Laser welding apparatus and method

Abstract

The application relates to a laser welding device and method, and belongs to the technical field of welding engineering. The laser welding device comprises a workbench and a laser assembly. The laser assembly comprises a fixing base, an extension arm and a laser. The workbench is configured to place a workpiece to be welded, and a first preset angle is formed between the workpiece to be welded and a horizontal plane. The fixing base is installed on the workbench. One end of the extension arm is hinged to the fixing base, and the other end of the extension arm is hinged to the laser. The laser is arranged above the workpiece to be welded. A second preset angle is formed between a laser beam emitted by the laser and a normal line of the workpiece to be welded. By adjusting the first preset angle and the second preset angle of the workpiece to be welded, the downward flow speed of the molten pools on the front side, left side and right side of a small hole is greatly reduced during laser welding, the volume of the molten pools sprayed from the bottom is greatly reduced, the formation of hump at the root of the weld is avoided, the collapse of the weld is prevented, and the influence of the weld on the workpiece is reduced.

Description

Technical Field

[0001] This application belongs to the field of welding engineering technology, specifically relating to a laser welding apparatus and method. Background Technology

[0002] Current welding technologies mainly include arc welding, gas shielded welding, laser welding, and friction welding. Among them, laser welding technology is the most widely used, with advantages such as fast heating speed, small welding deformation, and high processing flexibility.

[0003] In existing technologies, such as Figure 1 and Figure 2 As shown, two workpieces 100 to be welded are placed flat on the worktable. The laser is located on top of the workpieces to be welded. The laser beam acts vertically on the joint of the two workpieces 100 to be welded. When welding, the welding direction is +X. The laser penetrates the joint of the two workpieces 100 to be welded, causing the welding plates at the joint to melt together. After cooling, the shape is set and the welding is completed.

[0004] In the above scheme, under the action of the laser beam, the surface of the joint is sunken to form a keyhole (also known as a small hole). The reaction force F of the steam in the small hole 400 and the gravity G of the molten pool cause the molten pool on the front, left and right sides of the small hole 400 to flow downward along the hole wall, thereby forming a weld hump 900 at the root of the weld 600, which leads to weld collapse and affects the welding effect. Summary of the Invention

[0005] This application provides a laser welding apparatus and method to solve the problem in the prior art where, when workpieces are welded using laser welding technology, a weld hump forms at the root of the weld due to the action of welding steam and gravity, causing the weld to collapse and affecting the welding effect.

[0006] In a first aspect, this application provides a laser welding apparatus, which includes a workpiece to be welded, a worktable, and a laser assembly, wherein the laser assembly includes a fixed base, a telescopic arm, and a laser.

[0007] The workpiece to be welded is configured to be placed on the worktable, and the workpiece to be welded has a first preset angle with the horizontal plane;

[0008] The fixed base is mounted on the workbench. One end of the telescopic arm is hinged to the fixed base, and the other end of the telescopic arm is hinged to the laser. The workpiece to be welded is located below the laser. By rotating the laser, a second preset angle is formed between it and the normal of the workpiece to be welded.

[0009] The embodiments provided in this application also include a positioning component, which includes a base, a cylinder, a positioning plate, and a clamping plate;

[0010] Both the base and the cylinder are mounted on the worktable. One end of the positioning plate is hinged to the base, and the end of the positioning plate away from the fixed seat is hinged to the cylinder. The positioning plate is used to mount the workpiece to be welded. The first preset angle between the workpiece to be welded and the worktable is adjusted by adjusting the extension and retraction of the cylinder.

[0011] In the embodiments provided in this application, a jet assembly is also included, which includes an air tank and a nozzle connected to the air tank. The air tank is mounted on the worktable, and the nozzle is mounted on the laser.

[0012] In the embodiments provided in this application, the first preset included angle is 10-90 degrees, the second preset included angle is 5-45 degrees, and the sum of the first preset included angle and the second preset included angle is greater than 90 degrees.

[0013] Secondly, this application also provides a laser welding method applied to the laser welding apparatus described in the first aspect, comprising the following steps:

[0014] Two workpieces to be welded are mounted on the workbench, and the two workpieces to be welded have a first preset angle with the horizontal plane;

[0015] The laser that controls the laser welding device emits a laser beam, which is used to weld two workpieces to be welded, wherein the laser beam has a second preset angle with the normals of the two workpieces to be welded.

[0016] In the embodiments provided in this application, mounting the two workpieces to be welded on the worktable includes:

[0017] The two workpieces to be welded are placed flat on the workbench, which is an inclined plane and has a first preset angle with the horizontal plane, wherein the first preset angle is 10-90 degrees.

[0018] In the embodiments provided in this application, mounting the two workpieces to be welded on the worktable includes:

[0019] The workbench is provided with a positioning component, and the two workpieces to be welded are mounted on the positioning component. The positioning component makes the workpieces to be welded have a first preset angle with the horizontal plane, wherein the first preset angle is 10-90 degrees.

[0020] In the embodiments provided in this application, controlling the laser beam to weld the two workpieces includes:

[0021] The two workpieces to be welded are welded by controlling the welding power, welding speed, defocusing amount and oscillation amplitude of the laser beam;

[0022] The welding power is 1-2kW, the welding speed is 1-2m / min, the defocusing amount is 0-5mm, and the oscillation amplitude is 0-2mm.

[0023] In the embodiments provided in this application, the second preset angle is 5-45 degrees, the sum of the first preset angle and the second preset angle is greater than 90 degrees, and the sum of the first preset angle and the second preset angle is greater than 90 degrees.

[0024] In the embodiments provided in this application, controlling the laser beam to weld the two workpieces includes:

[0025] When controlling the laser beam to weld the two workpieces to be welded, a protective gas is blown onto the workpieces to be welded.

[0026] This application provides a laser welding apparatus and method. The laser welding apparatus includes a worktable and a laser assembly. The laser assembly includes a fixed base, a telescopic arm, and a laser. The worktable is configured to hold a workpiece to be welded, with the workpiece having a first preset angle with the horizontal plane. The fixed base is mounted on the worktable. One end of the telescopic arm is hinged to the fixed base, and the other end of the telescopic arm is hinged to the laser. The laser is positioned above the workpiece, and the laser beam emitted by the laser has a second preset angle with the normal of the workpiece. By adjusting the workpiece to have the first preset angle with the worktable and adjusting the laser beam to have the second preset angle with the normal of the workpiece, the resultant force of the laser beam acting on the molten pools on the front and left / right sides of the small hole in the workpiece is reduced. Consequently, the downward flow velocity of the molten pools on the front and left / right sides of the small hole is greatly slowed down, and the volume of the molten pool ejected from the bottom is significantly reduced. This avoids the formation of a hump at the weld root, prevents weld collapse, and reduces the impact of the weld on the workpiece. Attached Figure Description

[0027] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0028] Figure 1 This image shows the effect of laser welding causing weld seam collapse in a workpiece in the prior art.

[0029] Figure 2 for Figure 1 A diagram showing the effect of weld seam collapse on a workpiece from another angle;

[0030] Figure 3 This is a schematic diagram of the laser welding apparatus proposed in this application;

[0031] Figure 4 for Figure 3 Top view of the laser welding device after removing the laser assembly and jet assembly;

[0032] Figure 5 This is a flowchart of the laser welding method proposed in this application;

[0033] Figure 6 This is a schematic diagram of the structure of the workpiece to be welded using the laser welding method of this application;

[0034] Figure 7 for Figure 6 A structural schematic diagram of the workpiece to be welded from another angle;

[0035] Figure 8 This is a cross-sectional view of the weld obtained using the laser welding method described in this application.

[0036] Figure label:

[0037] 100 - Workpiece to be welded;

[0038] 200-laser beam;

[0039] 300-nozzle;

[0040] 400-small hole;

[0041] 500 - Base Material;

[0042] 600 - Weld;

[0043] 700-front molten pool;

[0044] 800-after molten pool;

[0045] 900 - Weld hump;

[0046] 1000-Workbench;

[0047] 1100 - Laser assembly; 1110 - Mounting base; 1120 - Telescopic arm; 1130 - Laser;

[0048] 1200 - Positioning component; 1210 - Base; 1220 - Cylinder; 1230 - Positioning plate; 1240 - Clamping plate; 1250 - Through hole;

[0049] 1300 - Jet assembly; 1310 - Gas tank.

[0050] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0051] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0052] The terms "first," "second," "third," "fourth," etc. (if present) in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of the invention described herein can be implemented, for example, in orders other than those illustrated or described herein.

[0053] In this application, the terms "exemplary" or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary" or "for example" in this application should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of terms such as "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0054] In the description of the embodiments of this application, it should be understood that the terms "inner", "outer", "upper", "bottom", "front", "rear", etc., indicate the orientation or positional relationship (if any) based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0055] Current welding technologies mainly include arc welding, gas shielded welding, laser welding, and friction welding. Among them, laser welding technology is the most widely used, with advantages such as fast heating speed, small welding deformation, and high processing flexibility.

[0056] For existing welding methods, such as Figure 1 and Figure 2 As shown, where Figure 1 This image shows the effect of laser welding causing weld seam collapse in a workpiece in the prior art. Figure 2 for Figure 1 The image shows the effect of the weld seam collapsing on the workpiece from another angle.

[0057] In the prior art, in order to weld two workpieces 100 together, the two workpieces 100 are usually placed flat on the worktable 100 and laser welding is performed on the joint to complete the welding of the two workpieces 100.

[0058] In this method, the welding direction is as follows: Figure 1 In the +X direction, the laser beam 200 melts the base material 500 to form a molten pool. The molten pool sinks to form a small hole 400. The molten pool at the front end of the small hole 400 is the front molten pool 700, and the molten pool at the rear end of the small hole 400 is the rear molten pool 800. The flow direction of the molten pool is the +Y direction. Due to the effect of the laser beam 200 (the energy of the laser beam 200 will not penetrate the bottom of the weld 600), the front molten pool 700 and the molten pools on the left and right sides flow downward under the action of gravity. The molten pool that flows to the bottom will flow backward to form the rear molten pool 800. After the rear molten pool 800 cools, it forms the weld 600, completing the welding.

[0059] However, in the above technical solution, when the molten pool flows to the bottom of the orifice 400, it will sink downward under the action of the molten pool's own gravity G and the reaction force F of the steam in the orifice 400, thus forming a weld hump 900 at the root of the weld 600, causing the weld 600 to collapse and affecting the use of the welded part.

[0060] In summary, this application proposes a laser welding apparatus and method to solve the problem in the prior art where, when welding workpieces using laser welding technology, a weld hump 900 forms at the root of the weld 600 due to the action of welding steam and gravity, causing the weld 600 to collapse and affecting the welding effect. The application will now be described in detail with reference to the accompanying drawings.

[0061] in, Figure 3 This is a schematic diagram of the laser welding apparatus proposed in this application; Figure 4 for Figure 3 Top view of the laser welding device after removing the laser assembly and jet assembly; Figure 5 This is a flowchart of the laser welding method proposed in this application; Figure 6 This is a schematic diagram of the structure of the workpiece to be welded using the laser welding method of this application; Figure 7 for Figure 6 A structural schematic diagram of the workpiece to be welded from another angle; Figure 8 This is a cross-sectional view of the weld obtained using the laser welding method described in this application.

[0062] In the above schematic diagram, F represents the reaction force of the vapor from the laser beam 200 on the molten pool, G represents the gravity of the molten pool, α represents the first preset angle, β represents the second preset angle, +X represents the direction of movement of the laser beam 200, and +Y represents the flow direction of the molten pool. This is the distance between the top of weld 600 and the upper surface of the workpiece 100 to be welded. This is the distance between the bottom of weld 600 and the upper surface of the workpiece 100 to be welded.

[0063] like Figure 3 , Figure 4 and Figure 6 As shown, this application also provides a laser welding apparatus, including a worktable 1000 and a laser assembly 1100. The laser assembly 1100 includes a fixed base 1110, a telescopic arm 1120 and a laser 1130.

[0064] The workbench 1000 is configured to place the workpiece 100 to be welded, and to make the workpiece 100 to be welded have a first preset angle with the horizontal plane.

[0065] The fixed base 1110 is mounted on the workbench 1000. One end of the telescopic arm 1120 is hinged to the fixed base 1110, and the other end of the telescopic arm 1120 is hinged to the laser 1130. The laser 1130 is positioned above the workpiece 100 to be welded, and the laser beam 200 emitted by the laser 1130 has a second preset angle between it and the normal of the workpiece 100 to be welded.

[0066] By adjusting the workpiece 100 to have a first preset angle with the worktable 1000, and adjusting the laser 1130 to have a second preset angle with the normal of the workpiece 100, the combined force of the laser 1130 acting on the front and left and right sides of the molten pool on the small hole 400 of the workpiece 100 is reduced. As a result, the downward flow speed of the molten pool on the front and left and right sides of the small hole 400 is greatly slowed down, and the volume of the molten pool ejected from the bottom is greatly reduced. This avoids the formation of a hump at the root of the weld 600, prevents the weld from collapsing, and reduces the impact of the weld on the workpiece.

[0067] The first preset angle is set to 10-90 degrees, the second preset angle is set to 5-45 degrees, and the sum of the first preset angle and the second preset angle is greater than 90 degrees.

[0068] The laser welding device also includes a positioning assembly 1200, which includes a base 1210, a cylinder 1220, a positioning plate 1230, and a clamping plate 1240.

[0069] The base 1210 and the cylinder 1220 are both mounted on the worktable 1000. One end of the positioning plate 1230 is hinged to the base 1210, and the end of the positioning plate 1230 away from the fixed seat 1110 is hinged to the cylinder 1220. The workpiece 100 to be welded is mounted on the positioning plate 1230. The first preset angle between the workpiece 100 to be welded and the worktable 1000 is adjusted by adjusting the extension and retraction of the cylinder 1220.

[0070] The laser welding device described above uses a mounting and positioning component 1200 to rotate the workpiece 100 to be welded, so that the workpiece 100 to be welded has a first preset angle with the horizontal plane.

[0071] The workpieces to be welded 100 are two flat plates with a thickness of 3mm. The two workpieces to be welded 100 are placed flat on the positioning plate 1230 and joined together. The clamping plate 1240 is installed on the top of the two workpieces to be welded 100. The bolts pass through the through hole 1250 on the clamping plate 1240 and connect to the blind hole (not shown in the figure) on the worktable 1000 to fix the workpieces to be welded 100.

[0072] Since the clamping plate 1240 in the above technical solution only needs to clamp part of the workpiece 100 to be welded, it can be applied to workpieces 100 of different sizes.

[0073] The cylinder 1220 located at the bottom of the positioning plate 1230 causes the positioning plate 1230 to rotate around the base 1210 by extension and retraction. The tilt angle of the positioning plate 1230 is the first preset included angle of the workpiece 100 to be welded.

[0074] It should be noted that, in order to avoid the positioning plate 1230 affecting the weld 600 of the workpiece 100 to be welded, a relief groove is provided in the middle of the positioning plate 1230, and the relief groove is located at the bottom of the joint of the two workpieces 100 to be welded.

[0075] The laser assembly 1100 is installed next to the positioning assembly 1200. The height of the fixed base 1110 is higher than the height of the base 1210. The telescopic arm 1120 installed on the base 1210 can rotate along the base 1210, and the rotation direction is towards the workpiece 100 to be welded. A laser 1130 is provided at the end of the telescopic arm 1120 away from the base 1210. The laser 1130 can rotate along the telescopic arm 1120, and the rotation direction of the laser 1130 is also towards the workpiece 100 to be welded.

[0076] In the embodiments provided in this application, a jet assembly 1300 is also included. The jet assembly 1300 includes an air tank 1310 and a nozzle 300 connected to the air tank 1310. The air tank 1310 is mounted on the worktable 1000, and the nozzle 300 is mounted on the laser 1130.

[0077] The gas storage tank 1310 and the nozzle 300 are connected by a gas supply pipe.

[0078] Combined with, for example Figure 5 and Figure 6 As shown, the laser welding method provided in this application includes the following steps:

[0079] S101. Two workpieces 100 to be welded are mounted on the worktable 1000, and the two workpieces 100 to be welded have a first preset angle with the horizontal plane.

[0080] S102. Control the laser beam 200 to weld the two workpieces 100 to be welded, wherein the laser beam 200 and the two workpieces 100 to be welded have a second preset angle.

[0081] In the above two steps, by adjusting the workpiece 100 to have a first preset angle with the worktable 1000, and adjusting the laser beam 200 to have a second preset angle with the workpiece 100, the combined force of the laser beam 200 acting on the front and left and right sides of the molten pool on the small hole 400 of the workpiece 100 is reduced. As a result, the downward flow speed of the molten pool on the front and left and right sides of the small hole 400 is greatly slowed down, and the volume of the molten pool ejected from the bottom is greatly reduced. This avoids the formation of a weld hump 900 at the root of the weld 600, prevents the weld 600 from collapsing, and reduces the impact of the weld 600 on the workpiece.

[0082] The workbench 1000 can be a fixed welding workbench 1000, a mobile welding workbench 1000, a rotary welding workbench 1000, a lifting welding workbench 1000, or a multi-functional swing arm welding workbench 1000, depending on the actual operation requirements.

[0083] The laser beam 200 can be a carbon dioxide laser beam 200, a solid-state laser beam 200, a carbon monoxide laser beam 200, or a fiber laser beam 200.

[0084] In the embodiments provided in this application, before welding the workpiece 100, an organic solvent is used to remove impurities from the upper and lower surfaces and the mating end faces of the base material 500 to avoid impurities affecting the welding effect. The thickness of the workpiece 100 used for welding is 0.5-3 mm.

[0085] like Figure 6 and Figure 7 As shown, in the embodiment provided in this application, two workpieces 100 to be welded are mounted on a workbench 1000, including: placing the two workpieces 100 to be welded flat on the workbench 1000, the workbench being an inclined plane and having a first preset angle with the horizontal plane, wherein the first preset angle is 10 degrees to 90 degrees.

[0086] In the above technical solution, by placing two workpieces 100 to be welded flat on a workbench 1000 with an inclined surface, a first preset angle is formed between the two workpieces 100 and the horizontal plane (e.g., ...). Figure 6 (α angle in the equation).

[0087] Combined Figure 3 and Figure 6As shown, in other embodiments, two workpieces 100 to be welded are mounted on a workbench 1000, including: a positioning component 1200 is provided on the workbench 1000, the two workpieces 100 to be welded are mounted on the positioning component 1200, and the positioning component 1200 has a first preset angle with the horizontal plane, the first preset angle being 10-90 degrees.

[0088] In the above technical solution, by setting a rotatable positioning component 1200 on the worktable 1000, the two workpieces 100 to be welded placed on the positioning component 1200 are made to have a first preset angle (e.g., ...) with the horizontal plane. Figure 6 (α angle in the equation).

[0089] Whether using a worktable 1000 with an inclined surface or a worktable 1000 with a positioning component 1200, welding is performed by tilting the workpiece 100 to be welded, and the first preset included angle can be adjusted between 10 degrees and 90 degrees.

[0090] In the embodiments provided in this application, controlling the laser beam 200 to weld two workpieces 100 includes: welding the two workpieces 100 by controlling the welding power, welding speed, defocusing amount and oscillation amplitude of the laser beam 200.

[0091] The welding power is 1-2kW, the welding speed is 1-2m / min, the decoking amount is 0-5mm, and the oscillation amplitude is 0-2mm.

[0092] In the laser welding process of this embodiment, the first preset angle, the second preset angle, the welding power, the welding speed, the defocusing amount, and the oscillation amplitude all affect the flow of the weld pool at 600°.

[0093] like Figure 6 and Figure 7 As shown, when the workpiece 100 to be welded forms a first preset angle with the horizontal plane, under the influence of gravity, the molten pool 800 behind the pinhole 400 will flow in the opposite direction of welding. Since the energy of the laser spot conforms to the Gaussian distribution, the energy density in the center of the laser spot is higher, so the temperature in the middle of the molten pool 800 behind the pinhole 400 is higher, and the temperature on both sides of the molten pool is lower, which makes the molten metal on both sides of the molten pool 800 behind the pinhole 400 easier to solidify. As the laser beam 200 moves forward, the molten metal is continuously replenished to the rear, which causes the molten metal on both sides of the molten pool behind the pinhole 400 to flow into the middle of the molten pool 800 behind the pinhole 400, thus forming a weld 600 that is slightly convex in the middle and slightly concave on both sides.

[0094] The larger the first preset included angle, the greater the effect of gravity on the molten pool 800 behind the orifice 400. This increases the flow rate of the molten metal in the middle of the molten pool 800 behind the orifice 400, and also accelerates the flow of the molten metal on both sides of the molten pool 8 behind the orifice 400 towards the center. and Increase, or decrease and It gets smaller.

[0095] Furthermore, as welding power increases, welding speed decreases, and decoking amount decreases, the heat input to the molten pool increases, resulting in more molten base material (500) in the molten pool. This leads to a greater gravity in the rear molten pool (800) of the pinhole (400), which in turn accelerates the flow of molten metal from both sides of the rear molten pool (800) towards the center, causing... and Increase, or decrease and It gets smaller.

[0096] In summary, the first preset angle, welding power, welding speed, defocusing amount, and oscillation amplitude all affect the weld 600. Therefore, by adjusting the above parameters to coordinate and optimize the first preset angle, welding power, welding speed, defocusing amount, and oscillation amplitude, the collapse of the weld 600 can be effectively avoided.

[0097] In other embodiments provided in this application, a second preset angle is also provided, wherein the second preset angle is 5 degrees to 45 degrees.

[0098] It should be noted that the first preset angle and the second preset angle can be freely combined within their applicable angle variation range according to the different materials and thicknesses of the workpiece 100 to be welded.

[0099] In the embodiments provided in this application, when the workpiece 100 to be welded forms a first preset angle with the plane, and the center line of the laser beam 200 forms a second preset angle with the normal of the workpiece 100 to be welded, the force of gravity on the front molten pool 700 and the molten pools on the left and right sides of the small hole 400 is further reduced.

[0100] When the sum of the first preset angle and the second preset angle is greater than 90°, the direction of the component of gravity and the direction of the reaction force of the steam in the orifice 400 on the molten pool are opposite. To a certain extent, this can offset the downward action of the reaction force of the steam in the orifice 400 on the molten pool, thereby reducing the resultant force acting on the front molten pool 700 and the molten pools on the left and right sides of the orifice 400. The downward flow speed of the front molten pool 700 and the molten pools on the left and right sides of the orifice 400 is greatly slowed down, and the volume of the molten pool ejected from the bottom is greatly reduced, thus avoiding the formation of a weld hump 900 at the root of the weld 600 and further preventing the collapse of the weld 600.

[0101] In summary, changes in the second preset angle will also affect the degree of collapse at the root of weld 600, and will also have a lateral impact. and The size of the weld can be controlled by changing the angle values ​​of the first preset included angle, the second preset included angle, the welding power, the welding speed, and the defocusing amount. and The size, thus obtaining such Figure 8 The weld morphology shown is 600.

[0102] Extensive process experiments have demonstrated that when using the laser welding method provided in this application to weld 0.5-3mm thick plates, setting the first preset angle to 10-90 degrees, the second preset angle to 5-45 degrees, with the sum of the first and second preset angles greater than 90 degrees, the welding speed to 1-2 m / min, the defocusing amount to 0-5mm, the oscillation amplitude to 0-2mm, and the welding power to 1-2 kW, ensures a weld seam thickness of 600 mm after the above parameter adjustments. ≤0.08mm The height difference of the upper surface of weld 600 is ≤0.1mm, which reduces the height difference and improves the welding effect, and avoids the collapse of weld 600 from affecting the subsequent processing of workpieces.

[0103] In the embodiments provided in this application, a protective gas is blown onto the workpiece 100 to be welded during the welding process. This is to prevent the focusing lens in the laser welding machine from being contaminated by metal vapor and sputtered by molten droplets, and to prevent the protective gas from being oxidized during the workpiece welding process.

[0104] The shielding gas can be selected according to the material being welded, and the main types include argon, nitrogen, and helium.

[0105] In the embodiments provided in this application, the protective gas used is argon gas with a content of 99.999%. Argon gas has low activity and hardly reacts chemically with common metals. It is inexpensive, has a high density, and can effectively protect the weld seam 600.

[0106] The flow rate of argon gas is 10-20 L / min.

[0107] The laser welding method provided in this application, using the aforementioned apparatus, employs the following operational steps:

[0108] Step 1: Provide two workpieces 100 with a thickness of 0.5-3mm and position them on the positioning plate 1230. Adjust the tilt angle of the positioning plate 1230 so that the workpieces 100 to be welded have a first preset angle with the horizontal surface. Before positioning, impurities on the upper and lower surfaces and mating ends of the workpieces 100 to be welded can be removed using an organic flux.

[0109] Step 2: Control the laser assembly 1100 to perform welding. First, rotate the laser 1130 so that the center line of the laser beam 200 forms a second preset angle with the normal of the workpiece 100 to be welded. Then, adjust the welding power of the laser 1130, adjust the extension and retraction speed of the telescopic arm 1120 to determine the welding speed, adjust the rotation amplitude of the telescopic arm 1120 to determine the laser welding defocusing amount, and determine the welding oscillation amplitude by adjusting the extension and retraction swing amplitude of the telescopic arm 1120 itself.

[0110] Step 3: Start the laser 1130, and the jet assembly 1300 simultaneously blows protective gas. The welding joint of the laser 1130 emits a laser beam 200 that radiates along the +X direction at the joint between the two workpieces 100 to be welded, thereby achieving laser welding.

[0111] Step 4: When the end point of the joint is reached, turn off the laser welding system, stop blowing the protective gas, and the welding process is complete.

[0112] The laser welding device proposed in this application can handle workpieces of different sizes, and the first preset angle and the second preset angle can be freely adjusted to meet the welding needs of different types of workpieces.

[0113] In summary, the laser welding apparatus and method provided in this application form a first preset angle between the workpiece to be welded and the horizontal plane, and a second preset angle between the center line of the laser beam and the normal of the workpiece to be welded. This reduces the resultant force acting on the front side of the aperture and the left and right sides of the molten pool, thereby greatly slowing down the downward flow velocity of the molten pool in front of the aperture and the left and right sides of the aperture, and significantly reducing the volume of the molten pool ejected from the bottom. This results in a weld that is slightly convex in the middle and slightly concave on both sides, avoiding the formation of a weld hump at the root of the weld and preventing weld collapse.

[0114] Furthermore, this application provides a laser welding method in which the workpiece to be welded forms a first preset angle with the horizontal plane. Under the action of gravity, the molten metal in the back pool of the pinhole will not flow back and will not disturb the back wall of the pinhole, thereby improving the stability of the pinhole and avoiding welding defects such as spatter.

[0115] The technical solutions of this application have been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it is readily understood by those skilled in the art that the scope of protection of this application is obviously not limited to these specific embodiments. The above embodiments are only used to illustrate the technical solutions of this application and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A laser welding apparatus characterized by comprising: It includes a worktable and a laser assembly, the laser assembly including a fixed base, a telescopic arm and a laser; The workbench is configured to place the workpiece to be welded, and the workpiece to be welded has a first preset angle with the horizontal plane; The fixed base is mounted on the workbench. One end of the telescopic arm is hinged to the fixed base, and the other end of the telescopic arm is hinged to the laser. The laser is positioned above the workpiece to be welded. The laser beam emitted by the laser has a second preset angle with the normal of the workpiece to be welded. The laser beam emitted by the laser will form a molten pool on the workpiece to be welded, and the molten pool will sink to form a small hole. It also includes a positioning component, which includes a base, a cylinder, a positioning plate, and a clamping plate; the base and the cylinder are both disposed on the worktable, one end of the positioning plate is hinged to the base, and the end of the positioning plate away from the fixed seat is hinged to the cylinder; the positioning plate is used to mount the workpiece to be welded, and the first preset angle between the workpiece to be welded and the worktable is adjusted by adjusting the extension and retraction of the cylinder; Wherein, the first preset included angle is 10-90 degrees, the second preset included angle is 5-45 degrees, and the sum of the first preset included angle and the second preset included angle is greater than 90 degrees; when the workpiece to be welded forms the first preset included angle with the horizontal plane, under the influence of the gravity of the molten pool, the molten pool behind the small hole will flow in the opposite direction of welding; when the sum of the first preset included angle and the second preset included angle is greater than 90°, the direction of the component force of the gravity of the molten pool and the direction of the reaction force of the steam in the small hole on the molten pool are opposite, so that the resultant force of the front molten pool and the molten pools on the left and right sides of the small hole is reduced.

2. The laser welding apparatus of claim 1, wherein, It also includes a jet assembly, which includes an air tank and a nozzle connected to the air tank. The air tank is mounted on the worktable, and the nozzle is mounted on the laser.

3. A laser welding method characterized by, The laser welding apparatus according to any one of claims 1-2 comprises the following steps: Two workpieces to be welded are mounted on the worktable of the laser welding device, and the two workpieces to be welded have a first preset angle with the horizontal plane; the mounting of the two workpieces to be welded on the worktable of the laser welding device includes: the two workpieces to be welded are mounted on the positioning component of the laser welding device, and the positioning component has a first preset angle with the horizontal plane, wherein the first preset angle is 10-90 degrees. The laser of the laser welding device emits a laser beam, which is used to weld two workpieces to be welded. The laser beam has a second preset angle with the normal of the two workpieces to be welded. The second preset angle is 5-45 degrees, and the sum of the first preset angle and the second preset angle is greater than 90 degrees.

4. The laser welding method according to claim 3, characterized in that, The welding of the two workpieces to be welded using a laser beam includes: The welding power, welding speed, defocusing amount, and oscillation amplitude of the laser beam are controlled to weld the two workpieces to be welded. The welding power is 1-2kW, the welding speed is 1-2m / min, the defocusing amount is 0-5mm, and the oscillation amplitude is 0-2mm.

5. The laser welding method according to claim 3, characterized in that, The welding of the two workpieces to be welded using a laser beam includes: When welding two workpieces to be welded using the laser beam, a protective gas is blown onto the workpieces to be welded.

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