A high-efficiency laser welding method for large-spacing double-sided lock bottom structure

Abstract

The present invention provides a high-efficiency laser welding processing method for a large-pitch double-sided lock bottom structure, comprising the following steps: measuring the typical dimensions and characteristic trajectories of the connecting seams to be welded on both sides of the double-sided lock bottom structure to be welded; setting the process parameters of the oscillating laser composite power modulation welding method according to the obtained typical dimensions and characteristic trajectories; welding the large-pitch double-sided lock bottom structure to be welded according to the set process parameters; the present invention can obtain two welds through one welding to realize the laser welding processing of the large-pitch double-sided lock bottom structure, thereby reducing the number of welding times and improving welding and production efficiency; this high-efficiency welding processing method has important economic value and engineering significance for reducing the welding processing cost of structural components and the rapid delivery of key products.

Description

Technical Field

[0001] The present invention belongs to the field of material welding, and in particular relates to a high-efficiency laser welding processing method for a large-spacing double-sided bottom-locking structure. Background Art

[0002] Welding is a common connection method in structural engineering. While ensuring weld quality, improving welding efficiency, thereby reducing welding costs and shortening product delivery cycles, is a key concern in practical production. Double-side lock-bottom structures are a common welded connection structure, widely used in aerospace and other fields. For large-pitch double-side lock-bottom structures, TIG welding is typically used to weld the lock bottom sections on both sides separately, completing the process in two separate welding steps. However, TIG welding itself is inherently inefficient, and the long two-step process reduces overall efficiency. The introduction of high-energy beam welding, such as laser welding, has improved process efficiency due to the high laser energy density, enabling welding at higher speeds. However, the two-step laser welding process remains relatively cumbersome and time-consuming. Therefore, achieving single-step laser welding of large-pitch double-side lock-bottom structures would significantly improve production efficiency, significantly reducing the cost of structural components and accelerating the delivery of critical products. Summary of the Invention

[0003] The purpose of the present invention is to provide a high-efficiency laser welding processing method for a large-spacing double-sided lock bottom structure, which solves the problem of low welding processing efficiency of the double-sided lock bottom structure in the prior art.

[0004] In order to achieve the above object, the technical solution adopted in the present invention is:

[0005] The present invention provides a high-efficiency laser welding method for a large-pitch double-side lock bottom structure, comprising the following steps:

[0006] Measure the typical dimensions and characteristic trajectories of the welded joints on both sides of the double-sided lock bottom structure to be welded;

[0007] The process parameters of the oscillating laser composite power modulation welding method are set according to the obtained typical size and characteristic trajectory;

[0008] The large-spacing double-sided lock bottom structure to be welded is welded according to the set process parameters.

[0009] Preferably, the typical dimensions include the spacing between the connecting seams to be welded on both sides and the depth of the connecting seams to be welded on both sides; and the characteristic trajectory is the trajectory of the connecting seams to be welded on both sides.

[0010] Preferably, the process parameters of the oscillating laser composite power modulation welding method are set according to the obtained typical size and characteristic trajectory, and the specific method is:

[0011] Set the machining path trajectory in the process parameters according to the feature trajectory;

[0012] Set the machining swing direction in the process parameters according to the distance between the two sides of the weld seams in the typical size;

[0013] The laser power in the process parameters is set according to the depth of the joint seams to be welded on both sides in typical dimensions.

[0014] Preferably, the processing path trajectory is a centerline trajectory between the connecting seams to be welded on both sides.

[0015] Preferably, the processing swing direction is a lateral swing, and the swing direction is perpendicular to the path trajectory of the connecting seam to be welded.

[0016] Preferably, based on the depth H1 of the joint to be welded on one side, the laser power P1 on that side is set, wherein P1 is less than or equal to 2×(H1+1)kW; based on the depth H2 of the joint to be welded on the other side, the laser power P2 on that side is set, wherein P2 is less than or equal to 2×(H2+1)kW.

[0017] Preferably, the swing laser composite power modulation welding method is used to weld the large-spacing double-side lock bottom structure to be welded, and the specific method is:

[0018] When the swing starts from the center line trajectory, the laser output power is the lower value P3; when it swings close to the joint to be welded on one side, the laser power is adjusted to the higher value P1;

[0019] When swinging from one side of the joint to be welded to the other side and approaching the center line trajectory, adjust the laser power to a lower value P3;

[0020] When the laser is swung close to the seam to be welded on the other side, the laser power is adjusted to a larger value P2.

[0021] Preferably, the process parameters of the oscillating laser composite power modulation welding method are specifically:

[0022] The laser power range is 0-25kW, the welding speed range is 0-10m / min, the swing amplitude range is 0-20mm, and the swing frequency range is 0-500Hz.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] The present invention provides a high-efficiency laser welding processing method for a large-pitch double-sided lock bottom structure. Compared with the traditional TIG welding and non-swinging laser welding which are performed in two consecutive processes, under the welding mode of swinging laser composite power modulation, two welds can be obtained through one longitudinal movement, thereby realizing the laser welding processing of a large-pitch double-sided lock bottom structure and improving production efficiency. This high-efficiency laser welding processing method has important economic value and engineering significance for reducing the welding processing cost of structural components and the rapid delivery of key products. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 Schematic diagram (cross-section) of the typical dimensions of the large-pitch double-side lock bottom structure of the present invention;

[0026] Figure 2 Schematic diagram of the characteristic trajectory of the large-spacing double-sided bottom lock structure in the present invention (top view);

[0027] Figure 3 Schematic diagram of the laser swing direction and range in the present invention;

[0028] Figure 4 Schematic diagram of the power of the swing laser composite power modulation scheme in the present invention;

[0029] Figure 5 Schematic diagram of the weld prepared by oscillating laser composite power modulation in the present invention. DETAILED DESCRIPTION

[0030] The present invention is described in further detail below with reference to the accompanying drawings:

[0031] like Figures 1 to 5 As shown, the high-efficiency laser welding processing method of a large-pitch double-side lock bottom structure described in the present invention includes the following steps:

[0032] Step 1: Measure and define the typical dimensions and characteristic trajectories of the large-spacing double-sided lock bottom structure, determine three typical dimensions, namely, the spacing D between the two sides of the welded joints, the depths H1 and H2 of the two sides of the welded joints, and two characteristic trajectories, namely, the trajectories l1 and l2 of the two sides of the welded joints.

[0033] Step 2: Grind, clean, and dry the cross-section of the weld seam on both sides of the double-sided lock bottom structure and the surrounding area of ​​10 mm on the upper and lower surfaces to obtain a processed lock bottom structure ready for welding;

[0034] Step 3: Based on the trajectories l1 and l2 of the two seams to be welded, the centerline trajectory between the two seams to be welded is used as the path trajectory in the longitudinal direction of the welding process, and is realized by means of a robot or motion platform;

[0035] Step 4: Based on the distance D between the two seams to be welded, set the welding process swing direction and range. The welding swing direction is set to lateral swing, and the swing direction is perpendicular to the path of the seam to be welded. This is achieved by swinging the welding head or galvanometer. The welding process swing range is greater than or equal to D + 0.5 mm.

[0036] Step 5: Based on the depth H1 of the joint to be welded on one side, the laser power P1 on that side is set, wherein P1 is less than or equal to 2×(H1+1)kW; based on the depth H2 of the joint to be welded on the other side, the laser power P2 on that side is set, wherein P2 is less than or equal to 2×(H2+1)kW;

[0037] Step 6: Use a transversely oscillating laser and matching power modulation scheme to weld the large-spacing double-sided lock bottom structure to ensure the power requirements of the joints to be welded on both sides, while minimizing the power in the central local area between the joints to be welded on both sides.

[0038] Step 7: During the welding process, spot fixing or tooling can be used to position or limit the double-sided lock bottom structure to suppress welding deformation; after welding, heat treatment or vibration aging can be used to eliminate the welding residual stress of the double-sided lock bottom structure.

[0039] Specifically:

[0040] In step 1, according to the welding process of the present invention, the typical size and characteristic trajectory of the large-pitch double-sided lock bottom structure are first measured and defined, and the distance D of the joints to be welded on both sides of the double-sided lock bottom structure is determined (e.g. Figure 1 ), the depth of the weld seams on both sides to be welded H1 and H2 (such as Figure 1 ), the joint tracks l1 and l2 to be welded on both sides (such as Figure 2 ).

[0041] In step 2, the cross-section of the weld seam on both sides of the double-sided welded lock bottom structure before welding and the upper and lower surface areas are polished in sequence using 400, 1000, 1500, 2000, 2500 and 3000 grit sandpaper, and then cleaned and dried for subsequent use.

[0042] In step 3, the laser trajectory is determined according to the measurement results of the seam spacing D on both sides of the double-sided lock bottom structure, the seam trajectories l1 and l2 on both sides, and the actual needs of the structure. Specifically, the longitudinal trajectory during laser welding is set to be the center line trajectory between the seam trajectories l1 and l2 on both sides, that is, D / 2 (such as Figure 2 ).

[0043] In step 4, the laser swing direction and range are set as follows Figure 3 shown.

[0044] In step 5, the laser power is determined based on the measurement results of the depths H1 and H2 of the seams to be welded on both sides of the double-sided lock bottom structure. Specifically, based on the depth H1 of the seam to be welded on one side, the laser power P1 on that side is set, where P1 is less than or equal to 2×(H1+1)kW; based on the depth H2 of the seam to be welded on the other side, the laser power P2 on that side is set, where P2 is less than or equal to 2×(H2+1)kW; assuming that H1 is less than H2, then P1 is less than P2.

[0045] In step 6, a high-efficiency laser welding method with transversely oscillating laser and matching power modulation is used to weld the large-spacing double-sided lock bottom structure to ensure the power requirements of the joints to be welded on both sides, while minimizing the power of the central local area between the joints to be welded on both sides. The specific parameter selection range is: laser power range is 0-25kW, welding speed range is 0-10m / min, swing amplitude range is 0-20mm, and swing frequency range is 0-500Hz.

[0046] Power modulation is to control the laser beam energy by controlling the output of laser power at different swinging positions during the laser welding process. Specifically: when the swing starts from the center line, the laser output power is a lower value P3, where the value range of the lower value P3 is 0 to P1 / 2; when it swings to the vicinity of the connection seam on one side, the laser power is adjusted to a larger value P1; in the process of swinging to the other side to be welded, the laser power is still adjusted to a lower value P3 near the center line; then when the light beam reaches the vicinity of another to be welded, the laser power is adjusted to a larger value P2; and so on, and the two welds required for the double-sided lock bottom structure are obtained through one welding, so as to achieve high-efficiency welding of the two to-be-welded connection seams of the double-sided lock bottom structure with a large spacing (such as Figure 3 、 Figure 4 and Figure 5 shown).

[0047] At the same time, when the laser swings close to the joint to be welded, the range of the laser power P1 and P2 is greater than or equal to 0.25mm on both sides of the joint to be welded (such as Figure 4 ).

[0048] At the same time, considering the situation that the lengths of the l1 and l2 trajectories are not equal, when both sides need to be welded, the laser power is P1 and P2 respectively when it swings to the welding positions on both sides; when one side has been welded and the other side has not yet been welded, it swings to the welded side, the laser power is 0, and the set power is still output on the unwelded side.

[0049] In summary, the present invention proposes a high-efficiency welding method for large-pitch, double-sided, bottom-locked structures. Compared to the two-pass process of conventional TIG welding and non-oscillating laser welding, the oscillating laser composite power-modulated welding method produces two welds in a single longitudinal pass. This achieves high-efficiency laser welding of large-pitch, double-sided, bottom-locked structures, reduces the number of welds, and improves production efficiency. This high-efficiency welding method has significant economic value and engineering significance for reducing the welding costs of structural components and expediting the delivery of key products.

Claims

1. A high-efficiency laser welding method for a large-spacing double-side lock bottom structure, characterized in that: The following steps are involved: Measure the typical dimensions and characteristic trajectories of the welded joints on both sides of the double-sided lock bottom structure to be welded; The process parameters of the oscillating laser composite power modulation welding method are set according to the obtained typical size and characteristic trajectory; Welding is performed on the large-spacing double-side lock bottom structure to be welded according to the set process parameters; The process parameters of the oscillating laser composite power modulation welding method are set according to the obtained typical size and characteristic trajectory. The specific method is: Set the machining path trajectory in the process parameters according to the feature trajectory; Set the machining swing direction in the process parameters according to the distance between the two sides of the weld seams in the typical size; Set the laser power in the process parameters according to the depth of the joint seams to be welded on both sides in typical dimensions; The swing laser composite power modulation welding method is used to weld the large-spacing double-side lock bottom structure to be welded. The specific method is: When the swing starts from the center line trajectory, the laser output power is the lower value P3; when it swings close to the joint to be welded on one side, the laser power is adjusted to the higher value P1; When swinging from one side of the joint to be welded to the other side and approaching the center line trajectory, adjust the laser power to a lower value P3; When the laser swings close to the seam to be welded on the other side, adjust the laser power to the larger value P2; Among them, the larger value P1 is less than or equal to 2×(H1+1) kW; the larger value P2 is less than or equal to 2×(H2+1) kW; the lower value P3 ranges from 0 to P1 / 2; H1 is the depth of the joint to be welded on one side; H2 is the depth of the joint to be welded on the other side.

2. A high-efficiency laser welding method for a large-pitch double-side lock bottom structure according to claim 1, characterized in that: The typical dimensions include the spacing between the connecting seams to be welded on both sides and the depth of the connecting seams to be welded on both sides; the characteristic trajectory is the trajectory of the connecting seams to be welded on both sides.

3. The high-efficiency laser welding method for a large-spacing double-side bottom-locking structure according to claim 1 is characterized in that: The processing path trajectory is the center line trajectory between the connecting seams to be welded on both sides.

4. The high-efficiency laser welding method for a large-spacing double-side bottom-locking structure according to claim 1 is characterized in that: The processing swing direction is a lateral swing, and the swing direction is perpendicular to the path trajectory of the connecting seam to be welded.

5. The high-efficiency laser welding method for a large-spacing double-side bottom-locking structure according to claim 1 is characterized in that: The specific process parameters of the swing laser composite power modulation welding method are: The laser power range is 0-25kW, the welding speed range is 0-10 m / min, the swing amplitude range is 0-20 mm, and the swing frequency range is 0-500 Hz.

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