A laser brazing system and a laser brazing method

Abstract

The present application relates to a kind of laser brazing system and laser brazing method, the first workpiece and second workpiece of lap joint form inner corner welding area and weld path, laser outputs laser beam to be irradiated to inner corner welding area, wire feeder outputs brazing filler wire, laser beam is irradiated to the brazing filler wire that is not continuously output in inner corner welding area, and brazing filler wire is fused covering and fills inner corner welding area, weld joint and wire feeder move along weld path to complete welding, the present application uses brazing filler wire in the inner corner area of workpiece splicing to carry out laser brazing, only brazing filler is melted in brazing process, and matched workpiece is only heated, brazing filler is melted and flows into the gap between workpiece and is combined with workpiece surface, reduce the thermal stress of workpiece, improve the problem of workpiece deformation in welding;Meanwhile, using the way of inner corner welding, brazing filler wire is filled into the right angle inner side area formed after workpiece splicing, avoid workpiece to be welded through.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of laser welding, in particular to a laser brazing system and a laser brazing method. BACKGROUND

[0002] Laser welding technology is to use laser as heat source, melt the welding wire, fill the welding wire melted by laser to the welding area, and complete the laser welding process. Some commodities need to be lightened as a whole, so thin workpieces are selected as much as possible. The welding of such thin workpieces has high requirements, because the sealing performance after welding needs to be guaranteed. Therefore, during the welding process, the workpiece cannot be welded through.

[0003] For example, with the development of new energy vehicles, the development demand for connection technology and surface quality of battery equipment, laser welding has been more and more used in the connection of automobile battery box.

[0004] In order to reduce the weight of the automobile battery box, thin plate workpieces are often used. The cover plate of the automobile battery box is large in size and needs to be welded for a long distance. During the welding process, thermal stress will cause material deformation. Therefore, a laser brazing method is needed to ensure the surface quality of the cover plate of the battery box and the air tightness. SUMMARY

[0005] The purpose of the present application is to provide a laser brazing method to solve the problems of deformation and welding through in the welding process of thin plates.

[0006] To achieve the above purpose, the present application provides a laser brazing system, which comprises: a first workpiece and a second workpiece that are overlapped and clamped, the gap between the overlapped first workpiece and the second workpiece is not greater than 0.5mm and forms an internal corner welding area and a welding path; a laser welding device comprising a laser, a welding head and a wire feeding mechanism is further provided, the laser is used to output a laser beam and irradiate the internal corner welding area through the welding head, the wire feeding mechanism outputs a brazing wire, the laser beam and the end of the brazing wire intersect at a point in the internal corner welding area; after starting the laser welding device, the wire feeding mechanism starts to output the welding wire to the internal corner welding area, the laser beam irradiates the continuously output brazing wire in the internal corner welding area, and the brazing wire is fused and filled in the internal corner welding area, and the welding head and the wire feeding mechanism move along the welding path to complete the welding.

[0007] In one embodiment, a fixed bracket is provided on the welding head, the fixed bracket has a circular arc through hole, and an adapter is provided on the wire feeding mechanism, the adapter is slidably connected to the circular arc through hole.

[0008] In one embodiment, a six-axis robot is also provided. On the one hand, the six-axis robot is used to adjust the relative position of the welding head and the wire feeding mechanism so that the laser beam intersects with the end of the welding wire at a point in the inner corner welding area. On the other hand, the six-axis robot is also used to move the welding head and the wire feeding mechanism along the welding path.

[0009] In one embodiment, the first workpiece is 1 to 3 mm thick, and the second workpiece is 0.3 to 1 mm thick.

[0010] In one embodiment, the brazing wire is silicon bronze or tin bronze with a diameter of 0.8 to 2 mm.

[0011] In one embodiment, an air blower coaxially arranged with the welding head is also provided, the angle between the air blower and the horizontal plane being 40° to 60°.

[0012] In one embodiment, the wire feeding mechanism further includes a wire feeding straight tube, and the included angle between the air blowing cylinder and the wire feeding straight tube is 45° to 60°.

[0013] A laser brazing method includes: overlapping and clamping a first workpiece and a second workpiece such that the gap between the first workpiece and the second workpiece is no greater than 0.3 mm, forming an inner corner welding area and a welding path; providing a laser welding apparatus including a laser, a welding head, and a wire feeding mechanism, wherein the laser is used to output a laser beam and irradiate the inner corner welding area through the welding head, the wire feeding mechanism outputs brazing wire, and the laser beam and the end of the brazing wire are adjusted to intersect at a point in the inner corner welding area; starting the laser welding apparatus, the wire feeding mechanism begins to output brazing wire into the inner corner welding area, the laser beam irradiates the continuously output brazing wire in the inner corner welding area, and the brazing wire melts and fills the inner corner welding area, and the welding head and the wire feeding mechanism move along the welding path to complete the welding.

[0014] In one embodiment, after welding is completed, the process further includes the steps of first shutting down the wire feeding mechanism and then shutting down the laser.

[0015] In one embodiment, the wire feeding mechanism is slidably and / or rotatably connected to the welding head to adjust the laser beam to intersect the end of the welding wire at a point in the inner corner welding area.

[0016] In one embodiment, the laser has a power of 700W to 850W, a scanning frequency of 60 to 80Hz, and the diameter of the laser beam output by the laser is 1.4 to 1.8mm.

[0017] In one embodiment, 1 / 2 to 2 / 3 of the laser beam spot area is adjusted to be located in a horizontal position.

[0018] In one embodiment, the wire feeding mechanism outputs brazing wire at a speed of 22-25 mm / s.

[0019] In one embodiment, the laser welding speed is 23–26 mm / s.

[0020] In one embodiment, an air blower coaxially arranged with the welding head is also provided, the angle between the air blower and the horizontal plane being 40° to 60°.

[0021] In one embodiment, the wire feeding mechanism further includes a wire feeding straight tube, and the included angle between the air blowing cylinder and the wire feeding straight tube is 45° to 60°.

[0022] The beneficial effects of this invention are:

[0023] This invention discloses a laser brazing system and method. Laser brazing is performed on the inner corner area of ​​workpiece splicing using a brazing filler wire. The melting temperature of the brazing filler wire is lower than that of the workpiece, so only the filler wire melts during the brazing process, while the mating workpieces are only heated. The molten filler wire flows into the gap between the workpieces and bonds with the workpiece surface, reducing the thermal stress on the workpiece and improving the problem of workpiece deformation during welding. Simultaneously, the use of an inner corner weld method allows the molten filler wire to fill the right-angled inner area formed after the workpiece splicing, preventing the workpiece from being welded through. Attached Figure Description

[0024] Fig. 1 This is a schematic diagram of a laser brazing system according to one embodiment of the present invention;

[0025] Fig. 2 A schematic diagram of another embodiment of a laser brazing system according to the present invention;

[0026] Fig. 3 A schematic diagram of the workflow in one embodiment of a laser brazing method according to the present invention. Detailed Implementation

[0027] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0028] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention 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 invention.

[0029] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0030] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0031] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0032] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0033] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0034] like Figs. 1-3 As shown, this embodiment provides a laser brazing system, including: a first workpiece 1 and a second workpiece 2 that are overlapped and clamped together, wherein the gap between the first workpiece 1 and the second workpiece 2 after overlap is no greater than 0.5 mm, forming an inner corner welding area and a welding path; a laser welding device including a laser, a welding head, and a wire feeding mechanism is also provided, wherein the laser is used to output a laser beam 6 and irradiate the inner corner welding area through the welding head, and the wire feeding mechanism outputs a brazing wire 3, wherein the laser beam 6 and the end of the brazing wire 3 intersect at a point in the inner corner welding area; after the laser welding device is started, the wire feeding mechanism begins to output the welding wire into the inner corner welding area, the laser beam irradiates the continuously output brazing wire in the inner corner welding area, and causes the brazing wire to melt and fill the inner corner welding area, and the welding head and the wire feeding mechanism move along the welding path to complete the welding.

[0035] In one embodiment, a laser brazing method is provided, comprising: overlapping and clamping a first workpiece 1 and a second workpiece 2 such that the gap between the first workpiece 1 and the second workpiece 2 is no greater than 0.3 mm, forming an inner corner welding area and a welding path; providing a laser welding apparatus including a laser, a welding head, and a wire feeding mechanism, wherein the laser outputs a laser beam 6 and irradiates the inner corner welding area through the welding head, the wire feeding mechanism outputs brazing wire 3, and the laser beam 6 and the end of the brazing wire 3 are adjusted to intersect at the same point in the inner corner welding area; starting the laser welding apparatus, the wire feeding mechanism begins to output brazing wire 3 into the inner corner welding area, the laser beam 6 irradiates the continuously output brazing wire 3 in the inner corner welding area, and the brazing wire 3 melts and fills the inner corner welding area, and the welding head and the wire feeding mechanism move along the welding path to complete the welding. Specifically, the inner corner welding area refers to the inner side of the right-angled area formed after the two workpieces are overlapped, and the welding path refers to the stacking path formed along the overlapping surfaces of the two workpieces. This embodiment describes a laser brazing method. Laser brazing is performed in the inner corner region of the workpiece splicing using brazing wire 3. The melting temperature of the brazing wire 3 is lower than that of the workpiece. Therefore, only the brazing wire is melted during the brazing process, while the mating workpieces are only heated. The melted brazing wire flows into the gap between the workpieces and bonds with the workpiece surface, reducing the thermal stress on the workpiece and improving the problem of workpiece deformation during welding. Simultaneously, the use of inner corner welding allows the molten brazing wire to fill the right-angled inner region formed after the workpiece splicing, preventing the workpiece from being welded through.

[0036] In one embodiment, after welding is completed, the process further includes the steps of first shutting down the wire feeding mechanism and then shutting down the laser to prevent the welding wire from piling up at the end of the welding path.

[0037] like Fig. 2 As shown, in one embodiment, the wire feeding mechanism is slidably and / or rotatably connected to the welding head or a coaxial air blower coaxially arranged with the welding head, so as to adjust the relative position of the laser beam 6 and the welding wire 3, so that the ends of the laser beam 6 and the welding wire 3 intersect at a point in the inner corner welding area.

[0038] In one embodiment, a fixed bracket 7 is provided on the welding head or the coaxial air blower 5 coaxially arranged with the welding head. The fixed bracket 7 includes an arc-shaped through hole 71. An adapter 8 is provided on the wire feeding mechanism. The adapter 8 is slidably and rotatably connected to the arc-shaped through hole 71. Specifically, the arc path of the arc-shaped through hole 71 is an arc-shaped through hole. The adapter 8 is provided with a convex connector that matches the arc-shaped through hole. The connector can slide in the arc-shaped through hole, thereby driving the wire feeding mechanism to be slidably connected to the welding head or the coaxial air blower 5 coaxially arranged with the welding head.

[0039] In one embodiment, a six-axis robot (not shown in the figure) is also provided. On the one hand, the six-axis robot is used to adjust the relative position of the welding head and the wire feeding mechanism so that the laser beam and the end of the welding wire intersect at a point in the inner corner welding area. On the other hand, the six-axis robot is also used to move the welding head and the wire feeding mechanism along the welding path.

[0040] In one embodiment, the first workpiece 1 is 1-3 mm thick, and the second workpiece 2 is 0.3-1 mm thick. For example, the first workpiece 1 and / or the second workpiece 2 are made of high-strength steel. More preferably, the thickness of the first workpiece is 1-2 mm, and the thickness of the second workpiece is 0.4-0.9 mm. A good welding effect is achieved by melting the brazing wire and creating a gap between the thinner workpiece and the weld metal.

[0041] In one embodiment, the brazing wire is silicon bronze or tin bronze with a diameter of 0.8 to 2 mm.

[0042] In one embodiment, the laser has a power of 700W to 850W, a scanning frequency of 60 to 80Hz, and the diameter of the laser beam output by the laser is 1.4 to 1.8mm.

[0043] In one embodiment, the wire feeding mechanism outputs welding wire at a speed of 22-25 mm / s.

[0044] In one embodiment, the laser welding speed is 23–26 mm / s.

[0045] By optimizing power and speed, the brazing wire is fully melted, and the amplitude and frequency of the output spot are optimized to ensure the spreading area of ​​the molten brazing wire, promote full filling of the overlapping inner corner area, and ensure strong welding and sealing.

[0046] In one embodiment, 1 / 2 to 2 / 3 of the laser beam's spot area is positioned horizontally. Optimizing the spot position ensures that the brazing wire collides with the inner corner wall plate when the robot rotates, preventing it from coalescing into spheres and resulting in a good weld.

[0047] In one embodiment, an air blower 5 is also provided, which is coaxially arranged with the welding head, and the angle α between the air blower 5 and the horizontal plane is 40° to 60°.

[0048] In one embodiment, the wire feeding mechanism further includes a wire feeding straight tube 4, and the included angle β between the air blowing cylinder and the wire feeding straight tube 4 is 45° to 60°.

[0049] By optimizing the welding angle and wire feeding angle, the molten brazing filler metal can be made to contact the workpiece more quickly, conduct heat, and complete the welding process.

[0050] It should be noted that, for those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention, and no reference numerals in the claims should be construed as limiting the scope of the claims.

[0051] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A laser brazing system, characterized in that, include: The first and second workpieces are overlapped and clamped together, with the gap between the overlapped first and second workpieces not exceeding 0.5mm, forming an inner corner welding area and a welding path; The system also includes a laser welding device comprising a laser, a welding head, and a wire feeding mechanism. The laser outputs a laser beam, which is then directed through the welding head to the inner corner welding area. One-half to two-thirds of the laser beam's spot area is positioned horizontally to optimize the spot position, ensuring that the welding wire collides with the inner corner wall during welding, thus preventing the welding wire from coalescing into a spherical shape. The welding head is equipped with a fixed bracket containing an arc-shaped through-hole. The wire feeding mechanism is equipped with an adapter that is slidably connected to the arc-shaped through-hole to facilitate adjusting the intersection of the laser beam and the end of the welding wire at a single point in the inner corner welding area. The wire feeding mechanism outputs the brazing wire. The first workpiece is 1-2 mm thick, and the second workpiece is 0.4-0.9 mm thick. After the laser welding device is started, the wire feeding mechanism starts to output brazing wire to the inner corner welding area. The laser beam irradiates the continuously output brazing wire in the inner corner welding area. The welding head and the wire feeding mechanism move along the welding path. The brazing wire melts in the gap formed by the overlap with the thinner workpiece to complete the welding.

2. The laser brazing system according to claim 1, characterized in that: A six-axis robot is also provided. On the one hand, the six-axis robot is used to adjust the relative position of the welding head and the wire feeding mechanism so that the laser beam and the end of the welding wire intersect at a point in the inner corner welding area. On the other hand, the six-axis robot is also used to move the welding head and the wire feeding mechanism along the welding path.

3. The laser brazing system according to claim 1, characterized in that: The brazing wire is made of silicon bronze or tin bronze with a diameter of 0.8 to 2 mm.

4. The laser brazing system according to claim 1, characterized in that: An air blower coaxially arranged with the welding head is also provided, wherein the angle between the air blower and the horizontal plane is 40° to 60°.

5. A laser brazing system according to claim 4, characterized in that: The wire feeding mechanism also includes a wire feeding straight tube, and the included angle between the air blowing cylinder and the wire feeding straight tube is 45°~60°.

6. A laser brazing method, characterized in that, Using the laser brazing system according to any one of claims 1-5 includes the following steps: Overlap and clamp the first and second workpieces so that the gap between the first and second workpieces is no more than 0.3mm and form an inner corner welding area and welding path; A laser welding apparatus is provided, comprising a laser, a welding head, and a wire feeding mechanism. The laser outputs a laser beam, which is then directed through the welding head to the inner corner welding area. The position of the laser beam is adjusted so that 1 / 2 to 2 / 3 of the laser beam spot area is located on a horizontal plane to optimize the spot position. This is used to ensure that the welding wire collides with the inner corner wall during the welding process, preventing the welding wire from agglomerating into a spherical shape. The welding head is equipped with a fixed bracket that includes an arc-shaped through hole. The wire feeding mechanism is equipped with an adapter that slides and connects to different positions of the arc-shaped through hole. The laser beam and the end of the welding wire are adjusted to intersect at a single point in the inner corner welding area. The wire feeding mechanism outputs brazing wire. The first workpiece is 1-2 mm thick, and the second workpiece is 0.4-0.9 mm thick. The laser welding device is started, and the wire feeding mechanism begins to output welding wire to the inner corner welding area. The laser beam irradiates the continuously output brazing wire in the inner corner welding area. The welding head and the wire feeding mechanism move along the welding path. The brazing wire melts in the gap formed by the overlap with the thinner workpiece until the welding is completed.

7. The laser brazing method according to claim 6, characterized in that: After welding is completed, the process also includes first shutting down the wire feeding mechanism and then shutting down the laser.

8. The laser brazing method according to claim 6, characterized in that: The brazing wire is made of silicon bronze or tin bronze with a diameter of 0.8 to 2 mm.

9. A laser brazing method according to claim 6, characterized in that: The laser has a power of 700W~850W, a scanning frequency of 60~80Hz, and the diameter of the laser beam output by the laser is 1.4~1.8mm.

10. A laser brazing method according to claim 6, characterized in that: The wire feeding mechanism outputs brazing wire at a speed of 22~25 mm / s.

11. A laser brazing method according to claim 6, characterized in that: The laser welding speed is 23~26 mm / s.

12. A laser brazing method according to claim 6, characterized in that: An air blower coaxially arranged with the welding head is also provided, wherein the angle between the air blower and the horizontal plane is 40° to 60°.

13. A laser brazing method according to claim 12, characterized in that: The wire feeding mechanism also includes a wire feeding straight tube, and the included angle between the air blowing cylinder and the wire feeding straight tube is 45°~60°.

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