Resistance double-point welding method suitable for braided silver-plated copper wire and ultra-thin copper layer

Abstract

This invention provides a method for resistance double-spot welding of braided silver-plated copper wire and ultra-thin copper layers, comprising the following steps: Step S1, placing the braided silver-plated copper wire on the ultra-thin copper layer pad; Step S2, bringing the upper and lower electrodes close to the ultra-thin copper layer pad; Step S3, moving the axes of the upper and lower electrodes to the center vertical line of the ultra-thin copper layer pad; Step S4, moving the upper and lower electrodes to the welding position, and then moving the lower electrode upwards until the ultra-thin copper layer pad bulges; Step S5, setting the welding parameters for the resistance spot welding machine; Step S6, flattening and compacting the braided silver-plated copper wire and the ultra-thin copper layer pad; Step S7, first welding the first resistance welding point away from the root of the braided silver-plated copper wire, and then welding the second resistance welding point. This invention uses three-axis positioning to control the movement of the upper and lower electrodes, meeting the needs of deep welding points and achieving precise positioning; through reasonable design, it achieves double-spot redundancy, reliable welding point quality, simple operation, and strong applicability.

Description

Technical Field

[0001] This invention relates to the field of welding technology, and more specifically, to a resistance double-spot welding method suitable for braided silver-plated copper wire and ultra-thin copper layer. Background Technology

[0002] Precision resistance welding technology is an indispensable interconnection method for electromechanical products, with wide applications in the automotive, shipbuilding, and aerospace fields. Ultra-thin copper layers and silver-plated braided copper strips, due to their excellent electrical conductivity and flexibility, have shown broad application prospects in space technology and the defense industry, especially in high-current fields such as battery circuits, where they are key connection materials for critical electronic products in my country's spacecraft and satellites.

[0003] The inventors believe that existing welding methods for ultra-thin copper layers and silver-plated braided copper strips are prone to problems affecting welding quality, such as unstable welding positions, small welding areas leading to weld burn-through, and shear deformation and cracking of the ultra-thin copper layer during compression. Therefore, there is a need for a resistance double-point welding method suitable for braided silver-plated copper wire and ultra-thin copper layers, achieving a redundant double-point interconnection design to ensure reliable weld quality. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the purpose of this invention is to provide a resistance double-spot welding method suitable for braided silver-plated copper wire and ultra-thin copper layers.

[0005] A method for resistance double-spot welding of braided silver-plated copper wire and ultra-thin copper layer provided by the present invention includes the following steps:

[0006] Step S1: Wipe the ultra-thin copper layer pads and place braided silver-plated copper wires on them;

[0007] Step S2: The upper and lower electrodes are controlled to approach the ultrathin copper layer pads by the upper and lower cantilever arms, respectively.

[0008] Step S3: Move the axis of the upper electrode and the lower electrode to the vertical line of the center of the ultrathin copper layer pad;

[0009] Step S4: Move the upper electrode and the lower electrode to the welding position, and then move the lower electrode upward to the protrusion of the ultra-thin copper layer pad;

[0010] Step S5: Set welding parameters for the resistance spot welding machine;

[0011] Step S6: Move the upper electrode downward to flatten and compact the braided silver-plated copper wire and the ultra-thin copper layer pad.

[0012] Step S7: First, weld the first resistance solder joint away from the root of the braided silver-plated copper wire, and then weld the second resistance solder joint close to the root of the braided silver-plated copper wire.

[0013] Preferably, in step S1, the ultrathin copper layer pad is 7mm × 10mm.

[0014] Preferably, in step S1, the ultra-thin copper layer pad is placed on the honeycomb panel fixture.

[0015] Preferably, in step S2, both the upper cantilever and the lower cantilever are mounted on the resistance spot welding machine. Both the upper cantilever and the lower cantilever include a combined cylinder that is thicker in the middle and thinner at both ends. The diameter ratio of the cylinders at both ends to the cylinder in the middle section of the combined cylinder is 0.4 to 0.8.

[0016] Preferably, in step S2, the upper electrode is installed at the end of the upper cantilever, and the end face diameter of the upper electrode is 2.4mm to 2.5mm; the lower electrode is installed at the end of the lower cantilever, and the end face diameter of the lower electrode is 3.8mm to 4.0mm; both the end faces of the upper electrode and the lower electrode are provided with rounded corners, and the radius of the rounded corners is 0.5mm to 1mm.

[0017] Preferably, in step S3, the resistance spot welding machine adjusts the alignment of the upper electrode and the lower electrode using triaxial positioning, and the distance between the upper electrode and the lower electrode and the end face of the ultra-thin copper layer pad is 14.5±0.2mm.

[0018] Preferably, in step S4, the height of the ultrathin copper layer pad is 0.1mm to 1mm, and the distance between the lower electrode and the edge of the ultrathin copper layer pad is at least 0.5mm.

[0019] Preferably, in step S5, the welding parameters include a welding current of 4.5kA to 9kA, a welding time of 6ms to 9ms, a welding pressure of 100N to 300N, a constant current mode for welding, and a single-pulse resistance welding or a double-pulse resistance welding method.

[0020] Preferably, in step S6, the upper electrode and the lower electrode apply pressure to the braided silver-plated copper wire and the ultra-thin copper layer pad through a pneumatic switch.

[0021] Preferably, in step S7, after the first resistance solder joint is welded, the lower electrode is controlled to move downward by 2mm and move 2.0mm toward the root of the braided silver-plated copper wire to weld the second resistance solder joint.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] 1. This invention uses a resistance spot welding machine to control the movement of the upper and lower electrodes through three-axis positioning, which meets the needs of deep welding points and achieves precise positioning. By first welding the first resistance welding point far away from the root of the braided silver-plated copper wire, and then welding the second resistance welding point close to the root of the braided silver-plated copper wire, the data is accurate. Through reasonable design, double-point redundancy is achieved, the welding point quality is reliable, the operation is simple, and the applicability is strong.

[0024] 2. This invention significantly improves the strength of the cantilever by adopting a structure where the upper and lower cantilevers are thinner at both ends and thicker in the middle, while reducing the internal resistance of the cantilever and ensuring the stability of the welding position. By adopting a structure with a small upper electrode surface and a large lower electrode surface, and using a rounded corner design, it avoids the non-parallelism of the electrode surfaces under cantilever deformation conditions, and solves the defect of reduced welding area caused by electrode misalignment under cantilever deformation conditions, resulting in weld point melting and penetration under local high current density.

[0025] 3. The present invention lifts the ultra-thin copper layer by 0.1mm to 1mm by lowering the electrode before welding, which can effectively reduce the relative displacement of the electrode in the vertical direction during the pressing process, prevent the ultra-thin copper layer from cracking due to shear deformation during the pressing process, and ensure the welding quality. Attached Figure Description

[0026] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0027] Figure 1 This is a schematic diagram illustrating the resistance welding of braided silver-plated copper wire and ultra-thin copper layer pads, which is the main feature of this invention.

[0028] Figure 2 This is a top view of two points for illustrating resistance welding, which is the main feature of this invention.

[0029] As shown in the figure:

[0030] Upper cantilever 1, lower cantilever 2, lower electrode 3

[0031] Top electrode 4 Braided silver-plated copper wire 5 Ultra-thin copper layer pad 6

[0032] Honeycomb panel fixture 7 First resistance solder joint 8 Second resistance solder joint 9 Detailed Implementation

[0033] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0034] like Figure 1 and 2 As shown, a resistance double-spot welding method for braided silver-plated copper wire and ultra-thin copper layer provided by the present invention includes the following steps:

[0035] Step S1: Wipe the ultra-thin copper layer pad 6 and place the braided silver-plated copper wire 5 on it;

[0036] Step S2: The upper electrode 4 and the lower electrode 3 are controlled to approach the ultrathin copper layer pad 6 by the upper cantilever 1 and the lower cantilever 2 respectively.

[0037] Step S3: Move the axis of the upper electrode 4 and the lower electrode 3 to the center vertical line of the ultrathin copper layer pad 6.

[0038] Step S4: Move the upper electrode 4 and the lower electrode 3 to the welding position, and then move the lower electrode 3 upward until the ultra-thin copper layer pad 6 protrudes.

[0039] Step S5: Set welding parameters for the resistance spot welding machine;

[0040] Step S6: Move the upper electrode 4 downward to flatten and compact the braided silver-plated copper wire 5 and the ultra-thin copper layer pad 6.

[0041] Step S7: First, weld the first resistance solder joint 8 away from the root of the braided silver-plated copper wire 5, and then weld the second resistance solder joint 9 close to the root of the braided silver-plated copper wire 5.

[0042] This application provides a resistance double-point welding method suitable for braided silver-plated copper wire and ultra-thin copper layer, in which two solder points are set for each ultra-thin copper layer pad to achieve double-point redundancy design.

[0043] In step S1, the ultra-thin copper layer pad 6 is 7mm × 10mm. This application takes the 7mm × 10mm ultra-thin copper layer pad 6 as an example, and each ultra-thin copper layer pad 6 is provided with two solder joints to achieve a dual-point redundancy design.

[0044] In step S1, the ultra-thin copper layer pad 6 is placed on the honeycomb panel fixture 7, which is used to fix the ultra-thin copper layer 6. The two are fixedly connected by positioning pins. After the ultra-thin copper layer 6 is placed on the honeycomb panel fixture 7, the ultra-thin copper layer pad 6 is wiped with a non-woven cloth soaked in alcohol to ensure that there is no excess material on the surface of the ultra-thin copper layer pad 6, and then the braided silver-plated copper wire 5 is placed.

[0045] In step S2, both the upper cantilever 1 and the lower cantilever 2 are mounted on the resistance spot welding machine. Both the upper cantilever 1 and the lower cantilever 2 include a combined cylinder that is thicker in the middle and thinner at both ends. The diameter of the middle section cylinder is the largest. The diameter ratio of the cylinders at both ends of the combined cylinder to the cylinder in the middle section is 0.4 to 0.8, which can significantly improve the strength of the cantilever and reduce the internal resistance of the cantilever, thus ensuring the stability of the welding position.

[0046] In step S2, the upper electrode 4 is installed at the end of the upper cantilever 1, and the diameter of the end face of the upper electrode 4 is 2.4mm to 2.5mm; the lower electrode 3 is installed at the end of the lower cantilever 2, and the diameter of the end face of the lower electrode 3 is 3.8mm to 4.0mm; both the end faces of the upper electrode 4 and the lower electrode 3 are rounded, with a radius of 0.5mm to 1mm. The electrodes adopt a structure with a smaller end face of the upper electrode 4 and a larger end face of the lower electrode 3, and adopt a rounded corner design. On the one hand, this avoids the non-parallelism of the electrode end faces under cantilever deformation conditions, and on the other hand, it solves the defect of reduced welding area caused by electrode misalignment under cantilever deformation conditions, resulting in weld point melting and penetration under local high current density.

[0047] In step S3, the resistance spot welding machine uses triaxial positioning to center and adjust the upper electrode 4 and lower electrode 3, with the distance between the upper electrode 4 and lower electrode 3 and the end face of the ultra-thin copper layer pad 6 being 14.5±0.2mm. After installation, the centering of the upper electrode 4 and lower electrode 3 is checked. Since the upper electrode 4 and lower electrode 3 move under the same command, no further centering is required. The resistance welding electrodes are positioned using triaxial positioning to meet the needs of deep weld joints.

[0048] In step S4, the height of the ultra-thin copper layer pad 6 is 0.1mm to 1mm, and the distance between the lower electrode 3 and the edge of the ultra-thin copper layer pad 6 is at least 0.5mm. Before welding, the lower electrode 3 lifts the ultra-thin copper layer pad 6 by 0.1mm to 1mm, which can effectively reduce the relative displacement of the electrode in the vertical direction during the clamping process, prevent the ultra-thin copper layer pad 6 from shearing deformation and cracking during the clamping process, and ensure the welding quality.

[0049] In step S5, the welding parameters are as follows: welding current is 4.5kA to 9kA, welding time is 6ms to 9ms, welding pressure is 100N to 300N, welding mode is constant current mode, and welding method is single-pulse resistance welding or double-pulse resistance welding.

[0050] In step S6, the upper electrode 4 and the lower electrode 3 apply pressure to the braided silver-plated copper wire 5 and the ultra-thin copper layer pad 6 via a pneumatic switch. A constant current source serves as the energy input, providing a pulsed current through the upper electrode 4 and the lower electrode 3. When the upper electrode 4 and the lower electrode 3 apply pressure to the braided silver-plated copper wire 5 and the ultra-thin copper layer pad 6, resistance welding is performed by energizing the wire.

[0051] In step S7, after the first resistance solder joint 8 is soldered, the lower electrode 3 is moved downwards by 2mm and then 2.0mm towards the root of the braided silver-plated copper wire 5 to solder the second resistance solder joint 9. The lower electrode 3 is in contact with the ultra-thin copper layer pad 6 during soldering. When translating the lower electrode 3, it needs to be moved downwards first to prevent interference between the lower electrode 3 and the ultra-thin copper layer pad 6.

[0052] Finally, turn off the resistance spot welding machine, and retract the resistance welding cantilever electrode tool by controlling the lead screw to complete the welding process.

[0053] This application achieves dual-point redundancy through reasonable design, ensuring reliable solder joint quality, simple operation, and strong applicability.

[0054] In the description of this application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "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 application 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 application.

[0055] Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. A method for resistance double-spot welding of braided silver-plated copper wire and ultra-thin copper layer, characterized in that, Includes the following steps: Step S1: Wipe the ultra-thin copper layer pad (6) and place the braided silver-plated copper wire (5) on it. Step S2: The upper electrode (4) and lower electrode (3) are controlled to approach the ultrathin copper layer pad (6) by the upper cantilever (1) and lower cantilever (2) respectively. Step S3: Move the axis of the upper electrode (4) and the lower electrode (3) to the center vertical line of the ultrathin copper layer pad (6); Step S4: Move the upper electrode (4) and the lower electrode (3) to the welding position, and then move the lower electrode (3) upward until the ultra-thin copper layer pad (6) protrudes; Step S5: Set welding parameters for the resistance spot welding machine; Step S6: Move the upper electrode (4) downward to flatten and compact the braided silver-plated copper wire (5) and the ultra-thin copper layer pad (6); Step S7: First, weld the first resistance solder joint (8) away from the root of the braided silver-plated copper wire (5), and then weld the second resistance solder joint (9) close to the root of the braided silver-plated copper wire (5). In step S2, the upper electrode (4) is installed at the end of the upper cantilever (1), and the end face diameter of the upper electrode (4) is 2.4mm~2.5mm; The lower electrode (3) is installed at the end of the lower cantilever (2), and the end face diameter of the lower electrode (3) is 3.8mm~4.0mm; The end faces of the upper electrode (4) and the lower electrode (3) are both provided with rounded corners, and the radius of the rounded corners is 0.5mm~1mm.

2. The resistance double-spot welding method for braided silver-plated copper wire and ultra-thin copper layer as described in claim 1, characterized in that, In step S1, the ultra-thin copper layer pad (6) is 7mm×10mm.

3. The resistance double-spot welding method for braided silver-plated copper wire and ultra-thin copper layer as described in claim 1, characterized in that, In step S1, the ultra-thin copper layer pad (6) is placed on the honeycomb panel fixture (7).

4. The resistance double-spot welding method for braided silver-plated copper wire and ultra-thin copper layer as described in claim 1, characterized in that, In step S2, the upper cantilever (1) and the lower cantilever (2) are both mounted on the resistance spot welding machine. The upper cantilever (1) and the lower cantilever (2) each include a combined cylinder that is thicker in the middle and thinner at both ends. The diameter ratio of the cylinders at both ends of the combined cylinder to the cylinder in the middle section is 0.4 to 0.

8.

5. The resistance double-spot welding method for braided silver-plated copper wire and ultra-thin copper layer as described in claim 1, characterized in that, In step S3, the resistance spot welding machine adjusts the upper electrode (4) and the lower electrode (3) by triaxial positioning, and the distance between the upper electrode (4) and the lower electrode (3) and the end face of the ultra-thin copper layer pad (6) is 14.5±0.2 mm.

6. The resistance double-spot welding method for braided silver-plated copper wire and ultra-thin copper layer as described in claim 1, characterized in that, In step S4, the height of the ultra-thin copper layer pad (6) is 0.1mm to 1mm, and the lower electrode (3) is at least 0.5mm away from the edge of the ultra-thin copper layer pad (6).

7. The resistance double-spot welding method for braided silver-plated copper wire and ultra-thin copper layer as described in claim 1, characterized in that, In step S5, the welding parameters include a welding current of 4.5kA to 9kA, a welding time of 6ms to 9ms, a welding pressure of 100N to 300N, a constant current mode for welding, and a single-pulse resistance welding or a double-pulse resistance welding method.

8. The resistance double-spot welding method for braided silver-plated copper wire and ultra-thin copper layer as described in claim 1, characterized in that, In step S6, the upper electrode (4) and the lower electrode (3) apply pressure to the braided silver-plated copper wire (5) and the ultra-thin copper layer pad (6) through a pneumatic switch.

9. The resistance double-spot welding method for braided silver-plated copper wire and ultra-thin copper layer as described in claim 1, characterized in that, In step S7, after the first resistance solder joint (8) is welded, the lower electrode (3) is controlled to move downward by 2mm and move 2.0mm toward the root of the braided silver-plated copper wire (5) to weld the second resistance solder joint (9).

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