Methods for controlling welding deformation of the rear floor assembly of aluminum alloy body-in-white

Abstract

This invention relates to a method for controlling welding deformation of the rear floor assembly of an aluminum alloy body-in-white. The invention designs a method for controlling welding deformation of the rear floor assembly of an aluminum alloy body-in-white by controlling welding process parameters, clamping positions, and welding sequence, thereby reducing the degree of deformation of the aluminum alloy rear floor assembly profile during welding. After optimization, the average absolute value of the final welding deformation of the aluminum alloy rear floor assembly is reduced from 1.659 mm to 0.735 mm, a reduction of 56%, significantly lowering welding deformation. The significantly reduced welding deformation of the aluminum alloy rear floor assembly of this invention ensures welding quality and dimensional accuracy.

Description

Technical Field

[0001] This invention relates to the field of vehicle manufacturing technology, and more particularly to a method for controlling welding deformation of the rear floor assembly of an aluminum alloy body-in-white. Background Technology

[0002] Aluminum alloy profiles are important structural components in existing aluminum body-in-white and are an indispensable part of the application of aluminum alloys in the automotive field. Due to inherent factors such as concentrated heat, rapid thermal conductivity, and large coefficient of thermal expansion, aluminum alloy welding is prone to welding thermal deformation. For profile frames, large post-weld deformation inevitably leads to increased costs for subsequent adjustments and straightening, while also affecting the welding production cycle and causing waste of production resources.

[0003] Existing welding deformation control methods do not specifically address welding deformation in aluminum alloy body-in-white rear floor assemblies. These methods are ineffective in reducing welding deformation in aluminum alloy body-in-white rear floor assemblies, and welding quality and dimensional accuracy cannot be guaranteed. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing technologies by providing a method for controlling welding deformation of the rear floor assembly of an aluminum alloy body-in-white, thus solving the problem.

[0005] This invention is achieved using the following technical solution:

[0006] A method for controlling welding deformation of the rear floor assembly of an aluminum alloy body-in-white includes the following steps:

[0007] (1) Clamp each aluminum alloy profile together in sequence using a welding clamping device to form the rear floor assembly of the body-in-white;

[0008] (2) The welding clamping device is set near the weld of the aluminum alloy profile, and the clamping force at each clamping point is the same and the direction is perpendicular to the surface of the pressed aluminum alloy profile.

[0009] (3) Set the welding process parameters; the welding process parameters include ambient temperature, relative humidity, absolute humidity, welding current, welding voltage, and welding speed;

[0010] (4) Set the welding sequence of the weld seam, first complete the welding of the outer aluminum alloy profile weld seam, and then weld the inner aluminum alloy profile weld seam. At the same time, adopt the cross welding sequence during the welding process.

[0011] As a further explanation of the invention, in step (1), the rear floor assembly of the body-in-white includes a front crossbeam of the rear floor, a left rear longitudinal beam of the rear floor, a rear crossbeam of the rear floor, a right rear longitudinal beam of the rear floor, a middle crossbeam of the rear floor, and a reinforcing longitudinal beam for the rear seats.

[0012] As a further explanation of the invention, in step (2), the clamping positions of the welding clamping device are distributed on both sides of the weld, and the distance between the positions and the weld is between 30 and 80 mm.

[0013] The clamping force of the welding clamping device is between 8000N and 12000N.

[0014] As a further explanation of the invention, in step (3), the ambient temperature is ≥18℃, the relative humidity range is ≤60%, and the absolute humidity range is ≤10.36g / m³. 3 The welding current range is 60-80A, the welding voltage range is 16.8-17.6V, and the welding speed range is 0.5-0.6m / min.

[0015] As a further explanation of the invention, in step (4), the weld is welded in one pass using a single weld.

[0016] Compared with the prior art, the present invention has the following beneficial technical effects:

[0017] This invention designs a method for controlling welding deformation of the aluminum alloy body-in-white rear floor assembly. By controlling welding process parameters, clamping positions, and welding sequence, the deformation of the aluminum alloy body-in-white rear floor assembly profile during welding is reduced. After optimization, the average absolute value of the final welding deformation of the aluminum alloy body-in-white rear floor assembly is reduced from 1.659 mm to 0.735 mm, a reduction of 56%, significantly lowering welding deformation. The significantly reduced welding deformation of the aluminum alloy body-in-white rear floor assembly of this invention ensures welding quality and dimensional accuracy. Attached Figure Description

[0018] The invention will be further described below with reference to the accompanying drawings:

[0019] Figure 1 This is a schematic diagram of the aluminum alloy body-in-white rear floor assembly provided in an embodiment of the present invention;

[0020] Figure 2 This is a schematic diagram of the clamping position of the rear floor assembly of the aluminum alloy body-in-white provided in an embodiment of the present invention;

[0021] Figure 3 This is a schematic diagram of the welding sequence of the aluminum alloy body-in-white rear floor assembly provided in an embodiment of the present invention;

[0022] Figure 4 A schematic diagram of the three-coordinate detection points of the rear floor assembly of the aluminum alloy body-in-white provided in an embodiment of the present invention. Detailed Implementation

[0023] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise explicitly specified and limited, the embodiments and features described in the embodiments of this application can be combined with each other. In the description of the present invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," and "connect" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention based on the specific circumstances.

[0024] like Figure 1-4 As shown, Figure 1 This is a schematic diagram of the aluminum alloy rear floor assembly provided in an embodiment of the present invention. 35 is the front crossbeam of the rear floor, 36 is the left rear longitudinal beam of the rear floor, 37 is the rear crossbeam of the rear floor, 38 is the right rear longitudinal beam of the rear floor; 39 is the middle crossbeam of the rear floor, and 40 is the rear seat reinforcement longitudinal beam.

[0025] Figure 2 This is a schematic diagram of the clamping position of the aluminum alloy rear floor assembly provided in an embodiment of the present invention.

[0026] Where a, b, c, d, e, f, g, h, i, j, k, l, m, and n represent the specific clamping positions;

[0027] Figure 3 This is a schematic diagram of the welding sequence of the aluminum alloy rear floor assembly provided in an embodiment of the present invention. There are a total of 34 welds, with 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, and 34 representing the specific weld locations.

[0028] Figure 4 This is a schematic diagram of the three-coordinate measuring machine (CMM) detection points for the aluminum alloy rear floor assembly provided in an embodiment of the present invention. 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, and 55 represent the specific locations of the three-coordinate measuring machine (CMM) points.

[0029] This embodiment discloses a method for controlling welding deformation of the rear floor assembly of an aluminum alloy body-in-white, wherein the rear floor assembly includes a front crossbeam 35, a left rear longitudinal beam 36, a rear crossbeam 37, a right rear longitudinal beam 38, a middle crossbeam 39, and a rear seat reinforcing longitudinal beam 40; the method for controlling welding deformation of the rear floor assembly of the aluminum alloy body-in-white includes the following steps:

[0030] (1) Clamp each aluminum alloy profile together in sequence using a welding clamping device to form the rear floor assembly of the body-in-white;

[0031] The alloy body-in-white rear floor assembly includes a rear floor front crossbeam 35, a rear floor left rear longitudinal beam 36, a rear floor rear crossbeam 37, a rear floor right rear longitudinal beam 38, a rear floor middle crossbeam 39, and a rear seat reinforcing longitudinal beam 40; preferably, the aluminum alloy body-in-white rear floor assembly uses 6082-T6 aluminum alloy with a profile thickness of 2mm.

[0032] S2: The welding clamping device is set near the weld of the aluminum alloy profile, and the clamping force at each clamping point is the same and the direction is perpendicular to the surface of the pressed aluminum alloy profile.

[0033] The welding clamping device is a flexible welding clamp used in the initial debugging of the body-in-white. The clamping positions of the flexible welding clamp are distributed on both sides of the weld, and the distance between the position and the weld is between 30 and 80 mm. The clamping force of the flexible welding clamp is between 8000 N and 12000 N. Preferably, the clamping position of the flexible welding clamp is 30 mm away from the weld.

[0034] S3: Set the welding process parameters; these parameters include ambient temperature ≥18℃, relative humidity range ≤60%, and absolute humidity range ≤10.36g / m³. 3 The welding current range is 60–80A, the welding voltage range is 16.8–17.6V, and the welding speed range is 0.5–0.6 m / min. Preferably, the ambient temperature is 20℃, the relative humidity is 45%, and the absolute humidity is 7.77 g / m³. 3 The welding current is 60A, the welding voltage is 16.8V, and the welding speed is 0.6m / min.

[0035] S4: Set the welding sequence of the weld seam, first complete the welding of the outer aluminum alloy profile weld seam, and then weld the inner aluminum alloy profile weld seam. At the same time, adopt a cross welding sequence during the welding process.

[0036] The rear floor assembly of the aluminum alloy body-in-white has a total of 34 welds, consisting of welds 1 to 34. The optimized welding sequence is simplified as follows:

[0037] 2-17-9-11-4-15-7-13-1-3-5-16-18-6-8-10-12-14-20-24-22-26-28-32-30-34-19-21-23-25-27-29-31-33, the welding method is a single-pass weld formed in one step.

[0038] The following comparative experiments were conducted using control groups 1, 2, and 3, respectively, under three conditions: selection of welding process parameters, setting of clamping position of welding clamping device, and adjustment of welding sequence, to obtain the welding deformation amount under the corresponding conditions.

[0039] Control group 1:

[0040] The rear floor assembly of the aluminum alloy body-in-white uses 6082-T6 aluminum alloy, with a profile thickness of 2mm, under ambient temperatures of 20℃, relative humidity of 45%, and absolute humidity of 7.77g / m³. 3 The welding sequence is simplified as follows:

[0041] 1-2-3-4-5-6-7-8-9-10-11-12-13-14-15-16-17-18-19-20-21-22-23-24-25-26-27-28-29-30-31-32-33-34. The welding clamp position is 80mm away from the weld. There are two sets of welding process parameters. One set is the process parameters corresponding to high heat input, specifically welding current 80A, welding voltage 17.6V, and welding speed 0.5m / min. The other set is the process parameters corresponding to low heat input, specifically welding current 60A, welding voltage 16.8V, and welding speed 0.6m / min. The welding deformation under these high and low heat input parameters is shown in Table 1.

[0042] Table 1: Welding Deformation of Aluminum Alloy Rear Floor Assembly under Different Welding Process Parameters

[0043]

[0044] As shown in Table 1, the average absolute value of welding deformation under high heat input parameters is 1.659 mm, and the average absolute value of welding deformation under low heat input parameters is 1.220 mm.

[0045] Control group 2:

[0046] The rear floor assembly of the aluminum alloy body-in-white uses 6082-T6 aluminum alloy with a profile thickness of 2mm. The welding current is 60A, the welding voltage is 16.8V, the welding speed is 0.6m / min, the ambient temperature is 20℃, the relative humidity is 45%, and the absolute humidity is 7.77g / m³. 3The welding sequence is simplified to 2-17-9-11-4-15-7-13-1-3-5-16-18-6-8-10-12-14-20-24-22-26-28-32-30-34-19-21-23-25-27-29-31-33. There are two sets of clamping positions: one set is at a distance of 80mm from the weld, and the other set is at a distance of 30mm from the weld. The welding deformation at the clamping positions at 80mm and 30mm from the weld is shown in Table 2.

[0047] Table 2: Welding Deformation of Aluminum Alloy Rear Floor Assembly under Different Clamping Conditions

[0048]

[0049] As shown in Table 2, the average absolute value of welding deformation at the clamping position 80mm from the weld is 1.220mm, and the average absolute value of welding deformation at the clamping position 30mm from the weld is 0.919mm.

[0050] Control group 3:

[0051] The rear floor assembly of the aluminum alloy body-in-white uses 6082-T6 aluminum alloy with a profile thickness of 2mm. The welding current is 60A, the welding voltage is 16.8V, the welding speed is 0.6m / min, the ambient temperature is 20℃, the relative humidity is 45%, and the absolute humidity is 7.77g / m³. 3 The clamping position is 30mm away from the weld. The welding sequence is compared with two sets. One set is the normal welding sequence, such as weld 1-2-3-4-5-6-7-8-9-10-11-12-13-14-15-16-17-18-19-20-21-22-23-24-25-26-27-28-29-30-31-32-33-34;

[0052] One group is for optimizing the welding sequence, such as weld seams.

[0053] The welding deformation amounts for the ordinary welding sequence and the optimized welding sequence are shown in Table 3.

[0054] Table 3: Welding Deformation of Aluminum Alloy Rear Floor Assembly under Different Welding Sequences

[0055]

[0056] As shown in Table 3, the average absolute value of the welding deformation using the ordinary welding sequence is 0.919 mm, while the average absolute value of the welding deformation using the optimized welding sequence is 0.735 mm.

[0057] As can be seen from the above control group 1, control group 2, control group 3 and this implementation, after optimization, the average absolute value of the final welding deformation of the rear floor assembly decreased from 1.659mm to 0.735mm, the degree of welding deformation was reduced by 56%, and the welding deformation was significantly reduced.

[0058] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of the equivalent elements of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0059] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for controlling welding deformation of the rear floor assembly of an aluminum alloy body-in-white, characterized in that, Includes the following steps: (1) Clamp each aluminum alloy profile together in sequence using a welding clamping device to form the rear floor assembly of the body-in-white; (2) Set the welding clamping device near the weld of the aluminum alloy profile, with the same clamping force at each clamping point and the direction perpendicular to the surface of the pressed aluminum alloy profile. (3) Set the welding process parameters; the welding process parameters include ambient temperature, relative humidity, absolute humidity, welding current, welding voltage, and welding speed; (4) Set the welding sequence of the weld seam, first complete the welding of the outer aluminum alloy profile weld seam, and then weld the inner aluminum alloy profile weld seam. At the same time, adopt a cross welding sequence during the welding process. In step (1), the rear floor assembly of the body-in-white includes the front crossbeam of the rear floor, the left rear longitudinal beam of the rear floor, the rear crossbeam of the rear floor, the right rear longitudinal beam of the rear floor, the middle crossbeam of the rear floor, and the rear seat reinforcement longitudinal beam. In step (4), the weld is welded in one pass using a single weld. The rear floor assembly of the aluminum alloy body-in-white has a total of thirty-four welds, consisting of weld one to weld thirty-four. The optimized welding sequence used is as follows: First, after the floor is completed, the rear crossbeam and the front crossbeam of the rear floor are welded to the left and right outer sides of the body of the left rear longitudinal beam and the right rear longitudinal beam of the rear floor, respectively, and welded in the following manner: weld 2, weld 17, weld 9 and weld 11 are welded together. After completion, the rear crossbeam of the rear floor and the front crossbeam of the rear floor are welded to the left and right inner sides of the body of the left rear longitudinal beam of the rear floor and the body of the right rear longitudinal beam of the rear floor, respectively, and welded in the manner of weld 4, weld 15, weld 7 and weld 13 intersecting. After completion, the rear crossbeam of the rear floor and the front crossbeam of the rear floor are welded to the remaining welds of the left rear longitudinal beam of the rear floor and the right rear longitudinal beam of the rear floor, respectively, and welded in the following order: weld 1, weld 3, weld 5, weld 16, weld 18, weld 6, weld 8, weld 10, weld 12, and weld 14. After completion, the crossbeams in the floor are welded to the front and rear sides of the left rear longitudinal beam and the right rear longitudinal beam of the floor, respectively, according to weld number 20, weld number 24, weld number 22, and weld number 26. Afterwards, the rear seat reinforcement longitudinal beams are welded to the left and right sides of the rear floor front crossbeam and the floor middle crossbeam, respectively, according to weld number 28, weld number 32, weld number 30, and weld number 34. After completion, the crossbeams in the floor are welded to the remaining welds of the left rear longitudinal beam and the right rear longitudinal beam of the floor, respectively, according to weld numbers 19, 21, 23, and 25. Finally, the rear seat reinforcement longitudinal beams were welded to the remaining welds of the rear floor front crossbeam and the floor middle crossbeam, according to weld numbers 27, 29, 31, and 33.

2. The method for controlling welding deformation of the rear floor assembly of the aluminum alloy body-in-white as described in claim 1, characterized in that, In step (2), the clamping positions of the welding clamping device are distributed on both sides of the weld, and the distance between the positions and the weld is between 30 and 80 mm. The clamping force of the welding clamping device is between 8000N and 12000N.

3. The method for controlling welding deformation of the rear floor assembly of the aluminum alloy body-in-white as described in claim 2, characterized in that, In step (3), the ambient temperature is ≥18℃, the relative humidity is ≤60%, the absolute humidity is ≤10.36g / m3, the welding current is 60~80A, the welding voltage is 16.8~17.6V, and the welding speed is 0.5~0.6m / min.

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