A method for welding a radar aluminum alloy reflector mesh

Abstract

The application discloses a welding method for a radar aluminum alloy reflecting net surface, and adopts the following measures for welding: 1) 20-40 process holes are punched on each vertical support plate of a parabolic structure, and a spring hook is installed on each process hole to paste the reflecting net to the vertical support; 2) a handheld laser welding is adopted, a wire is manually fed, the wire is Φ1.2mm-Φ2mm, the angle of wire feeding is 10-15°, and the gun mouth of the welding gun is 75°-90°; 3) laser welding parameters: argon protection is adopted, the peak power of the laser is 800-1000W, the spot welding duration is 700ms, and the spot welding interval time is 500ms; 4) welding sequence: taking the center as a reference point, welding is carried out from the center of the reflecting net to the periphery, and the distance between each welding point is 8mm-12mm; and 5) selecting a wire feeding mode: the wire feeding direction into the molten pool is distinguished according to the position of the reflecting net after being pasted to the vertical support. The welding method reduces the risk of fusing and deforming the reflecting net.

Description

Technical Field

[0001] This invention relates to the welding process of aluminum alloy reflector mesh for a certain type of low-altitude early warning radar, and more particularly to a welding method for the aluminum alloy reflector mesh of a radar. Background Technology

[0002] The radar reflector surface, also known as the reflector cross section, is an equivalent area. When the radar illumination energy intercepted by this area is scattered isotropically in all directions, the scattered power within a unit solid angle is exactly equal to the power scattered by the target within a unit solid angle toward the receiving antenna.

[0003] A certain type of radar reflector is made of aluminum alloy, which is lightweight and corrosion-resistant. The reflector has a parabolic structure with an area of ​​approximately 40 square meters and more than 10,000 weld points. The reflector is 1.2 mm thick, while the vertical support plate is 4 mm thick. The mesh openings are too small, and argon arc welding is used for welding. However, the spot welding between the reflector and the support plate causes significant deformation, making the reflector prone to melting and resulting in problems such as out-of-tolerance surface precision.

[0004] To meet the welding requirements in the process of manufacturing radar aluminum alloy reflector mesh, further exploration of welding technology is needed. Summary of the Invention

[0005] The purpose of this invention is to provide a welding method for radar aluminum alloy reflective mesh to solve the problems of easy melting and failure of reflective mesh and excessive precision of mesh surface.

[0006] To address this, the present invention provides a welding method for an aluminum alloy radar reflector mesh, employing the following measures: 1) Drilling 20-40 process holes on each vertical support plate of the parabolic structure, and installing spring hooks on each process hole to attach the reflector mesh to the vertical support; 2) Using handheld laser welding, manually feeding the welding wire (Φ1.2mm-Φ2mm), with a feeding angle of 10-15° and a welding torch nozzle angle of 75°-90°; 3) Selecting laser welding parameters: using argon gas protection, a laser peak power of 800-1000W; a spot welding duration of 700ms and a spot welding interval of 500ms; 4) Determining the welding sequence: using the center as the reference point, welding is performed from the center of the reflector mesh outwards, with a distance of 8mm-12mm between each welding point; 5) Selecting the wire feeding method: distinguishing the direction of the welding wire feeding into the molten pool based on the position of the reflector mesh after it is attached to the vertical support plate: ① manually feeding the wire from the top front, ② manually feeding the wire from the bottom back, ③ manually feeding the wire from the left front.

[0007] This invention has the following technical features / advantages: 1. Laser welding, even with manual wire feeding, can achieve high-precision welding. By controlling the focal position and power of the laser beam, the welding depth and width can be precisely controlled. This is crucial for radar reflector applications requiring high surface precision. In non-contact welding positions, the laser beam can complete the welding without direct contact with the workpiece surface. The use of a ceramic backing makes welding between thin reflector components much easier and reduces the risk of melting and deformation of the reflector.

[0008] 2. Laser welding offers rapid welding speeds. The high energy density of the laser beam can quickly heat and cool metal materials, thereby shortening the welding cycle, improving production efficiency, and reducing costs.

[0009] 3. The heat-affected zone (HAZ) of laser welding is smaller compared to traditional argon arc welding. Due to the high energy density of the laser beam and the high welding speed, laser welding can minimize the diffusion of heat around the welding area, thereby reducing the size of the HAZ and helping to maintain the original properties and material characteristics of the workpiece.

[0010] 4. The welding sequence for laser welding is as follows: starting from the center of the reflective mesh and proceeding outwards from the central reference point, with each welding point spaced 8mm-12mm apart to reduce welding deformation of the mesh surface (small deformation) and ensure surface accuracy <0.08mm.

[0011] In addition to the objectives, features, and advantages described above, the present invention has other objectives, features, and advantages. The invention will now be described in further detail with reference to the figures. Attached Figure Description

[0012] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 A schematic diagram showing the laying status of a certain type of radar reflector mesh is shown; Figure 2 A schematic diagram shows the reflective mesh surface being attached to a vertical support via spring hooks; Figure 3 This shows the working state of handheld laser welding on a reflective mesh surface; Figure 4 The image shows a scene of handheld laser welding of reflective mesh. Figure 5 A schematic diagram of the structure of the welded reflective mesh surface is shown; Figure 6 This is a flowchart of the welding method for the radar aluminum alloy reflective mesh of the present invention. Detailed Implementation

[0013] The present invention will be described in detail below with reference to the embodiments.

[0014] The radar reflector mesh material is 6063, and the vertical support plate material is 3A21. The chemical composition of the reflector mesh is listed in Table 1, and the mechanical properties are listed in Table 2.

[0015] Table 1: Chemical composition of aluminum alloys (mass fraction, %)

[0016] Table 2: Mechanical Properties of Aluminum Alloys

[0017] like Figure 6 As shown, the aluminum alloy reflective mesh is welded using a handheld laser welder with manual wire feeding, as detailed below: S1. Determine the process holes to be drilled on the vertical support plate before welding, increase the number of spring hooks, and reduce the gap t between the reflective mesh and the vertical support plate (0≤t<0.08mm).

[0018] exist Figure 1 In the process, the reflective mesh 1, which has a herringbone pattern, is laid on the vertical support plate 2 and is hung on the process holes 4 of the vertical support plate 2 by spring hooks 3, as shown in the figure below. Figure 2 As shown.

[0019] S2. Handheld laser welding is adopted, with manual wire feeding. The welding wire is Φ1.2mm-Φ2mm, the wire feeding angle is 10-15°, the welding torch nozzle angle is 75-90°, and the welding torch is held vertically against or not against the welding position. Figure 3 and Figure 4 As shown.

[0020] exist Figure 3 The welding torch 5 is placed against the welding position of the reflective mesh 1 and the welding wire 6 is fed. Figure 4 The staff member held a laser welder, stood in front of the reflective mesh 1, aimed at the welding position of the reflective mesh 1, fed the wire, and performed laser welding.

[0021] S3, using argon gas protection, scanning speed 400.0mm / s, scanning width 2.00-3.00mm, peak power 800-1000W; pulse frequency 2000Hz, spot welding duration 700ms, spot welding interval 500ms.

[0022] S4. Welding is carried out from the center of the reflective mesh outwards to reduce welding deformation and ensure surface accuracy.

[0023] S5. Determine the manual wire feeding method for welding based on the position of the reflective mesh and the vertical support plate: ① When the vertical support plate is in contact with the reflective mesh, the welding wire is manually fed from the top front; ② When some of the reflective mesh is in contact with some of the vertical and horizontal support plates, the welding wire is manually fed from the bottom rear; ③ When the horizontal support plate is in contact with the reflective mesh, the welding wire is manually fed from the left front.

[0024] Figure 5 The welding process diagram of the square mesh reflector is shown. The welding area forms a roughly circular weld point 7. The weld point 7 has a small area and does not affect / damage the surrounding reflector mesh. The spring hook 3 is removed after the entire reflector mesh is welded.

[0025] Other welding conditions are as follows: aluminum alloy reflective mesh and vertical support plates require sandblasting surface treatment, and handheld laser welding requires the use of compressed air.

[0026] The welding method of the present invention comprehensively covers the welding of radar aluminum alloy reflective mesh surfaces, and the implementation effect meets the technical conditions of current relevant standards. It can be practically applied to the welding of radar aluminum alloy reflective mesh surface structures.

[0027] The above description is merely an embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, substitutions, or improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A welding method for a radar aluminum alloy reflector mesh, characterized in that, include: 1) Drill 20-40 process holes on each vertical support plate of the parabolic structure, and install spring hooks on each process hole to attach the reflective mesh to the vertical support plate; 2) Handheld laser welding is adopted, with manual wire feeding. The welding wire is... 1.2mm— 2mm, wire feed angle is 10-15°, welding torch nozzle angle is 75°-90°; 3) Select laser welding parameters: use argon gas protection, laser peak power 800-1000W; spot welding duration 700ms, spot welding interval 500ms; 4) Determine the welding sequence: Using the center as the reference point, weld from the center of the reflective mesh outwards, with each welding point 8mm-12mm apart; 5) Selecting the wire feeding method: The direction of wire feeding into the molten pool is determined by the position of the reflective mesh after it is attached to the vertical support plate, including: ① manual wire feeding from the top front, ② manual wire feeding from the bottom rear, ③ manual wire feeding from the left front. ① When the vertical support plate is in contact with the reflector mesh, the welding wire is manually fed from the top front; ②When part of the critical reflective mesh around the perimeter is in contact with part of the vertical and horizontal support plates, manually feed the wire from the bottom rear. ③ When the horizontal and vertical support plates are in contact with the reflective mesh, manually feed the wire from the left front.

2. The welding method for the radar aluminum alloy reflector mesh according to claim 1, characterized in that, The radar reflector mesh is made of 6063 aluminum alloy, and the vertical support plate is made of 3A21 aluminum alloy.

3. The welding method for the radar aluminum alloy reflector mesh according to claim 1, characterized in that, The reflective mesh is 1.2 mm thick, the vertical support plate is 4 mm thick, and the mesh openings are square, rhomboid, or herringbone.

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