Laser welding method, laser welding device, and computer-readable storage medium

Abstract

The application provides a laser welding method, a laser welding device and a computer readable storage medium. The laser welding method comprises the following steps: obtaining process parameters required for laser welding; calculating a penetration depth prediction value by using a preset model according to the process parameters; receiving an instruction for starting welding in the case that the penetration depth prediction value meets a standard; and performing laser welding on a target object according to the instruction. The laser welding method provided by the application can reduce the labor cost, time cost and material cost of laser welding debugging, and improve the operation efficiency of the laser welding link.

Description

Technical Field

[0001] This invention relates to the field of welding technology, and more specifically to a laser welding method, a laser welding apparatus, and a computer-readable storage medium. Background Technology

[0002] In the manufacturing of lithium-ion batteries, the aluminum casing and cover plate are typically connected using laser welding. To ensure the safety performance of lithium-ion battery cells, the welding quality of the laser welding must meet requirements, with the penetration depth of the laser weld being an important standard reflecting the welding quality.

[0003] However, since the relationship between the process parameters and the penetration depth of laser welding is non-linear and complex, when adjusting the process parameters of laser welding, it is necessary to actually perform laser welding to check the penetration depth. Then, based on the debugging experience, the process parameters of laser welding are adjusted, and laser welding is performed again to check the penetration depth. Through such repeated trial and error, the penetration depth of laser welding is adjusted to meet the standard.

[0004] Therefore, the traditional welding debugging process requires repeated welding operations to determine the specific process parameters, which incurs significant labor, time, and material costs, thus affecting the operational efficiency of the laser welding process in manufacturing. Summary of the Invention

[0005] The embodiments of the present invention provide a laser welding method, a laser welding apparatus, and a computer-readable storage medium, which can reduce the labor cost, time cost, and material cost of laser welding debugging and improve the operational efficiency of laser welding.

[0006] An embodiment of the present invention provides a laser welding method, comprising the following steps:

[0007] Obtain the process parameters required for laser welding;

[0008] The predicted melting depth is calculated using a preset model based on the process parameters.

[0009] If the predicted penetration depth meets the predetermined standard, a command to start laser welding is received;

[0010] Laser welding is performed on the target object according to the instructions.

[0011] In one embodiment, the step of obtaining the process parameters required for laser welding includes obtaining at least one of the laser welding power, defocusing amount, and welding speed.

[0012] In one embodiment, the preset model includes:

[0013]

[0014] Where Y represents the predicted penetration depth, P represents the welding power, Z represents the decoking amount, v represents the welding speed, A represents the coefficient term, and B, C, and D represent the constant terms.

[0015] In one embodiment, before the step of calculating the predicted melt depth value using a preset model based on the process parameters, the method further includes the step of:

[0016] Obtain multiple actual values ​​of penetration depth, and calculate the values ​​of A, B, C, and D based on the actual values ​​of penetration depth and the corresponding welding power, decoking amount, and welding speed.

[0017] In one embodiment, the welding power is 800 to 1500 watts, the decoking amount is -3 to +3 mm, and the welding speed is 80 to 200 mm / s.

[0018] In one embodiment, the step of laser welding the target object according to the instructions includes:

[0019] Based on the welding power, defocusing amount, and welding speed corresponding to the predicted penetration value that meets the predetermined standard, laser welding is performed on the target object along a preset welding trajectory.

[0020] In one embodiment, the step of receiving a welding start command when the predicted penetration value meets the standard includes:

[0021] Obtain the standard value of the melt depth and the standard deviation of the standard value of the melt depth;

[0022] If the difference between the predicted penetration value and the standard penetration value does not exceed a preset multiple of the standard deviation of the standard penetration value, a welding start command is received.

[0023] In one embodiment, the preset multiple is greater than 2 and less than 4.

[0024] An embodiment of the present invention provides a laser welding apparatus, comprising:

[0025] The acquisition module is used to acquire the process parameters required for laser welding;

[0026] The calculation module is used to calculate the predicted melting depth based on the process parameters using a preset model;

[0027] A receiving module is configured to receive a command to initiate laser welding if the predicted penetration depth meets a predetermined standard; and

[0028] A laser welding module is used to perform laser welding on a target object according to the instructions.

[0029] Embodiments of the present invention also provide a computer-readable storage medium storing program code for causing a laser welding apparatus to perform the laser welding method described in the above embodiments.

[0030] In the embodiments of the present invention, the relationship between laser welding process parameters and penetration depth is established by designing a preset model. The penetration depth value is directly predicted by combining the laser welding process parameters, thereby estimating the laser welding quality and guiding the debugging of laser welding process parameters. This eliminates the need for repeated trial and error during actual welding operations to obtain laser welding process parameters that meet the standards. As a result, the labor cost, time cost, and material cost of laser welding debugging are reduced, and the operational efficiency of the laser welding process is improved. Attached Figure Description

[0031] Figure 1 This is a flowchart of a laser welding method provided in an embodiment of the present invention.

[0032] Figure 2 This is a schematic diagram comparing the predicted and actual melting depth values ​​in one embodiment of the present invention.

[0033] Figure 3 This is a block diagram of a laser welding apparatus provided in an embodiment of the present invention. Detailed Implementation

[0034] To make the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0035] like Figure 1 As shown, an embodiment of the present invention provides a laser welding method comprising the following steps:

[0036] Obtain the process parameters required for laser welding;

[0037] The predicted melting depth is calculated using a preset model based on the process parameters.

[0038] If the predicted penetration depth meets the predetermined standard, a command to start laser welding is received;

[0039] Laser welding is performed on the target object according to the instructions.

[0040] In this embodiment of the invention, the process parameters required for laser welding are first obtained, including welding power, defocusing amount, welding speed, welding trajectory, outer ring power, shielding gas flow rate, etc. Then, based on the obtained process parameters, a predicted penetration depth for laser welding is calculated using a preset model to estimate the welding quality under the obtained process parameters. If the predicted penetration depth meets a predetermined standard, it is considered that laser welding under the corresponding process parameters can meet the quality requirements of laser welding. Subsequently, a welding start command is received, and laser welding is performed on the target object according to the command. Specifically, the predetermined standard refers to a penetration depth standard, which reflects the welding quality requirements and typically varies depending on the welding application scenario.

[0041] This invention establishes the relationship between laser welding process parameters and penetration depth through the design of a preset model. It enables the prediction of penetration depth values ​​based on laser welding process parameters, thereby estimating laser welding quality and guiding the adjustment of laser welding process parameters. This eliminates the need for repeated trial and error during actual welding operations to obtain laser welding process parameters that meet standards. As a result, it reduces the labor, time, and material costs of laser welding debugging and improves the operational efficiency of the laser welding process.

[0042] In one embodiment of the present invention, the step of obtaining the process parameters required for laser welding includes: obtaining at least one of the laser welding power, defocusing amount, and welding speed. Welding power, defocusing amount, and welding speed are key process parameters for laser welding and are generally closely related to the quality of laser welding.

[0043] In one embodiment of the present invention, the preset model includes: Where Y represents the predicted penetration depth, P represents the welding power, Z represents the defocusing amount, v represents the welding speed, A represents the coefficient term, and B, C, and D represent the constant terms. According to the principle of energy conservation, the energy output by the laser during laser welding is equal to the sum of the energy absorbed by the metal and the energy reflected. Therefore, the relationship is established as: Welding power P * time t * laser absorptivity (laser energy absorbed by the welding metal) = metal specific heat capacity * metal density * metal volume (energy received by the welding metal). Here, the metal volume is approximated as penetration depth Y * welding trajectory, and the welding trajectory is equal to welding speed v * time t. Substituting these values, we get P * t * laser absorptivity = metal specific heat capacity * metal density Y * v * t. Since laser absorptivity, metal specific heat capacity, and metal density are inherent properties of the metal, they can be considered constant coefficients. This leads to the basic relationship Y = P / v, and further optimization yields a pre-defined model.

[0044] In one embodiment of the present invention, before the step of calculating the predicted penetration depth using a preset model based on the process parameters, the method further includes the step of: obtaining multiple actual penetration depth values, and calculating the values ​​of A, B, C, and D based on the actual penetration depth values ​​and the corresponding welding power, defocusing amount, and welding speed. Specifically, firstly, different combinations of laser welding process parameters are designed by selecting different values ​​of welding power, defocusing amount, and welding speed; then, laser welding tests are conducted based on the designed combinations of laser welding process parameters. After laser welding is completed, the weld cross-section is cut using a wire cutting method, and the actual penetration depth of the weld is measured. This establishes a dataset of different combinations of laser welding process parameters, i.e., welding power, defocusing amount, and welding speed, and the actual penetration depth of laser welding under the corresponding process parameters; finally, multiple sets of data are substituted into the preset model. The values ​​of A, B, C, and D with the highest fitting degree are obtained through fitting. For different laser welding application scenarios, the same method can be used to obtain the set of values ​​of A, B, C, and D with the highest fitting degree, thereby obtaining a penetration depth prediction formula that conforms to different welding conditions.

[0045] In one embodiment of the present invention, the welding power is 800–1500 watts, the defocusing amount is -3 to +3 mm, and the welding speed is 80–200 mm / s. The above-mentioned laser welding process parameter range is applicable to deep penetration welding modes, such as laser welding between the aluminum casing and cover plate of a lithium-ion battery.

[0046] In one embodiment of the present invention, the laser welding method is used for laser welding between the aluminum shell and the cover plate of a lithium-ion battery. Specifically, the welding power is 800-1500 watts, the defocusing amount is -3 to +3 mm, the welding speed is 80-200 mm / s, the outer ring power is 1000-1500 watts, and the shielding gas flow rate is 0.1-0.3 MPa. Different combinations of welding power, defocusing amount, and welding speed are designed within the above parameter range. The outer ring power is selected from a fixed value between 1000-1500 watts, and the shielding gas flow rate is selected from a fixed value between 0.1-0.3 MPa. The actual penetration depth under different combinations of laser welding process parameters is measured, and a dataset of welding power, defocusing amount, welding speed, and corresponding actual penetration depth values ​​is established. Finally, a penetration depth prediction formula is obtained by fitting the data. like Figure 2 As shown, 13 sets of test sample data were selected, and the data combinations of welding power, decoking amount, and welding speed in each set of test sample data were substituted into the penetration depth prediction formula. The predicted melt depth was obtained, and a comparative analysis was conducted between the predicted and actual melt depth values. The results show that the predicted melt depth calculated using this melt depth prediction formula exhibits good consistency with the actual melt depth value, where R... 2A value of 0.963 indicates that the melting depth prediction formula... It has good fitting performance and is suitable for laser welding between aluminum shells and cover plates of lithium-ion batteries. It can accurately predict the penetration depth based on the welding power, defocusing amount and welding speed of laser welding.

[0047] In one embodiment of the present invention, the step of laser welding a target object according to the instruction includes: laser welding the target object along a preset welding trajectory based on the welding power, defocusing amount, and welding speed corresponding to the predicted penetration depth value that meets a predetermined standard. Specifically, after the predicted penetration depth value meets the predetermined standard, laser welding is performed along the preset welding trajectory using the welding power, defocusing amount, and welding speed corresponding to the predicted penetration depth value that meets the standard. The preset welding trajectory includes a series of spatial coordinates corresponding to the welding position, which can be obtained through image scanning or tracking acquisition.

[0048] In one embodiment of the present invention, the step of receiving a command to start laser welding when the predicted penetration depth meets a predetermined standard includes: obtaining a standard penetration depth value and the standard deviation of the standard penetration depth value; and receiving a command to start laser welding when the difference between the predicted penetration depth value and the standard penetration depth value does not exceed a preset multiple of the standard deviation of the standard penetration depth value. The standard penetration depth value used to reflect welding quality requirements typically varies depending on the welding application scenario. Specifically, multiple penetration depth values ​​that meet welding quality requirements can be collected by actually performing laser welding, and the standard penetration depth value and its standard deviation can be calculated. The preset multiple of the standard deviation reflects the welding quality requirements, i.e., the allowable range of difference between the predicted penetration depth value and the standard penetration depth value.

[0049] In one embodiment of the present invention, the preset multiple is greater than 2 and less than 4. Specifically, the preset multiple can be set to 3, that is, when the difference between the predicted penetration value calculated using the preset model and the standard penetration value does not exceed 3 times the standard deviation, the predicted penetration value is considered to meet the quality standard of laser welding. The preset multiple can also be set to 2.5 or 3.5, that is, when the difference between the predicted penetration value calculated using the preset model and the standard penetration value does not exceed 2.5 times or 3.5 times the standard deviation, the predicted penetration value is considered to meet the quality standard of laser welding. The preset multiple being greater than 2 and less than 4 not only improves the welding qualification rate of laser welding performed according to the welding power, defocusing amount, and welding speed and other process parameters corresponding to the predicted penetration value that meets this standard, but also reduces the operational difficulty of the laser welding process parameter debugging stage to a certain extent, thereby balancing the welding quality and operational efficiency of the laser welding process.

[0050] like Figure 3 As shown, a laser welding apparatus 100 provided in one embodiment of the present invention includes:

[0051] Module 10 is used to acquire the process parameters required for laser welding;

[0052] Calculation module 20 is used to calculate the predicted melting depth value based on the process parameters using a preset model;

[0053] The receiving module 30 is used to receive a command to start laser welding when the predicted penetration value meets a predetermined standard.

[0054] And a laser welding module 40, used to perform laser welding on the target object according to the instructions.

[0055] The laser welding device 100 provided in this embodiment of the invention uses its calculation module 20 to predict the penetration depth based on the specific process parameters of laser welding, thereby estimating the quality of laser welding and guiding the adjustment of the process parameters of laser welding. This eliminates the need for repeated trial and error during actual welding operations to obtain laser welding process parameters that meet the standards, thereby reducing the labor, time, and material costs of laser welding debugging and improving the operational efficiency of the laser welding process.

[0056] In one embodiment of the present invention, the process parameters acquired by the acquisition module 10 include at least one of welding power, decoking amount, welding speed, welding trajectory, outer ring power, and shielding gas flow rate.

[0057] In one embodiment, the preset model of the calculation module 20 includes Where Y represents the predicted penetration depth, P represents the welding power, Z represents the decoking amount, v represents the welding speed, A represents the coefficient term, and B, C, and D represent the constant terms. This is the preset model. Applicable to various laser welding situations, specifically, the values ​​of A, B, C, and D can be obtained by collecting actual penetration values ​​under different welding power, defocusing amount, and welding speed conditions through actual welding experiments, and then inputting multiple sets of data into the preset model. By fitting the data, a formula for predicting the penetration depth that fits the corresponding welding conditions is obtained.

[0058] In one embodiment of the present invention, the laser welding module 40 is used to perform laser welding on a target object along a preset welding trajectory based on the welding power, defocusing amount, and welding speed corresponding to the predicted penetration depth value that conforms to the predetermined standard. Specifically, the laser welding module 40 includes a laser generator and a controller, which can control the laser generator to perform laser welding operations according to the acquired process parameters such as welding power, defocusing amount, welding speed, and welding trajectory.

[0059] One embodiment of the present invention provides a computer-readable storage medium storing program code, the program code being used to cause a computer to execute the laser welding method described in this embodiment of the present invention. For example, the program code can perform the following steps:

[0060] Obtain the process parameters required for laser welding;

[0061] The predicted melting depth is calculated using a preset model based on the process parameters.

[0062] If the predicted penetration depth meets the predetermined standard, a command to start laser welding is received;

[0063] Laser welding is performed on the target object according to the instructions.

[0064] The computer-readable storage medium can be any available medium that a computer can access, or a data storage device such as a server or data center that includes one or more sets of available media. The available media can be magnetic media (e.g., floppy disks, hard disks, magnetic tapes), optical media (e.g., digital video discs (DVDs)), or semiconductor media (e.g., solid-state drives (SSDs)).

[0065] The instructions of the program code can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the instructions of the program code can be transmitted from a website, computer, or server to the laser welding device via wired (e.g., coaxial cable, optical fiber, Digital Subscriber Line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means.

[0066] Those skilled in the art will recognize that the algorithmic steps and modules of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution.

[0067] The embodiments of the present invention have been described in detail above. The content of this specification should not be construed as limiting the scope of protection of the present invention.

Claims

1. A laser welding method, characterized in that, Includes the following steps: Obtain the process parameters required for laser welding, including welding power, defocusing amount, and welding speed; The predicted melting depth is calculated using a preset model based on the process parameters. If the predicted penetration depth meets the predetermined standard, a command to start laser welding is received; Perform laser welding on the target object according to the instructions; The preset model is a physical analytical model based on the principle of energy conservation, establishing the relationship between welding power, decoking amount, welding speed, and penetration depth. The physical analytical model is as follows: Where Y represents the predicted penetration depth, P represents the welding power, Z represents the decoking amount, v represents the welding speed, A represents the coefficient term, and B, C, and D represent the constant terms. Multiple actual penetration depth values ​​are obtained, and the values ​​of A, B, C, and D are calculated by fitting the actual penetration depth values ​​and the corresponding welding power, decoking amount, and welding speed. The step of calculating the predicted penetration depth using a preset model based on the process parameters includes: calculating the predicted penetration depth using the physical analytical model after fitting calculation based on the welding power, the decoking amount, and the welding speed.

2. The laser welding method according to claim 1, characterized in that, The welding power is 800-1500 watts, and the decoking amount is... The weld length is 3 to +3 mm, and the welding speed is 80 to 200 mm / s.

3. The laser welding method according to claim 1, characterized in that, The steps for performing laser welding on the target object according to the instructions include: Based on the welding power, defocusing amount, and welding speed corresponding to the predicted penetration value that meets the predetermined standard, laser welding is performed on the target object along a preset welding trajectory.

4. The method according to claim 3, characterized in that, The preset welding trajectory includes a series of spatial coordinates corresponding to the welding position, which can be obtained through image scanning or tracking acquisition.

5. The laser welding method according to any one of claims 1 to 4, characterized in that, If the predicted penetration depth meets the standard, the steps for receiving the instruction to start welding include: Obtain the standard value of the melt depth and the standard deviation of the standard value of the melt depth; If the difference between the predicted penetration value and the standard penetration value does not exceed a preset multiple of the standard deviation of the standard penetration value, a welding start command is received.

6. The method according to claim 5, characterized in that, The method further includes: Collect multiple penetration depth values ​​that meet welding quality requirements, and calculate the standard deviation of the penetration depth standard values.

7. The laser welding method according to claim 5, characterized in that, The preset multiple is greater than 2 and less than 4.

8. A laser welding apparatus, characterized in that, include: The acquisition module is used to acquire the process parameters required for laser welding, including welding power, defocusing amount, and welding speed. The calculation module is used to calculate the predicted weld penetration based on the process parameters using a preset model. The preset model is a physical analytical model established based on the principle of energy conservation, relating welding power, decoking amount, welding speed, and weld penetration. The physical analytical model is as follows: Where Y represents the predicted penetration depth, P represents the welding power, Z represents the defocusing amount, v represents the welding speed, A represents the coefficient term, and B, C, and D represent the constant term. Multiple actual penetration depth values ​​obtained through actual laser welding measurements are acquired, and the values ​​of A, B, C, and D are calculated by fitting. The receiving module is used to receive a command to start laser welding when the predicted penetration value meets a predetermined standard. as well as A laser welding module is used to perform laser welding on a target object according to the instructions. The calculation module is specifically used to calculate the predicted penetration depth based on the welding power, the decoking amount, and the welding speed using a physical analytical model that has been fitted after calculation.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores program code that causes the laser welding apparatus to perform the laser welding method as described in any one of claims 1 to 7.

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