A full-automatic manufacturing process of BMU

Abstract

The present application relates to a kind of BMU full-automatic manufacturing process, comprising S1, according to circuit design, each electrical device is installed to copper bar assembly, obtains assembly structure;S2, the connection area of electrical device and copper bar in assembly structure is successively carried out laser cleaning and laser welding;S3, first automatic optical detection is carried out to laser welding area, after detection, water cooling device is installed, obtains semi-finished product;S4, semi-finished product is carried out semi-finished product pressure test and semi-finished product performance test;S5, after test, BMS assembly is fixed to semi-finished product by laser welding, obtains BMU;S6, second automatic optical detection is carried out to laser welding area on BMU, product pressure test, product performance test, waterway air tightness test, three tests are passed and obtain qualified product.The present application realizes that each process step is formed intelligent processing unit, each unit is connected transmission by mechanical arm and conveyer belt, and the degree of intelligentization is high, assembly precision is high, and assembly cost is greatly reduced.

Description

Technical Field

[0001] This invention relates to the field of automated production technology, specifically to a fully automated manufacturing process for BMUs. Background Technology

[0002] The current BMU assembly method requires manual assistance. In many cases, the multiple workstations of the BMU operate discontinuously, meaning that some sections requiring manual assistance are independently operated equipment. After obtaining the semi-finished products for that section with manual assistance, the semi-finished products are manually transferred to the equipment for the next section. This results in low automation, chaotic equipment placement, and hinders the company's efforts to optimize the production site. At the same time, manual assistance increases the company's production costs, efficiency, and assembly accuracy. Therefore, it is necessary to provide a fully automated BMU manufacturing process to solve the above problems. Summary of the Invention This invention provides a fully automated manufacturing process for BMUs to solve the problems of high assembly costs, low efficiency, and poor precision caused by low automation in the prior art.

[0003] To achieve the above objectives, the embodiments of the present invention provide the following technical solutions: A fully automated BMU manufacturing process includes the following steps: S1. Install each electrical component onto the copper busbar assembly according to the circuit design to obtain the assembly structure; S2. Laser cleaning and laser welding are performed on the connection areas between electrical components and copper busbars in the assembly structure. S3. Perform the first automatic optical inspection on the laser welding area. After the inspection is passed, install the water cooling device to obtain the semi-finished product. S5. Conduct pressure resistance tests and performance tests on the semi-finished products. S6. After passing the test, the BMS component is fixed to the semi-finished product by laser welding to obtain the BMU. S7. Perform a second automatic optical inspection, finished product pressure test, finished product performance test, and waterway air tightness test on the laser welding area on the BMU. A qualified product is obtained after all three tests are passed.

[0004] Furthermore, in step S1, each electrical component is installed onto the component fixture, with the electrical contacts of the electrical components located on one or both sides of the component fixture. Then, the copper busbar is fixed onto the copper busbar fixture, and the component fixture and the copper busbar fixture are matched and merged, so that the copper busbar is detached from the copper busbar fixture and connected to the electrical contacts.

[0005] Furthermore, in S1, the component fixture is a mold specifically designed for production according to the circuit design and capable of fixing various electrical components, or a product housing or frame capable of fixing various electrical components according to the circuit design. The component fixture is provided with component mounting positions or component slots for installing various electrical components. The copper busbar fixture is a mold specifically designed for production according to the circuit design and used to fix copper busbars, or a frame for fixing copper busbars. The copper busbar fixture is provided with copper busbar mounting positions or copper busbar slots for installing various electrical components.

[0006] Furthermore, prior to step S1, assembly codes and material codes are added to both electrical components and copper busbars for material verification and traceability.

[0007] Furthermore, in step S2, laser cleaning includes using a CCD camera of a laser cleaning device to acquire an image of the non-electrical component side of the copper busbar, then using CCD camera software to perform image processing and feature extraction on the image, locking the connecting through-hole with electrical contacts inside the copper busbar and its surrounding area, or the electrical contacts passing through the connecting through-hole and their surrounding area; after determining the cleaning area, low-power laser cleaning is used.

[0008] Furthermore, after determining the cleaning area, CCD camera software is used to judge and adjust the concentricity and spacing of the welding workpieces; a laser rangefinder is used to measure the height of the laser head, and the laser focal length and defocus amount are adaptively adjusted; if there are multiple laser heads, the laser rangefinder is used to measure the height of each laser head separately, and the height difference between each laser head is adaptively adjusted.

[0009] Furthermore, in step S2, laser welding includes using a CCD camera to capture an image of the laser-cleaned side of the copper busbar, then using CCD camera software to process the image and extract features to lock the laser-cleaned area; using CCD device software to determine and adjust the concentricity and spacing of the workpieces to be welded; using a laser rangefinder to measure the height of the laser head and adaptively adjusting the laser focal length and defocus; if there are multiple laser heads, using a laser rangefinder to measure the height of each laser head separately and adaptively adjusting the height difference between each laser head; and after the parameters are adjusted, laser welding is performed.

[0010] Furthermore, the pre-laser welding air blowing protection and cooling protection includes setting up a fixture with a central hole exposing the laser welding area, and a liquid channel for cooling liquid is provided on the side of the fixture that contacts the copper busbar; the fixture is also provided with an air channel connecting to the central hole.

[0011] Furthermore, both the first and second automatic optical inspections include visual inspection and laser line scanning inspection. If either the visual inspection or the laser line scanning inspection fails, the inspected laser weld is deemed unqualified. The visual inspection uses a 2D camera to take pictures, and after image processing, feature extraction, and analysis of the weld area in the image, it checks for surface defects in the weld area one by one. If any surface defect is found, the visual inspection fails. The laser line scanning uses a laser line to form the product outline of the weld surface. The outline is analyzed by software to determine various defect factors. If any defect factor is found, the laser line scanning inspection fails.

[0012] The embodiments of the present invention have the following advantages: The present invention provides a fully automated BMU manufacturing process that integrates each process step into an intelligent processing unit. The units are connected and transported to each other via robotic arms and conveyor belts, resulting in a high degree of intelligence, high assembly precision, and significantly reduced assembly costs. Attached Figure Description

[0013] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0014] The structures, proportions, sizes, etc. illustrated in this specification are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed herein, and are not intended to limit the conditions under which the present invention can be implemented. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size, without affecting the effects and objectives that the present invention can produce, should still fall within the scope of the technical content disclosed in the present invention.

[0015] Figure 1 A process flow diagram of a fully automated BMU manufacturing process provided in an embodiment of the present invention; Figure 2 A detailed flow diagram of a fully automated BMU manufacturing process provided in an embodiment of the present invention; Figure 3 This is a structural diagram of an auxiliary tool in a fully automated BMU manufacturing process provided in an embodiment of the present invention. Detailed Implementation

[0016] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] like Figure 1-2 As shown, a fully automated BMU manufacturing process includes the following steps: S1. Install each electrical component onto the copper busbar assembly according to the circuit design to obtain the assembly structure.

[0018] In this technology, electrical components can be installed onto the copper busbar assembly using either manual or automated installation methods. The automated installation method involves installing each electrical component into a component fixture, with the electrical contacts of the electrical components located on one or both sides of the component fixture. Then, the copper busbar assembly is fixed onto the copper busbar fixture, and the component fixture and the copper busbar fixture are matched and merged to install the electrical components onto the copper busbar assembly.

[0019] To achieve automation, all electrical components are placed within a component fixture. This fixture is a mold specifically designed for manufacturing and fixing each electrical component according to the circuit design, or a product casing or frame designed to fix each component. After the components are pressed and installed, their electrical contacts are located on one or both sides of the fixture. From the perspective of an intelligent production line, it is preferable that the electrical contacts of each component are located on one side of the fixture. If there is a height difference between the electrical contacts of different components, the copper busbar assembly is designed to compensate for this height difference. Specifically, the fixture has component slots or mounting positions for fixing each component. These slots or mounting positions are designed according to the arrangement and shape of the components in the circuit diagram, preferably ensuring that as many components as possible have their electrical contacts on the same horizontal plane, facilitating one-time installation of the copper busbars and enabling mechanized automatic installation. The electrical components include pre-charge modules, relays, fuses, shunts, capacitors, etc.

[0020] The copper busbar assembly is mounted on a copper busbar fixture, which is a mold specifically designed for production according to the circuit design and used to fix the copper busbar assembly, or a frame with the function of fixing the copper busbar. The copper busbar fixture has a copper busbar slot for embedding the copper busbar assembly or a copper busbar mounting position for defining the position of the copper busbar. In the former case, the copper busbar assembly can be embedded and fixed in the slot; in the latter case, the copper busbar assembly can be fixed by gluing, welding, or tightening bolts. For ease of processing, the copper busbar assembly and the copper busbar fixture can be initially assembled as a single unit for subsequent assembly line assembly. The copper busbar assembly has connecting through holes that mate with the contacts, and the copper busbar fixture has cavities corresponding to these connecting through holes to expose them for subsequent welding processes. Because the arrangement of each electrical component is unique and asymmetrical, and the distribution of the electrical contacts is unique, the distribution of the connecting through holes is also unique, which can be used for positioning the copper busbar and matching the fixture.

[0021] After aligning the component fixture and the copper busbar fixture, they are merged so that the connecting through-hole of the copper busbar matches the electrical contact of the electrical component. After the two are connected, since the welding position is located on the outside of the copper busbar assembly where the electrical contact passes through, both fixtures need to be flipped simultaneously to align the welding position with the welding head. If there is a gap between the copper busbar slot and the copper busbar, when the copper busbar fixture is flipped and the opening faces downward, the copper busbar assembly will detach from the copper busbar fixture, realizing automated installation between the copper busbar assembly and the electrical component.

[0022] In this technology, assembly codes and material codes are added to both electrical components and copper busbars for material verification and traceability. This embodiment uses SN codes, with a fixed barcode scanner automatically scanning the assembly SN codes. The MES (Manufacturing Execution System) confirms the product status, verifying its identity (whether it's in production for this process) and the progress of the process.

[0023] S2. Laser cleaning and laser welding are performed on the connection areas between electrical components and copper busbars in the assembly structure.

[0024] S21 Laser Cleaning During laser welding, the oxide layer and oil on the surface of the copper busbar and electrical contacts can cause unstable welding, spatter, or pores. Therefore, these must be removed before laser welding.

[0025] S211 Confirm Cleaning Area The CCD camera of the laser cleaning equipment captures an image of the non-electrical component side of the copper busbar. If the copper busbar is laid on top of an electrical component, the CCD camera captures the upper side of the copper busbar. Then, the CCD camera software performs image processing and feature extraction on the image to locate the connecting through-holes with electrical contacts inside the copper busbar and their surrounding area, or the electrical contacts passing through the connecting through-holes and their surrounding area. The size of the area can be set by the software.

[0026] S212 Laser Cleaning After determining the cleaning area, use CCD camera software to judge and adjust the concentricity and spacing of the welding workpieces, preferably adjusting both concentricity and spacing to ≤0.3mm.

[0027] The laser head height is measured using a laser rangefinder in the laser cleaning equipment, and the laser focal length and defocus amount are adaptively adjusted. It is preferable that the adjustment values ​​for both focal length and defocus amount are ±0.5mm.

[0028] If there are multiple laser heads, use a laser rangefinder to measure the height of each laser head separately. If there is a height difference of ≤0.1mm between at least two laser heads, laser cleaning cannot be performed. The height difference between each laser head should be adaptively adjusted to meet the laser cleaning conditions.

[0029] After all parameters have been adjusted, use a low-power laser to clean the surface oxide layer and oil stains of the copper busbar and electrical contacts to ensure the adhesion stability of the two during subsequent laser welding.

[0030] S22 laser welding S221 Confirms Welding Area The CCD camera of the laser welding equipment captures images of the laser-cleaned side of the copper busbar. The CCD camera software is used to process the images and extract features to lock the laser-cleaned area. The size of the area can be set by the software.

[0031] S222 laser welding The concentricity and spacing of the welded workpieces are judged and adjusted using CCD equipment software, preferably with both concentricity and spacing ≤0.3mm.

[0032] The laser welding equipment adaptively adjusts the laser focal length and defocusing amount based on the height of the laser head measured by the laser rangefinder. Preferably, the adjustment values ​​for both focal length and defocusing amount are ±0.5mm.

[0033] If there are multiple laser heads, use a laser rangefinder to measure the height of each laser head separately. If the height difference between at least two laser heads is ≤0.1mm, laser welding cannot be performed. The height difference between each laser head should be adaptively adjusted until the laser welding conditions are met.

[0034] In this embodiment, the preferred parameters are peel force ≥1500N, welding tensile force ≥4000N, and welding internal resistance ≤15μΩ. The system monitors the laser welding process and collects parameters such as temperature and plasma gas in the welding area in real time to determine whether any abnormalities occur during the welding process.

[0035] After laser welding, dust removal is performed. The welded surface is placed downwards, the dust collection fixture is positioned, and air blowing, cleaning, dust collection, and electrostatic protection are activated simultaneously, including the blowing of plasma gas. In this step, it is preferable to press and seal the cavity before opening, as a sealed cavity helps to remove residue and control foreign objects.

[0036] Before welding, it is necessary to turn on the gas blowing protection, cooling protection, and fume removal protection. All of these should be stopped after welding is completed.

[0037] Gas blowing protection: Shielding gas is blown in to prevent surface oxidation and porosity, which can lead to poor appearance. In this technology, the blowing angle between the shielding gas and the weld surface is preferably 30°±1°.

[0038] Cooling protection: During the welding process, the temperature may become too high, which can cause the surrounding plastic parts to melt. Therefore, water cooling is provided. Specifically, the cooling water circulation is turned on and the cooling water comes into contact with the copper busbar.

[0039] like Figure 3 As shown, a separate fixture can be provided. This fixture has a central hole that exposes the laser welding area. A cooling liquid channel is provided on the side of the fixture that contacts the copper busbar. This channel is distributed around the central hole. In this embodiment, the cooling liquid is cold water. The fixture can also be provided with an air channel connecting to the central hole for air blowing protection.

[0040] Fume removal protection: During the welding process, fumes are easily generated, which can affect the passage of the laser beam and reduce the effect of laser welding. Therefore, a dust extraction device is used to remove the fumes generated during the welding process.

[0041] S3. Perform the first automatic optical inspection (AOI) on the laser welding area. After passing the inspection, install the water cooling device to obtain the semi-finished product.

[0042] The first automatic optical inspection includes visual inspection and laser line scan inspection. If either visual inspection or laser line scan inspection fails, the laser welding being inspected is deemed unqualified, and subsequent processing of the product is stopped.

[0043] The visual inspection uses a 2D camera to take pictures, and after image processing, feature extraction, and analysis of the weld area in the image, it checks for surface defects a~j in each weld area. If any surface defect is present, the visual inspection fails. The failure criteria for surface defects are as follows: a. Weld width 1.9~2.1mm; b. Pore size diameter ≤ 2mm; c. Burr height < 0.8mm; d. Weld indentation depth < 0.5mm; e. Weld offset ≤ 0.75; f. Surrounding copper busbars are not allowed: g blackened or yellowed ≥25%; h weld length or width > 1 / 2 weld width; Sol is not allowed; No splashing.

[0044] The laser line scan forms the product outline of the welding surface. Software analyzes the outline to identify various defects. If any defect is present, the laser scan fails the initial inspection. The main defects detected include at least one of the following: weld width, cracks, porosity, burr height, spatter, dent depth deviation, displacement, area of ​​blackened or yellowed weld points, and sol.

[0045] Since the copper busbar in this technology is a single planar structure, the cooling water device uses a cooling water plate with an internal circulating water channel. The cooling plate is directly attached to the copper busbar and fixed to the copper busbar or the housing with fastening screws to obtain a semi-finished product.

[0046] S5. Conduct pressure resistance tests and performance tests on the semi-finished products.

[0047] After the semi-finished product is moved to the set position, the automatic control probe contacts the semi-finished product to perform a withstand voltage test. The withstand voltage test includes testing for no less than 3 seconds under DC 800V conditions, with an initial leakage current ≤1mA, a post-test leakage current ≤10mA, an insulation resistance ≥10MΩ, a pre-charge resistance of 100Ω (±5%), an X capacitor of 100uF (±5%), and a Y capacitor of 0.1uF (±10%). If any of the following indicators fail, the withstand voltage test fails, and subsequent processes are stopped.

[0048] The pressure resistance test parameters are as follows: B+&P+: MAX,8mV @20A, meaning the maximum value measured under 20A test conditions does not exceed 8mV. B+ represents the positive terminal of the battery pack, and P+ represents the positive terminal of the heating module. It is used to measure the withstand voltage between the positive terminal of the battery pack and the positive terminal of the heater.

[0049] B+&FC: MAX,8mV @20A, meaning the maximum value measured under 20A test conditions does not exceed 8mV. B+ represents the positive terminal of the battery pack.

[0050] FC+&SY+: MAX,8mV @20A, meaning the maximum value measured under 20A test conditions does not exceed 8mV.

[0051] B-&P-: MAX,8mV @20A, meaning the maximum value measured under 20A test conditions does not exceed 8mV. B- represents the negative terminal of the battery pack, and P- represents the negative terminal of the heating module. It is used to measure the withstand voltage between the negative terminal of the battery pack and the negative terminal of the heater.

[0052] B-&FC-: MAX,8mV @20A, meaning the maximum value measured under 20A test conditions does not exceed 8mV. B- represents the negative terminal of the battery pack.

[0053] The semi-finished product performance test (EOL test) mainly involves powering on the semi-finished product to confirm whether its welding quality and functionality meet the requirements. After moving the semi-finished product to a set position, the automatic control probe contacts the semi-finished product to perform the EOL test. The EOL (End-of-Life) test is a comprehensive battery performance evaluation test that integrates various tests such as battery charge and discharge testing, battery safety detection, battery parameter analysis, battery management system (BMS) testing, and auxiliary function verification.

[0054] The performance testing of the semi-finished product includes the following tests: a. Insulation detection function test: By changing the insulation resistance values ​​of power supply HV+ and HV- to ground (connecting 1000kΩ, 500kΩ, and 100kΩ), the insulation resistance and alarm status are read.

[0055] b. Total voltage accuracy test: Compare the detected value of the output voltage of the semi-finished product with the total voltage acquisition value and the cumulative value of the individual unit voltages of the semi-finished product.

[0056] c. Open circuit voltage test: Close the charging relay using EOL software and measure the port voltage using a multi-function multimeter.

[0057] d. Charge / discharge circuit test: By closing and opening the designated (main positive / main negative, charging) relays of the semi-finished product, use a multi-function multimeter to detect the port voltage value when the relay is closed and opened. If the voltage value is normal, it indicates that the charge / discharge circuit is operating normally.

[0058] S6. After the test is passed, the BMS component is fixed to the semi-finished product by laser welding to obtain the BMU.

[0059] In this embodiment, the BMS component includes a main positive circuit, a pre-charging circuit, a fast charging circuit, a heating circuit, a main negative circuit, a signal acquisition circuit, and a control circuit. The main positive circuit is equipped with a main positive relay and a fuse. The pre-charging circuit is equipped with a pre-charge relay and a pre-charge resistor. The fast charging circuit is equipped with a fast charging relay. The heating circuit is equipped with a heating relay and a heating fuse. The main negative circuit is equipped with a main negative relay and a shunt. The signal acquisition circuit acquires the positive and negative signals of the main positive circuit, the pre-charging circuit, the fast charging circuit, the heating circuit, and the main negative circuit. The control circuit is connected to the positive and negative terminals of the main positive relay, the positive fuse, the pre-charge relay, the fast charging relay, the heating relay, the main negative relay, and the shunt. The BMS component uses a high-voltage board to integrate high-voltage circuits such as the main positive circuit, pre-charging circuit, fast charging circuit, heating circuit, and main negative circuit, and a low-voltage board to integrate low-voltage circuits such as signal acquisition circuit and control circuit. It also uses a first FPC board to connect the negative output of the high-voltage board, and a second FPC to connect the high-voltage board and the low-voltage board. Finally, it is fixed with a bracket, with the high-voltage board and the low-voltage board respectively set on both sides of the bracket, thereby reducing the laying area of ​​the BMS component by half, realizing miniaturization, zero wiring harness, and integrated design.

[0060] The high-voltage board and low-voltage board are sequentially bonded to the FPC board through adhesive hot pressing, hotbar welding, BMS performance testing, X-ray inspection, UV coating, and curing, and then integrated into a single unit. This unit is then assembled onto a bracket to form the BMS assembly. The bracket is then fixed to a copper busbar or housing; in this embodiment, screws are used for fixing. One electrical contact of the BMS module is connected to the copper busbar, and the other electrical contact of the BMS module is laser-welded to each electrical component via the FPC circuit board.

[0061] CCD inspection is performed on the laser welding area between the BMS module and the semi-finished product. Specifically, a 2D camera is used to take pictures, and software image analysis and feature extraction are performed to compare the features of the welding area with standard features to confirm whether the product has the following defects: 1. Check for any solder joints or missing solder joints, and analyze the solder joint formation. 2. There are no copper beads on the copper busbar, and copper slag remains.

[0062] If any of the above defects exist, the BMU processing is unqualified, and subsequent processes should be stopped.

[0063] S7. Perform a second automatic optical inspection, finished product pressure test, finished product performance test, and waterway air tightness test on the laser welding area on the BMU. A qualified product is obtained after all three tests are passed. The detection methods for the second automatic optical inspection and the finished product pressure test are the same as those for the first automatic optical inspection. The methods for the finished product pressure test and the semi-finished product pressure test are the same, so they will not be described again in this article.

[0064] The finished product performance test includes the following tests a~m (if any one of the tests a~m fails, the finished product performance test fails): a. Insulation resistance test: With the BMU insulation monitoring function turned off, use a Hipot tester to measure the insulation resistance between the main positive, main negative and charging positive of the battery pack and the enclosure. The resistance values ​​should meet the requirements.

[0065] b. AC / DC withstand voltage test: With the BMU insulation monitoring function turned off, use a Hipot tester to perform the following tests on the main positive, main negative, and charging positive sides of the battery pack facing the casing respectively: 1) Connect the positive terminal of the hitpot to the battery pack and the negative terminal to the casing; 2) Connect the positive port to the battery pack and the negative port to the casing; 3) Connect the Hipot positive to the charging positive and the negative to the casing.

[0066] c. CAN Termination Resistance Test: Use the EOL software to enable a multi-function multimeter to measure the resistance value of the CAN port.

[0067] d. Insulation detection function test: By changing the insulation resistance values ​​of battery HV+ and HV- to ground (connecting 1000kΩ, 500kΩ, and 100kΩ), read the insulation resistance and alarm status reported by the BMS.

[0068] e. Vehicle communication function test: With the keyon closed, connect to the vehicle CAN bus and check whether the total voltage, current, maximum and minimum voltage of the battery pack are normal through the EOL host computer software.

[0069] f. Internal communication function test: With the keyon closed, connect the internal CAN and check whether the battery pack's individual cell temperature, individual cell voltage, and other information are normal through the EOL host computer software.

[0070] g. Charging and communication function test (fast charging): 1) Simulate charging gun and charger signals according to national standards; 2) The charger and BMS handshake is performed using simulated messages; 3) Measure the 12V+ output voltage of the charging relay.

[0071] h. Total voltage accuracy test: Compare the detected value of the battery system output voltage with the BMS total voltage acquisition value and the cumulative value of the individual cell voltage.

[0072] i. Open circuit voltage test: Close the charging relay using EOL software and measure the port voltage using a multi-function multimeter.

[0073] j. Charge / discharge circuit test: By closing and opening the designated (main positive / main negative, charging) relays through the BMS, use a multi-function multimeter to detect the port voltage value when the relays are closed and open. If the voltage value is normal, it indicates that the charge / discharge circuit is operating normally.

[0074] k. Pre-charge relay continuity test: The pre-charge relay and the charging relay are closed sequentially by the BMS. The port voltage values ​​U1 and U2 of the battery pack are measured by a multi-function multimeter under the two states respectively. The ratio of U1 / U2 meets the requirements.

[0075] 1. Heating circuit resistance test: Use a multi-function multimeter to test the resistance of the heating connector interface.

[0076] m. High-voltage interlock: The high-voltage interlock signal line is controlled by EOL, and the corresponding status of BMS is read through CAN communication.

[0077] The waterway airtightness test includes connecting the tooling plug to the water pipe interface of the water-cooled plate after the product arrives, starting the airtightness test equipment, and the test standard is leakage ≤3ml / min (3sccm).

[0078] If the second automatic optical inspection, finished product pressure resistance test, finished product performance test, and waterway airtightness test all pass, the product casing undergoes appearance inspection, protective cover installation, and label affixing. After casing installation, a 2D camera is used to take pictures, and software image analysis and feature extraction are performed to compare the product's external features with standard features. The inspection includes: ①Is the label pasted in the correct position and with the correct content? ② Check if the connector pins are retracted or if the pins are bent; ③ Check if there are scratches or damage on the product's appearance.

[0079] Although the present invention has been described in detail above with general descriptions and specific embodiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A fully automated manufacturing process for BMUs, characterized in that, Includes the following steps: S1. Install each electrical component onto the copper busbar assembly according to the circuit design to obtain the assembly structure; Each electrical component is installed onto the component fixture, with the electrical contacts of the electrical components located on one or both sides of the component fixture. Then, the copper busbar is fixed onto the copper busbar fixture. The component fixture and the copper busbar fixture are matched and merged, so that the copper busbar is detached from the copper busbar fixture and connected to the electrical contacts. S2. Laser cleaning and laser welding are performed on the connection areas between electrical components and copper busbars in the assembly structure. The method of activating air blowing protection and cooling protection before laser welding includes setting up a fixture with a central hole that exposes the laser welding area, a liquid channel for cooling liquid in the side of the fixture that contacts the copper busbar, and an air channel that connects to the central hole. S3. Perform the first automatic optical inspection on the laser welding area. After the inspection is passed, install the water cooling device to obtain the semi-finished product. S4. Conduct pressure resistance tests and performance tests on the semi-finished products. S5. After the test is passed, the BMS component is fixed to the semi-finished product by laser welding to obtain the BMU. The BMS component includes a high-voltage board for integrating the main positive circuit, pre-charging circuit, fast charging circuit, heating circuit, and main negative circuit; a low-voltage board for integrating the signal acquisition circuit and control circuit; a first FPC board for connecting the negative output of the high-voltage board; a second FPC board for connecting the high-voltage board and the low-voltage board; and a bracket, with the high-voltage board and the low-voltage board respectively fixed on both sides of the bracket. The high-voltage board and low-voltage board are sequentially bonded to the FPC board through adhesive hot pressing, hotbar welding, BMS performance testing, X-ray testing, UV coating and curing, and then connected as a whole. They are then assembled onto a bracket to obtain the BMS assembly. The bracket is then fixed to the copper busbar or housing, so that one electrical contact of the BMS module is connected to the copper busbar, and the other electrical contact of the BMS module is connected to each electrical component by laser welding through the FPC circuit board. S6. Perform a second automatic optical inspection, finished product pressure test, finished product performance test, and waterway air tightness test on the laser welding area on the BMU. A qualified product is obtained after all three tests are passed.

2. The fully automated BMU manufacturing process according to claim 1, characterized in that: The component fixture in S1 is a mold specifically designed for production according to the circuit design and capable of fixing various electrical components, or a product housing or frame capable of fixing various electrical components according to the circuit design. The component fixture is provided with component mounting positions or component slots for installing various electrical components. A copper busbar fixture is a mold specifically designed for production and for fixing copper busbars according to circuit design, or a frame for fixing copper busbars. The copper busbar fixture is provided with copper busbar mounting positions or copper busbar slots for installing various electrical components.

3. The fully automated BMU manufacturing process according to claim 1, characterized in that: Before step S1, assembly codes and material codes are added to both electrical components and copper busbars for material verification and traceability.

4. The fully automated BMU manufacturing process according to claim 1, characterized in that: The laser cleaning in S2 includes using the CCD camera of the laser cleaning device to acquire an image of the non-electrical component side of the copper busbar, and then using CCD camera software to perform image processing and feature extraction on the image to locate the connecting through holes with electrical contacts inside the copper busbar and the surrounding area, or the electrical contacts passing through the connecting through holes and the surrounding area; after determining the cleaning area, low-power laser cleaning is used.

5. The fully automated BMU manufacturing process according to claim 4, characterized in that: After determining the cleaning area, use CCD camera software to judge and adjust the concentricity and spacing of the welding workpieces; Use a laser rangefinder to measure the height of the laser head and adaptively adjust the laser focal length and defocusing amount; If there are multiple laser heads, a laser rangefinder is used to measure the height of each laser head separately, and the height difference between each laser head is adaptively adjusted.

6. The fully automated BMU manufacturing process according to claim 1, characterized in that: The laser welding in S2 includes using a CCD camera to capture an image of the laser-cleaned side of the copper busbar, and then using CCD camera software to perform image processing and feature extraction on the image to lock the laser-cleaned area. Use CCD equipment software to determine and adjust the concentricity and spacing of the welded workpieces; Use a laser rangefinder to measure the height of the laser head and adaptively adjust the laser focal length and defocusing amount; If there are multiple laser heads, use a laser rangefinder to measure the height of each laser head separately and adaptively adjust the height difference between each laser head. After the parameters are adjusted, laser welding will be performed.

7. The fully automated BMU manufacturing process according to claim 1, characterized in that: Both the first automatic optical inspection and the second automatic optical inspection include visual inspection and laser line scan inspection. If either visual inspection or laser line scan inspection fails, the inspected laser welding is considered unqualified. The visual inspection uses a 2D camera to take pictures, and after image processing, feature extraction, and analysis of the solder joint area in the image, it checks the surface defects of the solder joint area one by one. If any surface defect is found, the visual inspection is unqualified. The laser line scan forms the product outline of the welding surface. The software analyzes the outline and judges various defects. If any defect exists, the laser scan test fails.

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