Welding method for aluminum alloy frame shaped like Chinese character'tian '

Abstract

The invention belongs to the technical field of welding, and discloses a welding method for an aluminum alloy material frame shaped like a Chinese character'tian ', which comprises the following steps: S1, determining operation equipment and the highest temperature value t of a welding arc during welding; s2, according to welding equipment, the welding voltage U, the welding current I and the welding speed v during welding are determined; s3, the maximum expansion and contraction amount of the aluminum alloy material in the free state during welding is determined; s4, determining the welding sequence of the frame shaped like the Chinese character'tian '; s5, reserved gaps of all welding seams during spot welding assembly are determined; s6, spot welding assembly is conducted on the workpiece; and S7, the workpieces are welded according to the determined welding sequence. Through calculation and practical experience, the welding sequence of the aluminum alloy material frame structure shaped like the Chinese character'tian 'in the welding process and the relation between the size of the reserved gap of the workpiece and the production environment temperature, the heat conductivity coefficient of the workpiece and the fixed point number of the workpiece shrinkage paths in the welding process are obtained, and therefore the purpose that the workpiece is changed with change in the welding process is achieved.

Description

Technical Field

[0001] This invention belongs to the field of welding technology and relates to a welding method for a grid-shaped frame made of aluminum alloy. Background Technology

[0002] With the continuous development of industrial technology, the demand for lightweight equipment is becoming increasingly prominent. Aluminum alloys, due to their low density, high specific strength and specific stiffness, as well as good corrosion resistance and other advantages, have been widely used in aerospace, armored vehicles, radar antennas, ships and other fields.

[0003] However, due to the high thermal conductivity of aluminum alloys (approximately 5 times that of low-carbon steel) and their large coefficient of thermal expansion (approximately 2 times that of low-carbon steel), deformation of aluminum alloys is difficult to control during welding, resulting in significant deformation and internal stress concentration in the welded workpiece. Consequently, the dimensions of the welded workpiece fail to meet usage requirements.

[0004] Currently, the industry primarily employs clamping and tooling to restrict deformation in aluminum alloy welding processes. However, the fundamental principle of these two methods is to hinder the natural deformation of the workpiece due to thermal expansion and contraction during welding by using external force. After welding, once the workpiece returns to room temperature, significant stress concentration occurs within the workpiece. Furthermore, clamping and tooling cannot guarantee that every part of the workpiece is securely fixed, and deformation often concentrates in areas where the clamping force is relatively weak. Therefore, these two methods cannot fundamentally solve the problem of welding deformation in aluminum alloy materials.

[0005] Compared to the two methods for preventing deformation in the welding process of aluminum alloy materials mentioned above, there are other methods in the industry such as the deformation method and the method of reserving shrinkage. However, in the welding process, welding process parameters such as the reserved and pre-deformation amounts need to be completed based on the operator's experience.

[0006] In particular, the welding of aluminum alloy "field" shaped frame structures is problematic because the components of this type of aluminum alloy frame are complex, there are many welds, and the heat input during welding is large. As a result, such workpieces are very prone to deformation during welding, and the welded workpieces cannot meet the usage requirements.

[0007] Therefore, there is an urgent need to develop a new welding method, especially a welding method for aluminum alloy grid-shaped frame structures. Summary of the Invention

[0008] (a) Purpose of the invention The purpose of this invention is to provide a welding method for a grid-shaped frame made of aluminum alloy, thereby reducing the deformation and stress concentration of the workpiece after welding. Compared with traditional welding processes that rely on clamping and tooling limitations, this invention addresses the welding of grid-shaped frame structures made of aluminum alloy by rationally planning the welding sequence and pre-emptively reserving welding deformation allowance, thus using deformation to control deformation and achieving the final welding effect, ensuring that the dimensions of the welded workpiece meet usage requirements. By calculating and deriving the relationship between various parameters during welding, the ideal processing effect is achieved, reducing the difficulty of worker operations and facilitating the further promotion of this welding method in related fields. This not only reduces the labor intensity of workers but also significantly improves the quality of the processed products.

[0009] (II) Technical Solution To address the aforementioned technical problems, this invention provides a method for welding a grid-shaped frame made of aluminum alloy, comprising the following steps: S1: Determine the equipment used for the operation and the maximum temperature t of the welding arc during welding; S2: Determine the welding voltage U, welding current I, and welding speed v based on the welding equipment; S3: Determine the maximum amount of expansion and contraction of the aluminum alloy material in its free state during welding; S4: Determine the welding sequence of the grid-shaped frame; S5: Determine the reserved gap for each weld during spot welding assembly; S6: Perform spot welding assembly on the workpiece; S7: Weld the workpiece according to the determined welding sequence.

[0010] Furthermore, in step S1, the working equipment selected is tungsten inert gas welding.

[0011] Furthermore, in step S4, the welding sequence is selected as diagonal welding.

[0012] Furthermore, in step S5, when the base material is welded at both ends, a reserved gap is left at each end.

[0013] Furthermore, in step S5, when the base material is welded at both ends, the gap reserved at the first end to be welded is 1 / 2 of the maximum expansion and contraction of the base material to be welded; the gap reserved at the second end to be welded is 1 / 3 of the maximum expansion and contraction of the base material to be welded.

[0014] Furthermore, in step S3, the relationship between the maximum expansion and contraction during welding and the nominal perimeter of the base material section, welding current, welding voltage, molten pool temperature, and welding speed is as follows:

[0015] Where L: maximum expansion and contraction of the material during welding; C: nominal perimeter of the base material cross-section; I: welding current; U: welding voltage; η: power coefficient of welding equipment; t: molten pool temperature; α: coefficient of linear expansion; v: welding speed.

[0016] Furthermore, the grid-shaped frame includes, in the shape of the grid, a horizontal beam I1 arranged at the top, a horizontal beam II2 arranged at the bottom, a longitudinal beam I3 arranged on the left, a longitudinal beam II4 arranged on the right, a horizontal beam III5 arranged in the middle, a short beam I6 arranged between horizontal beams I1 and III5, and a short beam II7 arranged between horizontal beams II2 and III5. The short beams I6 and II7 are collinear and parallel to the longitudinal beams I3 and II4, respectively.

[0017] Furthermore, within the grid-shaped frame, flat welds H1 and H2 are formed between the ends of longitudinal beam I3 and transverse beams I1 and II2, respectively; flat welds J1 and J2 are formed between the ends of longitudinal beam II4 and transverse beams I1 and II2, respectively; flat welds M1 and M2 are formed between short beam I6 and transverse beams I1 and III5, respectively; flat welds N1 and N2 are formed between short beam II7 and transverse beams II2 and III5, respectively; and flat welds N1 and N2 are formed between the ends of transverse beam III5 and longitudinal beams I3 and II4, respectively. Flat welds K1 and K2; in the four squares formed between beams I1, II2, I3, II4, III5, I6, and II7, fillet welds are formed at each corner. The fillet welds in the upper left square are numbered A1, A2, A3, and A4 clockwise; the fillet welds in the upper right square are numbered B1, B2, B3, and B4 clockwise; the fillet welds in the lower left square are numbered C1, C2, C3, and C4 clockwise; and the fillet welds in the lower right square are numbered D1, D2, D3, and D4 clockwise.

[0018] Furthermore, the aluminum alloy grid-shaped frame is assembled by spot welding. The spot welding sequence during assembly is as follows: H1-J1-H2-J2-K1-K2-M1-N1-M2-N2-A1-D4-B2-C3-A4-D1-B3-C2-A3-D2-B4-C1-A2-D3-C4-B1.

[0019] Furthermore, the reserved gaps during assembly and welding are as follows: the reserved gap for flat weld H1 is L / 2, the reserved gap for flat weld H2 is L / 3, the reserved gap for flat weld J1 is L / 2, the reserved gap for flat weld J2 is L / 3, the reserved gap for flat weld K1 is L / 2, the reserved gap for flat weld K2 is L / 3, the reserved gap for flat weld M1 is L / 2, the reserved gap for flat weld M2 is L / 3, the reserved gap for flat weld N1 is L / 2, and the reserved gap for flat weld N2 is L / 3. After determining the reserved gaps, spot welding is performed on A1, A2, A3, A4, B1, B2, B3, B4, C1, C2, C3, C4, D1, D2, D3, and D4 respectively. Then, the workpiece is welded according to the determined weld sequence.

[0020] (III) Beneficial Effects The above-mentioned technical solution provides a welding method for aluminum alloy grid-shaped frames. Through calculation and practical experience, it obtains the welding sequence of aluminum alloy grid-shaped frame structures and the relationship between the reserved gap size of the workpiece and the production environment temperature, the thermal conductivity of the workpiece, and the number of fixed points of the workpiece shrinkage path during the welding process, thereby realizing the transformation of the workpiece during welding. Attached Figure Description

[0021] Figure 1 Assembly position diagram of the grid-shaped frame before welding; Figure 2 A diagram showing the position of the grid-shaped frame after welding. Figure 3 Diagram showing the location of welds after welding the grid-shaped frame. Detailed Implementation

[0022] To make the objectives, contents, and advantages of the present invention clearer, the specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples.

[0023] Reference Figures 1 to 3 As shown, the specific steps of the aluminum alloy grid-shaped frame welding method in this embodiment are as follows: S1: Determine the equipment used for the operation and the maximum temperature t of the welding arc during welding; S2: Determine the welding voltage U, welding current I, and welding speed v based on the welding equipment; S3: Determine the maximum amount of expansion and contraction of the aluminum alloy material in its free state during welding; S4: Determine the welding sequence of the grid-shaped frame; S5: Determine the reserved gap for each weld during spot welding assembly; S6: Perform spot welding assembly on the workpiece; S7: Weld the workpiece according to the determined welding sequence.

[0024] Furthermore, in step S1, tungsten inert gas welding (TIG) equipment is preferred.

[0025] In step S4, the preferred welding sequence is diagonal welding.

[0026] In step S5, when the base material is welded at both ends, a reserved gap is left at each end.

[0027] In step S5, when the base material is welded at both ends, the gap reserved at the first end to be welded is 1 / 2 of the maximum expansion and contraction of the base material to be welded; the gap reserved at the second end to be welded is 1 / 3 of the maximum expansion and contraction of the base material to be welded.

[0028] In step S3, the relationship between the maximum expansion and contraction during welding and the nominal perimeter of the base material section, welding current, welding voltage, molten pool temperature, and welding speed is as follows:

[0029] Where L: maximum expansion and contraction of the material during welding; C: nominal perimeter of the base material cross-section; I: welding current; U: welding voltage; η: power coefficient of welding equipment; t: molten pool temperature; α: coefficient of linear expansion; v: welding speed.

[0030] In this embodiment, the grid-shaped frame includes, in the shape of the grid, a horizontal beam I1 arranged at the top, a horizontal beam II2 arranged at the bottom, a longitudinal beam I3 arranged on the left, a longitudinal beam II4 arranged on the right, a horizontal beam III5 arranged in the middle, a short beam I6 arranged between horizontal beam I1 and horizontal beam III5, and a short beam II7 arranged between horizontal beam II2 and horizontal beam III5. The short beam I6 and the short beam II7 are collinear and parallel to the longitudinal beam I3 and the longitudinal beam II4, respectively.

[0031] In the grid-shaped frame, flat welds H1 and H2 are formed between the two ends of longitudinal beam I3 and transverse beams I1 and II2, respectively; flat welds J1 and J2 are formed between the two ends of longitudinal beam II4 and transverse beams I1 and II2, respectively; flat welds M1 and M2 are formed between short beam I6 and transverse beams I1 and III5, respectively; flat welds N1 and N2 are formed between short beam II7 and transverse beams II2 and III5, respectively; and flat welds J1 and J2 are formed between the two ends of transverse beam III5 and longitudinal beams I3 and II4, respectively. Flat welds K1 and K2; in the four squares formed between beams I1, II2, I3, II4, III5, I6, and II7, fillet welds are formed at each corner. The fillet welds in the upper left square are A1, A2, A3, and A4 in clockwise order; the fillet welds in the upper right square are B1, B2, B3, and B4 in clockwise order; the fillet welds in the lower left square are C1, C2, C3, and C4 in clockwise order; and the fillet welds in the lower right square are D1, D2, D3, and D4 in clockwise order.

[0032] Spot weld and assemble the aluminum alloy material into a grid-shaped frame. One of the spot welding sequences during assembly is as follows: H1-J1-H2-J2-K1-K2-M1-N1-M2-N2-A1-D4-B2-C3-A4-D1-B3-C2-A3-D2-B4-C1-A2-D3-C4-B1.

[0033] After determining the spot welding sequence for assembly, determine the reserved gap during welding and assembly. At this time, the reserved gap for the flat weld H1 is L / 2, the reserved gap for the flat weld H2 is L / 3, the reserved gap for the flat weld J1 is L / 2, the reserved gap for the flat weld J2 is L / 3, the reserved gap for the flat weld K1 is L / 2, the reserved gap for the flat weld K2 is L / 3, the reserved gap for the flat weld M1 is L / 2, the reserved gap for the flat weld M2 is L / 3, the reserved gap for the flat weld N1 is L / 2, the reserved gap for the flat weld N2 is L / 3. After determining the reserved gap, perform spot welding and assembly on A1, A2, A3, A4, B1, B2, B3, B4, C1, C2, C3, C4, D1, D2, D3, and D4 respectively, and then weld the workpiece according to the determined weld sequence.

[0034] As can be seen from the above technical solution, the present invention calculates the natural shrinkage of the material, arranges the welding sequence of the workpiece reasonably, and reserves the weld gap scientifically, thereby reducing the deformation amount and stress concentration phenomenon after the workpiece is welded and processed. Compared with the traditional welding process of clamping with a fixture and restricting with a tooling, the present invention reserves the welding deformation amount in advance, so as to control the change with the change, thereby achieving the final welding effect and making the size of the welded workpiece meet the use requirements. By calculating and deriving the relationship between various parameters during the corrective welding, it provides theoretical guidance for the operators, facilitates the realization of the digitalization of the production process, and no longer relies solely on experience for production. The welding method for the grid-shaped frame made of aluminum alloy material achieves an ideal operation effect while reducing the operation difficulty of workers, which is conducive to the further promotion of this method in related fields, not only reducing the labor intensity of workers, but also greatly improving the quality of the products after production.

[0035] The above is only the preferred implementation manner of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and deformations can be made, and these improvements and deformations should also be regarded as the protection scope of the present invention.

Claims

1. A method of welding an aluminum alloy material diamond frame, characterized by, Includes the following steps: S1: Determine the equipment used for the operation and the maximum temperature t of the welding arc during welding; S2: Determine the welding voltage U, welding current I, and welding speed v based on the welding equipment; S3: Determine the maximum amount of expansion and contraction of the aluminum alloy material in its free state during welding; S4: Determine the welding sequence of the grid-shaped frame; S5: Determine the reserved gap for each weld during spot welding assembly; S6: Perform spot welding assembly on the workpiece; S7: Weld the workpiece according to the determined welding sequence.

2. The aluminum alloy material diamond frame welding method according to claim 1, characterized by, In step S1, the equipment used for the operation is tungsten inert gas welding.

3. The aluminum alloy material diamond frame welding method according to claim 2, characterized by, In step S4, the welding sequence is selected as diagonal welding.

4. The aluminum alloy material diamond frame welding method according to claim 3, characterized by, In step S5, when the base material is welded at both ends, a reserved gap is left at each end.

5. The aluminum alloy material diamond frame welding method according to claim 4, characterized by, In step S5, when the base material is welded at both ends, the gap reserved at the first end to be welded is 1 / 2 of the maximum expansion and contraction of the base material to be welded; the gap reserved at the second end to be welded is 1 / 3 of the maximum expansion and contraction of the base material to be welded.

6. The aluminum alloy material diamond frame welding method according to claim 5, characterized by, In step S3, the relationship between the maximum expansion and contraction during welding and the nominal perimeter of the base material section, welding current, welding voltage, molten pool temperature, and welding speed is as follows: Where L: maximum expansion and contraction of the material during welding; C: nominal perimeter of the base material cross-section; I: welding current; U: welding voltage; η: power coefficient of welding equipment; t: molten pool temperature; α: coefficient of linear expansion; v: welding speed.

7. The aluminum alloy material diamond frame welding method according to claim 6, characterized by, The grid-shaped frame includes, in the shape of the grid, a horizontal beam I (1) arranged at the top, a horizontal beam II (2) arranged at the bottom, a vertical beam I (3) arranged on the left, a vertical beam II (4) arranged on the right, a horizontal beam III (5) arranged in the middle, a short beam I (6) arranged between horizontal beam I (1) and horizontal beam III (5), and a short beam II (7) arranged between horizontal beam II (2) and horizontal beam III (5). The short beam I (6) and short beam II (7) are collinear and parallel to the vertical beam I (3) and the vertical beam II (4), respectively.

8. The aluminum alloy material diamond frame welding method according to claim 7, characterized by, In the grid-shaped frame, the two ends of longitudinal beam I (3) form flat welds H1 and H2 with crossbeams I (1) and II (2) respectively; the two ends of longitudinal beam II (4) form flat welds J1 and J2 with crossbeams I (1) and II (2) respectively; the two ends of short beam I (6) form flat welds M1 and M2 with crossbeams I (1) and III (5) respectively; the two ends of short beam II (7) form flat welds N1 and N2 with crossbeams II (2) and III (5) respectively; the two ends of crossbeam III (5) form flat welds with longitudinal beams I (3) and II (4) respectively. Flat welds K1 and K2 are formed between them respectively; in the four squares formed between beam I (1), beam II (2), longitudinal beam I (3), longitudinal beam II (4), beam III (5), short beam I (6), and short beam II (7), fillet welds are formed at each corner. The fillet welds of the upper left square are numbered A1, A2, A3, and A4 in clockwise order, the fillet welds of the upper right square are numbered B1, B2, B3, and B4 in clockwise order, the fillet welds of the lower left square are numbered C1, C2, C3, and C4 in clockwise order, and the fillet welds of the lower right square are numbered D1, D2, D3, and D4 in clockwise order.

9. The aluminum alloy material diamond frame welding method according to claim 8, characterized by, The aluminum alloy material T-shaped frame is spot-welded and assembled, and the sequence of spot welding during assembly is: H1-J1-H2-J2-K1-K2-M1-N1-M2-N2-A1-D4-B2-C3-A4-D1-B3-C2-A3-D2-B4-C1-A2-D3-C4-B1.

10. The aluminum alloy material diamond frame welding method according to claim 9, characterized by, The reserved gap during welding is: the reserved gap of the flat weld H1 is L / 2, the reserved gap of the flat weld H2 is L / 3, the reserved gap of the flat weld J1 is L / 2, the reserved gap of the flat weld J2 is L / 3, the reserved gap of the flat weld K1 is L / 2, the reserved gap of the flat weld K2 is L / 3, the reserved gap of the flat weld M1 is L / 2, the reserved gap of the flat weld M2 is L / 3, the reserved gap of the flat weld N1 is L / 2, and the reserved gap of the flat weld N2 is L / 3. After the reserved gap is determined, A1, A2, A3, A4, B1, B2, B3, B4, C1, C2, C3, C4, D1, D2, D3, and D4 are spot-welded and assembled, and then the workpiece is welded according to the determined welding sequence.

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