Compressing and shielding gas device for laser welding

Abstract

The utility model relates to the technical field of aluminum alloy laser welding, in particular to a pressing and shielding gas device for laser welding. Comprising a pressing block, and a plurality of through grooves penetrating through the pressing block are formed in the pressing block; a laser beam penetrates through the through groove to weld the welding seam, the structure replaces a traditional linear pressing block, the periphery of the through groove presses and fixes the welding seam in an annular mode, the attaching degree of a stacked welding head is increased, the assembling gap is effectively reduced, and the problems of welding leakage, poor surface and the like caused by the fact that the upper plate is too thin and the assembling gap is large are solved. The pressing block is of a cavity structure with the hollow interior, the protective gas holes are formed in the side wall of the through groove, protective gas is introduced into the cavity of the pressing block and output through the protective gas holes, a welding seam is protected in the welding process, a protective gas device does not need to be additionally arranged, and interference between the protective gas device and a tool is avoided. And the structure can be turned over at multiple angles according to the tool, and the applicability is high.

Description

Technical Field

[0001] The utility model relates to the technical field of aluminum alloy laser welding, in particular to a pressing and protective gas device for laser welding. Background Art

[0002] Many welding structures on the aluminum alloy body-in-white are made of thin plate lap joints, such as door panels, floors, front cabin water troughs and other parts. Lap joints are mostly produced by laser welding. Compared with traditional arc welding, laser welding has the advantages of high energy density, high welding efficiency, and low heat input. It is a high-quality and efficient welding method, but it requires strict assembly accuracy. The current lap joint clamping device mostly uses tooling to clamp at both ends of the weld area. The clamping area is two-point and has a small effective area. When the tooling interferes with the shielding gas exhaust in the laser welding mechanism, the welding position cannot be reached, and the weld cannot be protected, affecting the surface quality of the weld.

[0003] Chinese utility model patent CN201645047U (utility model name: welding equipment for thin plate lap welding; authorization announcement date: 2010.11.24) discloses a welding equipment for thin plate lap welding, wherein clamping devices are respectively provided on both sides of the welding head, and the clamping devices realize the clamping and relaxation of the welding workpiece, and the clamping device comprises a pressing roller and a pressing beam, the pressing beam comprises a front pressing beam and a rear pressing beam, and the pressing roller comprises a front pressing roller and a rear pressing roller, and the clamping and relaxation of the welding workpiece by the pressing roller and the pressing beam are controlled by a hydraulic system. This technical solution adopts a one-line tooling clamping method, which increases the clamping area compared to the traditional end-point clamping. However, there is still an assembly gap in the edge area of ​​the joint surface of the two plates. Since the upper plate is too thin, defects such as welding leakage and burn-through are prone to occur during the single laser welding process, which increases the defective rate of finished products and the repair cost. In addition, the device is not equipped with a shielding gas exhaust. If a movable shielding gas device is added at the weld, it is easy to interfere with the tooling and cannot be flipped together with the tooling. It is impossible to ensure that the shielding gas outlet direction is directly opposite to the weld direction, and it cannot be used for welding methods at different angles. Utility Model Content

[0004] In order to solve the problem of weld leakage that is easy to occur in the form of overlapped welding joints during the aluminum alloy laser welding process in the prior art and to solve the problem of improper shielding gas protection, the utility model provides a clamping and shielding gas device for laser welding, including a clamping block, the clamping block is provided with a plurality of through grooves penetrating the clamping block, the clamping block is connected to one end of a clamping arm, and the other end of the clamping arm is connected to a cylinder.

[0005] The compression block is a hollow cavity structure, and the side wall of the through groove is provided with a plurality of protective air holes, which communicate the inside and outside of the compression block;

[0006] The pressing arm is also fixedly connected with a protective gas pipe, one end of the protective gas pipe is connected with the pressing block and interconnected, and the other end of the protective gas pipe is connected with a protective gas flow regulating valve.

[0007] The plurality of protective air holes are evenly arranged on the side wall of the through groove.

[0008] Beneficial effects of the utility model:

[0009] (1) The device is provided with a clamping block, and a through groove is provided on the clamping block. The laser beam passes through the through groove to weld the weld. This structure replaces the traditional "I"-shaped clamping block. The weld is clamped and fixed in a ring manner around the through groove, thereby increasing the fit of the overlapped welding joint and effectively reducing the assembly gap, thereby avoiding problems such as welding leakage and surface defects caused by the upper plate being too thin and the assembly gap being large.

[0010] (2) The clamp block adopts a hollow cavity structure, and the side wall of the through groove is provided with a protective gas hole. The protective gas is passed into the cavity of the clamp block and discharged from the protective gas hole, which protects the weld during the welding process. There is no need to add an additional protective gas device to avoid interference between the protective gas device and the tooling. In addition, the structure can be flipped at multiple angles according to the tooling, and has strong applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 Schematic diagram of the structure of the clamping and shielding gas device used for laser welding;

[0012] Figure 2 Schematic diagram of the through slot structure;

[0013] Figure 3 Schematic diagram of welding assembly device and aluminum alloy product structure;

[0014] Figure 4 Schematic diagram of welding assembly device and aluminum alloy product assembly;

[0015] Figure 5 Schematic diagram of welding process for aluminum alloy products;

[0016] Figure 6 Schematic diagram of the laser welding device.

[0017] Reference numerals:

[0018] 1-Compression and protective gas device for laser welding; 11-Compression block; 12-Pressure arm; 13-Cylinder; 14-Protective gas pipe; 15-Protective gas flow regulating valve; 16-Through groove; 17-Protective air hole;

[0019] 2-welding assembly device; 21-tooling base, 22-pneumatic tightening device, 23-limiting block;

[0020] 3-laser welding device; 31-laser welding head; 32-online detection module; 33-focusing lens module; 34-optical fiber;

[0021] 4-aluminum alloy product; 41-frame; 42-crossbeam 1; 43-crossbeam 2; 44-cover plate. DETAILED DESCRIPTION

[0022] The technical solution will be further described in detail below in combination with the accompanying drawings and specific implementation methods of the present utility model.

[0023] See attached Figure 1 , 2 The utility model provides a clamping and shielding gas device 1 for laser welding, including a clamping block 11. The clamping block 11 is a cavity structure with a hollow interior. The clamping block 11 is provided with a plurality of through slots 16 penetrating the clamping block 11. The number of through slots 16 is set according to the size of the weld. The side wall of the through slot 16 is provided with a plurality of shielding gas holes 17. The plurality of shielding gas holes 17 are evenly arranged on the side wall of the through slot 16. The shielding gas holes 17 communicate with the interior and the exterior of the clamping block 11.

[0024] The clamping block 11 is connected to one end of the clamping arm 12, and the other end of the clamping arm 12 is connected to the cylinder 13. The cylinder 13 adopts the existing technical structure, which can drive the clamping arm 12 and the clamping block 11 to move, realize the clamping and opening and closing actions, and play the role of applying clamping force to the workpiece.

[0025] The pressing arm 12 is also fixedly connected with a shielding gas pipe 14, one end of which is connected to the pressing block 11, and the other end of which is connected to a shielding gas flow regulating valve 15, which is connected to a shielding gas cylinder. When the shielding gas flow regulating valve 15 is opened, the shielding gas in the shielding gas cylinder is sequentially transported to the cavity of the pressing block 11 through the shielding gas flow regulating valve 15 and the shielding gas pipe 14, and then discharged through the shielding gas hole 17, thereby protecting the weld. The shielding gas flow regulating valve 15 adopts the existing technical structure, and can adjust the shielding gas flow according to the requirements of the welding process, thereby increasing adaptability.

[0026] See attached Figure 3-6 , with Figure 3 , 4 The aluminum alloy product 4 in the example is used to explain the principle and welding process of the device; Figure 3 , 4The aluminum alloy product 4 includes a frame 41, a beam 1 42, a beam 2 43, and a cover plate 44. The frame 41 and the beam 1 42 and the beam 2 43 are welded together in the previous process. In the embodiment, the cover plate 44 needs to be welded to the beam 1 42 and the beam 2 43. The welding assembly device 2 used in this embodiment is a prior art structure, including a tooling base 21, a pneumatic tightening device 22, and a limit block 23. See the attached Figure 6 The laser welding device 3 used in this embodiment is a prior art structure, including a laser welding head 31, an online detection module 32, a focusing lens module 33, and an optical fiber 34. The online detection module 32 is used to detect the surface and internal quality of the weld online, which is convenient for analyzing the quality defects of the weld; the focusing lens module 33 is used to refract the laser beam into a light spot with concentrated energy; and the optical fiber 34 is used to transmit the laser. The welding process of this process is as follows:

[0027] First, the tooling base 21 is placed within the working range of the welding robot, and the limit block 23 and the pneumatic tightening device 22 are fixed by tightening the bolts.

[0028] Then, fit the frame 41 with the limit block 23, use the pneumatic tightening device 22 to tighten and fix the frame 41, assemble the cover plate 44 with the frame 41, control the cylinder 13 to move, and the pressing arm 12 drives the pressing block 11 to press and fix the cover plate 44. After pressing and fixing, the position of the pressing block 11 corresponds to the position of the weld, so that the fit between the overlapped welded plates is tighter.

[0029] Restart the laser welding device 3. During welding, the high-energy-density laser beam emitted by the laser welding head 31 passes through the through slot 16 and irradiates the area to be welded, so that the parent material is directly melted to form a weld. This device is suitable for laser self-melting welding, and the welding direction is not restricted. At the same time, the shielding gas is output to the welding area through the shielding gas hole 17 to protect the weld, ensure that the molten pool is filled with shielding gas, and suppress the scattering effect of metal vapor and plasma on the laser. The gas flow rate can be adjusted by the shielding gas flow regulating valve 22 to ensure the formation of the weld. The laser self-melting welding power is 3500~5500W, the defocusing amount is -4~+4, the welding speed is 2.0~5.5m / min, and the shielding gas flow rate is 10~30L / min.

[0030] After welding one side of the aluminum alloy product 4 is completed, the robot is moved to a safe area, the clamping and protective gas device 1 for laser welding is turned on, the pneumatic clamping device 22 is turned on, the aluminum alloy product 4 is turned over to the other side, and welding is performed again according to step 2. After welding is completed, the aluminum alloy product 4 is removed.

[0031] During the entire welding production process, the welding dimensions are detected by the online detection module 32 and the position of the welded parts is accurately recorded and archived, thereby realizing online detection of the welded parts.

Claims

1. A compression and protective gas device for laser welding, characterized in that: The invention comprises a pressing block (11), wherein the pressing block (11) is provided with a plurality of through slots (16) penetrating the pressing block (11), the pressing block (11) is connected to one end of a pressing arm (12), and the other end of the pressing arm (12) is connected to a cylinder (13).

2. A compression and protective gas device for laser welding according to claim 1, characterized in that: The pressing block (11) is a hollow cavity structure, and the side wall of the through groove (16) is provided with a plurality of protective air holes (17), and the protective air holes (17) communicate with the inside and outside of the pressing block (11); The pressing arm (12) is also fixedly connected to a protective gas pipe (14); one end of the protective gas pipe (14) is connected to the pressing block (11) and is interconnected; the other end of the protective gas pipe (14) is connected to a protective gas flow regulating valve (15).

3. A pressing and shielding gas device for laser welding according to claim 2, characterized in that: The plurality of protective air holes (17) are evenly arranged on the side wall of the through groove (16).

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