CN111515540B - Laser fuse welding device and welding method for two sides of thin plate T-shaped joint - Google Patents

Abstract

A double-sided laser fuse welding device and a welding method for a thin plate T-shaped joint. The welding device includes two sets of welding components on both sides of a vertical plate. The welding components include a laser, a TIG welding gun and a TIG power supply. The junction of one side of the bottom plate forms a keyhole and a molten pool, and a fuse arc is formed between the welding wire and the end of the TIG welding torch. The fuse arc does not contact with the vertical plate, the bottom plate and the molten pool. The liquid metal enters the molten pool through the slit reserved between the vertical plate and the bottom plate. In the invention, arcs with low energy are respectively used on both sides of the vertical plate to melt the welding wire, another beam of high-energy laser melts the base metal to form a key hole, and the molten metal formed by melting the welding wire enters the key hole through the gap between the vertical plate and the bottom plate Internally, since the welding wire is melted by the arc of low energy and is far away from the keyhole, the impact on the keyhole can be avoided, the welding stability can be improved, and the welding seam quality can be improved.

Description

A kind of double-sided laser fuse welding device and welding method of thin plate T-joint

technical field

The invention relates to the technical field of laser welding, in particular to a double-sided laser fuse welding device and a welding method for a thin plate T-shaped joint.

Background technique

A T-joint is a T-shaped joint formed by welding a bottom plate and a vertical plate vertically arranged in the middle of the bottom plate. It is widely used in aviation, aerospace and other fields. Because laser welding has the advantages of large penetration depth, small deformation and high welding efficiency, it is used in thin plate T-joint welding. However, laser welding has a small tolerance for seam gap. When the gap is too large or the gap is uneven, welding defects such as breakdown and welding leakage are easy to occur, which affects the quality of the weld. Therefore, it is necessary to add welding wire to improve the gap between the seams. tolerance.

The Chinese patent "Laser Wire Filling Welding Method for Marine Aluminum Alloy T-Profiles" published on 2007.08.01 discloses a method of welding by using laser wire-filling welding process on one side of the vertical plate and the bottom plate. Welding is performed on the other side of the riser and base plate using the same laser wire filler welding process. However, this method of forming a T-joint by two times of welding not only has low welding efficiency, but also has many welding processes, which is prone to problems such as welding seam stress concentration and welding seam deformation, which affect the quality of the welding seam.

The Chinese patent "A T-joint Double-beam Filling Wire Welding Process Control Device and Welding Method", published on 2019.01.15, discloses a method for synchronizing two sets of laser wire filling welding devices respectively located on both sides of the vertical plate weld. welding. However, in this method, the laser beam not only needs to form a keyhole and a molten pool, but also needs to melt the welding wire, and when the welding aluminum alloy material is a solid welding wire, the reflectivity of the laser beam is very high, which not only reduces the welding efficiency, but also Affects the stability of the laser energy applied to the welded workpiece. Since this method requires a laser beam to melt the welding wire, the welding wire must be sent to the edge of the keyhole. After the welding wire is melted, the liquid metal is directly filled into the keyhole, which will cause impact on the keyhole, affect the stability of the keyhole, and even cause the keyhole to close. Welding bubbles are generated, and eventually weld pores are formed, which affects the quality of the weld. When performing high-speed welding, due to the fast welding speed and the small diameter of the laser beam spot (usually 0.2mm), the slight fluctuation of the welding wire will affect the melting effect of the welding wire. The undercut weld is poorly formed, which has a great impact on the weld quality.

SUMMARY OF THE INVENTION

In order to solve the problems that the welding wire is not fully melted and the keyhole fluctuation is large in the process of double-sided laser wire filling welding of thin plate T-shaped joints, which ultimately affects the quality of the welding seam, the invention provides a double-sided laser fuse wire welding device for thin plate T-shaped joints and Welding method, this welding method uses arcs with low energy to melt the welding wire on both sides of the vertical plate, another beam of high-energy laser melts the base metal to form a key hole, and the molten metal formed by melting the welding wire enters through the gap between the vertical plate and the bottom plate. into the keyhole, thus avoiding the impact on the keyhole and improving the stability of the keyhole and the quality of the welding seam.

The technical solution adopted by the present invention to solve the above technical problems is: a double-sided laser fuse welding device for a thin plate T-shaped joint, the welding device includes two sets of identical welding components, and when welding the T-shaped joint, the two sets of The welding assemblies are respectively located on both sides of the vertical plate, each set of welding assemblies includes a laser for generating laser beams, a TIG welding torch and a TIG power source, and the laser beams in each set of the welding assemblies are irradiated at the junction of one side of the vertical plate and the bottom plate, and A keyhole and a molten pool are formed there, the negative electrode of the TIG power source is connected to the TIG welding gun, and the positive electrode is connected to the welding wire, so that a fuse arc is formed between the welding wire and the end of the TIG welding gun, and the fuse arc is connected to the vertical plate, The bottom plate and the molten pool are not in contact, and the liquid metal formed by melting the welding wire enters the molten pool through the thin seam reserved between the vertical plate and the bottom plate.

As an optimized solution of the above welding device, the width of the slit reserved between the vertical plate and the bottom plate is 0.01-0.2 mm, so as to form a capillary attraction effect on the liquid metal formed by melting the welding wire.

As another optimization scheme of the above welding device, the distance between the fuse arc and the vertical plate is 3-5mm, the distance between the fuse arc and the bottom plate is 3-5mm, and the distance between the fuse arc and the molten pool is 0.2-1.6mm mm.

As another optimized solution of the above welding device, the welding speed of each group of the welding components is 6-20 m/min.

As another optimized solution of the above welding device, the wire feeding of the welding wire is controlled by a wire feeding mechanism.

The welding method of the above-mentioned thin-plate T-joint double-sided laser fuse welding device includes the following steps:

1) Surface treatment of vertical plates and bottom plates to remove surface impurities;

2) Place the vertical plate and the bottom plate into the shape of a T-joint and fix it with a welding jig, and ensure that there is a slit between the vertical plate and the bottom plate;

3) According to the above description, place two sets of welding components on both sides of the vertical plate, and then start the laser, TIG power supply and wire feeding mechanism for wire feeding welding.

As an optimized solution of the above welding method, during the welding, argon or helium is sprayed above the molten pool 7 as an anti-oxidation protective gas, and the gas flow is 10-30 L/min.

As an optimization scheme of the above welding method, during the welding, the distance D _LA between the laser beam and the tungsten needle of the TIG welding gun is 1-10 mm, the distance h ₁ between the TIG welding gun and the skin is 2-8 mm, the θ ₁ welding wire and the The included angle of the skin is 10°-60°, β ₁ is the angle between the TIG welding torch and the skin is 40°-80°, the angle α between the laser beam and the T-joint rib is 40°-80°, the welding wire and the T The included angle θ ₂ of the vertical rib of the T-type joint is 10°-60°, and the included angle β ₂ of the TIG welding torch and the vertical rib of the T-shaped joint is 40°-80°.

The equipment used in the present invention, such as laser, two TIG power sources, two TIG welding torches, base material (vertical plate and bottom plate), wire feeding device, protective gas device, etc., are all in the prior art. Laser type can choose Nd: YAG laser, CO ₂ laser, fiber laser.

The thin plate T-joint in the present invention refers to a T-shaped joint formed by welding a bottom plate and a vertical plate, and the thin plate means that the thickness of the bottom plate and the vertical plate does not exceed 5mm.

Compared with the prior art, the present invention has the following beneficial effects:

1) In the present invention, arcs with low energy are used on both sides of the vertical plate to melt the welding wire, another beam of high-energy laser melts the base metal to form a key hole, and the molten metal formed by melting the welding wire enters through the gap between the vertical plate and the bottom plate. In the keyhole, since the welding wire is melted by the arc of low energy and is far away from the keyhole, the impact on the keyhole can be avoided, the welding stability can be improved, and the welding seam quality can be improved;

2) Since a small gap is reserved between the vertical plate and the bottom plate before welding, the liquid metal formed after the arc generated between the TIG welding gun and the welding wire melts the welding wire can continuously flow into the molten pool by the capillary action of the gap. It has been melted before being sent into the molten pool, and high-speed welding can avoid the undercut weld formation on the surface of the weld caused by insufficient melting of the welding wire; and the reserved gap can also improve the penetration rate of the laser. In order to improve the utilization rate of laser energy and ensure the penetration of the weld;

3) Since the arc is generated between the TIG torch and the welding wire, the arc does not directly act on the welding base metal, which reduces the heat input to the base metal, greatly reduces the deformation of the joint, and makes the base metal weld microstructure and grain. Small and improved mechanical properties.

Description of drawings

Fig. 1 is the welding working principle schematic diagram of the present invention;

Figure 2 is a front view of the positional relationship between the TIG welding torch, the welding wire, the laser beam and the base plate;

Figure 3 is a left side view of the positional relationship between the TIG welding torch, welding wire, laser beam and vertical plate;

Figure 4 is a cross-section of the weld seam of a conventional double-sided laser wire filler welding process;

Fig. 5 is the weld seam cross section of the present invention;

Reference numerals: 1, laser beam, 2, TIG torch, 3, wire feeding mechanism, 4, welding wire, 5, fuse arc, 6, keyhole, 7, molten pool, 8, vertical plate, 9, bottom plate, 10 , TIG power supply.

Detailed ways

The technical solutions of the present invention will be further elaborated below in conjunction with specific embodiments. The parts that are not specifically described in the following embodiments of the present invention, such as the specific structures of lasers, TIG power sources, TIG welding guns, wire feeding mechanisms, etc., are all in the art The prior art known to the skilled person will not be repeated here.

Example 1

As shown in FIG. 1 , a double-sided laser fuse welding device for a thin plate T-shaped joint, the welding device includes two sets of identical welding components, and when welding the T-shaped joint, the two sets of welding components are located on two sides of the vertical plate 8 respectively. side, each set of welding assemblies includes a laser for generating a laser beam 1, a TIG welding gun 2 and a TIG power source 10, and the laser beam 1 in each set of the welding assemblies is irradiated at the junction of one side of the vertical plate 8 and the bottom plate 9, and at the A keyhole 6 and a molten pool 7 are formed at the place, the negative electrode of the TIG power source 10 is connected to the TIG welding torch 2, and the positive electrode is connected to the welding wire 4, so that a fuse arc 5 is formed between the welding wire 4 and the end of the TIG welding torch 2, and the welding The wire arc 5 is not in contact with the vertical plate 8 , the bottom plate 9 and the molten pool 7 , and causes the molten metal formed by melting the welding wire 4 to enter the molten pool 7 through the slit reserved between the vertical plate 8 and the bottom plate 9 .

The welding method of the above-mentioned thin-plate T-joint double-sided laser fuse welding device includes the following steps:

1) Surface treatment of vertical plate 8 and bottom plate 9 to remove surface impurities;

2) Place the vertical plate 8 and the bottom plate 9 into the shape of a T-joint and fix it with a welding fixture, and ensure that there is a slit between the vertical plate 8 and the bottom plate 9;

3) According to the above description, place the two sets of welding components on both sides of the vertical plate 8, and then start the laser, the TIG power supply 10 and the wire feeding mechanism for wire feeding welding.

Example 2

This embodiment is an optimized and limited solution to the solution of Embodiment 1. The width of the slit reserved between the vertical plate 8 and the bottom plate 9 is preferably 0.01-0.2 mm, so that the welding wire 4 is melted and formed. The liquid metal forms a capillary attraction effect.

In this embodiment, the width of the slit reserved between the vertical plate 8 and the bottom plate 9 is more preferably 0.01-0.1 mm.

Example 3

This embodiment is another optimized and limited solution to the solution of Embodiment 1. The distance between the fuse arc 5 and the vertical plate 8 is 3-5mm, and the distance between the fuse arc 5 and the bottom plate 9 is 3-5mm. The distance between the fuse arc 5 and the molten pool 7 is 0.2-1.6 mm.

Example 4

This embodiment is another optimized and limited solution to the solution of Embodiment 1. The welding speed of each group of the welding components is 6-20 m/min. Compared with the prior art, the welding speed is obviously improved.

Example 5

This embodiment is another optimized and limited solution to the solution of Embodiment 1. The wire feeding of the welding wire 4 is controlled by the wire feeding mechanism 3 .

Example 6

This embodiment is another optimized and limited solution to the solution of Embodiment 1. During the welding, argon or helium is sprayed above the molten pool 7 as an anti-oxidation protective gas, and the gas flow rate is 10-30L/min .

Example 3

This embodiment is another optimized and limited solution to the solution of Embodiment 1. During the welding, as shown in Figures 2 and 3, the distance D _LA between the laser beam 1 and the tungsten needle of the TIG welding torch 2 is 1-10 mm, The distance _h1 between the TIG welding torch 2 and the bottom plate 9 is 2-8 mm, the included angle _θ1 between the welding wire 4 and the bottom plate 9 is 10°-60°, and the included angle β1 between the TIG welding torch 2 and the bottom plate ₉ is 40°-80°, The included angle α between the laser beam 1 and the vertical plate 8 is 40°-80°, the included angle θ2 between the welding wire 4 and the vertical plate ₈ is 10°-60°, and the included angle β2 between the TIG welding torch ₂ and the vertical plate 8 is 40° °-80°.

Comparative Experiment:

Compared with the welding method of the present invention, the conventional double-sided laser wire filling welding process is used to weld the T-joint. Under the same welding parameters, the cross-sections of the two welds are shown in Figures 4 and 5, respectively. It can be clearly seen from the figure that the welding seam of the conventional welding method is asymmetrical and has undercut defects (mainly because the welding wire needs the energy of the laser beam to melt, so the welding wire is generally sent to the edge of the keyhole, which will cause damage to the keyhole. Shock creates weld defects and affects the stability of laser energy delivery), while the welds of the present invention form well.

Claims (6)

1. The utility model provides a two side laser fuse welding set of sheet metal T type joint, this welding set include two sets of the same welding subassemblies, and when the welding T type connects, these two sets of welding subassemblies are in the both sides of riser (8) respectively, and every set of welding subassembly includes laser instrument, TIG welder (2) and TIG power (10) that produce laser beam (1), its characterized in that: laser beams (1) in each set of welding assembly irradiate the joint of one side of the vertical plate (8) and one side of the bottom plate (9) and form a keyhole (6) and a molten pool (7) at the joint, the negative electrode of the TIG power supply (10) is connected with the TIG welding gun (2), and the positive electrode of the TIG power supply is connected with the welding wire (4), so that a fuse wire electric arc (5) is formed between the welding wire (4) and the end part of the TIG welding gun (2), the fuse wire (5) is not in contact with the vertical plate (8), the bottom plate (9) and the molten pool (7), and liquid metal formed by melting the welding wire (4) enters the molten pool (7) through a reserved slit between the vertical plate (8) and the bottom plate (9); the width of a reserved slit between the vertical plate (8) and the bottom plate (9) is 0.01-0.2mm, so that the slit can form a capillary attraction effect on liquid metal formed by melting the welding wire (4); the distance between the fuse wire electric arc (5) and the vertical plate (8) is 3-5mm, the distance between the fuse wire electric arc (5) and the bottom plate (9) is 3-5mm, and the distance between the fuse wire electric arc (5) and the molten pool (7) is 0.2-1.6 mm.

2. The double-sided laser fuse welding device for the T-shaped joint of the thin plate as claimed in claim 1, wherein: the welding speed of each group of welding assemblies is 6-20 m/min.

3. The double-sided laser fuse welding device for the T-shaped joint of the thin plate as claimed in claim 1, wherein: the welding wire (4) is controlled by the wire feeding mechanism (3) to feed wires.

4. The welding method of the double-sided laser fuse welding device for the T-shaped joints of the thin plates as claimed in claim 1, characterized by comprising the following steps:

1) carrying out surface treatment on the vertical plate (8) and the bottom plate (9) to remove surface impurities;

2) the vertical plate (8) and the bottom plate (9) are placed into a T-shaped joint shape and fixed by a welding fixture, and a thin seam is reserved between the vertical plate (8) and the bottom plate (9);

3) two groups of welding assemblies are arranged on two sides of a vertical plate (8), and then a laser, a TIG power supply (10) and a wire feeding mechanism (3) are started to carry out wire feeding welding.

5. The welding method of the double-sided laser fuse welding device for the T-shaped joints of the thin plates as claimed in claim 4, wherein: during welding, argon or helium is sprayed above the molten pool (7) as an anti-oxidation protective gas, and the gas flow is 10-30L/min.

6. The welding method of the double-sided laser fuse welding device for the T-shaped joints of the thin plates as claimed in claim 4, wherein: During welding, the distance D between the laser beam (1) and the tungsten needle of the TIG welding gun (2)_LA1-10mm, and the distance h between the TIG welding gun (2) and the bottom plate (9)₁2-8mm, and the included angle theta between the welding wire (4) and the bottom plate (9)₁Is 10-60 degrees, and the included angle beta of the TIG welding gun (2) and the bottom plate (9)₁Is 40 degrees to 80 degrees, the included angle alpha between the laser beam (1) and the vertical plate (8) is 40 degrees to 80 degrees, and the included angle theta between the welding wire (4) and the vertical plate (8)₂10 degrees to 60 degrees, and the included angle beta between the TIG welding gun (2) and the vertical plate (8)₂Is 40-80 degrees.

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