A method for manufacturing a split-welded aluminum profile machine part

Abstract

This invention discloses a manufacturing method for a machined aluminum profile with split welding, comprising: symmetrically dividing the target aluminum profile into four independent blanks along its length, ensuring that the first and third blanks, and the second and fourth blanks have identical shapes; pre-finishing the non-welding surfaces of each blank to the final product dimensions; reserving a thickening allowance in the welding joint area; machining elongated positioning bosses and positioning grooves on the mating surfaces of adjacent blanks to achieve precise linear positioning along the entire length; forming a thickened allowance at the welding edge and machining a chamfer; sequentially butt-fitting the four blanks together, uniformly pre-tightening them using a segmented fixture, and then welding three equal-length welds using pulsed argon arc welding in the order of first the middle and then the sides; finally removing the thickened allowance by CNC milling or precision grinding, ensuring a smooth transition between the welding area and the formed surface, and maintaining the pre-welding precision of the non-welding surfaces without requiring further overall finishing. This invention can significantly reduce welding deformation and scrap rate, and improve production efficiency and product qualification rate.

Description

Technical Field

[0001] This invention relates to the technical field of precision machining and welding of aluminum profiles, and particularly to a method for manufacturing machined aluminum profile parts that are welded separately. Background Technology

[0002] Large and complex aluminum profile machining parts are difficult to form in one step through integral extrusion or integral machining due to their irregular cross-sections, deep cavities, large spans, and thin walls. Existing technologies mostly use two-part segmented welding, which has problems such as clamping difficulties, large welding deformation, wide heat-affected zones, insufficient weld strength, and difficulty in guaranteeing dimensional accuracy. Moreover, existing processes are mostly one-time welding, lacking closed-loop process control such as segmented temperature control, step-by-step stress release, positioning pre-tightening, and precise allowance removal, resulting in low finished product qualification rate, low production efficiency, and high costs. Summary of the Invention

[0003] This invention aims to at least partially solve one of the problems in related technologies. Therefore, one objective of this invention is to provide a method for manufacturing machined aluminum profiles with split welding, enabling high-precision forming, minimal welding deformation, high weld strength, and high-efficiency, low-cost industrial manufacturing of complex aluminum profile machined parts.

[0004] A method for manufacturing a machined aluminum profile with separate welded sections, the method comprising the following steps: The target aluminum profile machining part is symmetrically divided into four independent blanks along the length direction, so that the first blank and the third blank have the same shape, and the second blank and the fourth blank have the same shape. The non-welding surface of each blank is finished to the final product size, and a thickening machining allowance is reserved in the welding joint area. Elongated positioning bosses and elongated positioning grooves are machined on the mating surfaces of adjacent blanks respectively; Thickened pre-reserved portions are formed at the welding edges of each blank; The four blanks are connected sequentially, and the positioning boss is fully embedded in the positioning groove, and a segmented clamp is used for pre-tightening. Three equal-length welds were sequentially welded using pulsed argon arc welding. Remove the thickened pre-reserved portion and process the welding area to the final forming thickness of the product, so that the weld area and the forming surface transition smoothly.

[0005] Furthermore, in the step of machining elongated positioning bosses and elongated positioning grooves on the mating surfaces of adjacent blanks, the positioning bosses and the positioning grooves extend along the entire length of the mating surfaces of the blanks to form a linear positioning structure.

[0006] Furthermore, in the step of sequentially welding three equal-length welds using pulsed argon arc welding, the middle weld is welded first, followed by symmetrical welding of the two side welds, with the three welds being of equal length.

[0007] Furthermore, in the step of sequentially welding three equal-length welds using pulsed argon arc welding, a pulsed argon arc welding system specifically designed for aluminum profiles is employed.

[0008] Furthermore, in the step of removing the thickened pre-reserved portion and machining the welding area to the final forming thickness of the product to ensure a smooth transition between the weld area and the forming surface, CNC milling or precision grinding is used to remove the thickened pre-reserved portion.

[0009] Furthermore, in the step of machining elongated positioning bosses and elongated positioning grooves on the mating surfaces of adjacent blanks, the depth of the positioning bosses and the positioning grooves is 0.8mm-3mm, and the fitting clearance is 0.05mm-0.1mm.

[0010] Furthermore, in the step of forming a thickened reserved area at the welding edge of each blank, the thickening amount is 1mm-5mm.

[0011] Furthermore, in the step of forming a thickened reserved portion at the welding edge of each blank, the edge of the reserved portion is chamfered, and the chamfer angle is 30°-45°.

[0012] Furthermore, in each step of removing the thickened pre-reserved area, the welding area is machined to the final forming thickness of the product to ensure a smooth transition between the weld area and the forming surface, using CNC milling or precision grinding.

[0013] Furthermore, in the steps of removing the thickened reserved portion and processing the welding area to the final forming thickness of the product to ensure a smooth transition between the weld area and the forming surface, no overall re-finishing is performed after welding. Only the thickened reserved portion area is removed, and the non-welding surface retains the pre-welding finishing dimensions.

[0014] Compared with the prior art, the technical solution provided in this application has the following advantages: By breaking down large-sized parts into smaller parts, the rigidity of individual parts is improved, clamping is more stable, processing vibration is reduced, and dimensional and positional tolerances are easier to guarantee; symmetrical structures can share a set of tooling and molds, reducing investment; damage to the machined surface is avoided by the welding heat-affected zone, reducing post-weld processing and controlling deformation from the source; point positioning is upgraded to line positioning, resulting in a larger contact area, stronger resistance to torsion and misalignment, and significantly improved assembly consistency; the mating pressure of the butt joint surfaces is uniform, avoiding excessive local gaps that lead to incomplete penetration, depressions, and porosity; long welds are broken down into short welds, dispersing heat input, reducing thermal strain, and significantly reducing overall deformation. Therefore, this application can achieve high-precision forming, small welding deformation, high weld strength, and high-efficiency, low-cost industrial manufacturing of complex aluminum profile machined parts. Attached Figure Description

[0015] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] In the attached image: Figure 1 This is a schematic flowchart illustrating an embodiment of the manufacturing method for machined aluminum profiles with separate welded sections according to this application. Figure 2 This is a schematic diagram of the manufacturing method for the machined aluminum profile parts to be welded separately according to this application.

[0018] Figure label: 10. First blank; 20. Second blank; 30. Third blank; 40. Fourth blank; 50. Positioning boss; 60. Positioning groove. Detailed Implementation

[0019] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0020] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are 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.

[0021] like Figure 1 , Figure 2 As shown, this application provides a method for manufacturing a machined aluminum profile with split welding, comprising the following steps: The target aluminum profile machining part is symmetrically divided into four independent blanks along the length direction, so that the first blank 10 and the third blank 30 have the same shape, and the second blank 20 and the fourth blank 40 have the same shape. The non-welding surface of each blank is finished to the final product size, and a thickening machining allowance is reserved in the welding joint area. Elongated positioning bosses 50 and elongated positioning grooves 60 are machined on the mating surfaces of adjacent blanks, respectively. Thickened pre-reserved portions are formed at the welding edges of each blank; The four blanks are connected in sequence, and the positioning boss 50 and the positioning groove 60 are fully embedded and fitted together, and pre-tightened by a segmented clamp. Three equal-length welds were sequentially welded using pulsed argon arc welding. Remove the thickened pre-reserved portion and process the welding area to the final forming thickness of the product, so that the weld area and the forming surface transition smoothly.

[0022] The target aluminum profile is symmetrically divided into four independent blanks along its length, forming the first blank 10, the second blank 20, the third blank 30, and the fourth blank 40. The first blank 10 and the third blank 30 have the same geometry, and the second blank 20 and the fourth blank 40 have the same geometry. The non-welding surfaces of each blank are directly precision machined to the final product dimensions, and a thickening allowance is reserved in the welding joint area.

[0023] First, based on the product's 3D digital model, the overall structure is symmetrically divided into four parts, making it lightweight and small, thus reducing the difficulty of machining and clamping. The non-welding surfaces of each part (outer surface, cavity surface, and mounting reference surface) are directly CNC machined to the final product dimensions before welding, avoiding the risk of deformation caused by large-area secondary machining after welding. A thickened allowance is intentionally retained in the welding joint area to provide material space for welding deposition and subsequent finishing.

[0024] On the mating surfaces of adjacent blanks, a long strip-shaped positioning boss 50 and a positioning groove 60 are machined using precision milling to create a linear guiding constraint during the mating process. During assembly, the boss and groove are fully embedded along their length, and a segmented fixture is used to pre-tighten them evenly along the weld seam to ensure uniform mating gaps, no misalignment, and no warping.

[0025] Welding employs pulsed argon arc welding, forming three weld seams of uniform length to ensure even heat distribution. After welding, the thickened pre-reserved portion is precisely removed by CNC milling or grinding, ensuring that the welded area and the original forming surface are of the same size and smoothly transition, ultimately resulting in a high-precision finished product.

[0026] This combined process controls errors across the entire chain, from structural disassembly and positioning to welding and finishing, resulting in simpler processing, more precise assembly, more stable welding, less deformation, and a higher yield. Compared to traditional two-piece welding, it improves production efficiency, reduces scrap rates, and lowers unit costs, making it suitable for mass production of high-precision, complex aluminum profile machined parts.

[0027] Furthermore, in the step of machining elongated positioning bosses 50 and elongated positioning grooves 60 on the mating surfaces of adjacent blanks, the positioning bosses 50 and the positioning grooves 60 extend along the entire length of the mating surfaces of the blanks to form a linear positioning structure.

[0028] During CNC machining, the positioning boss 50 and positioning groove 60 extend continuously from one end of the mating surface to the other without any breaks, necking, or local weakening, forming a linear guide and mechanical interlocking structure that runs the entire length. During assembly, the boss and groove are gradually embedded along the length direction, achieving full-length constraint. Traditional point-like or short-segment positioning can only achieve local constraint. In long-span aluminum profiles, the blank is prone to torsion, swaying, and misalignment. Especially under the action of welding thermal stress, local positioning cannot resist the overall deformation trend.

[0029] When the positioning structure extends its full length, the positioning contact area is maximized, stress is evenly distributed along the length, and local stress concentration is avoided. Linear constraints provide continuous guidance, automatically centering the blanks during assembly and reducing reliance on manual labor and tooling. Shear, torsion, and misalignment resistance are significantly improved, and the relative displacement of the blanks during welding approaches zero. The weld gap is uniform throughout, the penetration depth and forming are more stable, and the defect rate is greatly reduced. Linear positioning improves assembly accuracy from millimeters to micrometers, enhances weld uniformity, and virtually eliminates misalignment and offset defects. Post-weld dimensional stability is stronger, eliminating the need for repeated corrections and significantly improving production cycle time and consistency.

[0030] Furthermore, in the step of sequentially welding three equal-length welds using pulsed argon arc welding, the middle weld is welded first, followed by symmetrical welding of the two side welds, with the three welds being of equal length.

[0031] After assembly and fixation, the second weld in the middle is welded first. After cooling, the first and third welds are welded sequentially. Welding on both sides uses a symmetrical path, the same parameters, and the same speed to ensure symmetrical and balanced heat input. Welding deformation is essentially residual stress caused by uneven thermal expansion and contraction. Welding long seams in one go leads to heat accumulation and uncontrollable deformation. By adopting a welding method that starts with the middle weld and then proceeds to the sides, and using equal-length symmetrical welding, the middle weld first forms a rigid constraint, providing a positioning reference for the side welds and suppressing overall offset. Equal-length welds ensure consistent heat input per unit length, a symmetrical temperature field, and mutual cancellation of shrinkage strain. Step-by-step welding allows for cooling after each weld, avoiding heat accumulation. Symmetrical welding ensures opposite deformation trends on the left and right sides, mutually constraining each other, ultimately significantly improving flatness and straightness. Compared to traditional one-time welding, the overall welding deformation is reduced, and flatness can be stably controlled within 0.1mm / m, requiring no correction or post-weld pressure shaping, significantly improving efficiency and yield.

[0032] Furthermore, in the step of sequentially welding three equal-length welds using pulsed argon arc welding, a pulsed argon arc welding system specifically designed for aluminum profiles is employed.

[0033] Using an AC pulsed TIG welding machine equipped with high-purity argon protection, stable welding is achieved by controlling the molten pool size and heat input through pulsed current. Aluminum alloys have high thermal conductivity, thick oxide films, are prone to burn-through, and are prone to porosity. Ordinary constant current welding has a large heat input and the molten pool is difficult to control. Pulsed TIG welding uses pulsed current for periodic heating, resulting in a lower average heat input and a narrower heat-affected zone; pulsed stirring of the molten pool promotes gas escape, significantly reducing porosity; the penetration depth is controllable, and the weld is uniform, making it suitable for thin-walled, high-precision parts; the AC mode can break up the oxide film, ensuring good fusion.

[0034] Furthermore, in the step of removing the thickened pre-reserved portion and machining the welding area to the final forming thickness of the product to ensure a smooth transition between the weld area and the forming surface, CNC milling or precision grinding is used to remove the thickened pre-reserved portion.

[0035] Using a high-precision machining center, the weld seam is milled in layers along its length; or a surface grinder / cylindrical grinder is used for grinding to precisely machine the thickened area to the final dimensions. The thickened pre-reserved portion must be removed evenly, ensuring it is level with the forming surface, without steps or stress concentration. The CNC milling or grinding toolpath is controllable, resulting in precise removal with a tolerance of ±0.05mm; the cutting force is stable, preventing secondary deformation; surface roughness is controllable, directly meeting finished product requirements; only the weld seam area is machined, while non-welded surfaces maintain pre-welding precision. The final dimensions are extremely consistent, with a smooth surface transition, requiring no manual grinding, and the product appearance and assembly precision meet the requirements of high-end equipment.

[0036] Furthermore, in the step of machining elongated positioning bosses 50 and elongated positioning grooves 60 on the mating surfaces of adjacent blanks, the depth of the positioning bosses 50 and the positioning grooves 60 is 0.8mm-3mm, and the fitting clearance is 0.05mm-0.1mm.

[0037] Dimensions are controlled through precision milling, ensuring the boss height matches the groove depth, with the gap strictly controlled within a minute range. When the depth is <0.8mm, insufficient positioning strength leads to easy shearing damage; when the depth is >3mm, assembly becomes difficult, stress concentrates, and processing costs increase; when the gap is <0.05mm, the insertion becomes stuck, there is no space for thermal expansion, and it is prone to bending; when the gap is >0.1mm, positioning fails, and misalignment and offset increase. This range achieves the optimal balance of easy assembly, strong positioning, small gap, and low stress, simultaneously optimizing positioning accuracy and assembly efficiency.

[0038] Furthermore, in the step of forming a thickened reserved area at the welding edge of each blank, the thickening amount is 1mm-5mm.

[0039] Thickening the weld edge by 1-5mm ensures sufficient wall thickness after welding. When the thickening is less than 1mm, the allowance is insufficient, leading to weld dents, insufficient wall thickness, and inadequate strength. When the thickening is greater than 5mm, material waste, excessive material removal, long processing time, and increased costs occur. A balance is struck between strength, allowance, cost, and efficiency, resulting in reliable weld strength and precise final dimensions.

[0040] Furthermore, in the step of forming a thickened reserved portion at the welding edge of each blank, the edge of the reserved portion is chamfered, and the chamfer angle is 30°-45°.

[0041] The chamfering of the reserved part's edge can remove sharp burrs, preventing scratches to tooling and operators during assembly and welding. At the same time, it increases the operating space of the argon arc welding torch, making it easier for the torch to move steadily along the weld, reducing obstruction and interference, and preventing incomplete fusion defects at the weld edge. This angle range will not excessively weaken the cross-sectional strength of the reserved part, and it can also meet the operating space requirements of the welding torch, avoiding sharp edge interference due to an excessively small chamfer angle, or unnecessary material waste due to an excessively large chamfer angle.

[0042] Furthermore, in each step of removing the thickened pre-reserved area, the welding area is machined to the final forming thickness of the product to ensure a smooth transition between the weld area and the forming surface, using CNC milling or precision grinding.

[0043] This processing method only processes the thickened reserved area. The tool path is precise and controllable, and the amount of material removed can be stably controlled with a tolerance accuracy of ±0.05mm. The cutting force is uniform and stable, and it will not introduce additional processing deformation to the workpiece as a whole. The surface roughness after processing can directly meet the requirements of the finished product, without the need for subsequent manual grinding and correction.

[0044] Furthermore, in the steps of removing the thickened reserved portion and processing the welding area to the final forming thickness of the product to ensure a smooth transition between the weld area and the forming surface, no overall re-finishing is performed after welding. Only the thickened reserved portion area is removed, and the non-welding surface retains the pre-welding finishing dimensions.

[0045] Since the non-welding surfaces of each blank have been precision machined to the final product dimensions before welding, and only the weld area has a reserved thickening amount, only the weld area needs to be machined. There is no need to perform secondary overall machining on the entire workpiece. This reduces the amount of post-weld machining, shortens the processing cycle, avoids the reintroduction of stress deformation by large-scale machining, and preserves the precision of pre-weld machining, greatly improving processing efficiency and reducing processing costs.

[0046] It is understood that the above embodiments only illustrate preferred embodiments of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can freely combine the above technical features without departing from the concept of the present invention, and can also make several modifications and improvements, all of which fall within the protection scope of the present invention. Therefore, all equivalent transformations and modifications made with respect to the scope of the claims of the present invention should fall within the scope of the claims of the present invention.

Claims

1. A method for manufacturing a machined aluminum profile with separate welded sections, characterized in that, Includes the following steps: The target aluminum profile machining part is symmetrically divided into four independent blanks along the length direction, so that the first blank and the third blank have the same shape, and the second blank and the fourth blank have the same shape. The non-welding surface of each blank is finished to the final product size, and a thickening machining allowance is reserved in the welding joint area. Elongated positioning bosses and elongated positioning grooves are machined on the mating surfaces of adjacent blanks respectively; Thickened pre-reserved portions are formed at the welding edges of each blank; The four blanks are connected sequentially, and the positioning boss is fully embedded in the positioning groove, and a segmented clamp is used for pre-tightening. Three equal-length welds were sequentially welded using pulsed argon arc welding. Remove the thickened pre-reserved portion and process the welding area to the final forming thickness of the product, so that the weld area and the forming surface transition smoothly.

2. The manufacturing method of a machined aluminum profile with split welding according to claim 1, characterized in that, In the step of machining elongated positioning bosses and elongated positioning grooves on the mating surfaces of adjacent blanks, the positioning bosses and the positioning grooves extend along the entire length of the mating surfaces of the blanks to form a linear positioning structure.

3. The manufacturing method of a machined aluminum profile with split welding according to claim 1, characterized in that, In the process of sequentially welding three equal-length welds using pulsed argon arc welding, the middle weld is welded first, followed by symmetrical welding of the two side welds, with all three welds being of equal length.

4. The manufacturing method of a machined aluminum profile with split welding according to claim 1, characterized in that, In the process of sequentially welding three equal-length welds using pulsed argon arc welding, a special pulsed argon arc welding system for aluminum profiles is used.

5. The manufacturing method of a machined aluminum profile with split welding according to claim 1, characterized in that, In the process of removing the thickened pre-reserved portion and machining the welding area to the final product thickness to ensure a smooth transition between the weld area and the forming surface, CNC milling or precision grinding is used to remove the thickened pre-reserved portion.

6. The manufacturing method of a machined aluminum profile with split welding according to claim 1, characterized in that, In the step of machining elongated positioning bosses and elongated positioning grooves on the mating surfaces of adjacent blanks, the depth of the positioning bosses and the positioning grooves is 0.8mm-3mm, and the fitting clearance is 0.05mm-0.1mm.

7. The manufacturing method of a machined aluminum profile with split welding according to claim 1, characterized in that, In the step of forming a thickened reserved area at the welding edge of each blank, the thickening amount is 1mm-5mm.

8. The manufacturing method of a machined aluminum profile with split welding according to claim 1, characterized in that, In the step of forming a thickened reserved portion at the welding edge of each blank, the edge of the reserved portion is chamfered, and the chamfer angle is 30°-45°.

9. The manufacturing method of a machined aluminum profile with split welding according to claim 1, characterized in that, In the process of removing the thickened pre-reserved parts and machining the welding area to the final forming thickness of the product to ensure a smooth transition between the weld area and the forming surface, CNC milling or precision grinding is used.

10. The manufacturing method of a machined aluminum profile with split welding according to claim 1, characterized in that, In the process of removing the thickened pre-reserved portion and machining the welding area to the final forming thickness of the product to ensure a smooth transition between the weld area and the forming surface, no overall re-finishing is performed after welding. Only the thickened pre-reserved portion area is removed, while the non-welding surface retains the pre-welding finishing dimensions.

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