A method for fixing the flatness of copper bar pin of nanocrystal product hot riveting

Abstract

The application discloses a hot riveting jig and a method of fixing the flatness of copper bar pins of nanocrystalline products by hot riveting suitable for industrial production. First, the copper bar and the nanocrystalline assembly are preliminarily assembled in a welding jig, then laser welding process is used for welding, and after the welding is completed, the nanocrystalline copper bar assembly product is assembled. Then, the nanocrystalline copper bar assembly product is fixed and limited in the hot riveting jig, the nanocrystalline copper bar product and the hot riveting jig are put into the pulse hot riveting welding equipment carrier for fixation, then the equipment is started, the plastic part in the nanocrystalline copper bar product is instantaneously hot-melted and cooled through the upper and lower welding heads, so that the copper bar pin is fixed on the same horizontal plane of the plastic part, and the copper bar pin is fixed on the same horizontal plane of the plastic part. Then, the nanocrystalline copper bar product is subjected to demolding treatment, and the qualified nanocrystalline assembly can be obtained. Through the method, the flatness of the copper bar pin of the nanocrystalline product is good, and when the customer performs reflow soldering, the yield of one-time welding is provided.

Description

Technical Field

[0001] The present invention relates to the field of ultra-high precision flatness of multiple pins of nanocrystalline copper busbar components for new energy electric vehicles through hot riveting, a hot riveting jig and a method for hot riveting the flatness of copper busbar pins of nanocrystalline products suitable for industrial production. Background Art

[0002] Nanocrystal hot-riveted, hot-melt plastic components secure copper busbar assemblies with high current carrying capacity, low cost, high integration, space savings, and ease of reflow soldering on PCBs. These components meet the requirements of rapid automated assembly. Compared to traditional coil windings, they are smaller, offer more stable copper busbar spacing, lower resistivity, and improved product performance and functionality, while also simplifying connector design. A customer employed a reflow soldering process to secure the nanocrystal with the copper busbar assembly to the PCB. The poor flatness of the copper busbar pins could lead to issues like open circuits and cold solder joints on the PCB, hindering customer use and compromising product quality.

[0003] To this end, the present invention proposes a hot riveting jig and a method for hot riveting the flatness of copper busbar pins of nanocrystalline products suitable for industrial production. Summary of the Invention

[0004] In view of the problems existing in the prior art, the purpose of the present invention is to provide a method for the flatness process of hot riveting the copper busbar pins of nanocrystalline products suitable for industrial production, so as to avoid the problem that the flatness of multiple pins of the copper busbar is greater than 0.1mm during the process of fixing the copper busbar pins.

[0005] To achieve the above object, the technical solution of the present invention is as follows:

[0006] A hot riveting jig includes a hot riveting jig body, a cavity is provided inside the hot riveting jig body, a mounting area for a nanocrystalline copper busbar assembly product is provided at the center of the cavity, and push rod assemblies are symmetrically provided on the left and right sides of the mounting area for aligning the copper busbar pins of the nanocrystalline copper busbar assembly product with the same plane. The bottoms of the push rod assemblies are fixed to the bottom plate of the riveting jig body, and the upper surfaces of the push rod assemblies on both sides are at the same height. Two clamping blocks are symmetrically provided on the front and rear sides of the mounting area, and the clamping blocks are fixed to the bottom plate of the riveting jig body.

[0007] Furthermore, the push rod assembly includes push rod 1, push rod 2, push rod 3 and push rod 4, which are arranged in sequence from top to bottom. The outer surface of each push rod is provided with elastic component 1 facing outward, and the outer surface of each clamping block is provided with elastic component 2 facing outward. All elastic components 1 and two elastic components 2 constitute a demolding mechanism for demolding the nanocrystalline copper busbar assembly product.

[0008] Furthermore, the elastic component includes a mounting disc and a spring. The mounting disc is fixed to the lower outer surface of the corresponding push rod. One end of the spring is mounted on the mounting disc, and the other end of the spring is mounted in a mounting groove corresponding to the upper surface of the base plate.

[0009] Furthermore, the second elastic component includes a second mounting disc and a second spring. The second mounting disc is mounted on the clamping block. One end of the second spring is mounted on the second mounting disc. The other end of the second spring is mounted in a second mounting groove corresponding to the upper surface of the base plate.

[0010] Furthermore, a positioning column 1 is provided on the left side of the installation area, and a positioning column 2 and a positioning column 3 are provided on the right side from top to bottom. The positioning column 1 and the positioning column 2 are both fixed on the bottom plate after passing through the hot riveting jig body, and the positioning column 3 is fixed in the side portion of the riveting jig body with thickness.

[0011] Furthermore, an upper port of the hot riveting jig body is provided with an upper cover, the upper cover is connected to the buckle through a rotating shaft, the lower end of the buckle is buckled on the bottom plate, and the hot riveting jig body and the bottom plate are fixedly connected by fastening screws.

[0012] The present invention also proposes a method for hot riveting the flatness of copper busbar pins of nanocrystalline products suitable for industrial production, wherein the hot riveting jig is the above-mentioned hot riveting jig; the method comprises the following specific steps:

[0013] S1: First, the copper busbar and nanocrystalline component are preliminarily assembled in a welding fixture. Then, the I-shaped copper sheet and the U-shaped copper sheet are welded using a laser welding process. After welding, a nanocrystalline copper busbar component product with 4 windings and 8 pin terminals is assembled.

[0014] S2: Fixing the nanocrystalline copper busbar assembly product assembled in step S1 in the hot riveting fixture so that the copper busbar pins are on the same surface;

[0015] S3: Place the nanocrystalline copper busbar product, which has been fixed and limited in step S2, together with the hot riveting fixture, into the carrier of the pulse hot riveting welding equipment and fix it. Then, turn on the equipment, adjust the carrier in the Z-axis direction to the specified position, and then use the upper and lower welding heads to instantly melt and cool the plastic parts in the nanocrystalline copper busbar product so that the copper busbar pins are fixed on the same horizontal plane of the plastic parts.

[0016] S4: After the copper busbar pins are fixed on the same horizontal plane as the plastic component in step S3, the nanocrystalline copper busbar product is demoulded to obtain a nanocrystalline component with a copper busbar pin flatness of less than 0.1 mm.

[0017] Furthermore, in step S1, after the copper busbar and the nanocrystalline component are preliminarily assembled in a laser welding fixture, the coplanarity of the copper busbar pins is less than 0.03 mm. In step S1, the welding power of the thick copper busbar is 80%, the welding process is linear short-distance circular jitter welding, and the jitter radius is controlled at 2.5 mm. The welding power of the thin copper busbar is 60%, the welding process is linear short-distance circular jitter welding, and the jitter radius is controlled at 1 mm.

[0018] The specific process of step S2 is as follows:

[0019] Place the nanocrystalline copper busbar assembly product assembled in step S1 in the installation area, where the copper busbar pins on the left and right sides cooperate with the upper surfaces of their corresponding push rods, so that the copper busbar pins of the nanocrystalline product are lifted up by the eight push rods in the hot riveting carrier, and the clamping blocks on the front and rear sides clamp the nanocrystalline copper busbar assembly product, and then cover it with the upper cover according to the position of the positioning column, and then fasten and lock the front and rear side buckles to keep the copper busbar pins on the same surface.

[0020] Furthermore, the specific process of step S3 is as follows:

[0021] S3.1: First stage: energy 40-50%, pulse heating duration 2-3s, temperature 350-370℃;

[0022] ① The vehicle reaches the designated position of 161.700 mm along the Y axis at a speed of 60.00 mm / s;

[0023] ② The upper four welding heads reach the designated position of 122.191 mm in the Z-axis direction, with an initial velocity of 60.00 mm / s;

[0024] ③ The Z-axis direction of the next two welding heads reaches the specified position of 41.950 mm, with an initial velocity of 60.00 mm / s;

[0025] S3.2: Second stage: energy 50-60%, pulse heating duration 12-15s, temperature 390-410℃;

[0026] ①The specified position in the Y-axis direction remains unchanged;

[0027] ② The upper four welding heads continue to descend in the Z-axis direction, with a buffer speed of 0.150 mm / s and a set buffer distance of 1.2 mm;

[0028] ③ The next two welding heads continue to rise in the Z-axis direction, with a buffer speed of 0.150 mm / s and a set buffer distance of 0.6 mm;

[0029] S3.3: Pressurize and heat the upper and lower welding heads simultaneously, with a pressure of 8-10 kg, and maintain the temperature and pressure for 10 seconds;

[0030] S3.4: Rapidly cool to 100-120°C, and keep the cooling time for 5-7 seconds to allow the plastic part to set;

[0031] S3.5: Raise the temperature to 150-200℃ for demoulding, and simultaneously lift the upper and lower welding heads by 1mm to reduce the pulling of the plastic parts near the copper busbar pins during the demoulding process, which may affect the flatness of the copper busbar pins.

[0032] Furthermore, in step S4, the nanocrystalline copper busbar product undergoes a demoulding process as follows:

[0033] First, open the front and rear buckles of the hot riveting fixture body to remove the upper cover, and then use all the elastic components one and two to push out the nanocrystalline copper busbar assembly product.

[0034] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0035] 1) The hot riveting jig of the present invention comprises push rod assemblies symmetrically arranged on the left and right sides of the installation area, with the upper surfaces of the push rod assemblies on both sides being at the same height. The copper busbar pins on the left and right sides of the nanocrystalline copper busbar assembly product cooperate with the upper surfaces of their corresponding push rods, so that the copper busbar pins of the nanocrystalline product are lifted by the eight push rods in the hot riveting carrier, so that the coplanarity of the copper busbar pins after the copper busbar and the nanocrystalline assembly are initially assembled in the welding jig is maintained at less than 0.03 mm;

[0036] 2) The hot riveting jig of the present invention is equipped with a first positioning post on the left side of the installation area, and two and three positioning posts are provided on the right side, from top to bottom, to facilitate the operator to accurately install the nanocrystalline copper busbar assembly product position, and even inexperienced workers can operate quickly and accurately;

[0037] 3) The present invention first preliminarily assembles the copper busbar and the nanocrystalline component in a welding jig so that the coplanarity of the copper busbar pins is less than 0.03 mm. Then, the I-shaped copper sheet and the U-shaped copper sheet are welded using a laser welding process. After welding, a nanocrystalline copper busbar component product with 4 windings and 8 pin terminals is assembled. Then, the nanocrystalline copper busbar component product is installed in the hot riveting jig of the present invention and fixedly limited so that the coplanarity of the copper busbar pins of the product is maintained at less than 0.03 mm. The nanocrystalline copper busbar product after fixed limitation is placed in a pulse hot riveting welding equipment carrier together with the hot riveting jig and fixed. Then, the equipment is turned on, the Z-axis direction carrier is adjusted to a specified position, and then the plastic parts in the nanocrystalline copper busbar product are instantly melted and cooled by the upper and lower welding heads so that the copper busbar pins are fixed on the same horizontal plane as the plastic parts. The copper busbar pins are fixed on the same horizontal plane as the plastic parts. Then, the nanocrystalline copper busbar product is demolded to obtain a nanocrystalline component with a copper busbar pin flatness of less than 0.1 mm.

[0038] 4) The copper busbar pin fixing process of the present invention has good pin flatness and excellent fixing reliability. When the customer performs reflow soldering, it provides a one-time soldering yield and saves solder paste usage.

[0039] 5) The present invention first laser welds the copper busbar to the nanocrystals to ensure that the copper busbar pins remain within a flatness of 0.03 mm during the welding process, thereby preventing the copper busbar from being deformed due to the high temperature of laser welding;

[0040] 6) The present invention uses a six-channel pulse heat riveting method that is performed simultaneously on the upper and lower sides to keep the copper busbar pin flatness within 0.1 mm, and the manufacturability is increased to 99%. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 Schematic diagram of the overall structure of the hot riveting jig in the present invention;

[0042] Figure 2 This is a schematic diagram of the main structure of the hot riveting jig in the invention;

[0043] Figure 3 Schematic diagram of the bottom plate structure of the hot riveting jig in the present invention;

[0044] Figure 4 This is a diagram showing the flatness test results of the product after heat riveting and curing in Example 1 of the present invention;

[0045] Figure 5 This is a diagram showing the flatness test results of the product after heat riveting and curing in Comparative Example 1 of the present invention;

[0046] Figure 6 This is a diagram showing the flatness test results of the product after heat riveting and curing in Comparative Example 2 of the present invention;

[0047] Figure 7 This is a diagram showing the flatness test results of the product after heat riveting and curing in Comparative Example 3 of the present invention;

[0048] Figure 8 This is a diagram showing the flatness test results of the product after heat riveting and curing in Comparative Example 4 of the present invention.

[0049] In the figure: 1. Hot riveting fixture body; 2. Mounting area; 3. Clamping block; 4. Bottom plate; 5. Push rod 1; 6. Push rod 2; 7. Push rod 3; 8. Push rod 4; 9. Mounting disc 1; 10. Spring 1; 11. Mounting disc 2; 12. Spring 2; 13. Positioning column 1; 14. Positioning column 2; 15. Positioning column 3; 16. Upper cover; 17. Fastening screw; 18. Buckle; 19. Rotating axis. DETAILED DESCRIPTION

[0050] The present invention will be further described below with reference to the accompanying drawings and embodiments, but the scope of protection of the present invention is not limited to the described scope.

[0051] Please refer to Figure 1-3 A hot riveting jig includes a hot riveting jig body 1, a cavity is provided inside the hot riveting jig body 1, an installation area 2 for a nanocrystalline copper busbar assembly product is provided at the center of the cavity, and push rod assemblies are symmetrically provided on the left and right sides of the installation area 2, which are used to make the copper busbar pins of the nanocrystalline copper busbar assembly product in the same plane, the bottom of the push rod assembly is fixed on the bottom plate 4 of the riveting jig body 1, and the upper surfaces of the push rod assemblies on both sides are at the same height, and two clamping blocks 3 are symmetrically provided at the front and rear ends of the installation area 2, and the clamping blocks 3 are fixed to the bottom plate 4 of the riveting jig body 1.

[0052] The ejector assembly includes ejector 1 5, ejector 2 6, ejector 3 7 and ejector 4 8, which are arranged in sequence from top to bottom. An elastic component 1 is provided on the outer surface of each ejector facing outward, and an elastic component 2 is provided on the outer surface of each clamping block 3 facing outward. All the elastic components 1 and the two elastic components 2 constitute a demolding mechanism for demolding the nanocrystalline copper busbar assembly product.

[0053] Elastic component 1 includes a mounting disc 19 and a spring 10. The mounting disc 19 is fixed to the lower outer surface of the corresponding push rod. One end of the spring 10 is mounted on the mounting disc 19, and the other end of the spring 10 is mounted in a mounting groove 1 corresponding to the upper surface of the base plate 4.

[0054] The second elastic component includes a second mounting disc 11 and a second spring 12. The second mounting disc 11 is mounted on the clamping block 3. One end of the second spring 12 is mounted on the second mounting disc 11. The other end of the second spring 12 is mounted in a corresponding mounting groove 2 on the upper surface of the base plate 4.

[0055] To facilitate accurate installation of the nanocrystalline copper busbar assembly, a first positioning post 13 is located on the left side of the mounting area 2, and two positioning posts 14 and 15 are located on the right side, from top to bottom. Both positioning posts 13 and 14 pass through the hot riveting jig body 1 and are secured to the base plate 4. Positioning post 3 15 is secured within the thick side portion of the jig body 1.

[0056] The upper end of the hot riveting jig body 1 is detachably provided with an upper cover 16. In this embodiment, the upper cover 16 is connected to the buckle 18 through a rotating shaft 19. The lower end of the buckle 18 is buckled on the base plate 4. Furthermore, positioning pins are symmetrically provided at both ends of the buckle to assist in positioning and locking the base plate 4. The hot riveting jig body 1 is fixedly connected to the base plate 4 by fastening screws 17.

[0057] Example 1

[0058] S1: First, the copper busbar and nanocrystalline component are preliminarily assembled in a laser welding fixture. Then, the I-shaped copper sheet and the U-shaped copper sheet are welded using the laser welding process. After welding, a nanocrystalline copper busbar component product with 4 windings and 8 pin terminals is assembled.

[0059] The welding power for thick copper busbar is 80%, and the welding process is linear short-distance circular jitter welding, with the jitter radius controlled at 2.5mm. The welding power for thin copper busbar is 60%, and the welding process is linear short-distance circular jitter welding, with the jitter radius controlled at 1mm.

[0060] S2: Place the nanocrystalline copper busbar assembly product assembled in step S1 in the installation area 2, wherein the copper busbar pins on the left and right sides cooperate with the upper surfaces of their corresponding push rods, so that the copper busbar pins of the nanocrystalline product are lifted up by the eight push rods in the hot riveting carrier. The clamping blocks 3 on the front and rear sides clamp the nanocrystalline copper busbar assembly product, and then cover it with the upper cover 16 according to the position of the positioning column. Then, the front and rear side buckles are fastened and locked to keep the copper busbar pins on the same surface;

[0061] S3: Place the nanocrystalline copper busbar product, which has been fixed and limited in step S2, together with the hot riveting fixture, into the carrier of the pulse hot riveting welding equipment and fix it. Then, turn on the equipment, adjust the carrier in the Z-axis direction to the specified position, and then use the upper and lower welding heads to instantly melt and cool the plastic parts in the nanocrystalline copper busbar product so that the copper busbar pins are fixed on the same horizontal plane of the plastic parts.

[0062] S3.1: The first stage: energy 40-50%, pulse heating duration 3s, temperature 360℃,

[0063] ① The vehicle reaches the designated position of 161.700 mm along the Y axis at a speed of 60.00 mm / s;

[0064] ② The upper four welding heads reach the designated position of 122.191mm in the Z-axis direction with an initial velocity of 60.00mm / s; the lower two welding heads reach the designated position of 41.950mm in the Z-axis direction with an initial velocity of 60.00mm / s;

[0065] S3.2: Second stage: energy 50-60%, pulse heating duration 14s, temperature 400℃.

[0066] ①The Y-axis direction remains unchanged

[0067] ② The upper four welding heads continue to descend in the Z-axis direction, with a buffer speed of 0.150 mm / s and a set buffer distance of 1.2 mm;

[0068] ③ The next two welding heads continue to rise in the Z-axis direction, with a buffer speed of 0.150 mm / s and a set buffer distance of 0.6 mm;

[0069] S3.3: The third stage: welding with simultaneous pressure and heating, the pressure is 9kg, and the temperature and pressure are kept constant for 10 seconds;

[0070] S3.4: The fourth stage: Rapid cooling to 110 ° C, cooling time is maintained for 6 seconds to allow the plastic part to set;

[0071] S3.5: The fifth stage: Heat to 185℃ for demoulding, and lift the height up and down by 1mm at the same time to reduce the plastic parts near the copper busbar pins from being pulled during the demoulding process, which affects the flatness of the copper busbar pins.

[0072] S4: After the copper busbar pins are fixed on the same horizontal plane as the plastic part in step S3, open the front and rear buckles of the hot riveting fixture body 1 to remove the upper cover 16, and then use all the elastic components one and two to push out the nanocrystalline copper busbar assembly product.

[0073] Flatness test conditions: Place the product after hot riveting in the VR optical inspection equipment to test the flatness of the 8 pins.

[0074] Depend on Figure 4 It can be seen from observation that the 8 pins of the copper busbar of the nanocrystalline component are fixed in flatness, and the pin coverage and wrapping are good, and the appearance meets the requirements.

[0075] After testing, the flatness of Example 1 is less than 0.1 mm, the flatness is suitable for reflow soldering, and the product is qualified.

[0076] Comparative Example 1

[0077] S1: First, the copper busbar and nanocrystalline component are preliminarily assembled in a common laser welding fixture. Then, the I-shaped copper sheet and the U-shaped copper sheet are welded using a laser welding process. After welding, a nanocrystalline copper busbar component product with 4 windings and 8 pin terminals is assembled.

[0078] The welding power for thick copper busbar is 80%, and the welding process is linear short-distance circular jitter welding, with the jitter radius controlled at 2.5mm. The welding power for thin copper busbar is 60%, and the welding process is linear short-distance circular jitter welding, with the jitter radius controlled at 1mm.

[0079] S2: Place the nanocrystalline copper busbar assembly product assembled in step S1 into the pulse hot riveting welding equipment carrier and fix it. Then turn on the equipment and perform upper hot riveting welding first. Then take out the product and perform lower hot riveting welding. The temperature is 350°C.

[0080] S3: After step S2 is completed, open the front and rear buckles of the hot riveting jig body 1 to remove the upper cover 16, and then use all the elastic components one and two to push out the nanocrystalline copper busbar assembly product.

[0081] Flatness test conditions: Place the product after hot riveting in the VR optical inspection equipment to test the flatness of the 8 pins.

[0082] Depend on Figure 5It can be seen from observation that after the upper and lower parts are hot-riveted and hot-melt welded, the copper busbar pins are obviously uneven.

[0083] The flatness of comparative example 1 was found to be unqualified after testing, and the average flatness value was greater than 0.5 mm.

[0084] Comparative Example 2

[0085] S1: First, the copper busbar and nanocrystalline component are preliminarily assembled in a laser welding fixture. Then, the I-shaped copper sheet and the U-shaped copper sheet are welded using the laser welding process. After welding, a nanocrystalline copper busbar component product with 4 windings and 8 pin terminals is assembled.

[0086] The welding power for thick copper busbar is 80%, and the welding process is linear short-distance circular jitter welding, with the jitter radius controlled at 2.5mm. The welding power for thin copper busbar is 60%, and the welding process is linear short-distance circular jitter welding, with the jitter radius controlled at 1mm.

[0087] S2: Place the nanocrystalline copper busbar assembly product assembled in step S1 into the pulse hot riveting welding equipment carrier and fix it. Then turn on the equipment and perform upper hot riveting welding first. Then take out the product and perform lower hot riveting welding. The temperature is 350°C.

[0088] S3: After step S2 is completed, open the front and rear buckles of the hot riveting jig body 1 to remove the upper cover 16, and then use all the elastic components one and two to push out the nanocrystalline copper busbar assembly product.

[0089] Depend on Figure 6 It can be seen from observation that after the upper and lower parts are hot-riveted and hot-melt welded, the copper busbar pins are obviously uneven.

[0090] The flatness of comparative example 2 was found to be unqualified after testing, with an average flatness value greater than 0.3 mm.

[0091] Comparative Example 3

[0092] S1: First, the copper busbar and nanocrystalline component are preliminarily assembled in a laser welding fixture. Then, the I-shaped copper sheet and the U-shaped copper sheet are welded using the laser welding process. After welding, a nanocrystalline copper busbar component product with 4 windings and 8 pin terminals is assembled.

[0093] The welding power for thick copper busbar is 80%, and the welding process is linear short-distance circular jitter welding, with the jitter radius controlled at 2.5mm. The welding power for thin copper busbar is 60%, and the welding process is linear short-distance circular jitter welding, with the jitter radius controlled at 1mm.

[0094] S2: Place the assembled nanocrystalline copper bar assembly product of step S1 in the installation area 2, wherein the copper bar pins on the left and right sides cooperate with the corresponding top rod upper surfaces, so that the nanocrystalline product copper bar pins are lifted by eight top rods in the hot riveting tool, the front and rear clamping blocks 3 clamp the nanocrystalline copper bar assembly product, then cover the upper cover 16 according to the position of the positioning column, and then tighten the buckle on the front and rear sides to lock, so that the copper bar pins are kept on the same plane;

[0095] S3: Place the nanocrystalline copper bar product fixed and limited in step S2 into the pulse hot riveting welding equipment carrier, then turn on the equipment, first perform upper hot riveting welding, then take out the hot riveting tool carrying the product, then perform lower hot riveting welding in another pulse hot riveting welding equipment carrier, and the temperature is 350℃;

[0096] S4: Then open the front and rear buckles of the hot riveting tool main body 1 to remove the upper cover 16, and then use all the elastic components and two elastic components to lift out and remove the nanocrystalline copper bar assembly product.

[0097] By Figure 7 It can be observed that after the upper and lower hot riveting hot melting welding, the unevenness of the copper bar pins is obviously improved,

[0098] The flatness of the test comparative example 3 is unqualified, and the average flatness is greater than 0.2mm.

[0099] Comparative example 4

[0100] S1: First, assemble the copper bar and nanocrystalline assembly in the laser welding tool, then use the laser welding process to weld the I-shaped copper sheet and U-shaped copper sheet, and after welding, assemble the nanocrystalline copper bar assembly product with 4 windings and 8 pin terminals;

[0101] The welding power of the thick copper bar is 80%, the welding process is straight line short distance ring shaking welding, and the shaking radius is controlled at 2.5mm; the welding power of the thin copper bar is 60%, the welding process is straight line short distance ring shaking welding, and the shaking radius is controlled at 1mm;

[0102] S2: Place the assembled nanocrystalline copper bar assembly product of step S1 in the installation area 2, wherein the copper bar pins on the left and right sides cooperate with the corresponding top rod upper surfaces, so that the nanocrystalline product copper bar pins are lifted by eight top rods in the hot riveting tool, the front and rear clamping blocks 3 clamp the nanocrystalline copper bar assembly product, then cover the upper cover 16 according to the position of the positioning column, and then tighten the buckle on the front and rear sides to lock, so that the copper bar pins are kept on the same plane;

[0103] S3: Place the nanocrystalline copper busbar product, which has been fixed and limited in step S2, together with the hot riveting fixture, into the carrier of the pulse hot riveting welding equipment and fix it. Then turn on the equipment and perform upper hot riveting welding first. Then, remove the product and perform lower hot riveting welding. The temperature is 350°C.

[0104] S4: Then open the front and rear buckles of the hot riveting jig body 1 to remove the upper cover 16, and then use all the elastic components one and two to push out the nanocrystalline copper busbar assembly product.

[0105] Depend on Figure 8 It can be seen from the observation that after the upper and lower parts are hot-riveted and hot-melt welded, the unevenness of the copper busbar pins is significantly improved.

[0106] The flatness of comparative example 4 was found to be unqualified after testing, with an average flatness value greater than 0.1 mm.

[0107] In the present invention, the laser welding jig is a laser welding jig with a limiting structure; the ordinary welding jig refers to a laser welding jig without a limiting structure.

[0108] It can be seen from Example 1 and Comparative Examples 1-4 that, by the method of the present invention, the copper busbar and the nanocrystalline component are first preliminarily assembled in a laser welding jig, so that the coplanarity of the copper busbar pins is less than 0.03 mm, and then the I-type copper sheet and the U-shaped copper sheet are welded using a laser welding process. After welding, a nanocrystalline copper busbar assembly product with 4 windings and 8 pin terminals is assembled. The nanocrystalline copper busbar assembly product is then installed in the hot riveting jig of the present invention and fixedly limited so that the coplanarity of the copper busbar pins of the product is maintained at less than 0.03 mm. The nanocrystalline copper busbar product after fixed limit is placed in a pulse hot riveting welding equipment carrier together with the hot riveting jig and fixed. The equipment is then turned on, the Z-axis direction carrier is adjusted to a specified position, and then the plastic parts in the nanocrystalline copper busbar product are instantly melted and cooled by the upper and lower welding heads, so that the copper busbar pins are fixed on the same horizontal plane of the plastic parts. The copper busbar pins are fixed on the same horizontal plane of the plastic parts, and then the nanocrystalline copper busbar product is demolded to obtain a nanocrystalline component with a copper busbar pin flatness of less than 0.1 mm.

Claims

1. A method for hot riveting copper busbar pin flatness fixation for nanocrystalline products suitable for industrial production, characterized in that The hot riveting jig comprises a hot riveting jig body (1), wherein a cavity is provided inside the hot riveting jig body (1), wherein an installation area (2) for a nanocrystalline copper busbar assembly product is provided at the center of the cavity, and push rod assemblies for placing the copper busbar pins of the nanocrystalline copper busbar assembly product in the same plane are symmetrically provided on the left and right sides of the installation area (2), the bottom of the push rod assembly is fixed on the bottom plate (4) of the riveting jig body (1), and the upper surfaces of the push rod assemblies on both sides are at the same height, and two clamping blocks (3) are symmetrically provided on the front and rear sides of the installation area (2), and the clamping blocks (3) are fixed on the bottom plate (4) of the riveting jig body (1); It includes the following specific steps: S1: First, the copper busbar and nanocrystalline component are preliminarily assembled in a laser welding fixture. Then, the I-shaped copper sheet and the U-shaped copper sheet are welded using the laser welding process. After welding, a nanocrystalline copper busbar component product with 4 windings and 8 pin terminals is assembled. S2: Fixing the nanocrystalline copper busbar assembly product assembled in step S1 in the hot riveting fixture so that the copper busbar pins are on the same surface; S3: Place the nanocrystalline copper busbar product, which has been fixed and limited in step S2, together with the hot riveting fixture, into the carrier of the pulse hot riveting welding equipment and fix it. Then, turn on the equipment, adjust the carrier in the Z-axis direction to the specified position, and then use the upper and lower welding heads to instantly melt and cool the plastic parts in the nanocrystalline copper busbar product so that the copper busbar pins are fixed on the same horizontal plane of the plastic parts. S4: After the copper busbar pins are fixed on the same horizontal surface of the plastic component in step S3, the nanocrystalline copper busbar product is demoulded to obtain a nanocrystalline component with a copper busbar pin flatness of less than 0.1 mm; In step S1, the copper busbar and the nanocrystalline component are initially assembled in a laser welding fixture, and the coplanarity of the copper busbar pins is less than 0.03 mm. In step S1, the welding power of the thick copper busbar is 80%, the welding process is linear short-distance circular jitter welding, and the jitter radius is controlled to be 2.5 mm. The welding power of the thin copper busbar is 60%, the welding process is linear short-distance circular jitter welding, and the jitter radius is controlled to be 1 mm. The specific process of step S2 is as follows: The nanocrystalline copper busbar assembly product assembled in step S1 is placed in the installation area (2), wherein the copper busbar pins on the left and right sides cooperate with the upper surfaces of their corresponding push rods, so that the copper busbar pins of the nanocrystalline product are lifted up by the eight push rods in the hot riveting carrier, and the clamping blocks (3) on the front and rear sides clamp the nanocrystalline copper busbar assembly product, and then the upper cover (16) is covered according to the position of the positioning column, and then the buckles on the front and rear sides are fastened and locked to keep the copper busbar pins on the same surface; The specific process of step S3 is as follows: S3.1: First stage: energy 40-50%, pulse heating duration 2-3s, temperature 350-370℃; ① The vehicle reaches the designated position of 161.700 mm along the Y axis at a speed of 60.00 mm / s; ② The upper four welding heads reach the designated position of 122.191 mm in the Z-axis direction, with an initial velocity of 60.00 mm / s; ③ The Z-axis direction of the next two welding heads reaches the specified position of 41.950 mm, with an initial velocity of 60.00 mm / s; S3.2: Second stage: energy 50-60%, pulse heating duration 12-15s, temperature 390-410℃; ①The specified position in the Y-axis direction remains unchanged; ② The upper four welding heads continue to descend in the Z-axis direction, with a buffer speed of 0.150 mm / s and a set buffer distance of 1.2 mm; ③ The next two welding heads continue to rise in the Z-axis direction, with a buffer speed of 0.150 mm / s and a set buffer distance of 0.6 mm; S3.3: Pressurize and heat the upper and lower welding heads simultaneously, with a pressure of 8-10 kg, and maintain the temperature and pressure for 10 seconds; S3.4: Rapidly cool to 100-120°C and keep the cooling time for 5-7 seconds to allow the plastic part to set; S3.5: Raise the temperature to 150-200℃ for demoulding, and simultaneously lift the upper and lower welding heads by 1mm to reduce the pulling of plastic parts near the copper busbar pins during demoulding, which may affect the flatness of the copper busbar pins.

2. The method for hot riveting copper busbar pin flatness of nanocrystalline products suitable for industrial production according to claim 1, characterized in that The ejector assembly comprises ejector 1 (5), ejector 2 (6), ejector 3 (7) and ejector 4 (8) which are arranged in sequence from top to bottom. An elastic component 1 is arranged on the outer surface of each ejector facing outward, and an elastic component 2 is arranged on the outer surface of each clamping block (3) facing outward. All the elastic components 1 and the two elastic components 2 constitute a demoulding mechanism for demoulding a nanocrystalline copper busbar assembly product.

3. The method for hot riveting copper busbar pin flatness of nanocrystalline products suitable for industrial production according to claim 2, characterized in that The elastic component includes a mounting disc (9) and a spring (10), wherein the mounting disc (9) is fixed to the lower outer surface of the corresponding push rod, one end of the spring (10) is mounted on the mounting disc (9), and the other end of the spring (10) is mounted in a mounting groove corresponding to the upper surface of the bottom plate (4).

4. The method for hot riveting copper busbar pin flatness of nanocrystalline products suitable for industrial production according to claim 2, characterized in that The elastic component 2 includes a mounting disc 2 (11) and a spring 2 (12), wherein the mounting disc 2 (11) is mounted on the clamping block (3), one end of the spring 2 (12) is mounted on the mounting disc 2 (11), and the other end of the spring 2 (12) is mounted in a mounting groove 2 correspondingly provided on the upper surface of the base plate (4).

5. The method for hot riveting copper busbar pin flatness of nanocrystalline products suitable for industrial production according to claim 1, characterized in that A positioning column 1 (13) is provided on the left side of the installation area (2), and a positioning column 2 (14) and a positioning column 3 (15) are provided on the right side thereof from top to bottom. The positioning column 1 (13) and the positioning column 2 (14) are both fixed on the bottom plate (4) after passing through the hot riveting jig body (1), and the positioning column 3 (15) is fixed in the side portion of the riveting jig body (1) having thickness.

6. The method for hot riveting copper busbar pin flatness of nanocrystalline products suitable for industrial production according to claim 1, characterized in that An upper cover (16) is provided at the upper end of the heat riveting jig body (1), the upper cover (16) is connected to the buckle (18) via a rotating shaft (19), the lower end of the buckle (18) is buckled onto the bottom plate (4), and the heat riveting jig body (1) and the bottom plate (4) are fixedly connected via a fastening screw (17).

7. The method for hot riveting copper busbar pin flatness of nanocrystalline products suitable for industrial production according to claim 1, characterized in that Step S4: The demoulding process of the nanocrystalline copper busbar product is as follows: First, open the front and rear buckles (18) of the hot riveting fixture body (1) and remove the upper cover (16), and then use all the elastic components one and two to push out the nanocrystalline copper busbar assembly product and remove it.

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