A welding detection method for lithium ion battery sealing nails

Abstract

The present application relates to a kind of welding detection methods of lithium ion battery sealing nail, comprising the following steps: S1, after being assembled with glue nail, it is assembled with battery cover plate injection port;S2, the trajectory of the nail of sealing nail is compared and judged by CCD system, the data result of the photo obtained is calculated by the calculation software in system, obtains welding trajectory and transmits welding trajectory instruction to laser welding equipment;S3, pre-point welding and full welding are carried out to sealing nail by laser welding equipment;S4, sealing nail is tested by pressing;S5, quality side leakage detection is carried out to the battery of welded sealing nail by helium system, also provide a kind of welding detection device of lithium ion battery sealing nail, sealing nail is pushed into containing cavity after being adsorbed by adsorption component, glue dispensing machine is glued to sealing nail in the process of sealing nail being lowered by cutting knife, cutting knife is glued to glue nail at the same time after being cut to glue nail, improve work efficiency.

Description

Technical Field

[0001] This invention relates to the field of energy storage battery equipment technology, and more specifically to a welding inspection method for lithium-ion battery sealing nails. Background Technology

[0002] Lithium-ion batteries are power sources that provide power to power tools. They are widely used in various fields due to their advantages such as long lifespan, practicality, safety, large capacity, small size, and light weight. As a new energy source, lithium-ion batteries are widely used in our lives, and aluminum-cased batteries are one of the most widely used battery types due to their safety advantages. In the lithium-ion battery production process, the sealing nail welding is a crucial component of the battery cell and is the final laser welding process. Therefore, the yield rate of this process is critical; scrapping products at this final stage results in significant cost losses for battery manufacturers.

[0003] Currently, most battery manufacturers in the new energy industry use YAG pulse welding equipment for sealing nail welding processes. This is because YAG lasers, equipped with arbitrary waveform real-time energy negative feedback technology, possess excellent single-pulse energy stability, ultimately achieving a first-pass welding success rate of ≥99.5%. However, YAG lasers are not without their limitations. Their power has an upper limit; the maximum power currently available on the market is 600W. This power limitation restricts the welding frequency, forcing the current practice to use a collimated head for pulse welding.

[0004] Chinese patent CN115846920B discloses a welding method for a battery sealing pin. The welding method includes: inserting the sealing pin into the electrolyte injection hole of a battery end cap, wherein the battery end cap has a heating area surrounding the sealing pin; placing a heating device in the heating area; activating the heating device to heat the heating area; and activating a welding device to weld the sealing pin, wherein the temperature at the welding position of the sealing pin is higher than the temperature of the heating area. The battery sealing pin welding method provided in this application can solve the problem of cracks appearing at the welding position of the sealing pin due to rapid cooling after welding, thereby ensuring the sealing effect of the sealing pin and reducing the battery leakage rate.

[0005] However, the inventors discovered that in actual production, the maximum weld penetration depth of the sealing nail is 0.3mm to 0.7mm. During the formation of the molten pool, there is a gap between the sealing nail and the cover plate, and the gap between each set of sealing nails and the cover plate is not the same. The molten pool with low penetration depth experiences different stresses when solidifying in the face of different gaps. In most cases, the molten pool with low penetration depth will produce cracks in the wide gaps. This excessively low penetration depth not only affects the welding strength but also increases the probability of cracks appearing at the weld. Crack defects seriously affect the performance of the battery cell and even threaten the safety of the battery cell. It is necessary to manually inspect each post-weld battery cell under a 30x magnifying glass. Therefore, how to improve the welding quality of the sealing nails in lithium-ion power batteries and at the same time improve their safety performance is a technical problem that urgently needs to be solved. Summary of the Invention

[0006] The purpose of this invention is to address the shortcomings of existing technologies by providing a welding inspection method for lithium-ion battery sealing nails. This method involves assembling the sealing nail and adhesive nail, inserting it into the electrolyte inlet of the battery cover, and comparing the placement trajectory of the sealing nail using a CCD system. The resulting image data is then processed by the system's calculation software to obtain the welding trajectory, which is transmitted to a laser welding device. The laser welding device then performs pre-spot welding and full welding on the sealing nail, followed by a pressure test. A helium gas system is used to detect leaks in the battery with the welded sealing nail. The synergistic effect of the CCD system and the welding process shortens the welding time while achieving good welding results. This reduces the number of personnel required for visual inspection and the labor intensity, saving costs and achieving the goal of reducing manpower and increasing efficiency.

[0007] The technical solution of the present invention is as follows:

[0008] A welding inspection method for lithium-ion battery sealing nails includes the following steps:

[0009] S1. Assemble the sealing nail and the glue nail, and then assemble them with the liquid injection port of the battery cover.

[0010] S2. The placement trajectory of the sealing nail is compared and judged by the CCD system. The data results of the obtained photos are calculated by the calculation software in the system to obtain the welding trajectory and the welding trajectory command is transmitted to the laser welding equipment.

[0011] S3. Pre-tack welding and full welding of the sealing nails are performed using laser welding equipment;

[0012] S4. Perform a pressure test on the sealing nails;

[0013] S5. Perform quality side leakage detection on the battery with welded sealing nails using a helium gas system.

[0014] This invention also provides a welding inspection device for lithium-ion battery sealing nails. After the sealing nail is adsorbed by the adsorption component, it is pushed into the receiving cavity. During the process of the cutting blade driving the sealing nail down, the dispensing machine applies glue to the sealing nail. After the cutting blade cuts the glue nail, the sliding component moves the glue nail to one side of the receiving cavity. The pushing component pushes the sealing nail and the glue nail to bond together, so that the sealing nail and the glue nail are assembled into one piece and inserted into the liquid injection port of the battery cover. This replaces the traditional method of manually inserting the sealing nail into the liquid injection port and then sealing the sealing nail, thus improving work efficiency.

[0015] The technical solution of the present invention is as follows:

[0016] A welding inspection device for lithium-ion battery sealing nails includes a base, a dispensing machine disposed on one side of the base, and a transport track disposed on the same side of the base for transporting the sealing nails. An adsorption component is disposed on one side of the transport track. A driving component and a cutting component driven by the driving component are disposed on the base. The cutting component includes a cutting blade and a receiving cavity formed in the cutting blade. A sliding component is disposed along the moving path of the cutting blade. A bearing component and a pushing component are disposed on the base. The bearing component includes a support seat for holding the sealing nail. The adsorption component adsorbs the sealing nail and pushes it into the receiving cavity. The dispensing machine dispenses adhesive onto the sealing nail as the driving component drives the cutting blade and the sealing nail to descend. The sliding component moves the sealing nail to one side of the receiving cavity while the cutting blade cuts the sealing nail. The pushing component pushes the sealing nail to adhere to the adhesive.

[0017] As a preferred embodiment, the adsorption assembly includes a base plate fixedly mounted on a transmission track, a sliding seat slidably mounted on the base plate, a cylinder fixedly mounted on the sliding seat, a suction cup fixedly mounted on the cylinder, a piston slidably mounted inside the cylinder, a piston rod fixedly mounted on the piston, a first limiting rod slidably mounted inside the cylinder, an air hole opened on the cylinder, a stop rod fixedly mounted on the sliding seat, a channel fixedly mounted on the transmission track, a fixing rod and a limiting post fixedly mounted on the channel, a second limiting rod slidably mounted on the fixing rod, and a sliding plate slidably mounted on the base plate. The piston rod is fixedly connected to the sliding plate. The piston has arc-shaped surfaces on both sides that cooperate with the first limiting rod. Springs are provided between the first limiting rod and the cylinder, and between the second limiting rod and the channel. The second limiting rod cooperates with a sealing pin. The diameter of the channel is the same as the diameter of the sealing pin.

[0018] As a preferred embodiment, the drive assembly includes a support frame fixedly mounted on the base, a motor fixedly mounted on the support frame, a first lead screw rotatably mounted on the support frame, and a guide rod fixedly mounted on the support frame, wherein the first lead screw is fixedly connected to the motor output shaft.

[0019] As a preferred embodiment, the cutting assembly further includes a sliding plate slidably disposed on the first lead screw and a plurality of third limiting rods slidably disposed on the receiving cavity. The cutting blade is fixedly connected to the sliding plate, the sliding plate cooperates with the guide rod, a spring is provided between the third limiting rod and the receiving cavity, and the third limiting rod cooperates with the sealing pin. The diameter of the receiving cavity is the same as the diameter of the channel.

[0020] As a preferred embodiment, the sliding assembly includes a groove formed on the base, a second lead screw rotatably disposed within the groove, a rotating shaft rotatably disposed on the base, a gear fixedly disposed on the rotating shaft, and a rack fixedly disposed on the sliding plate. The gear meshes with the rack, and both the second lead screw and the rotating shaft are provided with pulleys, with a belt disposed between the pulleys.

[0021] As a preferred embodiment, the bearing assembly further includes a first slider and a second slider slidably disposed in the slide groove, a U-shaped seat fixedly disposed on the first slider, and a baffle fixedly disposed on the bearing seat. The second slider is fixedly connected to the bearing seat, and both the U-shaped seat and the bearing seat are engaged with rubber nails.

[0022] As a preferred embodiment, the push assembly includes a ring sleeve slidably disposed on the base, a push rod fixedly disposed on the ring sleeve, and a cylinder fixedly disposed on the support frame. The cylinder output shaft is fixedly connected to the ring sleeve, and the push rod cooperates with a sealing pin.

[0023] As a preferred embodiment, the push rod is provided with a rubber layer.

[0024] As a preferred embodiment, both the U-shaped base and the support base are provided with anti-slip textures.

[0025] The beneficial effects of this invention are as follows:

[0026] 1. This invention utilizes a CCD system in conjunction with pulsed laser welding to acquire welding trajectories, screen for defective products, and improve production efficiency. Deep penetration welding has a lower probability of cracking during molten pool formation compared to shallow penetration welding, and improves the sealing of the injection holes. Simultaneously, the output power and pulse width waveform of the welding equipment can be appropriately reduced, resulting in a smoother and more consistent weld surface, achieving a first-pass welding success rate of ≥99.5%. The excellent sealing effect extends battery life and safety, and the reduced probability of cracking effectively reduces the labor intensity and quantity of visual inspection, saving costs.

[0027] 2. The present invention also includes an adsorption component and a cutting component. After the sealing nail is brought into the cutting blade receiving cavity by the suction cup, the cutting blade descends to cut the adhesive nail while simultaneously bonding the sealing nail to the adhesive nail. This replaces the traditional method of manually inserting the adhesive nail into the battery cover's liquid injection port and then covering the battery cover with the sealing nail, thus improving work efficiency.

[0028] In summary, this invention has the advantages of good welding effect and high efficiency, and is suitable for the field of energy storage battery equipment technology. Attached Figure Description

[0029] The invention will be further described below with reference to the accompanying drawings:

[0030] Figure 1 The image shows the welding effect of the sealing nail obtained in Example 1;

[0031] Figure 2 This is a welding effect diagram of the sealing nail obtained in Example 2;

[0032] Figure 3 This is a welding effect diagram of the sealing nail obtained in Example 3;

[0033] Figure 4 This is a welding effect diagram of the sealing nail obtained in Example 4;

[0034] Figure 5 The image shows the metallographic image of the sealing nail obtained in Example 4.

[0035] Figure 6 This is a welding effect diagram of the sealing nail obtained in Example 5;

[0036] Figure 7 This is a welding effect diagram of the sealing nail obtained in Example 6;

[0037] Figure 8 Metallographic image of the sealing nail obtained in Example 7;

[0038] Figure 9 Metallographic image of the sealing nail obtained in Example 8;

[0039] Figure 10 This is a welding effect diagram of the sealing nail obtained in Example 9;

[0040] Figure 11 The image shows the test results.

[0041] Figure 12 This is a schematic diagram of the welding testing device.

[0042] Figure 13 This is a schematic diagram of the adsorption component.

[0043] Figure 14 This is a structural diagram of the driving component and the cutting component;

[0044] Figure 15 A structural schematic diagram of the sliding component, the load-bearing component, and the jacking component;

[0045] Figure 16A schematic diagram showing the state when the first limiting rod contacts the piston while the cylinder slides and adsorbs the sealing nail;

[0046] Figure 17 for Figure 16 Enlarged view of point A in the middle;

[0047] Figure 18 A schematic diagram showing the state when the cylinder moves the sealing pin and the piston to slide synchronously.

[0048] Figure 19 This is a schematic diagram showing the state when the cylinder pushes the sealing pin into the receiving cavity while the vent slides to the front of the piston.

[0049] Figure 20 for Figure 19 Enlarged view at point B in the middle;

[0050] Figure 21 This is a schematic diagram showing the state of the plastic nail as it slides after the cutting blade cuts it.

[0051] Figure 22 A schematic diagram showing the state when the push rod pushes the sealing nail and the adhesive nail to adhere;

[0052] Figure reference numerals: 1 sealing nail, 2 glue nail, 4 base, 5 dispensing machine, 6 transmission track, 7 adsorption assembly, 71 base plate, 72 sliding seat, 73 cylinder, 74 suction cup, 75 piston, 76 piston rod, 77 first limit rod, 78 air hole, 79 stop rod, 710 channel, 711 fixing rod, 712 limit post, 713 second limit rod, 714 sliding plate, 8 drive assembly, 81 support frame, 82 motor, 83 first lead screw. 84 Guide rod, 9 Cutting assembly, 91 Cutting blade, 92 Receiving cavity, 93 Sliding plate, 94 Third limit rod, 10 Sliding assembly, 101 Slide groove, 102 Second lead screw, 103 Rotating shaft, 104 Gear, 105 Rack, 11 Bearing assembly, 111 Bearing seat, 112 First slider, 113 Second slider, 114 U-shaped seat, 115 Baffle, 12 Pushing assembly, 121 Ring sleeve, 122 Push rod, 123 Cylinder. Detailed Implementation

[0053] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0054] Example 1

[0055] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0056] A welding inspection method for lithium-ion battery sealing nails includes the following steps:

[0057] S1. After assembling the sealing nail 1 and the adhesive nail 2, assemble them with the liquid injection port of the battery cover.

[0058] S2. The placement trajectory of the sealing nail 1 is compared and judged by the CCD system. The data results of the obtained photos are calculated by the calculation software in the system to obtain the welding trajectory and the welding trajectory command is transmitted to the laser welding equipment.

[0059] S3. The sealing nail 1 is pre-spot welded with a peak power of 4.0kW and full welded with a peak power of 6.0kW using a laser welding equipment. The welding parameters are QCW mode, welding speed 7mm / s, number of firing points 105, welding frequency 21Hz, pulse width 4.5ms, and defocusing amount 0mm.

[0060] S4. Perform a pressure test on sealing nail 1;

[0061] S5. Perform quality side leakage detection on the battery of welded sealing nail 1 using a helium gas system.

[0062] at last, Figure 1 The welding effect diagram of the sealing nail obtained by the welding method provided in this embodiment is shown. It can be seen that the low peak power results in a shallow weld pool depth and cracks appear. The welded sealing nail in this embodiment was also inspected, and the inspection items included: weld appearance, presence of cracks, maximum penetration depth, linear penetration depth, maximum penetration depth, and compressive strength. The test results are attached. Figure 11 .

[0063] Example 2

[0064] A welding inspection method for lithium-ion battery sealing nails includes the following steps:

[0065] S1. After assembling the sealing nail 1 and the adhesive nail 2, assemble them with the liquid injection port of the battery cover.

[0066] S2. The placement trajectory of the sealing nail 1 is compared and judged by the CCD system. The data results of the obtained photos are calculated by the calculation software in the system to obtain the welding trajectory and the welding trajectory command is transmitted to the laser welding equipment.

[0067] S3. The sealing nail 1 is pre-spot welded with a peak power of 4.0kW and full welded with a peak power of 6.3kW using a laser welding equipment. The welding parameters are QCW mode, welding speed 7mm / s, number of firing points 105, welding frequency 21Hz, pulse width 4.5ms, and defocusing amount 0mm.

[0068] S4. Perform a pressure test on sealing nail 1;

[0069] S5. Perform quality side leakage detection on the battery of welded sealing nail 1 using a helium gas system.

[0070] at last, Figure 2 The welding effect diagram of the sealing nail obtained by the welding method provided in this embodiment is shown. It can be seen that the low peak power results in a shallow weld pool depth, and cracks also appear. The welded sealing nail in this embodiment was also inspected, and the inspection items included: weld appearance, presence of cracks, maximum penetration depth, linear penetration depth, maximum penetration depth, and compressive strength. The test results are shown in the appendix. Figure 11 .

[0071] Example 3

[0072] A welding inspection method for lithium-ion battery sealing nails includes the following steps:

[0073] S1. After assembling the sealing nail 1 and the adhesive nail 2, assemble them with the liquid injection port of the battery cover.

[0074] S2. The placement trajectory of the sealing nail 1 is compared and judged by the CCD system. The data results of the obtained photos are calculated by the calculation software in the system to obtain the welding trajectory and the welding trajectory command is transmitted to the laser welding equipment.

[0075] S3. The sealing nail 1 is pre-spot welded with a peak power of 4.0kW and full welded with a peak power of 6.6kW using a laser welding equipment. The welding parameters are QCW mode, welding speed 7mm / s, number of firing points 105, welding frequency 21Hz, pulse width 4.5ms, and defocusing amount 0mm.

[0076] S4. Perform a pressure test on sealing nail 1;

[0077] S5. Perform quality side leakage detection on the battery of welded sealing nail 1 using a helium gas system.

[0078] at last, Figure 3 The welding effect diagram of the sealing nail obtained by the welding method provided in this embodiment is shown. The peak power weld has a smooth appearance, and the maximum penetration depth reaches 0.9075mm without any cracks. The welded sealing nail in this embodiment was also inspected, and the inspection items included: weld appearance, presence or absence of cracks, maximum penetration depth, straight penetration depth, maximum penetration depth, and compressive strength. The test results are attached. Figure 11 .

[0079] Example 4

[0080] A welding inspection method for lithium-ion battery sealing nails includes the following steps:

[0081] S1. After assembling the sealing nail 1 and the adhesive nail 2, assemble them with the liquid injection port of the battery cover.

[0082] S2. The placement trajectory of the sealing nail 1 is compared and judged by the CCD system. The data results of the obtained photos are calculated by the calculation software in the system to obtain the welding trajectory and the welding trajectory command is transmitted to the laser welding equipment.

[0083] S3. The sealing nail 1 is pre-spot welded with a peak power of 4.0kW and full welded with a peak power of 6.9kW using a laser welding equipment. The welding parameters are QCW mode, welding speed 7mm / s, number of firing points 105, welding frequency 21Hz, pulse width 4.5ms, and defocusing amount 0mm.

[0084] S4. Perform a pressure test on sealing nail 1;

[0085] S5. Perform quality side leakage detection on the battery of welded sealing nail 1 using a helium gas system.

[0086] at last, Figure 4 The welding effect diagram of the sealing nail obtained by the welding method provided in this embodiment is shown. The peak power welding has a smooth appearance, with no bursts or cracks, and good sealing performance. Figure 5 Metallographic images of the weld were presented, showing a maximum penetration depth of 1.0211 mm, an effective penetration depth of 0.462 mm, and a maximum weld width of 1.3069 mm. The welded sealing nails in this embodiment were also inspected, including: weld appearance, presence of cracks, maximum penetration depth, straight penetration depth, and compressive strength. The test results are attached. Figure 11 .

[0087] Example 5

[0088] A welding inspection method for lithium-ion battery sealing nails includes the following steps:

[0089] S1. After assembling the sealing nail 1 and the adhesive nail 2, assemble them with the liquid injection port of the battery cover.

[0090] S2. The placement trajectory of the sealing nail 1 is compared and judged by the CCD system. The data results of the obtained photos are calculated by the calculation software in the system to obtain the welding trajectory and the welding trajectory command is transmitted to the laser welding equipment.

[0091] S3. The sealing nail 1 is pre-spot welded with a peak power of 4.0kW and full welded with a peak power of 7.2kW using a laser welding equipment. The welding parameters are QCW mode, welding speed 7mm / s, number of firing points 105, welding frequency 21Hz, pulse width 4.5ms, and defocusing amount 0mm.

[0092] S4. Perform a pressure test on sealing nail 1;

[0093] S5. Perform quality side leakage detection on the battery of welded sealing nail 1 using a helium gas system.

[0094] at last, Figure 6 The welding effect diagram of the sealing nail obtained by the welding method provided in this embodiment is shown. The peak power welding appearance is rough and black. Excessive power is prone to defects such as spatter and bursts during welding. At the same time, the welding sealing nail in this embodiment is inspected. The inspection items include: welding appearance, presence of cracks, maximum penetration depth, linear penetration depth, maximum penetration depth, and compressive strength. The test results are shown in the appendix. Figure 11 .

[0095] Example 6

[0096] A welding inspection method for lithium-ion battery sealing nails includes the following steps:

[0097] S1. After assembling the sealing nail 1 and the adhesive nail 2, assemble them with the liquid injection port of the battery cover.

[0098] S2. The placement trajectory of the sealing nail 1 is compared and judged by the CCD system. The data results of the obtained photos are calculated by the calculation software in the system to obtain the welding trajectory and the welding trajectory command is transmitted to the laser welding equipment.

[0099] S3. The sealing nail 1 is pre-spot welded with a peak power of 4.0kW and full welded with a peak power of 6.9kW using a laser welding equipment. The welding parameters are QCW mode, welding speed 7mm / s, number of firing points 105, welding frequency 15Hz, pulse width 4.5ms, and defocusing amount 0mm.

[0100] S4. Perform a pressure test on sealing nail 1;

[0101] S5. Perform quality side leakage detection on the battery of welded sealing nail 1 using a helium gas system.

[0102] at last, Figure 7 The welding effect diagram of the sealing nail obtained by the welding method provided in this embodiment is shown. The welding frequency is high, the welding surface is rough and uneven, the overlap rate of the weld marks is low, and the penetration depth at the intersection of two weld marks is insufficient, which may cause poor battery sealing. At the same time, the sealing nail after welding in this embodiment was inspected. The inspection items include: welding appearance, presence of cracks, maximum penetration depth, straight penetration depth, maximum penetration depth, and compressive strength. The test results are shown in the appendix. Figure 11 .

[0103] Example 7

[0104] A welding inspection method for lithium-ion battery sealing nails includes the following steps:

[0105] S1. After assembling the sealing nail 1 and the adhesive nail 2, assemble them with the liquid injection port of the battery cover.

[0106] S2. The placement trajectory of the sealing nail 1 is compared and judged by the CCD system. The data results of the obtained photos are calculated by the calculation software in the system to obtain the welding trajectory and the welding trajectory command is transmitted to the laser welding equipment.

[0107] S3. The sealing nail 1 is pre-spot welded with a peak power of 4.0kW and full welded with a peak power of 6.9kW using a laser welding equipment. The welding parameters are QCW mode, welding speed 7mm / s, number of firing points 105, welding frequency 21Hz, pulse width 4.5ms, and defocusing amount -1mm.

[0108] S4. Perform a pressure test on sealing nail 1;

[0109] S5. Perform quality side leakage detection on the battery of welded sealing nail 1 using a helium gas system.

[0110] at last, Figure 8 Metallographic images of the sealing nail obtained by the welding method provided in this embodiment are shown. It can be seen that the decoking depth of -1mm is relatively shallow, with a maximum penetration depth of 0.7026mm. The welded sealing nail in this embodiment was also inspected, including: weld appearance, presence of cracks, maximum penetration depth, linear penetration depth, and compressive strength. The test results are attached. Figure 11 .

[0111] Example 8

[0112] A welding inspection method for lithium-ion battery sealing nails includes the following steps:

[0113] S1. After assembling the sealing nail 1 and the adhesive nail 2, assemble them with the liquid injection port of the battery cover.

[0114] S2. The placement trajectory of the sealing nail 1 is compared and judged by the CCD system. The data results of the obtained photos are calculated by the calculation software in the system to obtain the welding trajectory and the welding trajectory command is transmitted to the laser welding equipment.

[0115] S3. The sealing nail 1 is pre-spot welded with a peak power of 4.0kW and full welded with a peak power of 6.9kW using a laser welding equipment. The welding parameters are QCW mode, welding speed 7mm / s, number of firing points 105, welding frequency 21Hz, pulse width 4.5ms, and defocusing amount 1mm.

[0116] S4. Perform a pressure test on sealing nail 1;

[0117] S5. Perform quality side leakage detection on the battery of welded sealing nail 1 using a helium gas system.

[0118] at last, Figure 9 Metallographic images of the sealing nail obtained by the welding method provided in this embodiment are shown. It can be seen that a 1mm decoking depth results in a relatively deep penetration, with a maximum penetration depth of 1.2736mm. In summary... Figure 8 and Figure 9 It is known that the defocusing amount fluctuates within the range of -1mm to +1mm, which has a significant impact on the welding penetration effect. Therefore, the defocusing amount is controlled to be fixed and taken within the range of -0.5mm to 0mm, with 0mm being the preferred value. At the same time, the sealing nails after welding in this embodiment are inspected. The inspection items include: welding appearance, presence of cracks, maximum penetration, linear penetration, maximum penetration, and pressure resistance. The test results are shown in the appendix. Figure 11 .

[0119] Example 9

[0120] A welding inspection method for lithium-ion battery sealing nails includes the following steps:

[0121] S1. After assembling the sealing nail 1 and the adhesive nail 2, assemble them with the liquid injection port of the battery cover.

[0122] S2. The placement trajectory of the sealing nail 1 is compared and judged by the CCD system. The data results of the obtained photos are calculated by the calculation software in the system to obtain the welding trajectory and the welding trajectory command is transmitted to the laser welding equipment.

[0123] S3. The sealing nail 1 is pre-spot welded with a peak power of 4.0kW and full welded with a peak power of 6.9kW using a laser welding equipment. The welding parameters are QCW mode, welding speed 7mm / s, number of firing points 105, welding frequency 21Hz, pulse width 8ms, and defocusing amount 0mm.

[0124] S4. Perform a pressure test on sealing nail 1;

[0125] S5. Perform quality side leakage detection on the battery of welded sealing nail 1 using a helium gas system.

[0126] at last, Figure 10 The welding effect diagram of the sealing nail obtained by the welding method provided in this embodiment is shown. It can be seen that the 8ms pulse width results in a rough and uneven welding surface, affecting the battery appearance. The molten pool formation range is large, making it prone to spatter, bursts, or other defects. The welded sealing nail in this embodiment was also inspected. The inspection items included: welding appearance, presence of cracks, maximum penetration depth, linear penetration depth, maximum penetration depth, and compressive strength. The test results are shown in the appendix. Figure 11 .

[0127] From the appendix Figure 11The following conclusions can be drawn from the detection data:

[0128] Data from Examples 1, 2, 3, and 4 show that increasing the peak power during full welding significantly improves welding crack conditions and battery sealing. Data from Examples 4 and 5 shows that excessively high peak power during full welding (i.e., high power and high heat transfer) is detrimental to a smooth appearance and can easily lead to spatter and a rough, uneven surface. Data from Examples 4 and 6 shows that reducing the welding frequency results in a lower overlap rate of the weld marks and insufficient penetration at the intersection of two weld marks, potentially causing poor battery sealing and a rough weld surface. Data from Examples 4, 7, and 8 shows that fluctuations in defocusing amount within the range of -1mm to +1mm have a significant impact on the welding penetration effect. The defocusing amount is controlled to be fixed within the range of -0.5mm to 0mm, with 0mm being preferred. Data from Examples 4 and 9 show that an increased welding pulse width leads to longer heating time and less concentrated power, resulting in larger weld marks, longer weld width, and a laterally extended weld pool, with an effective penetration depth of 0.7588mm. The welding trajectory is rough and uneven, affecting the weld appearance and easily causing spatter, bursts, or other defects. Therefore, the optimal solution in the welding method provided by this invention is: a pre-spot welding peak power of 4.0kW, a full-weld peak power of 6.6-6.9kW, welding parameters using QCW mode, a welding speed of 7mm / s, 105 firing points, a welding frequency of 21Hz, a pulse width of 4.5ms, and a defocusing amount of 0mm. This method achieves good welding results, improves the safety performance of lithium-ion batteries, reduces the number of personnel and labor intensity required for visual inspection, and saves costs.

[0129] Example 10

[0130] like Figures 12 to 22As shown, a lithium-ion battery sealing nail welding inspection device includes a base 4, a dispensing machine 5 disposed on one side of the base 4, and a transmission track 6 disposed on one side of the base 4 for transmitting sealing nails 1. An adsorption component 7 is disposed on one side of the transmission track 6. A driving component 8 and a cutting component 9 driven by the driving component 8 are disposed on the base 4. The cutting component 9 includes a cutting blade 91 and a receiving cavity 92 formed on the cutting blade 91. A sliding component 10 is disposed along the moving path of the cutting blade 91. A bearing component 11 and a pushing component 12 are disposed on the base 4. The bearing component 11 includes a bearing seat 111 for bearing the sealing nails 2. The adsorption component... 7 is used to adsorb the sealing nail 1 and push it into the receiving cavity 92. The dispensing machine 5 is used to dispense glue to the sealing nail 1 during the process of the drive assembly 8 driving the cutting blade 91 and the sealing nail 1 to descend. The sliding assembly 10 is used to cut the glue nail 2 with the cutting blade 91 and simultaneously drive the glue nail 2 to one side of the receiving cavity 92. The pushing assembly 12 is used to push the sealing nail 1 and the glue nail 2 to bond. The transmission track 6 is connected to a vibratory plate, which is used to transmit the sealing nail 1. The glue nail 2 is indirectly moved by the traction wheel. After the sealing nail 1 and the glue nail 2 are bonded, they are taken out by the robot. Then the glue nail 2 is pushed onto the carrier 111.

[0131] It is worth mentioning that, such as Figures 16 to 20As shown, the adsorption assembly 7 includes a base plate 71 fixedly mounted on the transmission track 6, a sliding seat 72 slidably mounted on the base plate 71, a cylinder 73 fixedly mounted on the sliding seat 72, a suction cup 74 fixedly mounted on the cylinder 73, a piston 75 slidably mounted inside the cylinder 73, a piston rod 76 fixedly mounted on the piston 75, a first limiting rod 77 slidably mounted inside the cylinder 73, an air hole 78 opened on the cylinder 73, a stop rod 79 fixedly mounted on the sliding seat 72, a channel 710 fixedly mounted on the transmission track 6, a fixing rod 711 and a limiting post 712 fixedly mounted on the channel 710, a second limiting rod 713 slidably mounted on the fixing rod 711, a sliding plate 714 slidably mounted on the base plate 71, and a piston rod. 76 is fixedly connected to the slide plate 714. The piston 75 has arc-shaped surfaces on both sides that cooperate with the first limiting rod 77. Springs are provided between the first limiting rod 77 and the cylinder 73, and between the second limiting rod 713 and the channel 710. The second limiting rod 713 cooperates with the sealing nail 1. The diameter of the channel 710 is the same as the diameter of the sealing nail 1. A driving device is provided on the base plate 71, which can drive the sliding seat 72 to slide back and forth. The slide plate 714 slides in the sliding groove opened on the base plate 71 through the sliding block, and a spring is provided between the sliding block and the sliding groove. Telescopic rods are provided between the first limiting rod 77 and the second limiting rod 713 and the spring for guidance. In use, the sealing nail 1 on the transmission track 6 is transmitted to the channel 710 at the same time as the limiting post 71. 2. The sealing nail 1 is limited to a position so that it is coaxial with the channel 710. At the same time, the second limiting rod 713 supports the sealing nail 1 to prevent it from tipping over. Then, the driving device moves the sliding seat 72 and the cylinder 73 closer to the sealing nail 1. At this time, the piston rod 76, piston 75 and slide plate 714 remain stationary under the action of the spring. Therefore, the sliding of the cylinder 73 toward the sealing nail 1 will cause the suction cup 74 to generate suction until the sealing nail 1 is attracted. At the same time, the first limiting rod 77 contacts the piston 75, and the stop rod 79 simultaneously reaches between the two sealing nails 1 to block the next sealing nail 1. When sliding continues, the spring at the first limiting rod 77 has a greater elastic force than the spring at the slide plate 714. Therefore, the first limiting rod 77 pushes the piston 75, Piston rod 76 and slide plate 714 slide together. At this time, piston 75 slides synchronously with cylinder 73. After suction cup 74 adsorbs sealing nail 1 and pushes open second limiting rod 713, it slides in channel 710. As it slides to receiving cavity 92, slide plate 714 slides to the bottom of sliding groove. When cylinder 73 continues to slide, during the process of pushing sealing nail 1 into receiving cavity 92, because slide plate 714 remains stationary after being limited, first limiting rod 77 is pushed open by piston 75. Air hole 78 slides to the front of piston 75. First limiting rod 77 is located in front of piston 75. After sealing nail 1 enters receiving cavity 92, suction cup 74 releases its suction force. At the same time, after piston 75 is no longer limited by first limiting rod 77, slide plate 714 resets under the action of spring.At this point, gas enters the cylinder 73 through the vent 78, so no suction force is generated at the suction cup 74. Subsequently, the drive device resets the cylinder 73 and the stop rod 79, preparing for the next push. In this way, the sealing pin 1 can be smoothly pushed into the receiving cavity 92, improving assembly efficiency.

[0132] In addition, such as Figure 14 As shown, the drive assembly 8 includes a support frame 81 fixedly mounted on the base 4, a motor 82 fixedly mounted on the support frame 81, a first lead screw 83 rotatably mounted on the support frame 81, and a guide rod 84 fixedly mounted on the support frame 81. The first lead screw 83 is fixedly connected to the output shaft of the motor 82. In use, when the sealing nail 1 is pushed into the receiving cavity 92, the motor 82 drives the cutting blade 91 to descend and cut the adhesive nail 2.

[0133] It needs to be emphasized that, such as Figure 21 As shown, the cutting assembly 9 also includes a sliding plate 93 slidably disposed on the first lead screw 83 and several third limiting rods 94 slidably disposed on the receiving cavity 92. The cutting blade 91 is fixedly connected to the sliding plate 93, and the sliding plate 93 cooperates with the guide rod 84. A spring is provided between the third limiting rod 94 and the receiving cavity 92, and the third limiting rod 94 cooperates with the sealing nail 1. The diameter of the receiving cavity 92 is the same as the diameter of the channel 710. A telescopic rod is provided between the third limiting rod 94 and the spring for guidance. In use, when the motor 82 drives the first lead screw 83 to rotate, the sliding plate 93 drives the cutting blade 91 to descend to a certain distance and then stops. The glue dispensing machine 5 dispenses glue onto the sealing nail 1 to facilitate subsequent bonding with the glue nail 2.

[0134] It should be further explained that, such as Figure 21 As shown, the sliding assembly 10 includes a groove 101 formed on the base 4, a second lead screw 102 rotatably disposed in the groove 101, a rotating shaft 103 rotatably disposed on the base 4, a gear 104 fixedly disposed on the rotating shaft 103, and a rack 105 fixedly disposed on the sliding plate 93. The gear 104 meshes with the rack 105. Both the second lead screw 102 and the rotating shaft 103 are provided with pulleys, and a belt is provided between the pulleys. In use, the cutting blade 91 descends and cuts the plastic nail 2 through the blade. Before the sealing nail 1 contacts the plastic nail 2, the rack 105 meshes with the gear 104, driving the gear 104, the rotating shaft 103, and the second lead screw 102 to rotate, driving the support seat 111 to move, so that the cut plastic nail 2 moves.

[0135] It is worth mentioning that, such as Figure 22As shown, the bearing assembly 11 also includes a first slider 112 and a second slider 113 slidably disposed in the slide groove 101, a U-shaped seat 114 fixedly disposed on the first slider 112, and a baffle 115 fixedly disposed on the bearing seat 111. The second slider 113 is fixedly connected to the bearing seat 111. The U-shaped seat 114 and the bearing seat 111 both cooperate with the adhesive nail 2. In use, when the second lead screw 102 rotates, it drives the first slider 112, the second slider 113, the bearing seat 111 and the U-shaped seat 114 to move away from the receiving cavity 92 until the distance between the adhesive nail 2 and the receiving cavity 92 is exactly equal to the thickness of a sealing nail 1. By moving the adhesive nail 2 backward, it prevents the adhesive nail 2 from sticking to the surface of the sealing nail 1 when the sealing nail 1 descends, which would cause the adhesive nail 2 to scrape the glue on the sealing nail 1 to the side, resulting in poor bonding effect.

[0136] Furthermore, such as Figure 22 As shown, the push assembly 12 includes a ring 121 slidably disposed on the base 4, a push rod 122 fixedly disposed on the ring 121, and a cylinder 123 fixedly disposed on the support frame 81. The output shaft of the cylinder 123 is fixedly connected to the ring 121. The push rod 122 cooperates with the sealing nail 1. In use, after the adhesive nail 2 has moved, the sealing nail 1 descends and becomes coaxial with the adhesive nail 2. The cylinder 123 drives the ring 121 and the push rod 122 to push the sealing nail 1 to open the third limit rod 94 and push it out of the receiving cavity 92 to adhere to the adhesive nail 2. Then, the adhesive sealing nail 1 and adhesive nail 2 are removed by a robot and installed into the electrolyte inlet of the battery cover.

[0137] In addition, such as Figure 15 As shown, a rubber layer is provided on the push rod 122 to prevent damage to the sealing pin 1.

[0138] In addition, such as Figure 15 As shown, both the U-shaped base 114 and the support base 111 are provided with anti-slip textures to ensure that the rubber nail 2 can be moved when the U-shaped base 114 and the support base 111 move.

[0139] Work process

[0140] As the sealing nail 1 is transmitted to the channel 710, the limiting post 712 limits the sealing nail 1, making the sealing nail 1 coaxial with the channel 710. At the same time, the second limiting rod 713 supports the sealing nail 1. Subsequently, the driving device drives the sliding seat 72 and the cylinder 73 to move closer to the sealing nail 1. At this time, the piston rod 76, piston 75 and sliding plate 714 remain stationary under the action of the spring. Therefore, the sliding of the cylinder 73 toward the sealing nail 1 will cause the suction cup 74 to generate suction force until the sealing nail 1 is adsorbed. At the same time, the first limiting rod 77 contacts the piston 75. When the stop lever 79 reaches between the two sealing nails 1, it blocks the latter sealing nail 1. As the sliding continues, the first limiting lever 77 pushes the piston 75, piston rod 76, and sliding plate 714 to slide. At this time, the piston 75 slides synchronously with the cylinder 73. The suction cup 74 adsorbs the sealing nail 1, pushes open the second limiting lever 713, and slides within the channel 710. As it slides to the receiving cavity 92, the sliding plate 714 slides to the bottom of the sliding groove. When the cylinder 73 continues to slide, during the process of pushing the sealing nail 1 into the receiving cavity 92, the sliding plate 714... After the 14th limit is reached, it remains stationary. Therefore, the first limit rod 77 is pushed open by the piston 75. The air hole 78 and the first limit rod 77 are located in front of the piston 75. After the sealing nail 1 enters the receiving cavity 92, the suction cup 74 cancels its suction force. Then, the motor 82 drives the first lead screw 83 to rotate. The sliding plate 93 drives the cutting blade 91 and the sealing nail 1 to descend and stop. The glue dispensing machine 5 dispenses glue onto the sealing nail 1. Afterward, the cutting blade 91 descends and cuts the glue nail 2 through the blade. Before the sealing nail 1 contacts the glue nail 2, the rack 105 and the gear 104 mesh first. The moving gear 104, rotating shaft 103, and second lead screw 102 rotate, driving the bearing seat 111 to move, so that the cut-off glue nail 2 moves until the distance between the glue nail 2 and the receiving cavity 92 is exactly equal to the thickness of a sealing nail 1. Finally, after the sealing nail 1 and the glue nail 2 are coaxial, the cylinder 123 drives the ring sleeve 121 and push rod 122 to push the sealing nail 1 to open the third limit rod 94 and push it out of the receiving cavity 92 to adhere to the glue nail 2. Then, the robot arm takes out the adhered sealing nail 1 and glue nail 2 and installs them into the battery cover liquid injection port.

[0141] In the description of this invention, it should be understood that the terms "front and back", "left and right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or component 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 the invention.

[0142] Of course, those skilled in the art should understand that the term "a" should be understood as "at least one" or "one or more". That is, in one embodiment, the number of an element can be one, while in another embodiment, the number of the element can be multiple. The term "a" should not be understood as a limitation on the quantity.

[0143] The above description, in conjunction with the accompanying drawings, represents only preferred embodiments of the present invention. However, the present invention is not limited to the above embodiments. It should be noted that those skilled in the art can make various modifications and improvements without departing from the structure of the present invention. These modifications and improvements should also be considered within the scope of protection of the present invention and will not affect the effectiveness and practicality of the present invention.

Claims

1. A welding inspection method for lithium-ion battery sealing nails, comprising the following steps: S1. After assembling the sealing nail (1) and the glue nail (2), assemble them with the liquid injection port of the battery cover. S2. The placement trajectory of the sealing nail (1) is compared and judged by the CCD system. The data results of the obtained photos are calculated by the calculation software in the system to obtain the welding trajectory and the welding trajectory instruction is transmitted to the laser welding equipment. S3. Pre-tack welding and full welding of the sealing nail (1) are performed using laser welding equipment; S4. Perform a pressure test on the sealing nail (1); S5. Perform quality side leakage detection on the battery of the welded sealing nail (1) using a helium gas system; In step S1, the sealing nail (1) and the glue nail (2) are assembled by an assembly device. The assembly device includes a base (4), a glue dispensing machine (5) disposed on one side of the base (4), and a transmission track (6) disposed on one side of the base (4) for transmitting the sealing nail (1). An adsorption component (7) is disposed on one side of the transmission track (6). A driving component (8) and a cutting component (9) driven by the driving component (8) are disposed on the base (4). The cutting component (9) includes a cutting blade (91) and a receiving cavity (92) opened on the cutting blade (91). A sliding component (10) is disposed on the moving path of the cutting blade (91). The base ( 4) The upper part is provided with a bearing component (11) and a pushing component (12). The bearing component (11) includes a bearing seat (111) for bearing the glue nail (2). The adsorption component (7) is used to adsorb the sealing nail (1) and push it into the receiving cavity (92). The dispensing machine (5) is used to dispense glue on the sealing nail (1) during the process of the driving component (8) driving the cutting blade (91) and the sealing nail (1) to descend. The sliding component (10) is used to drive the glue nail (2) to one side of the receiving cavity (92) while the cutting blade (91) cuts the glue nail (2). The pushing component (12) is used to push the sealing nail (1) and the glue nail (2) to bond.

2. The welding inspection method for lithium-ion battery sealing nails according to claim 1, characterized in that: The adsorption assembly (7) includes a base plate (71) fixedly mounted on the transmission track (6), a sliding seat (72) slidably mounted on the base plate (71), a cylinder (73) fixedly mounted on the sliding seat (72), a suction cup (74) fixedly mounted on the cylinder (73), a piston (75) slidably mounted inside the cylinder (73), a piston rod (76) fixedly mounted on the piston (75), a first limiting rod (77) slidably mounted inside the cylinder (73), an air hole (78) opened on the cylinder (73), a stop bar (79) fixedly mounted on the sliding seat (72), a channel (710) fixedly mounted on the transmission track (6), and a fixed... A fixed rod (711) and a limiting post (712) are set on the channel (710), a second limiting rod (713) is slidably set on the fixed rod (711), and a sliding plate (714) is slidably set on the base plate (71). The piston rod (76) is fixedly connected to the sliding plate (714). The piston (75) has arc-shaped surfaces on both sides and cooperates with the first limiting rod (77). Springs are provided between the first limiting rod (77) and the cylinder (73), and between the second limiting rod (713) and the channel (710). The second limiting rod (713) cooperates with the sealing nail (1). The diameter of the channel (710) is the same as the diameter of the sealing nail (1).

3. The welding inspection method for lithium-ion battery sealing nails according to claim 2, characterized in that: The drive assembly (8) includes a support frame (81) fixedly mounted on the base (4), a motor (82) fixedly mounted on the support frame (81), a first lead screw (83) rotatably mounted on the support frame (81), and a guide rod (84) fixedly mounted on the support frame (81). The first lead screw (83) is fixedly connected to the output shaft of the motor (82).

4. The welding inspection method for lithium-ion battery sealing nails according to claim 3, characterized in that: The cutting assembly (9) further includes a sliding plate (93) slidably disposed on the first lead screw (83) and a plurality of third limiting rods (94) slidably disposed on the receiving cavity (92). The cutting blade (91) is fixedly connected to the sliding plate (93). The sliding plate (93) cooperates with the guide rod (84). A spring is provided between the third limiting rod (94) and the receiving cavity (92), and the third limiting rod (94) cooperates with the sealing nail (1). The diameter of the receiving cavity (92) is the same as the diameter of the channel (710).

5. The welding inspection method for lithium-ion battery sealing nails according to claim 4, characterized in that: The sliding assembly (10) includes a groove (101) opened on the base (4), a second lead screw (102) rotatably disposed in the groove (101), a rotating shaft (103) rotatably disposed on the base (4), a gear (104) fixedly disposed on the rotating shaft (103), and a rack (105) fixedly disposed on the sliding plate (93). The gear (104) meshes with the rack (105). Both the second lead screw (102) and the rotating shaft (103) are provided with pulleys and a belt is provided between the pulleys.

6. The welding inspection method for a lithium-ion battery sealing nail according to claim 5, characterized in that: The bearing assembly (11) further includes a first slider (112) and a second slider (113) slidably disposed in the slide groove (101), a U-shaped seat (114) fixedly disposed on the first slider (112), and a baffle (115) fixedly disposed on the bearing seat (111). The second slider (113) is fixedly connected to the bearing seat (111), and the U-shaped seat (114) and the bearing seat (111) are both engaged with the rubber nail (2).

7. The welding inspection method for lithium-ion battery sealing nails according to claim 3, characterized in that: The push assembly (12) includes a ring (121) slidably disposed on the base (4), a push rod (122) fixedly disposed on the ring (121), and a cylinder (123) fixedly disposed on the support frame (81). The output shaft of the cylinder (123) is fixedly connected to the ring (121), and the push rod (122) cooperates with the sealing nail (1).

8. The welding inspection method for a lithium-ion battery sealing nail according to claim 7, characterized in that: The push rod (122) is provided with a rubber layer.

9. The welding inspection method for a lithium-ion battery sealing nail according to claim 6, characterized in that: Both the U-shaped seat (114) and the bearing seat (111) are provided with anti-slip textures.

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