Friction stir head mounting height and angle planning device and method suitable for curved surface welding

Abstract

The invention discloses a friction stir head installation height and angle planning device and method suitable for curved surface welding. The device comprises a conical emission source, a camera, a point laser source, a first line light source and a second line light source. The conical emission source generates two concentric circular ring light spots on the surface of a standard plane, the two concentric circular ring light spots deform to form two different concentric elliptical ring light spots on the surface of a concave welding workpiece and the surface of a convex welding workpiece, and the camera shoots images of the surfaces of the welding workpieces. The curved surface type of the welding workpiece is determined according to the directions of the long axes of the two concentric elliptical rings in the surface image of the welding workpiece, and the position of the point laser source is adjusted according to the curved surface type of the welding workpiece, so that the pressing height of the friction stir head is determined. The angle of the friction stir head is adjusted until the center line of the conical emission source is perpendicular to the surface of the center area of the welding workpiece. The included angle between the stirring head and the surface of the weldment is automatically simulated and corrected before welding, and recognition and welding of a specific curved surface can be achieved.

Description

Technical Field

[0001] The invention relates to a friction stir welding technology, and in particular to a device and method for planning the installation height and angle of a friction stir welding head suitable for curved surface welding. Background Art

[0002] Friction stir welding (FSW) relies on high-speed rotation of a stir head at the weld joint, generating frictional heat. During this process, the stir head must penetrate the workpieces and move relative to them. Compared to traditional fusion welding, FSW offers high welding efficiency, minimal deformation, and low energy consumption. It avoids deformation and defects such as porosity and cracks caused by excessive heat input, significantly improving weld quality. While traditional FSW offers many advantages, it also has limitations. For non-planar structures, such as curved and three-dimensional structures, movement and positioning of the stir head become particularly challenging, making effective welding difficult. Therefore, traditional FSW is primarily suitable for welding flat materials such as sheets and billets. Complex three-dimensional or curved structures require alternative welding methods or specialized tooling design, which undoubtedly increases the difficulty and cost of welding. While some innovative FSW techniques have emerged with the continuous advancement of technology, such as static shoulder FSW and robotic welding, these techniques still struggle to fully overcome the limitations of planar welding. Therefore, future research is needed to further explore and develop FSW techniques applicable to non-planar structures to meet a wider range of welding needs.

[0003] Prior art (publication number CN109048039A) provides a universal head for friction stir welding of curved surfaces, as well as a universal head welding method for friction stir welding of curved surfaces, which can perform all-round welding on curved surface workpieces. However, when welding curved surfaces, the contact state between the stir head and the weld surface constantly changes during the welding process, resulting in differences in heat input and material flow at different parts of the weld, making the weld microstructure uneven and making weld consistency difficult to ensure. Due to the change in the shape of the curved surface, the contact state and heat input between the weld joint and the curved surface will change during the welding process, resulting in uneven width, depth, and microstructure of the weld, which is prone to defects. For example, at the inflection point or sudden change in curvature of the surface, these locations are prone to welding defects such as cracks and holes. When welding complex weld surfaces, in order to ensure welding quality, it is often necessary to reduce the welding speed. The welding speed is greatly reduced, resulting in low overall production efficiency. This is a major factor limiting the widespread application of friction stir welding in industries with large-scale production needs. Summary of the Invention

[0004] Purpose of the invention: The purpose of the present invention is to provide a stirring friction head installation height and angle planning device and planning method suitable for curved surface welding, which can automatically simulate and correct the angle between the stirring head and the weldment surface before formal welding.

[0005] Technical solution: The installation height and angle planning device of the friction stir head suitable for curved surface welding of the present invention comprises a main body bracket, the center of the lower half of the main body bracket is hollowed out, a conical emission source is arranged at the center of the top surface of the hollowed-out part, and a camera is arranged at intervals just below the conical emission source, and the camera is mounted on the main body bracket through a fourth telescopic fixing rod; a third telescopic fixing rod is horizontally mounted on one side of the main body bracket, and a first telescopic fixing rod is horizontally mounted on the other side thereof, and the third telescopic fixing rod and the first telescopic fixing rod are symmetrically arranged about the central axis of the main body bracket; a point laser source is rotatably mounted on the end of the third telescopic fixing rod, and a first line light source is rotatably mounted on the end of the first telescopic fixing rod; the front of the main body bracket is horizontally mounted The second telescopic fixed rod is perpendicular to the first telescopic fixed rod, and the second line light source is rotatably installed at the end of the second telescopic fixed rod; the conical emission source generates two concentric circular ring light spots on the standard plane surface, and the two concentric circular ring light spots are transformed into two different concentric elliptical ring light spots on the surface of the concave welding workpiece and the convex welding workpiece. The camera captures the surface image of the welding workpiece, and the surface type of the welding workpiece is determined according to the direction of the long axis of the two concentric elliptical rings in the surface image of the welding workpiece, and the position of the point laser source is adjusted according to the surface type of the welding workpiece, thereby determining the downward pressure height of the stir friction head, and adjusting the angle of the stir friction head until the center line of the conical emission source is perpendicular to the surface of the central area of the welding workpiece.

[0006] Furthermore, the first line light source and the second line light source generate linear light spots on the surface of the welding workpiece, and the two linear light spots intersect to form a cross light spot, and the intersection point of the cross light spot coincides with the center of the two concentric circular light spots.

[0007] Furthermore, the center line of the conical emission source and the light generated by the point laser source are on the same plane.

[0008] Furthermore, the light emitted by the first line light source is on a vertical plane, the light emitted by the second line light source is on another vertical plane, the two vertical planes are perpendicular to each other, and the center line of the conical emission source coincides with the intersection of the two vertical planes.

[0009] Based on the same inventive concept, the present invention provides a method for planning the installation height and angle of a friction stir head for curved surface welding. The planning method is applied to the above-mentioned device for planning the installation height and angle of a friction stir head for curved surface welding, comprising:

[0010] Install the upper part of the friction stir head installation height and angle planning device as a clamping end into the friction stir head installation hole of the friction stir welding robot execution end;

[0011] Turning on the power of the friction stir welding robot and the friction stir head installation height and angle planning device, calibrating the friction stir head installation height and angle planning device, projecting lasers emitted by the first line light source, the second line light source, the cone emission source, and the point laser source onto the standard plane surface, and when the centerline of the cone emission source is perpendicular to the standard plane surface, adjusting the friction stir head installation height and the angle planning device height so that the diameter of the smaller circular spot of the two concentric circular spots generated by the cone emission source is equal to the diameter of the friction stir welding head shoulder;

[0012] After calibration, the friction stir head installation height and angle planning device is moved downward. During this process, the center of the cross-shaped light spot generated by the first and second line light sources is ensured to always be located on the center line of the conical emission source. The camera captures the surface image of the welding workpiece, analyzes the surface image of the welding workpiece to determine the type of welding workpiece surface, and adjusts the position of the point light spot generated by the point laser source according to the type of welding workpiece surface to ensure that the point light spot always falls on point O or point B, thereby determining the downward pressure height of the friction stir welding robot.

[0013] The head of the friction stir welding robot is adjusted to ensure that the retractable fixed rod is parallel to the welding forward direction; the camera captures the surface image of the welding workpiece, and the friction stir welding robot is operated according to the captured surface image of the welding workpiece to make the pixel lengths of line segments AB and CD equal, and the pixel lengths of line segments EF and GH equal, thereby determining the angle of the friction stir welding head in the friction stir welding robot; the coordinate position of each joint of the friction stir welding robot at this time is recorded, and the friction stir head installation height and angle planning device is moved upward, and the friction stir welding robot enters the next point calibration;

[0014] Repeat the above steps until the stirring head angles at all required points on the welding path are adjusted.

[0015] Furthermore, the type of the welding workpiece surface is determined as follows:

[0016] When the two concentric circular light spots transform into two concentric elliptical light spots with the line segment EH as the major axis on the surface of the welding workpiece, it indicates that the surface of the welding workpiece is concave. At this time, the major axis EH of the two concentric elliptical light spots coincides with the welding direction;

[0017] When the two concentric circular light spots are transformed into two concentric elliptical light spots with line segment AD as the major axis on the surface of the welding workpiece, it indicates that the surface of the welding workpiece is convex. At this time, the major axis AD of the two concentric elliptical light spots is perpendicular to the welding direction.

[0018] Furthermore, when the surface of the welding workpiece is concave, the position of the point laser source is adjusted so that the point light spot generated by the point laser source on the surface of the welding workpiece coincides with point O. At this time, the height of the conical emission source from the weld is the spatial position where the stir friction head is pressed down to reach the surface of the welding workpiece.

[0019] Furthermore, the small circular light spot and the large circular light spot in the two concentric circular light spots intersect with the first line light source and the second line light source respectively to generate line segment AB, line segment CD, line segment EF, and line segment GH;

[0020] When the surface of the welding workpiece is convex, the position of the point laser source is adjusted so that the point light spot generated by the point laser source on the surface of the welding workpiece coincides with point B. At this time, the height of the conical emission source from the weld is the spatial position where the stir friction head is pressed down to reach the surface of the welding workpiece.

[0021] Furthermore, before adjusting the angle of the friction stir welding head in the friction stir welding robot, the position of the upper head of the friction stir welding robot is adjusted first so that the line spot generated by the second line light source on the surface of the welding workpiece coincides with the weld.

[0022] Furthermore, the friction stir welding robot is operated according to the captured image of the welding workpiece surface so that the pixel lengths of line segment AB and line segment CD are equal, and the pixel lengths of line segment EF and line segment GH are equal, thereby determining the angle of the friction stir welding head in the friction stir welding robot, including:

[0023] When the pixel length of line segment AB in the image captured by the camera is less than the pixel length of line segment CD, it indicates that the central axis of the cone-shaped emission source is tilted to the left. Conversely, when the pixel length of line segment AB is greater than the pixel length of line segment CD, it indicates that the central axis of the cone-shaped emission source is tilted to the right. In the case of tilting to the left or right, adjust the nose of the machine so that it tilts in the opposite direction until the pixel length of line segment AB equals the pixel length of line segment CD.

[0024] When the pixel length of line segment EF in the image captured by the camera is less than the pixel length of line segment GH, it indicates that the central axis of the conical emission source is tilted forward; conversely, when the pixel length of line segment EF is greater than the pixel length of line segment GH, it indicates that the central axis of the conical emission source is tilted backward; when tilted forward or backward, adjust the nose so that it tilts in the opposite direction until the pixel length of line segment EF is equal to the pixel length of line segment GH.

[0025] Beneficial effects: Compared with the prior art, the present invention has the following significant technical effects: (1) It can automatically simulate and correct the angle between the stirring head and the weld surface before welding, and can realize the welding of planes, inclined surfaces, and specific curved surfaces; (2) If there are multiple identical welds, the data recorded in the first welding process can be put into use for batch welding, eliminating the measurement steps and realizing high-speed and high-efficiency welding during the welding process; (3) The real-time adjustment of the angle between the welding head and the weld surface reduces defects and improves the uniformity of the weld structure; (4) The present invention has a simple structure, strong practicality, is easy to implement and convenient to assemble. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0027] Figure 2 for Figure 1 The main view;

[0028] Figure 3 is a schematic diagram of the installation of the fourth telescopic fixing rod;

[0029] Figure 4 This is a principle diagram of the optical path for concave welding workpieces according to the present invention;

[0030] Figure 5 This is the optical path principle diagram of the present invention for convex surface welding workpieces

[0031] Figure 6 Schematic diagram of the curved surface weldment type applicable to the present invention;

[0032] Figure 7 Schematic diagram for determining the surface type of weldment;

[0033] Figure 8 Schematic diagram of the height adjustment device;

[0034] Figure 9 Schematic diagram of the angle between the center line of the cone formed by the conical emission source and the circular spot and the friction stir head;

[0035] Figure 10 This is the image captured by the camera when welding the convex surface;

[0036] Figure 11 This is the image taken by the camera when welding concave surfaces. DETAILED DESCRIPTION

[0037] The technical solution of the present invention is described in detail below in conjunction with specific implementation methods and the accompanying drawings.

[0038] Example 1

[0039] like Figure 1-2As shown, the present invention's friction stir head installation height and angle planning device for curved surface welding includes a main frame, a first linear light source 1, a second linear light source 2, a conical emission source 3, a point laser source 4, a camera 5, a first telescopic fixing rod 6, a second telescopic fixing rod 7, a third telescopic fixing rod 8, a fourth telescopic fixing rod 9, and a bolt 10. Optional models for the point laser source 4 include the Z-LASER series: Z5M18B-F-635-lg90ZM18RF, Z1D-635-PE-24; and the Easy-Laser series: XT20, XT22, and XT24. Optional models for the conical emission source 3 include the Z-LASER series: Z30M18B-F-520-lg45ZM18RF, E90. Optional models for the first linear light source 1 and the second linear light source 2 include the IPG Photonics series: YLR-10000, ruDisk6002, or HighLight FL-4000. The camera 5 can be selected from BRIGHT optech 405 and Hengjiangjun NTS300. The first telescopic fixed rod 6, the second telescopic fixed rod 7, the third telescopic fixed rod 8 and the fourth telescopic fixed rod 9 can be selected from XMSJ DC series and TUNKERS V series. The specific installation method of each component is as follows: the center of the lower half of the main bracket is hollowed out, and a conical emission source 3 is set at the center of the top surface of the hollow part. The conical emission source 3 is located in the center of the main bracket and is fixed by the fixing groove of the main bracket. In this embodiment, the conical emission source 3 is fixed to the center of the top surface of the hollow part through the base, and the base is connected to the main bracket and the cover plate 12 with bolts 10. The camera 5 is spaced apart directly below the conical emission source 3. There is a certain distance between the camera 5 and the conical emission source 3. The distance needs to ensure that the camera 5 does not affect the circular laser emitted by the conical emission source 3 from being projected onto the surface of the weld. The wire of the camera 5 is fixed on the fourth telescopic fixed rod 9. In this embodiment, the angle between the fourth telescopic fixed rod 9 and the stir friction head installation height and angle planning device is 45°. Figure 3 shown.

[0040] The camera 5 is located at the center of the main bracket. The camera 5 is located inside the hollow part and is installed on the main bracket through the fourth telescopic fixed rod 9. The axis of the camera 5 coincides with the axis of the conical emission source 3. The third telescopic fixed rod 8 is horizontally installed on one side of the main bracket, and the first telescopic fixed rod 6 is horizontally installed on the other side. The third telescopic fixed rod 8 and the first telescopic fixed rod 6 are symmetrically arranged about the central axis of the main bracket. The end of the third telescopic fixed rod 8 is rotatably installed with a point laser source 4, and the point laser source 4 can rotate a certain angle around the end of the third telescopic fixed rod 8. The end of the first telescopic fixed rod 6 is rotatably installed with a first line light source 1, and the first line light source 1 can rotate a certain angle around the end of the first telescopic fixed rod 6. The second telescopic fixed rod 7 is horizontally installed on the front of the main bracket. The second telescopic fixed rod 7 and the first telescopic fixed rod 6 are perpendicular to each other, and the angle between the second telescopic fixed rod 7 and the first telescopic fixed rod 6 is 90 degrees. Figure 4 As shown. A second linear light source 2 is pivotally mounted on the end of the second telescopic fixed rod 7, and can rotate around the end of the second telescopic fixed rod 7 to a certain angle. A cover plate 12 is installed above the main frame, and the entire structure is secured by side bolts 10. The first telescopic fixed rod 6, the second telescopic fixed rod 7, the third telescopic fixed rod 8, and the fourth telescopic fixed rod 9 are all connected to the main frame via bolts. Connect the wires of the first linear light source 1, the second linear light source 2, the cone-shaped emission source 3, the point laser source 4, and the camera 5 to the computer.

[0041] like Figure 4 and Figure 5 As shown, the light emitted by the first line light source 1 lies on a vertical plane (Plane 1), and the light emitted by the second line light source 2 lies on another vertical plane (Plane 2). The two vertical planes (Plane 1 and Plane 2) are perpendicular to each other, and the centerline of the conical emission source 3 coincides with the intersection of the two vertical planes. The first and second line light sources 1 and 2 produce linear light spots on the surface of the weld workpiece. The two linear light spots intersect to form a cross light spot, and the intersection point (point O) of the cross light spot coincides with the center of the two concentric circular light spots. The conical emission source 3 produces two concentric circular light spots on the standard plane surface. The point laser source 4 produces a point light spot on the surface of the weld workpiece. The centerline of the conical emission source 3 and the light emitted by the point laser source 4 lie on the same plane (Plane 1). The small and large circular light spots in the two concentric circular light spots intersect with the first and second line light sources 1 and 2, respectively, to produce line segments AB, CD, EF, and GH.

[0042] The two concentric circular light spots transform into two different concentric elliptical light spots on the concave and convex surfaces of the workpiece. Camera 5 captures the workpiece surface image and determines the type of curved surface based on the orientation of the major axes of the two concentric elliptical rings in the workpiece surface image. The position of point laser source 4 is adjusted based on the curved surface type, thereby determining the downward pressure height of the friction stir head. The angle of the friction stir head is then adjusted until the centerline of the conical emission source 3 is perpendicular to the central area of the workpiece surface.

[0043] like Figure 6 As shown, Figure 6 Figure (a) is a schematic diagram of a concave weldment workpiece. Figure 6 Figure (b) shows a convex weldment. This device is applicable to both concave and convex weldments. Concave and convex surfaces are distinguished as follows: a concave surface is an inward-concave semi-elliptical curved surface with a symmetrical weld seam 11. A convex surface is an outward-convex semi-elliptical curved surface with a symmetrical weld seam 11.

[0044] like Figure 7 As shown, Figure 7 Figure (a) is a schematic diagram of the imaging of two concentric ring light spots on the concave welding workpiece surface. Figure 7 Figure (b) is a schematic diagram of the imaging of two concentric ring light spots on the convex surface of the welding workpiece. The conical emission source 3 generates two concentric ring light spots on the welding workpiece surface. The two concentric ring light spots are transformed into different elliptical ring light spots on the concave and convex surfaces respectively. The type of surface can be determined by the direction of the major axis of the elliptical ring: in the case of a concave surface, the circular ring light spot is transformed into an elliptical ring light spot with the line segment EH as the major axis, as shown in Figure 3. Figure 7 As shown in Figure (a), the major axis EH of the concave elliptical ring spot coincides with the welding direction; in the case of the convex surface, the circular ring spot is transformed into an elliptical ring spot with the line segment AD as the major axis. Figure 7 As shown in Figure (b), the major axis AD of the convex elliptical ring spot is perpendicular to the welding direction.

[0045] like Figure 8 As shown, Figure 8 Figure (a) is a schematic diagram of the height adjustment device for concave welding workpieces. Figure 8 Figure (b) is a schematic diagram of the height adjustment device for convex surface welding. The principle of the friction stir head installation height and angle planning device of the present invention for downward pressure height adjustment relative to concave or convex surface welding workpieces is as follows:

[0046] After the friction stir head installation height and the center line of the angle planning device are adjusted so that they are perpendicular to the surface of the workpiece, the height can be adjusted: the angle between the third telescopic fixed rod 8 and the central axis of the point laser source 4 is b. When welding a concave workpiece, the height of the friction stir head angle planning device from the workpiece surface is WO = the length of the telescopic fixed rod n × tanb; Figure 8 As shown, when welding convex workpieces, the depth of the friction stir weld head into the weldment needs to be increased by an additional h, where h = r * tan b. This means the press-down height = (nr) * tan b + m, where m is the weld thickness and r is the radius of the friction stir weld shoulder. The height should be approximate based on the distance between the friction stir weld shoulder and the stirring needle. The distance between the point laser source 4 and the conical emission source 3 on the mounting plane of the adjustment device needs to be predetermined. This height can be maintained by controlling the length of the fourth telescopic fixing rod 9.

[0047] The maximum angle a between the light emitted by the conical emission source 3 and the horizontal plane is 45-60 degrees, and the maximum angle between the light emitted by the first line light source 1 or the second line light source 2 and the weldment surface is much larger than a.

[0048] The stirring friction head installation height and angle planning device of the present invention can automatically simulate and correct the angle between the stirring head and the weld surface before welding, can realize the identification and welding of specific curved surfaces, achieve high-speed and efficient welding during the welding process, reduce defects, and improve the uniformity of the weld structure. The present invention is suitable for welds with relatively flat surfaces.

[0049] Example 2

[0050] The method for planning the installation height and angle of a friction stir head for curved surface welding of the present invention is applied to the device for planning the installation height and angle of a friction stir head for curved surface welding described in Example 1, and comprises the following steps:

[0051] S1. Install the upper half of the friction stir head angle planning device as a clamping end into the friction stir head mounting hole of the execution end of the friction stir welding robot.

[0052] The installation height and angle planning device of the friction stir head is installed at the same position as the friction stir head, but not at the same time, that is, the friction stir head is installed only when the formal welding is carried out; the angle between the clamping end of the friction stir head installation height and angle planning device and its own cover plate 12 is in the range of 87-90°, and the direction of the second telescopic fixed rod 7 where the second linear light source 2 is located should be kept parallel to the welding (weld 11) direction during each welding, and the angular direction of the angle is opposite to the welding direction, while the directions of the first telescopic fixed rod 6 and the third telescopic fixed rod 8 are perpendicular to the welding (weld) direction. Figure 9 shown.

[0053] S2. Start the power supply of the friction stir welding robot and the friction stir head installation height and angle planning device, calibrate the friction stir head installation height and angle planning device, project the lasers emitted by the first line light source 1, the second line light source 2, the conical emission source 3 and the point laser source 4 onto the standard plane surface, adjust the friction stir head installation height and the angle planning device height so that the diameter of the small circular spot in the two concentric circular spots generated by the conical emission source 3 is equal to the diameter of the friction stir welding head shoulder.

[0054] like Figure 4 As shown, before the friction stir head installation height and angle planning device scans the weld seam 11 of a concave or convex workpiece, it needs to be calibrated. When the centerline of the conical emission source 3 is perpendicular to the standard plane surface, that is, when line segment AB = line segment CD and line segment EF = line segment GH, the friction stir head installation height and angle planning device is adjusted so that the diameter of the small circular spot is equal to the diameter of the friction stir welding head shoulder.

[0055] S3, simulate the stirring head entering the lowering stage: after calibration, move the stirring friction head installation height and angle planning device downward. During this process, ensure that the center of the cross-intersecting light spot generated by the first line light source 1 and the second line light source 2 is always located on the center line of the conical emission source 3; the camera 5 captures the surface image of the welding workpiece, analyzes the surface image of the welding workpiece to determine the type of the welding workpiece surface, and adjusts the position of the point light spot generated by the point laser source 4 according to the type of the welding workpiece surface to ensure that the point light spot always falls on point O or point B, thereby determining the downward pressing height of the stirring friction head in the stirring friction welding robot.

[0056] In this embodiment, the method for determining the type of the welding workpiece surface is as follows:

[0057] When the two concentric circular light spots transform into two concentric elliptical light spots with the line segment EH as the major axis on the surface of the welding workpiece, it indicates that the surface of the welding workpiece is concave. At this time, the major axis EH of the two concentric elliptical light spots coincides with the welding direction;

[0058] When the two concentric circular light spots are transformed into two concentric elliptical light spots with line segment AD as the major axis on the surface of the welding workpiece, it indicates that the surface of the welding workpiece is convex. At this time, the major axis AD of the two concentric elliptical light spots is perpendicular to the welding direction.

[0059] like Figure 4As shown, when the centerline of the conical laser source W is perpendicular to the weld surface, that is, line segment AB = line segment CD, and line segment EF = line segment GH. If the workpiece surface is concave, the position of the point laser source 4 is adjusted. Specifically, the length of the third telescopic fixed rod 8 on which the point laser source 4 resides and the angle of the point laser source 4 at its end are adjusted so that the point light spot produced by the point laser source 4 on the workpiece surface coincides with point O (the intersection of the cross light spots). At this point, the height of the conical emission source 3 from the weld 11 is the spatial position where the friction stir head presses down to reach the workpiece surface.

[0060] like Figure 5 As shown, when the centerline of the conical laser source 3 is perpendicular to the weld surface, that is, line segment AB = line segment CD, and line segment EF = line segment GH. At this time, the intersection of the small circular light spot and the cross line is O. The small circular light spot and the large circular light spot in the two concentric circular light spots intersect with the first line light source 1 and the second line light source 2 to produce line segments AB, CD, EF, and GH, respectively. When the weld surface is convex, the position of the point laser source 4 is adjusted so that the point laser source 4 on the weld surface coincides with point B. At this time, the height of the conical emission source 3 from the weld 11 is the spatial position where the friction stir head presses down to reach the weld surface. In this embodiment, after the light spot emitted by the point laser source 4 is set at position O, only the vertical distance between the point laser source 4 and the center line of the cone-shaped emission source 3 is changed, rather than the displacement of the point laser source 4 relative to the center line of the cone-shaped emission source 3. That is, by adjusting the length of the third telescopic fixing rod 8, the point laser source 4 can be moved horizontally until the light spot generated by the point laser source 4 coincides with position B. Figure 5 shown.

[0061] First, ensure that the centerline of the conical emission source 3 is perpendicular to the surface of the weld 11. After confirming the concave and convex surface forms, for concave surfaces, when the spot produced by the point laser source 4 coincides with the center of the cross-line spot, the height at this time is the spatial position where the stirring tip reaches the weld surface. For convex surfaces, the intersection of the small circular spot and the cross-line is at point B. When this point coincides with the spot produced by the point laser source, the height at this time is the spatial position where the stirring tip reaches the weld surface.

[0062] S4, adjusting the head of the friction stir welding robot to ensure that the retractable fixed rod 7 is parallel to the welding forward direction; the camera (5) captures the surface image of the welding workpiece; operating the friction stir welding robot according to the captured surface image of the welding workpiece, so that the pixel lengths of line segment AB and line segment CD are equal, and the pixel lengths of line segment EF and line segment GH are equal, thereby determining the angle of the friction stir welding head in the friction stir welding robot; recording the coordinate positions of each joint of the friction stir welding robot at this time, moving the friction stir head installation height and angle planning device upward, and the friction stir welding robot enters the next point calibration.

[0063] Before adjusting the angle of the friction stir welding head in the friction stir welding robot, first adjust the position of the upper head of the friction stir welding robot so that the line spot generated by the second line light source 2 on the surface of the welding workpiece coincides with the weld 11, thereby ensuring that the center line of the conical emission source is perpendicular to the surface of the welding center area.

[0064] In this embodiment, the friction stir welding robot is operated so that the pixel lengths of line segments AB and CD are equal, and the pixel lengths of line segments EF and GH are equal, thereby determining the angle of the friction stir welding head in the friction stir welding robot, as follows:

[0065] like Figure 10 As shown, Figure 10 Figure (a) is a schematic diagram of the central axis of the conical emission source tilted forward when the surface is convex. Figure 10 Figure (b) is a schematic diagram of the central axis of the conical emission source tilting backward when the surface is convex. Figure 10 Figure (c) is a schematic diagram showing that the central axis of the conical emission source is tilted to the left when the surface is convex. Figure 10 Figure (d) is a schematic diagram of the central axis of the conical emission source tilting to the right when the surface is convex. Figure 11 As shown, Figure 11 Figure (a) is a schematic diagram of the concave surface with the central axis of the conical emission source tilted forward. Figure 11 Figure (b) is a schematic diagram of the concave surface with the central axis of the conical emission source tilted backward. Figure 11 Figure (c) is a schematic diagram showing that the central axis of the conical emission source is tilted to the left when the surface is concave. Figure 11 Figure (d) is a schematic diagram of the concave surface where the central axis of the conical emission source is tilted to the right.

[0066] like Figure 10 As shown in the figure, when the surface of the welding workpiece is convex, the line segment EH is the long axis of the two concentric elliptical ring spots. Figure 11 As shown in the figure, when the surface of the welding workpiece is concave, the line segment AD is the major axis of the two concentric elliptical ring light spots. When the pixel length of the line segment EF in the image captured by the camera 5 is less than the pixel length of the line segment GH, the conical emission source 3 is not perpendicular to the welding direction, indicating that the central axis of the conical emission source 3 is tilted forward, as shown in the figure. Figure 10 Figure (a) and Figure 11 As shown in Figure (a); on the contrary, when the pixel length of line segment EF is greater than the pixel length of line segment GH, it indicates that the central axis of the cone-shaped emission source 3 is tilted backward, as shown in FIG. Figure 10 Figure (b) and Figure 11As shown in Figure (b); when tilting forward or backward, the operator adjusts the head of the machine according to the image taken by the camera 5, so that the head tilts slightly in the opposite direction until the pixel length of the line segment EF is equal to the pixel length of the line segment GH.

[0067] When the pixel length of the line segment AB in the image captured by the camera 5 is less than the pixel length of the line segment CD, it indicates that the central axis of the cone-shaped emission source 3 is tilted to the left, as shown in FIG. Figure 10 Figure (c) and Figure 11 As shown in Figure (c); on the contrary, when the pixel length of line segment AB is greater than the pixel length of line segment CD, it indicates that the central axis of the cone-shaped emission source 3 is tilted to the right, as shown in Figure (c). Figure 10 Figure (d) and Figure 11 As shown in Figure (d) above, when tilting to the left or right, the operator adjusts the machine head based on the image captured by camera 5, tilting it slightly in the opposite direction until the pixel length of line segment AB equals the pixel length of line segment CD. When line segment AB equals line segment CD and line segment EF equals line segment GH, the central axis of the conical emitter is perpendicular to the weld surface. S5: Repeat steps S3 and S4 above until the stirring head angle is adjusted at all required points along the welding path.

Claims

1. A device for planning the installation height and angle of a friction stir head for curved surface welding, characterized by: The invention comprises a main frame, wherein the center of the lower half of the main frame is hollowed out, a cone-shaped emission source (3) is arranged at the center of the top surface of the hollowed-out portion, a camera (5) is arranged at intervals just below the cone-shaped emission source (3), and the camera (5) is mounted on the main frame via a fourth telescopic fixing rod (9); A third telescopic fixed rod (8) is horizontally mounted on one side of the main frame, and a first telescopic fixed rod (6) is horizontally mounted on the other side thereof, the third telescopic fixed rod (8) and the first telescopic fixed rod (6) being symmetrically arranged about the central axis of the main frame; a point laser source (4) is rotatably mounted on the end of the third telescopic fixed rod (8), and a first line light source (1) is rotatably mounted on the end of the first telescopic fixed rod (6); A second telescopic fixing rod (7) is horizontally mounted on the front of the main frame, the second telescopic fixing rod (7) and the first telescopic fixing rod (6) are perpendicular to each other, and a second linear light source (2) is rotatably mounted on the end of the second telescopic fixing rod (7); The conical emission source (3) generates two concentric circular light spots on a standard plane surface, and the two concentric circular light spots are transformed into two different concentric elliptical light spots on the surface of a concave welding workpiece and a convex welding workpiece. The camera (5) captures an image of the welding workpiece surface, and determines the surface type of the welding workpiece according to the direction of the long axis of the two concentric elliptical rings in the welding workpiece surface image. The position of the point laser source (4) is adjusted according to the surface type of the welding workpiece, thereby determining the downward pressure height of the stir friction head, and adjusting the angle of the stir friction head until the center line of the conical emission source (3) is perpendicular to the surface of the central area of the welding workpiece.

2. The device for planning the installation height and angle of a friction stir head for curved surface welding according to claim 1, characterized in that: The first line light source (1) and the second line light source (2) generate linear light spots on the surface of the welding workpiece, and the two linear light spots intersect to form a cross light spot, and the intersection point of the cross light spot coincides with the center of the two concentric circular light spots.

3. The device for planning the installation height and angle of a friction stir head for curved surface welding according to claim 1, characterized in that: The center line of the conical emission source (3) and the light generated by the point laser source (4) are on the same plane.

4. The device for planning the installation height and angle of a friction stir head for curved surface welding according to claim 1, wherein: The light emitted by the first line light source (1) is on a vertical plane, and the light emitted by the second line light source (2) is on another vertical plane. The two vertical planes are perpendicular to each other, and the center line of the conical emission source (3) coincides with the intersection of the two vertical planes.

5. A method for planning the installation height and angle of a friction stir head suitable for curved surface welding, characterized in that: The planning method is applied to the device for planning the installation height and angle of a friction stir head for curved surface welding as described in claim 1, comprising: Install the upper part of the friction stir head installation height and angle planning device as a clamping end into the friction stir head installation hole of the friction stir welding robot execution end; The power supply of the friction stir welding robot and the friction stir head installation height and angle planning device is started, and the friction stir head installation height and angle planning device is calibrated. The lasers emitted by the first line light source (1), the second line light source (2), the cone emission source (3) and the point laser source (4) are projected onto the standard plane surface. When the center line of the cone emission source (3) is perpendicular to the standard plane surface, the height of the friction stir head installation height and angle planning device is adjusted so that the diameter of the small circular light spot in the two concentric circular light spots generated by the cone emission source (3) is equal to the diameter of the friction stir welding head shaft shoulder. After calibration, the installation height and angle planning device of the friction stir head is moved downward. During this process, it is ensured that the center of the cross light spot generated by the first line light source (1) and the second line light source (2) is always located on the center line of the conical emission source (3); the camera (5) captures the surface image of the welding workpiece, analyzes the surface image of the welding workpiece to determine the type of the welding workpiece surface, and adjusts the position of the point light spot generated by the point laser source (4) according to the type of the welding workpiece surface to ensure that the point light spot always falls on point O or point B, thereby determining the downward pressing height of the friction stir welding head in the friction stir welding robot; The head of the friction stir welding robot is adjusted to ensure that the retractable fixed rod is parallel to the welding forward direction; the camera (5) captures the surface image of the welding workpiece, and the friction stir welding robot is operated according to the captured surface image of the welding workpiece, so that the pixel lengths of line segment AB and line segment CD are equal, and the pixel lengths of line segment EF and line segment GH are equal, thereby determining the angle of the friction stir welding head in the friction stir welding robot; the coordinate position of each joint of the friction stir welding robot at this time is recorded, and the installation height and angle planning device of the friction stir welding head is moved upward, and the friction stir welding robot enters the next point calibration; Repeat the above steps until the stirring head angles at all required points on the welding path are adjusted.

6. The method for planning installation height and angle of a friction stir head for curved surface welding according to claim 5, characterized in that: The method for determining the type of the welding workpiece surface is as follows: When the two concentric circular light spots transform into two concentric elliptical light spots with the line segment EH as the major axis on the surface of the welding workpiece, it indicates that the surface of the welding workpiece is concave. At this time, the major axis EH of the two concentric elliptical light spots coincides with the welding direction; When the two concentric circular light spots are transformed into two concentric elliptical light spots with line segment AD as the major axis on the surface of the welding workpiece, it indicates that the surface of the welding workpiece is convex. At this time, the major axis AD of the two concentric elliptical light spots is perpendicular to the welding direction.

7. The method for planning installation height and angle of a friction stir head for curved surface welding according to claim 5, wherein: When the surface of the welding workpiece is concave, the position of the point laser source (4) is adjusted so that the point light spot generated by the point laser source (4) on the surface of the welding workpiece coincides with point O. At this time, the height of the cone-shaped emission source (3) from the weld seam (11) is the spatial position where the friction stirring head is pressed down to reach the surface of the welding workpiece.

8. The method for planning installation height and angle of a friction stir head for curved surface welding according to claim 5, wherein: The small circular light spot and the large circular light spot in the two concentric circular light spots intersect with the first line light source (1) and the second line light source (2) respectively to generate line segment AB, line segment CD, line segment EF, and line segment GH; When the surface of the welding workpiece is convex, the position of the point laser source (4) is adjusted so that the point light spot generated by the point laser source (4) on the surface of the welding workpiece coincides with point B. At this time, the height of the cone-shaped emission source (3) from the weld seam (11) is the spatial position where the friction stirring head is pressed down to reach the surface of the welding workpiece.

9. The method for planning installation height and angle of a friction stir head for curved surface welding according to claim 5, characterized in that: Before adjusting the angle of the friction stir welding head in the friction stir welding robot, the position of the upper head of the friction stir welding robot is adjusted first so that the line light spot generated by the second line light source (2) on the surface of the welding workpiece coincides with the weld (11).

10. The method for planning installation height and angle of a friction stir head for curved surface welding according to claim 6, wherein: The friction stir welding robot is operated according to the captured image of the welding workpiece surface so that the pixel lengths of line segment AB and line segment CD are equal, and the pixel lengths of line segment EF and line segment GH are equal, thereby determining the angle of the friction stir welding head in the friction stir welding robot, including: When the pixel length of the line segment AB in the image captured by the camera (5) is less than the pixel length of the line segment CD, it indicates that the central axis of the conical emission source (3) is tilted to the left; conversely, when the pixel length of the line segment AB is greater than the pixel length of the line segment CD, it indicates that the central axis of the conical emission source (3) is tilted to the right; in the case of tilting to the left or right, the head of the machine is adjusted so that the head is tilted in the opposite direction until the pixel length of the line segment AB is equal to the pixel length of the line segment CD; When the pixel length of the line segment EF in the image captured by the camera (5) is less than the pixel length of the line segment GH, it indicates that the central axis of the conical emission source (3) is tilted forward; conversely, when the pixel length of the line segment EF is greater than the pixel length of the line segment GH, it indicates that the central axis of the conical emission source (3) is tilted backward; in the case of tilting forward or backward, the head of the machine is adjusted so that the head is tilted in the opposite direction until the pixel length of the line segment EF is equal to the pixel length of the line segment GH.

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