A method for laser focus calibration of a laser welding machine

Abstract

This application relates to the field of laser welding machine technology and discloses a method for laser focus calibration in a laser welding machine. The method includes: detecting and acquiring the weld position of a first steel plate and a second steel plate; calibrating the initial position of the laser spot based on the weld, such that the initial position is close to or at the center of the weld; shifting the laser spot to one side of the first steel plate and continuously performing cupping tests on the weld; stopping the cupping tests when the weld between the first and second steel plates cracks, and recording the first total shift; controlling the laser spot back to the initial position, shifting the laser spot to one side of the second steel plate, and continuously performing cupping tests on the weld; stopping the cupping tests when the weld between the first and second steel plates cracks, and recording the second total shift; calculating the center position of the weld based on the first and second total shifts. This application can accurately calibrate the position of the laser spot relative to the weld center, ensuring the stability of the welding quality.

Description

Technical Field

[0001] This application relates to the field of laser welding machine technology, and in particular, to a method for laser focus calibration of a laser welding machine. Background Technology

[0002] Laser welding machines are widely used in steel production lines with high continuity requirements, especially those with heat treatment processes. These lines demand a constant speed for the strip steel. Although loopers provide buffering, a single unsuccessful weld can still cause the production line to slow down and re-weld, resulting in scrap steel. Therefore, the stability of laser welding quality is crucial for continuous production. The stability of laser welding quality depends on the reliability of the overall functional precision of the welding machine. This overall functional precision is a complex and intricate system that ultimately ensures that the laser focus is located at the center of the weld at every point. Therefore, laser focus verification and calibration are essential steps in ensuring weld quality. Summary of the Invention

[0003] The purpose of this application is to provide a method for laser focus calibration of a laser welding machine. This application can accurately calibrate the position of the laser spot and the center of the weld, ensuring the stability of the welding quality of the welding machine.

[0004] Other features and advantages of this application will become apparent from the following detailed description, or may be learned in part from practice of this application.

[0005] According to one aspect of the embodiments of this application, a method for laser focus calibration of a laser welding machine is provided. The method includes: detecting and acquiring the weld position of a first steel plate and a second steel plate; calibrating the initial position of a laser spot according to the weld, such that the initial position is close to the center of the weld or such that the initial position is at the center of the weld; shifting the laser spot to one side of the first steel plate and continuously performing a cupping test on the weld; stopping the cupping test when the weld between the first steel plate and the second steel plate cracks, and recording a first total shift; controlling the laser spot to return to the initial position, shifting the laser spot to one side of the second steel plate, and continuously performing a cupping test on the weld; stopping the cupping test when the weld between the first steel plate and the second steel plate cracks, and recording a second total shift; calculating the center position of the weld based on the first total shift and the second total shift.

[0006] In some embodiments, before detecting and obtaining the weld position of the first steel plate and the second steel plate, the method further includes: obtaining the first steel plate and the second steel plate, and joining the first steel plate and the second steel plate together, wherein the joining point of the first steel plate and the second steel plate is the weld position.

[0007] In some embodiments, the GAP value at the joint between the first steel plate and the second steel plate is set to 0.

[0008] In some embodiments, in the process of shifting the laser spot to one side of the first steel plate and continuously performing cupping tests on the weld, the method includes: shifting the laser spot to one side of the first steel plate, shifting by a first displacement for the first time, shifting by a second displacement for the second time and each subsequent shift, and performing a cupping test on the weld after each shift of the laser spot.

[0009] In some embodiments, in controlling the laser spot to return to its initial position, shifting the laser spot to one side of the second steel plate, and continuously performing cupping tests on the weld, the method includes: shifting the laser spot to one side of the second steel plate, shifting by a first displacement amount the first time, and shifting by a second displacement amount the second time and each subsequent time, and performing a cupping test on the weld after each shift of the laser spot.

[0010] In some embodiments, the first displacement is set to 0.1 mm.

[0011] In some embodiments, the second displacement is set to 0.05 mm.

[0012] In some embodiments, in calculating the center position of the weld based on the first total offset and the second total offset, the method includes: calculating a reference value based on the first total offset and the second total offset; and moving the initial position of the laser spot according to the reference value to obtain a final position, the final position being the center of the weld.

[0013] In some embodiments, the reference value is calculated using the following formula when calculating the reference value based on the first offset total and the second offset total:

[0014] XY / 2=Z;

[0015] Where X is the first offset total, Y is the second offset total, and Z is the reference value.

[0016] In some embodiments, in moving the initial position of the laser spot according to the reference value, the method includes: when the Z value is positive, the initial position of the laser spot is shifted Z to one side of the first steel plate; when the Z value is negative, the initial position of the laser spot is shifted Z to one side of the second steel plate; when the Z value is 0, the initial position of the laser spot is at the center of the weld.

[0017] Compared with the prior art, the significant advantages of the technical solution of this application are as follows: This application can accurately calibrate the position of the laser spot and the weld center, ensuring the stability of the welding quality. It improves upon the error inherent in traditional methods of visually calibrating the laser focus position. By obtaining the first and second total offsets through a cupping test, a reference value is calculated based on the first and second total offsets, and the final position is determined using the reference value, thus more effectively ensuring the accuracy of laser spot calibration.

[0018] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0019] The above and other features and advantages of this application will become more apparent from a detailed description of exemplary embodiments thereof with reference to the accompanying drawings.

[0020] Figure 1 A flowchart illustrating a method for laser focus calibration of a laser welding machine according to an embodiment of this application is shown;

[0021] Figure 2 A schematic diagram of a structure according to an embodiment of this application is shown. Detailed Implementation

[0022] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided to make this application more comprehensive and complete, and to fully convey the concept of the exemplary embodiments to those skilled in the art.

[0023] Furthermore, the described features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. Numerous specific details are provided in the following description to give a thorough understanding of embodiments of this application. However, those skilled in the art will recognize that the technical solutions of this application can be practiced without one or more of the specific details, or other methods, components, apparatuses, steps, etc., can be employed. In other instances, well-known methods, apparatuses, implementations, or operations are not shown or described in detail to avoid obscuring various aspects of this application.

[0024] The block diagrams shown in the accompanying drawings are merely functional entities and do not necessarily correspond to physically independent entities. That is, these functional entities can be implemented in software, in one or more hardware modules or integrated circuits, or in different network and / or processor devices and / or microcontroller devices.

[0025] The flowcharts shown in the accompanying drawings are merely illustrative and do not necessarily include all content and operations / steps, nor do they necessarily have to be performed in the described order. For example, some operations / steps can be broken down, while others can be combined or partially combined; therefore, the actual execution order may change depending on the specific circumstances.

[0026] The stability of laser welding quality depends on the reliability of the overall functional precision of the welding machine. The overall functional precision of the laser welding machine is a complex and cumbersome precision system, which ultimately ensures that the laser focus is located at the center 4 of weld 3 at every point. Therefore, laser focus verification and calibration are crucial steps in ensuring the welding quality of weld 3.

[0027] The technical solutions of the embodiments of this application are briefly described below:

[0028] To address the aforementioned problems, this application provides a method for laser focus calibration of a laser welding machine, according to some embodiments, such as... Figure 1 As shown, the method includes:

[0029] Step 101: Detect and obtain the position of the weld 3 between the first steel plate 1 and the second steel plate 2;

[0030] Step 102: Determine the initial position of the laser spot according to the weld 3, so that the initial position is close to the center 4 of the weld 3 or the initial position is at the center 4 of the weld 3;

[0031] Step 103: Shift the laser spot to one side of the first steel plate 1 and continuously perform cupping tests on the weld 3;

[0032] Step 104: The cupping test is stopped when the weld 3 between the first steel plate 1 and the second steel plate 2 cracks, and the first offset total is recorded;

[0033] Step 105: Control the laser spot to return to the initial position, shift the laser spot to one side of the second steel plate 2, and continuously perform cupping tests on the weld 3;

[0034] Step 106: The cupping test is stopped when the weld 3 between the first steel plate 1 and the second steel plate 2 cracks, and the total second offset is recorded.

[0035] Step 107: Calculate the position of the center 4 of the weld 3 based on the first total offset and the second total offset.

[0036] Based on the above embodiments, such as Figure 2 As shown, prepare carbon steel plates of normal thickness and good shape. Note that the inlet and outlet clamps must be made of steel plates with the same thickness and material. Steel plates of different materials absorb laser heat differently, which will affect the judgment of the focal position.

[0037] Obtain a first steel plate 1 and a second steel plate 2, and connect them together. The connection point of the first steel plate 1 and the second steel plate 2 is the weld seam 3. Set the GAP value of the connection point of the first steel plate 1 and the second steel plate 2 to 0.

[0038] By observing with the naked eye or a magnifying glass, the initial position of the laser spot is roughly marked at the center 4 of weld 3.

[0039] The position of the laser spot is gradually shifted towards the entrance direction (that is, towards the first steel plate 1), and cupping tests are continuously performed on weld 3.

[0040] When the cupping test causes the weld 3 of the first steel plate 1 and the second steel plate 2 to crack, the cupping test is stopped, and the offset distance of the laser spot is recorded as the first total offset.

[0041] Then, the laser spot is controlled to return to its initial position and gradually shifted towards the exit direction (that is, towards the second steel plate 2), and cupping tests are performed on weld 3 again.

[0042] When the cupping test causes the weld 3 of the first steel plate 1 and the second steel plate 2 to crack, the cupping test is stopped, and the offset distance of the laser spot is recorded as the second total offset.

[0043] Finally, the position of the center 4 of weld 3 is calculated based on the first total offset and the second total offset.

[0044] This application can accurately pinpoint the position of the laser spot relative to the center 4 of the weld seam 3, ensuring the stability of the welding quality of the welding machine.

[0045] To enable those skilled in the art to better understand this application, the following will be combined with Figures 1 to 2 The details of this application are described in detail.

[0046] According to some embodiments, in step 103, during the process of shifting the laser spot to one side of the first steel plate 1 and continuously performing a cupping test on the weld 3, the method includes:

[0047] The laser spot is shifted to one side of the first steel plate 1. The first shift is by the first displacement, and the second shift and subsequent shifts are by the second displacement. After each shift of the laser spot, a cupping test is performed on the weld 3.

[0048] Based on the above embodiment, the laser spot is offset towards the entrance direction (i.e., towards the first steel plate 1). After the first offset of the laser spot, a cupping test is performed on weld 3. If the cupping test is qualified, the laser spot is offset a second time, and the cupping test is performed on weld 3 again. If the cupping test is qualified, the laser spot is offset a third time, and the cupping test is performed on weld 3 again. If the cupping test performed on weld 3 after the third offset of the laser spot is unqualified, weld 3 will crack. At this time, the cupping test is stopped, and the offset distance of the laser spot is recorded as the first offset total.

[0049] According to some embodiments, in step 105, during the process of controlling the laser spot to return to its initial position, shifting the laser spot to one side of the second steel plate 2, and continuously performing a cupping test on the weld 3, the method includes:

[0050] The laser spot is shifted to one side of the second steel plate 2. The first shift is by the first displacement, and the second shift and subsequent shifts are by the second displacement. After each shift of the laser spot, a cupping test is performed on the weld 3.

[0051] Based on the above embodiment, the laser spot is controlled to return to its initial position, and then offset towards the exit direction (i.e., towards the second steel plate 2). After the first offset, a cupping test is performed on weld 3. If the cupping test is successful, the laser spot is offset a second time, and the cupping test is performed on weld 3 again. If the cupping test is successful, the laser spot is offset a third time, and the cupping test is performed on weld 3 again. If the cupping test on weld 3 fails after the third offset, weld 3 will crack. At this time, the cupping test is stopped, and the offset distance of the laser spot is recorded as the second total offset.

[0052] The first displacement and the second displacement can be set according to actual needs. In some embodiments, the first displacement is set to 0.1 mm and the second displacement is set to 0.05 mm.

[0053] According to some embodiments, in step 107, the method for calculating the center 4 position of weld 3 based on the first offset total and the second offset total includes:

[0054] The reference value is calculated based on the first total offset and the second total offset;

[0055] The initial position of the laser spot is moved according to the reference value to obtain the final position, which is the center 4 of the weld 3.

[0056] Based on the above embodiments, in calculating the reference value according to the first total offset and the second total offset, the reference value is calculated using the following formula:

[0057] (XY) / 2 = Z;

[0058] Where X is the first offset total, Y is the second offset total, and Z is the reference value.

[0059] Furthermore, in moving the initial position of the laser spot according to the reference value, the method includes:

[0060] When the Z value is positive, the initial position of the laser spot is shifted by Z to one side of the first steel plate 1;

[0061] When the Z value is negative, the initial position of the laser spot shifts to one side of the second steel plate 2 by Z.

[0062] When the Z value is 0, the initial position of the laser spot is the center 4 of the weld 3.

[0063] After the offset is completed, the final position is obtained, which is at the center 4 of weld 3.

[0064] This application can accurately calibrate the position of the laser spot relative to the center 4 of the weld seam 3, ensuring the stability of the welding quality. It improves upon the error inherent in traditional methods of visually calibrating the laser focus position. By obtaining the first and second total offsets through a cupping test, a reference value is calculated based on the first and second total offsets, and the final position is determined using the reference value, thus more effectively ensuring the accuracy of the laser spot calibration.

[0065] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the embodiments disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein.

[0066] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. A method for calibrating the laser focus of a laser welding machine, characterized in that, The method includes: The location of the weld seam between the first and second steel plates is obtained through detection. The initial position of the laser spot is determined according to the weld, such that the initial position is close to the center of the weld or such that the initial position is at the center of the weld; The laser spot is shifted to one side of the first steel plate, and cupping tests are continuously performed on the weld. The cupping test was stopped when the weld between the first and second steel plates cracked, and the total first offset was recorded. The laser spot is controlled to return to its initial position, and then shifted to one side of the second steel plate. Cupping tests are then performed on the weld continuously. The cupping test was stopped when the weld between the first and second steel plates cracked, and the total second offset was recorded. The center position of the weld is calculated based on the first total offset and the second total offset. Before detecting and obtaining the weld positions of the first and second steel plates, the method further includes: Obtain a first steel plate and a second steel plate, and connect the first steel plate and the second steel plate together. The connection point between the first steel plate and the second steel plate is the weld position. In the process of offsetting the laser spot to one side of the first steel plate and continuously performing cupping tests on the weld, the method includes: The laser spot is shifted to one side of the first steel plate. The first shift is by the first displacement, and the second shift and subsequent shifts are by the second displacement. After each shift of the laser spot, a cupping test is performed on the weld. In the process of controlling the laser spot to return to its initial position, shifting the laser spot to one side of the second steel plate, and continuously performing cupping tests on the weld, the method includes: The laser spot is shifted to one side of the second steel plate. The first shift is by the first displacement, and the second shift and subsequent shifts are by the second displacement. After each shift of the laser spot, a cupping test is performed on the weld.

2. The method according to claim 1, characterized in that, The GAP value at the joint between the first steel plate and the second steel plate is set to 0.

3. The method according to claim 1, characterized in that, The first displacement is set to 0.1 mm.

4. The method according to claim 3, characterized in that, The second displacement is set to 0.05 mm.

5. The method according to claim 4, characterized in that, In calculating the center position of the weld based on the first total offset and the second total offset, the method includes: The reference value is calculated based on the first total offset and the second total offset; The initial position of the laser spot is moved according to the reference value to obtain the final position, which is the center of the weld.

6. The method according to claim 5, characterized in that, In calculating the reference value based on the first total offset and the second total offset, the reference value is calculated using the following formula: (XY) / 2 = Z; Where X is the first offset total, Y is the second offset total, and Z is the reference value.

7. The method according to claim 6, characterized in that, In moving the initial position of the laser spot according to the reference value, the method includes: When the Z value is positive, the initial position of the laser spot is shifted by Z to one side of the first steel plate; When the Z value is negative, the initial position of the laser spot shifts to one side of the second steel plate by Z. When the Z value is 0, the initial position of the laser spot is at the center of the weld.

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