BMU full-automatic manufacturing process

Abstract

The invention relates to a BMU full-automatic manufacturing process which comprises the following steps: S1, installing each electric device on a copper bar assembly according to a circuit design to obtain an assembly structure; s2, laser cleaning and laser welding are sequentially carried out on the connection area of the electric device and the copper bar in the assembly structure; s3, first automatic optical detection is conducted on the laser welding area, a water cooling device is installed after detection is passed, and a semi-finished product is obtained; s4, performing a semi-finished product pressure resistance test and a semi-finished product performance test on the semi-finished product; s5, after the test is passed, fixing the BMS assembly to the semi-finished product through laser welding to obtain a BMU; and S6, second automatic optical detection, finished product pressure resistance test, finished product performance test and water channel air tightness test are conducted on the laser welding area on the BMU, and qualified products are obtained after the three tests pass. Intelligent processing units are formed in all the process steps, all the units are connected and conveyed through the mechanical arms and the conveying belts, the intelligent degree is high, the assembly precision is high, and the assembly cost is greatly reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of automated production, and in particular to a fully-automatic manufacturing process for a BMU. Background Art

[0002] The current BMU assembly method requires manual assistance. In most cases, multiple workstations of the BMU are operated discontinuously, that is, some work sections that require manual assistance are separate equipment. After obtaining the semi-finished products of the work section through manual assistance, the semi-finished products of the work section are manually transferred to the equipment of the next work section. The assembly automation level is low, and the placement of assembly equipment is chaotic, which is not conducive to the implementation of enterprise optimization of production sites. At the same time, manual assistance increases the production cost, production efficiency, and assembly accuracy of the enterprise to a certain extent. Therefore, it is necessary to provide a BMU fully automatic production process to solve the above problems. Summary of the invention The embodiment of the present invention provides a fully automatic BMU manufacturing process to solve the problems of high assembly cost, low efficiency and poor precision caused by low automation in the prior art.

[0003] In order to achieve the above purpose, the embodiment of the present invention provides the following technical solutions: A BMU fully automatic production process comprises the following steps: S1. Install various electrical components onto the copper busbar assembly according to the circuit design to obtain an assembly structure; S2. Laser cleaning and laser welding are performed on the connection area between the electrical components and the copper busbar in the assembly structure; S3, performing a first automatic optical inspection on the laser welding area, installing a water cooling device after the inspection passes, and obtaining a semi-finished product; S5. Conduct pressure test and performance test on semi-finished products; S6. After the test is passed, the BMS assembly is fixed to the semi-finished product by laser welding to obtain a BMU; S7. Perform the second automatic optical inspection, finished product pressure resistance test, finished product performance test, and water channel air tightness test on the laser welding area on the BMU. Qualified products are obtained after passing all three tests.

[0004] Furthermore, in S1, each electrical component is installed on a component jig, and the electrical contacts of the electrical components are located on one side or both sides of the component jig. Then, the copper busbar is fixed on the copper busbar jig, and the component jig and the copper busbar jig are matched and combined, so that the copper busbar is separated from the copper busbar jig and connected to the electrical contacts.

[0005] Furthermore, the component jig in S1 is a mold specially used for production and capable of fixing various electrical components according to the circuit design, or a product housing or frame that can fix various electrical components according to the circuit design, and the component jig is provided with component mounting positions or component embedding grooves for installing various electrical components; the copper busbar jig is a mold specially used for production and fixing copper busbars according to the circuit design, or a frame for fixing copper busbars, and the copper busbar jig is provided with copper busbar mounting positions or copper busbar embedding grooves for installing various electrical components.

[0006] Furthermore, before S1, assembly codes and material codes are added to the electrical components and copper bars for material verification and tracing.

[0007] Furthermore, the laser cleaning in S2 includes using a CCD camera of a laser cleaning device to capture an image of the non-electrical device side of the copper busbar, and then using CCD camera software to perform image processing and feature extraction on the photo, 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 its surrounding area; after determining the cleaning area, use low-power laser cleaning.

[0008] Furthermore, after determining the cleaning area, use the CCD camera software to determine 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 defocus; if there are multiple laser heads, use a laser rangefinder to measure the heights of the multiple laser heads separately, and adaptively adjust the height difference between each laser head.

[0009] Furthermore, 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 photo to lock the laser-cleaned area; using CCD device software to determine and adjust the concentricity and spacing of the welding workpieces; using a laser rangefinder to measure the height of the laser head, and adaptively adjust the laser focal length and defocus; if there are multiple laser heads, using a laser rangefinder to measure the heights of the multiple laser heads respectively, and adaptively adjust the height difference between each laser head; after the parameters are adjusted, laser welding is performed.

[0010] Furthermore, the air blowing protection and cooling protection are turned on before laser welding, including setting up a tool with a center hole exposing the laser welding area, and a liquid channel for cooling liquid is provided in the side of the tool in contact with the copper busbar; an air channel connected to the center hole is provided on the tool.

[0011] Furthermore, the first automatic optical inspection and the second automatic optical inspection both include visual inspection and laser line scan inspection. If either the visual inspection or the laser line scan inspection fails, the laser welding being inspected fails. The visual inspection uses a 2D camera to take pictures, and through image processing and feature extraction, analyzes the weld area in the image, and checks the surface defects of the welding area one by one. If any surface defects exist, the visual inspection fails. The laser line scan uses laser line scanning to form the product contour of the welding surface, and analyzes the contour through software to determine various undesirable factors. If any undesirable factors exist, the laser first scan inspection fails.

[0012] The embodiments of the present invention have the following advantages: The BMU fully automatic manufacturing process of the present invention realizes the formation of intelligent processing units for each process step, and each unit is connected and transmitted by a robot arm and a conveyor belt, which has a high degree of intelligence, high assembly accuracy, and greatly reduced assembly costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the implementation methods of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the implementation methods or the description of the prior art. Obviously, the drawings in the following description are only exemplary, and for ordinary technicians in this field, other implementation drawings can be derived from the provided drawings without creative work.

[0014] The structures, proportions, sizes, etc. illustrated in this specification are only used to match the contents disclosed in the specification so as to facilitate understanding and reading by persons familiar with the technology. They are not used to limit the conditions under which the present invention can be implemented, and therefore have no substantial technical significance. Any structural modification, change in proportion or adjustment of size shall still fall within the scope of the technical contents disclosed in the present invention without affecting the effects and purposes that can be achieved by the present invention.

[0015] Figure 1 A process flow chart of a BMU fully automatic manufacturing process provided by an embodiment of the present invention; Figure 2 A detailed flow chart of a BMU fully automatic manufacturing process provided by an embodiment of the present invention; Figure 3 A structural diagram of an auxiliary tool in a BMU fully automatic manufacturing process provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0016] The following is a description of the implementation of the present invention by specific embodiments. People familiar with the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0017] like Figure 1-2 As shown, a BMU fully automatic production process includes the following steps: S1. Install various electrical components onto the copper busbar assembly according to the circuit design to obtain an assembly structure.

[0018] In the present technology, electrical components can be installed on the copper busbar assembly by manual installation or automated installation, wherein the automated installation method includes installing each electrical component into a component jig, wherein the electrical contacts of the electrical components are located on one side or both sides of the component jig, and then the copper busbar assembly is fixed on the copper busbar jig, and the component jig is matched and combined with the copper busbar jig to install the electrical components on the copper busbar assembly.

[0019] In order to achieve automation, all electrical components are placed in a component jig, which is a mold specially used to produce and fix each electrical component according to the circuit design, or a product shell or frame that can fix each electrical component according to the circuit design. After the electrical components are pressed and installed, the electrical contacts of each electrical component are located on one side or both sides of the jig. Based on the perspective of the intelligent assembly line, it is preferred that the electrical contacts of each electrical component are located on one side of the jig. If there is a height difference between the electrical contacts of each electrical component, the corresponding copper busbar is designed to make up for the height difference when designing the copper busbar assembly. Specifically, the jig is provided with a component embedding groove or component mounting position for fixing each electrical component. The component embedding groove or component mounting position is designed according to the arrangement position of each electrical component in the circuit diagram and the appearance of the electrical component. It is preferred to make the electrical contacts of as many electrical components as possible in the same horizontal plane, which is convenient for the one-time installation of the copper busbar and can realize mechanized automatic installation. The electrical components are pre-charged modules, relays, fuses, shunts, capacitors, etc.

[0020] The copper bar assembly is arranged on a copper bar fixture, and the copper bar fixture is a mold specially used for production and fixing the copper bar assembly according to the circuit design, or a frame with the function of fixing the copper bar. The copper bar fixture is provided with a copper bar embedding groove for embedding the copper bar assembly or a copper bar mounting position for limiting the position of the copper bar. The former copper bar assembly can be embedded in the copper bar embedding groove for fixing, and the latter copper bar assembly can be fixed by pasting, welding, fastening bolts, etc. For the convenience of processing, the copper bar assembly and the copper bar fixture can be used as a component first, and then assembled for subsequent assembly lines. The copper bar assembly is provided with a connecting through hole that matches the contact, and the copper bar fixture is provided with a cavity corresponding to the connecting through hole, which is used to expose the connecting through hole of the copper bar assembly, which is convenient for the later welding process. Since the arrangement of each electrical component is unique and asymmetric, the distribution of the electrical contacts is unique, so the distribution of the connecting through hole is also unique, which can be used for the positioning of the copper bar and the matching of the fixture.

[0021] The component jig and the copper busbar jig are matched and merged, so that the connection holes of the copper busbar match the electrical contacts of the electrical device. After the two are connected, since the welding position is located outside the electrical contacts passing through the copper busbar assembly, it is necessary to flip the two jigs synchronously to make the welding position correspond to the welding head. If there is a gap between the copper busbar slot and the copper busbar, when the copper busbar jig is flipped and the opening is downward, the copper busbar assembly will be separated from the copper busbar jig, realizing the automated installation between the copper busbar assembly and the electrical components.

[0022] In this technology, assembly codes and material codes are added to electrical components and copper bars for material verification and traceability. In this embodiment, SN codes are used, and a fixed barcode scanner is set to automatically scan the assembly SN code. MES confirms the product status, on the one hand to confirm the identity and whether it is the production status of this process; on the other hand to confirm the process progress.

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

[0024] S21 Laser Cleaning During laser welding, the oxide layer and oil stains on the surface of the copper busbar and the electrical contact will cause unstable welding and easily cause spatter or hole explosion, so they need to be processed before laser welding.

[0025] S211 Confirm the clean area Use the CCD camera of the laser cleaning equipment to collect images of the non-electrical device side of the copper busbar. If the copper busbar is laid on top of the electrical device, the CCD camera collects the upper side of the copper busbar. Then use the CCD camera software to process and extract features from the photos, and lock 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 its surrounding area. The area size can be set by the software.

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

[0027] The laser rangefinder of the laser cleaning equipment is used to measure the height of the laser head, and the laser focal length and defocus amount are adaptively adjusted, preferably the adjustment values ​​of the focal length and defocus amount are both ±0.5mm.

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

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

[0030] S22 Laser Welding S221 Confirm welding area Use the CCD camera of the laser welding equipment to collect images of the laser-cleaned side of the copper busbar, use the CCD camera software to process and extract features from the photos, and lock the laser-cleaned area. The size of the area can be set by the software.

[0031] S222 Laser Welding Use CCD equipment software to judge and adjust the concentricity and spacing of the welding workpieces, preferably when the concentricity and spacing are both ≤0.3mm.

[0032] The laser welding equipment adaptively adjusts the laser focal length and defocus amount according to the height of the laser head measured by the laser rangefinder, preferably the adjustment values ​​of the focal length and defocus amount are both ±0.5mm.

[0033] If there are multiple laser heads, use a laser rangefinder to measure the heights of the multiple laser heads 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 is adaptively adjusted to meet the laser welding conditions.

[0034] In this embodiment, the peeling force is preferably ≥1500N, the welding tensile force is ≥4000N, and the welding internal resistance is ≤15μΩ. During the laser welding process, the system monitors and collects parameters such as the temperature and plasma gas in the welding area in real time to determine whether there is any abnormality in the welding process.

[0035] After laser welding, dust removal is performed. The welding surface is facing down, the dust collection tool is in place, and the blowing, cleaning, dust collection, and electrostatic protection are started simultaneously, including the plasma gas blowing. In this step, it is preferred to press and seal before opening, and the sealed cavity is more conducive to the suction of residues and the control of foreign matter.

[0036] Before welding, it is necessary to turn on the air blowing protection, temperature reduction protection, and smoke removal protection, and stop all of them after welding is completed.

[0037] Blowing protection: The shielding gas starts blowing to prevent surface welding oxidation and hole explosion, which leads to poor appearance. In this technology, the blowing angle between the shielding gas and the welding surface is preferably 30°±1°.

[0038] Cooling protection: During the welding process, the instantaneous temperature is prone to be too high, which can easily cause the surrounding plastic parts to melt. Therefore, water is used to cool down. Specifically, the cooling water circulation is turned on, and the cooling water is in contact with the copper busbar.

[0039] like Figure 3 As shown, a tool can be set up separately, and a central hole is provided in the tool to expose the laser welding area. A liquid channel for cooling liquid is provided in the side of the tool that contacts the copper bar, and the liquid channel is distributed around the central hole. In this embodiment, the cooling liquid is cold water. An air channel connected to the central hole can also be provided on the tool for air blowing protection.

[0040] Smoke removal protection: During the welding process, smoke is easily generated, which will affect the penetration of the laser beam and reduce the effect of laser welding. Therefore, a dust suction device is operated to suck out the smoke generated during the welding process.

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

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

[0043] The visual inspection uses a 2D camera to take pictures, and after image processing and feature extraction, the solder joint area in the image is analyzed to check the surface defects a~j of the soldering area one by one. If any surface defects exist, the visual inspection fails. The failure criteria for the surface defects are as follows: aWelding seam width 1.9~2.1mm; b. Pore size diameter ≤ 2mm; c Burr height < 0.8mm; d. Weld concave depth < 0.5 mm; eWeld offset ≤ 0.75; f. Surrounding copper bars are not allowed: g Black or yellow ≥ 25%; h weld length or width>1 / 2 weld width; iNo sol is allowed; jNo splash.

[0044] The laser line scan uses laser line scan to form the product contour of the welding surface. The software analyzes the contour and determines multiple undesirable factors. If any undesirable factors exist, the laser scan test fails. The main undesirable factors include: at least one of weld width, cracks, pore size, burr height, spatter, depression depth deviation, displacement, black or yellow area of ​​weld point, and sol.

[0045] Since the copper busbar in this technology is a flat structure, the cold water device uses a cold water plate containing a circulating water channel. The cooling surface of the cold water plate is directly attached to the copper busbar and fixed to the copper busbar or shell with fastening screws to obtain a semi-finished product.

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

[0047] After the semi-finished product is moved to the set position, the probe is automatically controlled to contact the semi-finished product and a withstand voltage test is performed on the semi-finished product. The withstand voltage test includes a test time of not less than 3s under the condition of DC 800V, an initial leakage current ≤1mA, a leakage current ≤10mA after endurance, 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 are unqualified, the withstand voltage test is unqualified and subsequent processes are stopped.

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

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

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

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

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

[0053] The semi-finished product performance test (EOL test) is mainly a semi-finished product power-on test to confirm whether the semi-finished product welding quality and function meet the requirements. After the semi-finished product is moved to the set position, the probe is automatically controlled to contact the semi-finished product for EOL testing. EOL (End-of-Life) testing is a comprehensive battery performance evaluation test that integrates multiple tests such as battery charge and discharge testing, battery safety testing, battery parameter analysis, battery management system (BMS) testing, and auxiliary function verification.

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

[0055] bTotal voltage accuracy test: Compare the detected value of the semi-finished product output voltage with the collected value of the semi-finished product total voltage and the accumulated value of the single cell voltage.

[0056] cOpen circuit voltage test: Close the charging relay through the EOL software and use a multi-function multimeter to measure the port voltage.

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

[0058] S6. After the test is passed, the BMS assembly 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, wherein the main positive circuit is provided with a main positive relay and a fuse, the pre-charging circuit is provided with a pre-charging relay and a pre-charging resistor, the fast charging circuit is provided with a fast charging relay, the heating circuit is provided with a heating relay and a heating fuse, the main negative circuit is provided with a main negative relay and a shunt, the signal acquisition circuit respectively collects 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, and the control circuit is respectively connected to the positive and negative electrodes of the main positive relay, the positive fuse, the pre-charging 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 a main positive circuit, a pre-charging circuit, a fast charging circuit, a heating circuit, and a main negative circuit, and uses a low-voltage board to integrate low-voltage circuits such as a signal acquisition circuit and a control circuit. A first FPC board is used to connect the negative output of the high-voltage board, and a second FPC is used to connect the high-voltage board and the low-voltage board. Finally, a bracket is used to fix them. The high-voltage board and the low-voltage board are respectively arranged on both sides of the bracket, thereby reducing the laying area of ​​the BMS component, halving its area, and realizing miniaturization, zero wiring harness, and integrated design.

[0060] The high-voltage board and the low-voltage board are connected to the FPC board through hot-pressing fixation with adhesive, hotbar welding, BMS performance testing, X-ray testing, UV coating and curing, and then assembled on a bracket to obtain a BMS component. The bracket is then fixed to the copper bus or the shell. In this embodiment, screws are used to fix the BMS module so that one pole of the electrical contact is connected to the copper bus, and the other pole of the electrical contact of the BMS module is connected to each electrical device through laser welding through the FPC circuit board.

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

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

[0063] S7. Perform the second automatic optical inspection, finished product pressure test, finished product performance test, and water channel air tightness test on the laser welding area on the BMU. Qualified products are obtained after all three tests are passed. The inspection method of the second automatic optical inspection is the same as that of the first automatic optical inspection, and the method of the finished product pressure test is the same as that of the semi-finished product pressure test, so it will not be repeated in this article.

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

[0065] b. AC / DC withstand voltage test: Turn off the BMU insulation monitoring function and use the Hipot tester to perform the following tests on the main positive, main negative and charging positive sides of the battery pack: 1) Hipot positive connects to the battery pack and negative connects to the case; 2) Hipot positive connects to battery pack negative, negative connects to case; 3) Hipot positive connection for charging and negative connection for the case.

[0066] c. CAN terminal resistance test: Enable the multi-function multimeter through the EOL software to measure the resistance value of the CAN port.

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

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

[0069] f. Internal communication function test: When key on is closed, connect the internal CAN and check whether the cell temperature, cell voltage and other information of the battery pack are normal through the EOL host computer software.

[0070] g. Charging communication function test (fast charging): 1) Simulate charging gun and charger signals according to national standards; 2) Handshake between the charger and BMS through analog messages; 3) Measure the 12V+ output voltage of the charging relay.

[0071] h. Total voltage accuracy test: The detected value of the battery system output voltage is compared with the BMS total voltage collection value and the accumulated value of the single cell voltage.

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

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

[0074] k. Pre-charge relay on-off test: Close the pre-charge relay and the charging relay in sequence through the BMS, and use a multi-function multimeter to detect the terminal voltage values ​​U1 and U2 of the battery pack in the two states respectively. The ratio of U1 / U2 meets the requirements.

[0075] 1. Heating circuit resistance test: Use a multi-function ammeter to detect the resistance of the heating aviation plug interface.

[0076] m. High-voltage interlock: Control the on / off of the high-voltage interlock signal line through EOL, and read the corresponding status of BMS through CAN communication.

[0077] The water channel air tightness test includes connecting the tooling plug to the water pipe interface of the water cooling plate after the product is in place, and starting the air tightness test equipment to test, and the detection standard is leakage ≤3ml / min (3sccm).

[0078] If the second automatic optical inspection, finished product pressure test, finished product performance test, and water channel air tightness test are all qualified, the product shell is inspected for appearance, the protective cover is installed, and the label is attached. After the shell is installed, a 2D camera is used to take pictures, and the software image analysis and feature extraction are used to compare the product appearance features with the standard features. The inspection content includes: ①Whether the content of the label pasting position is correct; ② Whether the connector pins are withdrawn or crooked; ③Whether there are any scratches or damages on the product appearance.

[0079] Although the present invention has been described in detail above by general description and specific embodiments, it is obvious to those skilled in the art that some modifications or improvements can be made to the present invention. Therefore, these modifications or improvements made without departing from the spirit of the present invention all belong to the scope of protection claimed by the present invention.

Claims

1. A fully automatic BMU production process, characterized in that: The following steps are involved: S1. Install various electrical components onto the copper busbar assembly according to the circuit design to obtain an assembly structure; S2. Laser cleaning and laser welding are performed on the connection area between the electrical components and the copper busbar in the assembly structure; S3, performing a first automatic optical inspection on the laser welding area, installing a water cooling device after the inspection passes, and obtaining a semi-finished product; S4. Conduct semi-finished product pressure resistance test and semi-finished product performance test on semi-finished products; S5. After the test is passed, the BMS assembly is fixed to the semi-finished product by laser welding to obtain a BMU; S6. Perform the second automatic optical inspection, finished product pressure resistance test, finished product performance test, and water channel air tightness test on the laser welding area on the BMU. Qualified products are obtained after passing all three tests.

2. A BMU fully automatic production process according to claim 1, characterized in that: In S1, each electrical component is installed on a component jig, and the electrical contacts of the electrical components are located on one side or both sides of the component jig. Then, the copper busbar is fixed on the copper busbar jig, and the component jig and the copper busbar jig are matched and combined, so that the copper busbar is separated from the copper busbar jig and connected to the electrical contacts.

3. A BMU fully automatic production process according to claim 2, characterized in that: The component jig in S1 is a mold specially used for production and capable of fixing various electrical components according to the circuit design, or a product housing or frame capable of fixing various electrical components according to the circuit design, and the component jig is provided with component mounting positions or component embedding grooves for mounting various electrical components; The copper busbar jig is a mold specially used for producing and fixing the copper busbar according to the circuit design, or a frame for fixing the copper busbar. The copper busbar jig is provided with copper busbar mounting positions or copper busbar embedding grooves for installing various electrical components.

4. A BMU fully automatic production process according to claim 1, characterized in that: Before S1, assembly codes and material codes are added to electrical components and copper bars for material verification and tracing.

5. A BMU fully automatic production process according to claim 1, characterized in that: The laser cleaning in S2 includes using a CCD camera of a laser cleaning device to capture an image of the non-electrical device side of the copper busbar, and then using CCD camera software to perform image processing and feature extraction on the photo, locking the connecting through hole with an electrical contact inside the copper busbar and its surrounding area, or the electrical contact passing through the connecting through hole and its surrounding area; after determining the cleaning area, use low-power laser cleaning.

6. A BMU fully automatic production process according to claim 5, characterized in that: After determining the cleaning area, use the CCD camera software to determine 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 defocus; If there are multiple laser heads, a laser rangefinder is used to measure the heights of the multiple laser heads respectively, and the height difference between the laser heads is adaptively adjusted.

7. A BMU fully automatic production process according to claim 1, characterized in that: The laser welding in S2 includes using a CCD camera to collect 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 photo to lock the laser-cleaned area; Use CCD equipment software to determine and adjust the concentricity and spacing of welding workpieces; Use a laser rangefinder to measure the height of the laser head and adaptively adjust the laser focal length and defocus; If there are multiple laser heads, use a laser rangefinder to measure the heights of the multiple laser heads respectively, and adaptively adjust the height difference between the laser heads; After the parameters are adjusted, laser welding is performed.

8. A BMU fully automatic production process according to claim 7, characterized in that: The blowing protection and cooling protection are turned on before laser welding, including setting a tool, the tool has a central hole exposing the laser welding area, and a liquid channel for cooling liquid is provided in the side of the tool in contact with the copper busbar; The tooling is provided with an air passage connected to the central hole.

9. A BMU fully automatic production process according to claim 1, characterized in that: The first automatic optical inspection and the second automatic optical inspection both include visual inspection and laser line scan inspection. If the visual inspection fails or the laser line scan inspection fails, the inspected laser welding fails. The visual inspection uses a 2D camera to take pictures, and after image processing and feature extraction, the solder joint area in the image is analyzed to check the surface defects of the soldering area one by one. If any surface defects exist, the visual inspection fails. The laser line scan uses laser line scan to form the product contour of the welding surface. The contour is analyzed by software to determine various undesirable factors. If any undesirable factor exists, the laser scan detection fails.

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