second air knife 7 has a function of blowing off by-products that cannot be avoided even by the first air knife 6. Furthermore, an internal pressure may be applied to the tip of the laser head 2 that irradiates the laser light L to suppress the intrusion of by-products into the laser head 2.

[0036] The first air knife 6 is disposed, for example, on the bottom plate 51 of the straightening plate 5, and has an ejection part 61 that ejects the supplied compressed air, and a nozzle part 62 that stabilizes the ejection direction of the compressed air. If the nozzle part 62 interferes with the laser light L, an opening for projecting the laser light L may be formed in the nozzle part 62.

[0037] The second air knife 7 is disposed at an upper stage closer to the laser head 2 than the first air knife 6. The second air knife 7 has a jetting portion 71 and a nozzle portion 72, similar to the first air knife 6. When the nozzle portion 72 interferes with the laser light L, an opening for projecting the laser light L may be formed in the nozzle portion 72.

[0038] The straightening vane 5 has a function of straightening the flow of the compressed air ejected from the first air knife 6, and also of limiting the induction of surrounding air to the rear (downstream) of the straightening vane 5.

[0039] The straightening plate 5 may have a thrust amplifier plate 55 that is disposed only forward in the ejection direction of the compressed air supplied from the first air knife 6 and that amplifies the thrust of the compressed air. The thrust amplifier plate 55 has, for example, a pointed end 55a formed so as to narrow the cross-sectional area of ​​the flow path of the compressed air from upstream to downstream, and a partition portion 55b disposed downstream of the pointed end 55a and that keeps the flow path of the compressed air divided into left and right.

[0040] Tip 55a has, for example, a substantially triangular prism shape and has a height corresponding to the compressed air supplied from first air knife 6. By arranging such tip 55a, the flow path cross-sectional area of ​​the compressed air can be gradually narrowed, and the flow velocity of the compressed air can be improved.

[0041] The partition portion 55b has, for example, a substantially rectangular prism shape and is formed at the same height as the tip 55a. By disposing the partition portion 55b, the flow of compressed air divided into left and right by the tip 55a can be maintained up to the rear (downstream) of the straightening plate 5, and the flow of compressed air can be stabilized. Note that the shape of the thrust amplifier plate 55 including the tip 55a and the partition portion 55b is not limited to the configuration shown in the figure.

[0042] The straightening plate 5 may also have an orifice 56 formed in a region including the pointed end 55a. The orifice 56 is a portion where the flow passage cross-sectional area of ​​the compressed air is partially narrowed. The orifice 56 may be formed by narrowing the interval between the side walls 52, or may be formed by adding a protrusion to the side walls 52. By forming such an orifice 56, the flow passage cross-sectional area of ​​the compressed air can be effectively gradually reduced by a synergistic effect with the pointed end 55a.

[0043] The straightening plate 5 may have a backflow prevention plate 57 disposed on the outer surface of the bottom plate 51 to suppress the backflow of air between the trailer house 4 and the straightening plate 5. The backflow prevention plate 57 has, for example, a pyramidal shape formed so that the cross-sectional area gradually increases from the upstream to the downstream. The shape of the backflow prevention plate 57 is not limited to the configuration shown in the figure.

[0044] By placing such a backflow prevention plate 57, an escape route can be created for air leaking from the first opening 41 and the second opening 42 of the trailer house 4, and air stagnating between the air straightening plate 5 can be removed.

[0045] The straightening plate 5 may have a plurality of exhaust ports 58 formed on the side wall 52 closer to the laser head 2 than the injection position of the compressed air supplied from the second air knife 7. By forming such exhaust ports 58, the flow rate of the compressed air can be adjusted. The size, shape, position, number, and other conditions of the exhaust ports 58 can be set arbitrarily.

[0046] The laser-arc hybrid welding apparatus 1 has a drive device 9 that moves the laser head 2, welding torch 3, trailer house 4, straightening plate 5, first air knife 6, and second air knife 7 along the welding direction. The laser head 2, welding torch 3, trailer house 4, and straightening plate 5 are integrated together by, for example, a bracket 91. The first air knife 6 and second air knife 7 are fixed to the straightening plate 5. For the sake of convenience of explanation, the bracket 91 is omitted from Figs. 2 and 3.

[0047] The driving device 9 may be, for example, an industrial robot that moves the bracket 91 along the welding direction, or may be a mobile cart. The driving device 9 can move the laser head 2, the welding torch 3, the trailer house 4, and the baffle plate 5 in the welding direction, thereby making the device more compact. Note that, although the components on the welding device side are moved in the welding direction in this embodiment, the workpiece 10 to be welded may be moved in the opposite direction to the welding direction.

[0048] According to the laser-arc hybrid welding apparatus 1 of this embodiment described above, the trailer house 4, the baffle plate 5, the first air knife 6 and the second air knife 7 can separate the molten metal from the air, thereby reducing the occurrence of blowholes and achieving sound welding quality.

[0049] The present invention is not limited to the above-described embodiment, and various modifications are possible without departing from the spirit of the present invention. [Explanation of symbols]

[0050] 1. Laser-arc hybrid welding equipment 2 Laser Head 3. Welding torch 4. Trailer House 5 Rectifier plate 6. First Air Knife 7. Second Air Knife 8. Inert gas supply equipment 9. Drive Unit 10 Welding object 11 Fixed base 21 Laser Oscillator 22 Light path 31 Filler metal supply device 32 Arc welding power source 41 First opening 42 Second opening 43 Skirt Club 51 Bottom plate 52 Side wall 53 First opening 54 Second opening 55 Thrust amplifier plate 55a Point 55b Partition 56 Orifice 57 Backflow prevention plate 58 Exhaust port 61,71 Spout part 62,72 Nozzle section 81 Nozzle 91 Bracket L Laser light P Welding W filler metal

Claims

1. In a laser-arc hybrid welding apparatus for welding aluminum alloys by using both laser welding and arc welding, a laser head that irradiates a laser beam onto a weld; a welding torch for supplying a filler metal to the weld; a trailer house that encloses the welding portion in a state in which the laser light irradiated from the laser head can be projected onto the welding portion and a tip of the welding torch can be inserted therethrough; a straightening plate disposed between the laser head and the trailer house and having a bottom plate extending in a welding direction and a pair of side walls; a first air knife that supplies compressed air along a longitudinal direction of the straightening plate; A second air knife is disposed between the first air knife and the laser head and supplies compressed air along a longitudinal direction of the air straightening plate; an inert gas supply device for supplying an inert gas into the trailer house; A laser-arc hybrid welding apparatus comprising:

2. 2. The laser-arc hybrid welding device according to claim 1, wherein the air straightening plate includes a thrust amplifier plate that is arranged only in front of the injection direction of the compressed air supplied from the first air knife and amplifies the thrust of the compressed air.

3. 3. The laser-arc hybrid welding device according to claim 2, wherein the thrust amplifier plate has a pointed end formed so as to narrow a flow passage cross-sectional area of ​​the compressed air from the upstream to the downstream.

4. 4. The laser-arc hybrid welding device according to claim 3, wherein the thrust amplifier plate has a partition portion disposed downstream of the pointed end portion and maintaining a state in which a flow path of the compressed air is divided into left and right portions.

5. The laser-arc hybrid welding apparatus according to claim 3 , wherein the current plate has an orifice formed in a region including the pointed end.

6. 2. The laser-arc hybrid welding apparatus according to claim 1, wherein the airflow straightening plate has a backflow prevention plate disposed on an outer surface of the bottom plate and suppressing a backflow of air between the trailer house and the airflow straightening plate.

7. 7. The laser-arc hybrid welding device according to claim 6, wherein the backflow prevention plate has a pyramidal shape formed so that a cross-sectional area gradually increases from the upstream to the downstream.

8. 2. The laser-arc hybrid welding apparatus according to claim 1, wherein the air straightening plate has a plurality of exhaust ports formed on the side wall closer to the laser head than an injection position of the compressed air supplied from the second air knife.

9. 2. The laser-arc hybrid welding apparatus of claim 1, wherein the trailer house has a heat resistant skirt portion that contacts a surface of the workpiece to be welded.

10. 2. The laser-arc hybrid welding apparatus of claim 1, further comprising a driving device that moves the laser head, the welding torch, the trailer house, the baffle plate, the first air knife, and the second air knife along a welding direction.

Images