A laser signal conversion structure and a laser welding quality monitoring device

Abstract

The application belongs to the technical field of laser welding and relates to a laser signal conversion structure and a laser welding quality monitoring device. The laser signal conversion structure comprises: an attenuation member for reducing the light intensity of laser; a light focusing member for focusing laser; a light filtering member for filtering laser; a first collimating member for converting the focused laser into parallel light beams; and a light signal conversion member for receiving the laser passing through the first collimating member and converting the light signal into an electric signal. In the first direction, the attenuation member, the light focusing member, the light filtering member and the light signal conversion member are sequentially distributed, and the first collimating member is arranged between the light filtering member and the light focusing member or between the light signal conversion member and the light filtering member. The laser attenuation member attenuates the light intensity, and then the light is focused by the light focusing member. Then, the light filtering member controls the beam cross-sectional size of the laser, thereby eliminating stray light. Finally, the first collimating member converts the diffused state into a straight state until the light signal conversion member receives it.

Description

Technical Field

[0001] This application relates to the field of laser welding technology, and more specifically, to a laser signal conversion structure and a laser welding quality monitoring device. Background Technology In existing laser processing technologies, in order to detect various parameters of the laser in real time and determine whether the laser is in a preset working state, it is usually necessary to receive the laser through a sensor, convert the laser light signal into a physical quantity, and then determine the state of the laser through the physical quantity.

[0002] However, due to the high intensity and wide irradiation range of lasers, sensors typically cannot directly receive the laser light during laser processing, or even the sub-lasers split from it. Therefore, existing technologies cannot accurately acquire the laser's optical signal, leading to inaccurate assessments of the laser's operating state and ultimately resulting in low-quality and inefficient laser-processed products. Utility Model Content

[0003] The technical problem to be solved by the embodiments of this application is that when existing sensors receive lasers, the laser intensity and irradiation range do not meet the requirements, resulting in the inability to accurately obtain the laser state.

[0004] To solve the above-mentioned technical problems, the embodiments of this application adopt the following solutions: A laser signal conversion structure for converting laser light into an electrical signal, comprising: Attenuation components are used to reduce the intensity of laser light. A focusing element for focusing the laser beam; A filter element for filtering the laser light; The first collimator is used to convert the focused laser into a parallel beam. An optical signal converter is used to receive laser light passing through the first collimator and convert the optical signal into an electrical signal; In this configuration, along the first direction, the attenuator, the focusing element, the filter, and the optical signal conversion element are distributed sequentially, and the first collimator is disposed between the filter and the focusing element, or the first collimator is disposed between the optical signal conversion element and the filter.

[0005] Furthermore, the laser signal conversion structure also includes a light homogenizer, which is disposed between the optical signal conversion element and the filter element.

[0006] Furthermore, the focusing element is a plano-convex lens, the filter element is an aperture stop, the first collimator is a biconcave lens, and the first collimator is disposed between the filter element and the focusing element.

[0007] Furthermore, the laser signal conversion structure also includes a first driving member, which is connected to the optical signal conversion member and is used to drive the optical signal conversion member to move along a direction perpendicular to the laser.

[0008] Furthermore, the laser signal conversion structure also includes a control component, the optical signal conversion component includes a receiving area and a sensing area, the sensing area is arranged around the receiving area, and the receiving area is used to receive the laser; When the sensing area detects laser irradiation, the control unit controls the first driving unit to drive the optical signal conversion unit to move until the sensing area no longer detects laser irradiation.

[0009] Furthermore, the aforementioned focusing element is a plano-convex lens, the filtering element is an aperture stop, and the first collimating element is a plano-convex lens, located between the filtering element and the optical signal conversion element.

[0010] Furthermore, the laser signal detection structure also includes a second driving member, which is connected to the filter and is used to drive the filter to move between the attenuator and the optical signal conversion member.

[0011] Furthermore, the first collimator includes a first sub-collimator, a second sub-collimator, and a third sub-collimator, which are sequentially distributed along the direction from the attenuator to the optical signal conversion device. The first sub-collimator and the third sub-collimator are biconvex lenses. The second sub-collimator includes a convex surface and a concave surface. The convex surface faces the first sub-collimator, and the concave surface is disposed relative to the convex surface and faces inward toward the second sub-collimator.

[0012] Accordingly, this application also provides a laser welding quality monitoring device, which includes the laser signal conversion structure described in any of the above embodiments.

[0013] Furthermore, the laser welding quality monitoring device also includes a laser head, a reflector, multiple linearly distributed beam splitters, and multiple laser signal conversion structures. The laser signal conversion structures and the beam splitters are arranged in a one-to-one correspondence. The laser head is used to emit a detection laser, the reflector is used to reflect the laser to the multiple beam splitters, and the beam splitters are used to split the laser, with at least a portion of the split laser irradiating the corresponding laser signal conversion structure.

[0014] Compared with the prior art, the embodiments of this application have the following main advantages: In this application, the laser attenuator attenuates the light intensity; then, it is focused by the focusing element so that its irradiation range is located within the sensing area of ​​the optical signal converter; next, the filter element controls the size of the laser beam cross-section, thereby eliminating stray light; finally, the first collimator converts it from a diffused state to a direct state, so that the laser accurately irradiates the sensing area of ​​the optical signal converter, and the light intensity is equal at all points in the sensing area. Attached Figure Description

[0015] To more clearly illustrate the solutions in this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the optical signal conversion structure of this application when the collimator is located between the filter and the focusing element; Figure 2 This is a schematic diagram of the optical signal conversion structure of this application when the collimator is located between the filter and the optical signal conversion component; Figure 3 This is a schematic diagram of the optical signal conversion structure of this application when the collimator includes a first sub-collimator, a second sub-collimator, and a third sub-collimator. Figure 4 This is a schematic diagram of the structure of the laser welding quality monitoring device of this application when the collimator is located between the filter and the optical signal conversion device; Figure 5 This is a schematic diagram of the structure of the laser welding quality monitoring device of this application when the collimator is located between the filter and the optical signal conversion device.

[0017] Figure label: 10. Workpiece processing; 20. Focused beam; 21. Laser; 30. Laser head; 40. Second collimator; 50. Beam splitter; 60. Reflector; 100. Attenuator; 200. Focusing beam; 300. Filter; 400. Optical signal converter; 500. First collimator; 510. First sub-collimator; 520. Second sub-collimator; 530. Third sub-collimator; 600. Beam homogenizer. Detailed Implementation

[0018] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. Furthermore, it should be understood that the specific embodiments described herein are only for illustration and explanation of this application and are not intended to limit this application.

[0019] In this application, unless otherwise stated, directional terms such as "upper" and "lower" generally refer to the upper and lower positions of the device in its actual use or operating state, specifically the orientation shown in the accompanying drawings; while "inner" and "outer" refer to the outline of the device. Furthermore, in the description of this application, the term "comprising" means "including but not limited to". The terms first, second, third, etc., are used merely as illustrative purposes and do not impose numerical requirements or establish a numerical order.

[0020] In this application, "and / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. A and B can be singular or plural.

[0021] In this application, "at least one" means one or more, and "more than one" means two or more. "At least one," "at least one of the following," or similar expressions refer to any combination of these items, including any combination of single or multiple items. For example, "at least one of a, b, or c," or "at least one of a, b, and c," can both mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple.

[0022] Various embodiments of this application may exist in the form of a range; it should be understood that the description in the form of a range is merely for convenience and brevity and should not be construed as a rigid limitation on the scope of this application; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single numerical values ​​within that range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and single numbers within the range, such as 1, 2, 3, 4, 5, and 6, regardless of the range. Furthermore, whenever a numerical range is referred to herein, it means including any referenced number (fraction or integer) within the referred range.

[0023] Please refer to Figures 1-2This application provides a laser signal conversion structure for converting laser 21 into an electrical signal, comprising: Attenuator 100 is used to reduce the light intensity of laser 21; Concentrator 200, used for focusing laser 21; Filter element 300 is used to filter laser 21; The first collimator 500 is used to convert the focused laser 21 into a parallel beam. The optical signal converter 400 is used to receive the laser 21 passing through the first collimator 500 and convert the optical signal into an electrical signal. Along the first direction, the attenuator 100, the focusing element 200, the filter element 300, and the optical signal conversion element are distributed in sequence. The first collimator 500 is disposed between the filter element 300 and the focusing element 200, or the first collimator 500 is disposed between the optical signal conversion element 400 and the filter element 300.

[0024] In this embodiment, firstly, during the process of the laser 21 passing through the laser signal conversion structure, its intensity is attenuated by the attenuator 100, thereby preventing excessive light intensity from damaging the optical signal conversion device 400 or reducing detection accuracy; secondly, it also prevents the surface substrate of the filter 300 and the first collimator 500 from heating and deforming after being irradiated by the laser 21, thereby preventing a reduction in the service life of the laser signal conversion structure; then, after the laser 21 is attenuated by the attenuator 100, it can still be focused by the focusing device 200, so that its irradiation range is within the sensing area of ​​the optical signal conversion device 400, thereby preventing the laser 21 from irradiating the other circuit components of the optical signal conversion device 400 and affecting the accuracy and service life of the optical signal conversion device 400; then, the filter 300 can further control the beam cross-section size of the laser 21, thereby eliminating stray light and making the irradiation range and intensity of the laser 21 conform to the sensing area of ​​the optical signal conversion device 400; finally, the first collimator 500 in Figure 1 or Figure 2 When positioned as shown, it can convert the laser 21 from the focusing element 200 or the filter element 300 from a diffused state to a direct state, thereby ensuring that the laser 21 accurately illuminates the sensing area of ​​the optical signal conversion element 400, and that the light intensity is equal at all points in the sensing area.

[0025] In summary, the optical signal conversion structure of this embodiment can effectively reduce the light intensity of the laser 21 and control the irradiation range of the laser 21, so that the optical signal conversion unit 400 can accurately obtain the current information of the laser 21, thereby improving the processing quality of the laser 21.

[0026] It should be understood that the attenuator 100 can be a center density filter, which can absorb part of the light energy and convert it into heat, thereby reducing the light intensity, or reduce the light intensity by reflecting the light signal, or reduce the light intensity by scattering the laser 21 through a rough surface.

[0027] Further, please refer to Figure 1 and Figure 2 The laser signal conversion structure also includes a light homogenizer 600, which is disposed between the optical signal conversion component 400 and the filter component 300.

[0028] In this embodiment, firstly, the homogenizer 600 can homogenize the laser 21 filtered by the light filter 300, making the light intensity distribution more uniform; secondly, the homogenizer 600 can also eliminate hot spots or dark areas in the laser 21 beam, avoiding damage to the optical signal converter 400 caused by excessive local energy; then, the uniform light intensity distribution makes the signal received by the optical signal converter 400 more stable and reliable, improving the accuracy and consistency of electrical signal conversion, and ultimately improving the accuracy of laser 21 processing quality detection.

[0029] Further, please refer to Figure 1 The focusing element 200 is a plano-convex lens, the filter element 300 is an aperture stop, and the first collimator 500 is a biconcave lens. The first collimator 500 is disposed between the filter element 300 and the focusing element 200.

[0030] In this embodiment, firstly, using a plano-convex lens as a focusing element 200 can effectively focus the laser 21 and improve energy utilization; secondly, using an aperture as a filter element 300 can precisely control the beam diameter and effectively block stray light interference; then, a biconcave lens as a first collimator 500 is located between the filter element 300 and the focusing element 200. It has a negative focal length, which can reduce optical distortions such as spherical aberration that may occur in the subsequent optical path due to an excessively large beam convergence angle, so that the laser 21 can more accurately illuminate the sensing area of ​​the optical signal conversion element 400 and improve the stability of the detection signal.

[0031] It should be understood that the focusing element 200 can also be a biconvex lens. Compared with a biconvex lens, a plano-convex lens has a higher aberration, thus producing a smaller light spot, so as to focus the laser 21 onto the receiving area of ​​the optical signal converter.

[0032] Further, please refer to Figure 1 The laser signal conversion structure also includes a first driving element, which is connected to the optical signal conversion element 400 and is used to drive the optical signal conversion element 400 to move in a direction perpendicular to the laser 21.

[0033] In this embodiment, firstly, the first driving component can fine-tune the position of the optical signal converter 400 to ensure that its sensing area is accurately aligned with the laser beam 21; secondly, this design can compensate for installation errors or positional deviations caused by long-term use, thereby improving the reliability of the system; and thirdly, the adjustable position of the optical signal converter 400 enables it to adapt to the detection requirements of laser 21 with different power or modes, enhancing the applicability and flexibility of the entire laser signal conversion structure.

[0034] Further, please refer to Figure 1 The laser signal conversion structure also includes a control component. The optical signal conversion component 400 includes a receiving area and a sensing area. The sensing area is arranged around the receiving area, and the receiving area is used to receive the laser 21. When the sensing area detects laser 21 irradiation, the control unit controls the first driving unit to drive the optical signal conversion unit to move until the sensing area no longer detects laser 21 irradiation.

[0035] In this embodiment, firstly, the sensing area serves as a position deviation detection unit, which can monitor in real time whether the laser 21 deviates from the receiving area; secondly, the control unit cooperates with the first driving unit to achieve closed-loop control, ensuring that the laser 21 always accurately illuminates the center of the receiving area, thereby improving the automation level and long-term stability of the detection system.

[0036] Further, please refer to Figure 2 The aforementioned focusing element 200 is a plano-convex lens, the filter element 300 is an aperture stop, and the first collimator 500 is a plano-convex lens, located between the filter element 300 and the optical signal conversion element 400.

[0037] In this embodiment, firstly, the plano-convex lens serves as the first collimator 500 and is located after the filter 300, which can effectively convert the diffused laser 21 into a parallel beam; secondly, when the plano-convex lens serves as the first collimator 500, it has good optical stability and wear resistance, thus improving the service life and reliability of the entire laser signal conversion structure, while ensuring the collimation effect of the laser 21.

[0038] Further, please refer to Figure 2 The laser 21 signal detection structure also includes a second driving element, which is connected to the filter element 300 and is used to drive the filter element 300 to move between the attenuator element 100 and the optical signal conversion element (X direction in the figure).

[0039] In this embodiment, firstly, the second driving member can precisely adjust the position of the filter 300, thereby controlling the effective aperture through which the light beam passes; secondly, this design allows for dynamic adjustment of the filtering effect according to the power of the laser 21 and the detection requirements, improving the adaptability of the system; and thirdly, the movable filter 300 can optimize the beam quality, reduce stray light interference, and further improve the accuracy of optical signal conversion and the signal-to-noise ratio.

[0040] Further, please refer to Figure 3 The first collimator 500 includes a first sub-collimator 510, a second sub-collimator 520, and a third sub-collimator 530. Along the direction from the attenuator 100 to the optical signal conversion device, the first sub-collimator 510, the second sub-collimator 520, and the third sub-collimator 530 are distributed sequentially. The first sub-collimator 510 and the third sub-collimator 530 are biconvex lenses. The second sub-collimator 520 includes a convex surface and a concave surface. The convex surface faces the first sub-collimator 510, and the concave surface is disposed relative to the convex surface and faces inward toward the second sub-collimator 520.

[0041] In this embodiment, the plano-convex lens has a better spherical aberration correction effect than the biconvex lens, but its processing cost and assembly requirements are higher. In this embodiment, by inserting the concave surface of the second sub-collimator 520 between the two biconvex lenses, negative spherical aberration can be introduced to compensate for the positive spherical aberration caused by the first sub-collimator 510 and the second sub-collimator 520, thereby reducing the wavefront distortion of the laser beam 21 to a smaller range. This improves the accuracy of the laser 21 received by the optical signal conversion device at a lower cost, thereby improving the processing quality.

[0042] It should be understood that after passing through the first two lenses, the beam has been initially collimated. The curvature of the third sub-collimator 530 is reduced, resulting in a gentler converging effect on the beam. This helps to obtain an output beam with higher parallelism and more uniform energy distribution, thus improving the accuracy of optical signal conversion. Therefore, the convexity of the third sub-collimator 530 can be less than that of the first sub-collimator 510.

[0043] Accordingly, this application also provides a laser welding quality monitoring device, which includes the laser signal conversion structure of any of the above embodiments.

[0044] In this embodiment, since the laser welding quality monitoring device includes the laser signal conversion structure of any of the above embodiments, the laser 21 is attenuated by the attenuator 100 during its passage through the laser signal conversion structure, thereby preventing excessive light intensity from damaging the optical signal conversion component 400 or reducing detection accuracy. Secondly, it also prevents the surface substrate of the filter 300 and the first collimator 500 from heating and deforming after being irradiated by the laser 21, thereby preventing a reduction in the service life of the laser signal conversion structure. Then, after the laser 21 is attenuated by the attenuator 100, it can still be focused by the focusing component 200, so that its irradiation range is within the sensing area of ​​the optical signal conversion component 400, thereby preventing the laser 21 from irradiating the other circuit components of the optical signal conversion component 400 and affecting the accuracy and service life of the optical signal conversion component 400. Then, the filter 300 can further control the beam cross-section size of the laser 21, thereby eliminating stray light and making the irradiation range and intensity of the laser 21 conform to the sensing area of ​​the optical signal conversion component 400. Finally, the first collimator 500 in Figure 1 or Figure 2 When positioned as shown, it can convert the laser 21 from the focusing element 200 or the filter element 300 from a diffused state to a direct state, thereby ensuring that the laser 21 accurately illuminates the sensing area of ​​the optical signal conversion element 400, and that the light intensity is equal at all points in the sensing area.

[0045] In summary, the laser welding quality monitoring device of this embodiment has an accurate detection structure and a long service life, which can effectively improve the quality and efficiency of laser welding.

[0046] Furthermore, the laser welding quality monitoring device also includes a laser head 30, a reflector 60, multiple linearly distributed beam splitters 50, and multiple laser signal conversion structures. The laser signal conversion structures and beam splitters 50 are arranged in a one-to-one correspondence. The laser head 30 is used to emit a detection laser 21, the reflector 60 is used to reflect the laser 21 to the multiple beam splitters 50, the beam splitters 50 are used to split the laser 21, and at least a portion of the split laser 21 irradiates the corresponding laser signal conversion structure.

[0047] In this embodiment, firstly, the parallel design of multiple laser signal conversion structures enables multi-point synchronous detection of laser 21, improving detection efficiency; secondly, the beam splitter 50 system can reasonably distribute a beam of laser 21 to each detection unit, ensuring detection consistency; finally, this design can also disperse the light intensity of laser 21.

[0048] It should be understood that, such as Figure 4 and Figure 5As shown, a workpiece 10 can be placed below the laser head 30, and the workpiece 10 is processed by the focused beam 20 emitted by the laser head 30. During the processing, a portion of the focused beam 20 can be reflected and detected by the laser signal conversion structure as laser 21 in the above embodiment; alternatively, the laser head 30 can split the focused beam 20 and laser 21 in the above embodiment according to a certain ratio, and this portion of laser 21 is reflected by the reflector 60. In this case, the actual power and working condition of the focused beam 20 can be obtained by calculating the ratio. A second collimator 40 can also be provided between the reflector 60 and the first beam splitter 50 in contact with the laser 21 to improve the laser 21.

[0049] Accordingly, this application also provides a laser welding quality inspection system, which includes a laser welding quality monitoring device, a data acquisition card, and a host computer as described in any of the above embodiments. After receiving the optical signal, the optical signal converter can process the optical signal into an electrical signal and transmit it to the data acquisition card. The data acquisition card then transmits the signal to the host computer and interacts with it. The host computer is connected to the laser head 30 to control the current processing power of the laser 21 in real time, thereby promptly eliminating processing problems and improving processing quality.

[0050] Obviously, the embodiments described above are only some embodiments of this application, not all embodiments. The accompanying drawings show preferred embodiments of this application, but do not limit the patent scope of this application. This application can be implemented in many different forms; rather, the purpose of providing these embodiments is to provide a more thorough and comprehensive understanding of the disclosure of this application. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing specific embodiments, or make equivalent substitutions for some of the technical features. Any equivalent structures made using the content of this application's specification and drawings, directly or indirectly applied to other related technical fields, are similarly within the scope of patent protection of this application.

[0051] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, combinations, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. A laser signal conversion structure for converting laser light into an electrical signal, characterized in that, include: Attenuation components are used to reduce the intensity of laser light. A focusing element for focusing the laser beam; A filter element for filtering the laser light; The first collimator is used to convert the focused laser into a parallel beam. An optical signal converter is used to receive laser light passing through the first collimator and convert the optical signal into an electrical signal; In this configuration, along the first direction, the attenuator, the focusing element, the filter, and the optical signal conversion element are distributed sequentially, and the first collimator is disposed between the filter and the focusing element, or the first collimator is disposed between the optical signal conversion element and the filter.

2. The laser signal conversion structure according to claim 1, characterized in that, The laser signal conversion structure further includes a light homogenizer, which is disposed between the optical signal conversion component and the filter component.

3. The laser signal conversion structure according to claim 1, characterized in that, The focusing element is a plano-convex lens, the filter element is an aperture stop, the first collimator is a biconcave lens, and the first collimator is disposed between the filter element and the focusing element.

4. The laser signal conversion structure according to claim 3, characterized in that, The laser signal conversion structure further includes a first driving element, which is connected to the optical signal conversion element and is used to drive the optical signal conversion element to move along a direction perpendicular to the laser.

5. The laser signal conversion structure according to claim 4, characterized in that, The laser signal conversion structure further includes a control component. The optical signal conversion component includes a receiving area and a sensing area. The sensing area is arranged around the receiving area, and the receiving area is used to receive the laser. When the sensing area detects laser irradiation, the control unit controls the first driving unit to drive the optical signal conversion unit to move until the sensing area no longer detects laser irradiation.

6. The laser signal conversion structure according to claim 1, characterized in that, The focusing element is a plano-convex lens, the filtering element is an aperture stop, and the first collimating element is a plano-convex lens, located between the filtering element and the optical signal conversion element.

7. The laser signal conversion structure according to claim 6, characterized in that, The laser signal detection structure further includes a second driving element, which is connected to the filter element and is used to drive the filter element to move between the attenuator element and the optical signal conversion element.

8. The laser signal conversion structure according to claim 1, characterized in that, The first collimator includes a first sub-collimator, a second sub-collimator, and a third sub-collimator. Along the direction from the attenuator to the optical signal conversion device, the first sub-collimator, the second sub-collimator, and the third sub-collimator are distributed sequentially. The first sub-collimator and the third sub-collimator are biconvex lenses. The second sub-collimator includes a convex surface and a concave surface. The convex surface faces the first sub-collimator, and the concave surface is disposed relative to the convex surface and faces inward toward the second sub-collimator.

9. A laser welding quality monitoring device, characterized in that, The laser welding quality monitoring device includes the laser signal conversion structure described in any one of claims 1 to 8.

10. The laser welding quality monitoring device according to claim 9, characterized in that, The laser welding quality monitoring device further includes a laser head, a reflector, multiple linearly distributed beam splitters, and multiple laser signal conversion structures. The laser signal conversion structures and beam splitters are arranged in a one-to-one correspondence. The laser head is used to emit a detection laser, the reflector is used to reflect the laser to the multiple beam splitters, and the beam splitters are used to split the laser, with at least a portion of the split laser irradiating the corresponding laser signal conversion structure.

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