Laser welding device and method capable of real-time monitoring of welding penetration

Abstract

The present invention discloses a laser welding device and method capable of real-time monitoring of welding penetration, belonging to the technical field of laser welding, comprising a laser processing module, a penetration measurement module and a control module. The device arranges the measuring light emitted by the penetration measurement module and the welding laser coaxially so that the measuring light can be accurately incident on the molten pool and reflect an echo signal, thereby avoiding measurement errors caused by optical path deviation. The control module is simultaneously connected to the penetration measurement module and the laser processing module, and utilizes high-frequency signal transmission and processing capabilities to quickly obtain the transmitted signal and the echo signal and calculate and analyze real-time penetration information. The device can also control the laser processing module to adjust parameters in time when the penetration is abnormal, so that the penetration is always maintained within the set range, thereby realizing high-precision real-time closed-loop feedback from measurement to control, greatly improving the stability and consistency of welding quality, reducing the scrap rate, and improving production efficiency.

Description

Technical Field

[0001] The present invention belongs to the technical field of laser welding, and in particular relates to a laser welding device and method capable of monitoring welding penetration in real time. Background Art

[0002] In the booming development of modern manufacturing, laser welding has been widely used in many fields such as automobile manufacturing, aerospace, and electronic equipment due to its significant advantages such as high precision, high speed, and small heat-affected zone. From the precision welding of automobile bodies to the connection of aircraft engine parts, to the assembly of tiny electronic components, laser welding plays an indispensable and key role.

[0003] During laser welding, the laser energy converges to a single point, forming a transient molten pool at the weld location. The depth of the molten pool (penetration) is a crucial parameter in laser welding and plays a decisive role in weld quality. Too shallow a penetration, and the weld joint may be insufficiently strong, potentially leading to serious quality issues such as loosening and breakage during product use. Excessive penetration can burn through the workpiece, resulting in material waste, increased production costs, and even damage to the integrity of the entire product structure. Therefore, monitoring penetration is generally necessary during laser welding.

[0004] At present, the monitoring of penetration depth generally includes the following methods: 1) Post-metallographic section analysis. Although it can provide relatively accurate penetration depth data, it is a destructive test and can only be performed on samples after welding. It cannot monitor the changes in penetration depth in real time during the welding process. It cannot remedy the quality problems that have already occurred in time. It can only be used for post-quality evaluation and process improvement reference, and cannot achieve real-time quality control of the welding process; 2) Methods based on photoelectric sensor monitoring, which mainly collect photoelectric signals during the welding process and indirectly infer the welding quality based on the signal fluctuation range. However, since it cannot directly obtain the exact value of penetration depth, its accuracy is greatly reduced. Once the photoelectric signal is interfered with by the outside world, such as welding The strong electromagnetic interference and plasma fluctuations generated during the process can easily lead to misjudgment, resulting in an incorrect assessment of the welding quality, which in turn affects the stability of the entire production process and the reliability of product quality; 3) Monitoring methods based on multi-band light radiation intensity, optical images, and sound waves, although they can reflect certain characteristics of the welding process to a certain extent, they all have a common fatal weakness - they are extremely susceptible to interference from the welding environment. In actual welding sites, factors such as high temperature, strong light, flying metal particles, diffuse welding smoke, and complex and changeable plasma are intertwined, seriously interfering with the accuracy and stability of these monitoring signals, making it difficult for them to work stably and reliably in complex industrial environments. Summary of the Invention

[0005] In response to one or more of the above-mentioned defects or improvement needs in the prior art, the present invention provides a laser welding device and method that can monitor the welding penetration in real time. It can realize dynamic monitoring of the welding penetration during the welding process and adjust the welding process parameters in real time according to the monitoring results, forming a closed-loop feedback control of the penetration measurement and welding parameter adjustment, so as to ensure the stability and consistency of the welding quality and improve production efficiency and product qualification rate.

[0006] To achieve the above objectives, one aspect of the present invention provides a laser welding device and method capable of real-time monitoring of welding penetration, which includes a laser processing module, a penetration measurement module, and a control module;

[0007] The laser processing module is connected to the control module and includes a motion module and a welding head module provided on the motion module, wherein the welding head module is used to emit welding laser, and the motion module is used to drive the welding head module to move along the welding direction of the workpiece;

[0008] The penetration measurement module is connected to the control module and the welding head module, and includes an FMCW laser radar sensor for continuously transmitting and receiving measurement light at high frequency, and the measurement light can pass through the welding head module and be incident into the molten pool coaxially with the welding laser;

[0009] The welding head module emits a welding laser to weld the workpiece, and the FMCW laser radar sensor emits a measuring light and feeds back a transmission signal to the control module. The measuring light hits the bottom of the molten pool and is reflected back to the FMCW laser radar sensor. The FMCW laser radar sensor feeds back an echo signal to the control module. The control module calculates and analyzes the penetration depth based on the time difference between the reflected signal and the echo signal, and issues corresponding control instructions to the laser processing module based on the penetration depth information, so that the penetration depth is always maintained within the set range during the welding process.

[0010] As a further improvement of the present invention, the penetration measurement module also includes a focusing component, which is arranged between the FMCW lidar sensor and the laser processing module and is connected to the welding head module to adjust the focus of the measuring light through the focusing component.

[0011] As a further improvement of the present invention, the focusing assembly includes a manual focusing unit, which preliminarily adjusts the focus of the measuring light to within the molten pool.

[0012] As a further improvement of the present invention, the focusing assembly also includes an automatic focusing unit, which includes a focusing mirror and a moving part. The focusing mirror is connected to the moving part, and the moving part is connected to the control module. The control module controls the moving part to drive the focusing mirror to move, and positions the focus of the measuring light so that the focus of the measuring light is always located in the molten pool.

[0013] As a further improvement of the present invention, the penetration measurement module further includes a signal transmission unit, which is arranged between the FMCW laser radar sensor and the focusing assembly and includes a fiber coupler, an optical fiber, and a fiber coupling point;

[0014] One end of the fiber coupler is connected to the FMCW lidar sensor, and the other end is connected to the optical fiber. The fiber coupler includes a collimator and a focusing lens arranged in sequence along the emission direction of the measurement light to couple the measurement light into the optical fiber. The optical fiber extends to the optical fiber coupling point, and the measurement light is transmitted through the optical fiber and diverges to the focusing assembly at the optical fiber coupling point.

[0015] As a further improvement of the present invention, the welding head module includes a welding laser, a collimating component, a beam splitter and a focusing component;

[0016] The welding laser is emitted along a first direction, and the collimating assembly is arranged in the first direction for converting the welding laser into a parallel beam;

[0017] The beam splitter is arranged at a certain angle to the first direction to reflect the parallel light beam in the second direction;

[0018] The focusing assembly is arranged in the second direction, and is used to focus the welding laser into a light spot on the workpiece;

[0019] The measuring light enters the welding head module along the second direction, is transmitted to the focusing component through the beam splitter, and is emitted into the molten pool by the focusing component.

[0020] As a further improvement of the present invention, the welding head module includes a welding laser, a collimating component, a beam splitter, a reflecting unit and a focusing component;

[0021] The welding laser is emitted along a second direction, and the collimating assembly is arranged in the second direction for converting the welding laser into a parallel beam;

[0022] The beam splitter is arranged at a certain angle to the second direction to reflect the parallel light beam to the first direction, and the welding laser is reflected to the focusing assembly through the reflection unit;

[0023] The focusing assembly is arranged in the second direction, and is used to focus the welding laser into a light spot on the workpiece;

[0024] The measuring light enters the welding head module along a first direction, is transmitted to the reflecting unit through the spectroscope, and the reflecting unit reflects the measuring light and emits the measuring light into the molten pool through the focusing component.

[0025] As a further improvement of the present invention, the reflection unit includes a reflector and a lens vibration assembly; the reflector is connected to the lens vibration assembly to reflect the welding laser onto the focusing assembly; the lens vibration assembly can drive the reflector to swing to change the incident position of the welding laser on the workpiece.

[0026] As a further improvement of the present invention, the reflection unit includes an X-galvanometer assembly and a Y-galvanometer assembly, the X-galvanometer assembly is used to deflect the welding laser in the X-axis direction, and the Y-galvanometer assembly is used to deflect the welding laser in the Y-axis direction, so as to deflect the welding laser onto the focusing assembly and change the incident position of the welding laser on the workpiece.

[0027] Another aspect of the present invention provides a laser welding method capable of real-time monitoring of weld penetration, wherein welding is performed using the laser welding device capable of real-time monitoring of weld penetration, comprising the following steps:

[0028] (1) The welding head module continuously emits welding laser to the workpiece according to the set process parameters, and the motion module drives the welding head module to move along the welding direction and form a molten pool at the welding position;

[0029] (2) The FMCW lidar sensor continuously emits measurement light into the molten pool and feeds back the emission signal to the control module;

[0030] (3) The FMCW lidar sensor receives the echo signal of the measurement light and feeds it back to the control module;

[0031] (4) The control module calculates and analyzes the depth of penetration in real time; when the depth of penetration exceeds the set range, the control module controls the laser processing module to stop working; when the depth of penetration is within the set range, the control module controls the laser processing module to adjust the process parameters in real time so that the depth of penetration is always close to the ideal target value; when the depth of penetration is close to the ideal target value, the laser processing module continues to weld the workpiece according to the current process parameters.

[0032] The above-mentioned improved technical features can be combined with each other as long as they do not conflict with each other.

[0033] In general, the above technical solutions conceived by the present invention have the following beneficial effects compared with the prior art:

[0034] (1) The laser welding device of the present invention can monitor the welding penetration in real time. By arranging the measuring light and the welding laser coaxially, the measuring light can be accurately incident into the molten pool and reflect the echo signal, thereby avoiding the measurement error caused by the optical path deviation. The control module is connected with the penetration measurement module and the laser processing module at the same time. By utilizing the high sensitivity of the FMCW laser radar system and the high-frequency signal transmission and processing capabilities of the control system, the signal can be quickly acquired and the real-time penetration information can be calculated and analyzed. When the penetration is abnormal, the laser processing module can be controlled to adjust the parameters in time to keep the penetration within the set range. The high-precision real-time closed-loop feedback from measurement to control is realized, which greatly improves the stability and consistency of the welding quality, reduces the scrap rate, and improves the production efficiency.

[0035] (2) The laser welding device of the present invention can monitor the welding penetration in real time. It forms an automatic and manual collaborative focusing mechanism by arranging a manual focusing unit and an automatic focusing unit in the focusing assembly. Manual focusing is used to achieve rapid positioning during the initial installation of the equipment or large-scale adjustment. The control module controls the automatic focusing unit to dynamically adjust the focus of the measuring light in real time during the welding process to adapt to the rapid changes in the depth and shape of the molten pool, ensuring that the measuring light is always focused on the optimal position, thereby achieving high-precision penetration measurement and increasing the measurement range of the penetration measurement module, effectively avoiding welding quality problems caused by inaccurate penetration measurement.

[0036] (3) The laser welding device and method of the present invention, which can monitor the welding penetration in real time, realizes long-distance transmission of the measuring light signal by setting a signal transmission unit in the penetration measurement module, thereby avoiding interference caused by environmental problems; by integrating the measuring light sensor, signal transmission unit and focusing component into the penetration measurement module, it realizes the completion of multiple key functions such as emission of measuring light, focus adjustment, signal acquisition and transmission in a compact module, thereby improving the integrity and stability of the system and reducing signal interference and loss that may be caused by the dispersion of components.

[0037] (4) The laser welding method of the present invention can monitor the welding penetration in real time. During the laser welding process, the method transmits and receives the measurement light signal in real time, and processes and analyzes it instantly through the control module, thereby realizing dynamic monitoring of the penetration depth and making corresponding adjustments at the moment when the penetration depth deviates. While ensuring the continuity of the welding process, it maintains a high-quality welding effect, thereby greatly improving the controllability and stability of the welding quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0039] Figure 1 1 is a schematic structural diagram of a laser welding device capable of real-time monitoring of welding penetration in a first embodiment of the present invention;

[0040] Figure 2 Schematic diagram of the structure of a laser welding device capable of real-time monitoring of welding penetration in a second embodiment of the present invention;

[0041] Figure 3 Schematic diagram of the structure of the laser welding device capable of real-time monitoring of welding penetration in the third embodiment of the present invention;

[0042] Figure 4 1 is a schematic structural diagram of a laser welding device capable of real-time monitoring of welding penetration in a fourth embodiment of the present invention;

[0043] Figure 5 Schematic diagram of the structure of a laser welding device capable of real-time monitoring of welding penetration in a fifth embodiment of the present invention;

[0044] Figure 6 It is a structural schematic diagram of a laser welding device capable of real-time monitoring of welding penetration in embodiment 6 of the present invention.

[0045] In all the drawings, the same figure marks represent the same technical features, specifically: 10, welding head module; 11, welding laser; 12, collimation assembly; 13, spectrometer; 14, focusing assembly; 15, reflector; 16, lens vibration assembly; 17, X-galvanometer assembly; 18, Y-galvanometer assembly; 20, penetration depth measurement module; 21, FMCW lidar sensor; 211, measuring light; 22, manual focusing unit; 23, automatic focusing unit; 24, fiber optic coupling point; 25, fiber optic coupler; 251, collimation mirror; 252, focusing mirror; 30, workpiece; 40, molten pool; 50, control module. DETAILED DESCRIPTION

[0046] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only intended to illustrate the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

[0047] In the description of the present invention, it should be understood that, unless otherwise expressly specified and limited, the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be understood as limiting the present invention.

[0048] Furthermore, unless otherwise expressly specified or limited, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise expressly specified or limited.

[0049] In the present invention, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection; direct connection, or indirect connection through an intermediate medium; internal communication between two components, or interaction between two components, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0050] In the present invention, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediary. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0051] Example:

[0052] See also Figures 1 to 6The laser welding device capable of real-time monitoring of welding penetration in a preferred embodiment of the present invention includes a laser processing module, a penetration measurement module 20 and a control module 50, wherein the penetration measurement module 20 is connected to the laser processing module, and the control module 50 is simultaneously connected to the laser processing module and the penetration measurement module 20, so as to weld the workpiece 30 through the laser processing module, and monitor the welding penetration in real time through the penetration measurement module 20, and transmit the monitoring results to the control module 50 in real time. The control module 50 calculates and analyzes the monitoring results in real time, and controls the laser processing module to adjust the processing parameters in real time, so that the welding penetration of the workpiece 30 is always maintained within the set range, so as to improve the welding effect and welding accuracy.

[0053] like Figure 1 As shown in , the laser processing module in the preferred embodiment includes a welding head module 10 and a motion module, wherein the welding head module 10 is arranged on the motion module for laser welding the workpiece 30 and moves along the welding direction of the workpiece 30 driven by the motion module.

[0054] Specifically, if Figure 1 As shown in the figure, the welding head module 10 in the preferred embodiment includes a welding laser 11, a collimating component 12, a spectroscope 13 and a focusing component 14. The welding laser 11 emitted by the welding head module 10 is converted into a parallel light beam by the collimating component 12. The parallel light beam is reflected by the spectroscope 13 and converged into a light spot on the workpiece 30 to be welded through the focusing component 14, and the workpiece 30 to be welded is welded.

[0055] like Figures 1-3 As shown in FIG, in one embodiment of the present invention, the welding laser 11 is emitted along a first direction, the collimating component 12 is arranged in the first direction, and the beam splitter 13 is arranged at a certain angle to the first direction. Figures 1-3 The center is set at an angle of 45 degrees, so that the welding laser 11 passes through the collimating component 12 and is reflected in the second direction by the spectrometer 13; accordingly, the focusing component 14 is set in the second direction, and the welding laser 11 is focused by the focusing component 14 and emitted along the second direction to the workpiece 30 to be welded.

[0056] like Figures 4-6 As shown in FIG, in another specific embodiment of the present invention, the welding laser 11 is emitted along the second direction, the collimating component 12 is arranged in the second direction, and the beam splitter 13 is arranged at a certain angle relative to the second direction. Figures 4-6 The center is set at an angle of 45 degrees, so that the welding laser 11 passes through the collimating component 12 and is reflected in the first direction by the spectrometer 13; at the same time, a reflecting unit is also provided in the first direction to reflect the welding laser 11 reflected by the spectrometer 13 to the focusing component 14; accordingly, the focusing component 14 is set in the second direction, and the welding laser 11 is focused by the focusing component 14 and emitted along the second direction to the workpiece 30 to be welded.

[0057] Preferably, if Figure 4 In the embodiment shown in , the reflecting unit includes a reflector 15, and the reflector 15 is arranged at a certain angle to the first direction. Further preferably, as Figure 5 As shown in the figure, the reflection unit also includes a lens vibration component 16, and the reflector 15 is arranged on the lens vibration component 16, so that during the laser welding process, the reflector 15 is driven to swing by the lens vibration component 16, and the angle between the reflector 15 and the first direction is continuously changed. The position where the reflector 15 is reflected and incident on the workpiece 30 is continuously changed, so that the energy of the welding laser 11 incident on the workpiece 30 is more evenly dispersed, the shape of the formed molten pool 40 is more uniform, and the quality of the formed weld is better.

[0058] Preferably, if Figure 6 In the specific embodiment shown in , the reflection unit includes an X-galvanometer assembly 17 and a Y-galvanometer assembly 18, which are spaced apart from each other. The X-galvanometer assembly 17 is used to deflect the welding laser 11 in the X-axis direction, and the Y-galvanometer assembly 18 is used to deflect the welding laser 11 in the Y-axis direction. After being deflected by the X-galvanometer assembly 17 and the Y-galvanometer assembly 18, the welding laser 11 is incident in the second direction. In a specific configuration, the welding laser 11, after being reflected by the beam splitter 13, can first be reflected by the X-galvanometer assembly 17 and then by the Y-galvanometer assembly 18 to the focusing assembly 14, or first be reflected by the Y-galvanometer assembly 18 and then by the X-galvanometer assembly 17 to the focusing assembly 14.

[0059] Furthermore, the output end of the penetration measurement module 20 in the preferred embodiment is connected to the welding head module 10, including an FMCW laser radar sensor 21, which is used to continuously emit high-frequency measuring light 211, and the measuring light 211 can be incident into the molten pool 40 through the welding head module 10, and reflected back into the FMCW laser radar sensor 21 when it contacts the bottom of the molten pool 40; at the same time, the measuring light 211 and the welding laser 11 are coaxially arranged, so that the measuring light 211 can be accurately incident into the molten pool 40 and reflect the echo signal, effectively avoiding measurement errors caused by optical path deviation.

[0060] like Figures 1-3 As shown in , when the welding laser 11 is emitted along the first direction, the measuring light 211 enters the welding head module 10 along the second direction, is transmitted through the spectrometer 13 along the second direction to the focusing component 14, and the measuring light 211 is emitted into the molten pool 40 through the focusing component 14.

[0061] like Figures 4-6As shown in , when the welding laser 11 is emitted along the second direction, the measuring light 211 enters the welding head module 10 along the first direction, and is transmitted to the reflecting unit through the spectrometer 13. The reflecting unit reflects the measuring light 211 onto the focusing component 14, and emits the measuring light 211 into the molten pool 40 through the focusing component 14.

[0062] It is understandable that, in actual settings, the measuring light 211 and the welding laser 11 are set to be lights of different wavelengths, so that the measuring light 211 can pass through the spectroscope 13 while the welding laser 11 is reflected by the spectroscope 13 .

[0063] At the same time, the FMCW lidar sensor 21 is connected to the control module 50 to feed back the transmission signal and echo signal of the measuring light 211 to the control module 50 in real time. The control module 50 calculates and analyzes the melting depth based on the time difference between the received transmission signal and the echo signal, thereby realizing dynamic monitoring of the melting depth.

[0064] Accordingly, the control module 50 is connected to the laser processing module to control the welding operation of the laser processing module in real time according to the calculated penetration depth, control the laser processing module to stop working or automatically adjust the welding process parameters, so that the penetration depth is always maintained within the set range during the welding process, effectively ensuring the stability and consistency of the welding quality, and improving production efficiency and product qualification rate.

[0065] It can be understood that when the depth of penetration calculated by the control module 50 exceeds the set range, the laser processing module is controlled to immediately stop welding to prevent the production of more defective welding products; when the depth of penetration is within the set range, the process parameters of the welding head module 10, such as laser power, welding speed, pulse frequency, etc., can be automatically adjusted so that the depth of penetration is always close to the ideal target value, thereby improving the stability and reliability of welding and reducing quality fluctuations caused by fluctuations in process parameters.

[0066] Furthermore, the penetration measurement module 20 also includes a focusing component, which is arranged between the FMCW lidar sensor 21 and the laser processing module to adjust the focus of the measuring light 211 incident into the molten pool 40 through the focusing component; at the same time, the focusing component is connected and set on the welding head module 10, so that the output port of the penetration measurement module 20 moves synchronously with the welding head module 10.

[0067] Preferably, if Figure 1As shown in the figure, the focusing assembly includes a manual focusing unit 22 for coarsely adjusting the focus of the measuring light 211. It can be understood that there are differences in the optical configurations of different welding head modules 10, which leads to large differences in the focusing of the measuring light 211 on the workpiece 30 when the depth measurement module 20 is integrated into different welding head modules 10. When the equipment is initially installed or the welding head module 10 is adjusted over a large range, the manual focusing unit 22 can be used to preliminarily adjust the focus of the measuring light 211 to the molten pool 40, thereby meeting the requirements of the depth measurement module 20 to adapt to different welding head modules 10 and improving the applicability of the depth measurement module 20.

[0068] Preferably, if Figure 2 As shown in , the focusing assembly further includes an automatic focusing unit 23 for fine-tuning the focus of the measuring light 211 so that the incident focus of the measuring light 211 is always on the molten pool 40 .

[0069] Specifically, the automatic focusing unit 23 includes a focusing mirror and a moving part. The focusing mirror is arranged on the moving part, and the moving part is connected to the control module 50. The control module 50 controls the moving part to drive the focusing mirror to perform precise adjustment and real-time dynamic adjustment of the focus of the measuring light 211 to adapt to the rapid changes in the depth and shape of the molten pool 40, ensuring that the measuring light 211 is always focused on the optimal position of the molten pool 40, so that the echo signal captured by the FMCW lidar sensor 21 is stronger, thereby realizing high-precision melting depth monitoring, while further reducing the interference of environmental factors on the measurement accuracy, and ensuring the reliability of the monitoring data.

[0070] Preferably, the penetration measurement module 20 further includes a signal transmission unit, which is disposed between the FMCW laser radar sensor 21 and the focusing assembly to transmit the measurement light 211 over a long distance.

[0071] Specifically, if Figure 3 As shown in the figure, the signal transmission unit includes a fiber coupler 25, a fiber coupling point 24 and an optical fiber, wherein one end of the fiber coupler 25 is connected to the FMCW lidar sensor 21, and the other end is connected to the optical fiber. The fiber coupler 25 includes a collimating mirror 251 and a focusing mirror 252 arranged in sequence along the emission direction of the measuring light 211 to couple the measuring light 211 into the optical fiber. Accordingly, the other end of the optical fiber extends to the fiber coupling point 24, so that the measuring light 211 transmitted through the optical fiber is diverged to the focusing component at the fiber coupling point 24, thereby realizing long-distance signal transmission in some specific environments and avoiding interference of environmental problems on the measurement signal, thereby improving the environmental adaptability of the penetration measurement module 20.

[0072] Furthermore, the present invention also includes a laser welding method capable of real-time monitoring of welding penetration, comprising the following steps:

[0073] (1) The welding head module 10 continuously emits a welding laser 11 toward the workpiece 30 according to the set process parameters. The motion module drives the welding head module 10 to move along the welding direction and forms a molten pool 40 at the welding position.

[0074] (2) The FMCW lidar sensor 21 continuously emits measurement light 211 into the molten pool 40 and feeds back the emission signal to the control module 50;

[0075] (3) The FMCW lidar sensor 21 receives the echo signal of the measurement light 211 and feeds it back to the control module 50;

[0076] (4) The control module 50 calculates and analyzes the penetration depth in real time; when the penetration depth exceeds the set range, the control module 50 controls the laser processing module to stop working; when the penetration depth is within the set range, the control module 50 controls the laser processing module to adjust the process parameters in real time so that the penetration depth is always close to the ideal target value; when the penetration depth is close to the ideal target value, the welding head module 10 continues to weld the workpiece 30 according to the current process parameters;

[0077] The laser welding device of the present invention can monitor the welding penetration in real time. By making the welding laser focus coaxial with the measuring light focus and the coordinated work of the components in the penetration measurement module, it can accurately obtain the reflected echo signal in the molten pool, thereby achieving high-precision measurement of the penetration depth, effectively avoiding welding quality problems caused by inaccurate penetration measurement, such as insufficient strength of the weld joint or burning through the workpiece.

[0078] The laser welding device of the present invention, which can monitor welding penetration in real time, uses a control system to accurately analyze the echo signals collected by the FMCW lidar sensor, effectively filtering out various noise interferences generated during the welding process (such as signal fluctuations caused by plasma fluctuations and welding smoke scattering), further improving the accuracy and stability of penetration monitoring, making the monitoring data more reliable, and providing a solid data foundation for the precise control of the welding process.

[0079] The laser welding device of the present invention can monitor the welding penetration in real time. It can emit measurement light and receive echo signals in real time during the welding process through the penetration measurement module. The control module quickly processes this information with the help of high-frequency signal transmission, realizing dynamic real-time monitoring of the penetration depth. It can detect the moment when a slight deviation in the penetration depth occurs, and can send control instructions to the laser processing module in an extremely short time (for example, within a few milliseconds). This rapid response capability enables the penetration depth during the welding process to always be maintained within the set ideal range, greatly improving the consistency and stability of the welding quality, significantly reducing the scrap rate, and improving production efficiency.

[0080] The laser welding device of the present invention can monitor the welding penetration in real time. When faced with complex welding conditions, such as rapid changes in penetration during high-speed welding, irregular shapes of the molten pool during swing welding, keyhole collapse, spatter and other abnormal conditions, it uses a special optical path design and an adaptive signal processing mechanism to enable it to quickly adapt to the changes in penetration under these complex conditions, adjust welding parameters in time, ensure the continuity and high-quality completion of the welding process, and effectively solve the problem of inaccurate monitoring or inability to monitor in real time under complex conditions by traditional monitoring methods.

[0081] The laser welding device of the present invention can monitor the welding penetration in real time, and realizes closed-loop feedback control of the laser processing module based on the monitored penetration information through the control module. It can not only stop the welding head in time when the penetration exceeds the allowable range to prevent the production of more defective welding products, but also automatically adjust the process parameters of the welding head (such as laser power, welding speed, pulse frequency, etc.), so that the welding system can continuously optimize the welding process parameters during long-term operation, so that the penetration is more stably close to the ideal target value, thereby improving the stability and reliability of the entire welding production line, reducing quality fluctuations caused by fluctuations in process parameters, reducing equipment maintenance costs and labor costs, and also extending the service life of the equipment, thereby improving the production efficiency and market competitiveness of the enterprise.

[0082] The intelligent closed-loop feedback control mechanism of the present invention enables the welding system to automatically adapt to changes in different materials, workpieces of different thicknesses and different welding process requirements without frequent human intervention, greatly improving the degree of automation and intelligence of the welding process.

[0083] It will be easily understood by those skilled in the art that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A laser welding device capable of real-time monitoring of welding penetration, characterized in that: Includes laser processing module, penetration depth measurement module and control module; The laser processing module is connected to the control module and includes a motion module and a welding head module provided on the motion module, wherein the welding head module is used to emit welding laser, and the motion module is used to drive the welding head module to move along the welding direction of the workpiece; The penetration measurement module is connected to the control module and the welding head module, and includes an FMCW laser radar sensor, a focusing assembly, and a signal transmission unit; the FMCW laser radar sensor is used to continuously transmit and receive measurement light at high frequency, and the measurement light can be incident into the molten pool through the welding head module and coaxially with the welding laser; the focusing assembly is arranged between the FMCW laser radar sensor and the laser processing module, and is connected to the welding head module to adjust the focus of the measurement light through the focusing assembly; the signal transmission unit is arranged between the FMCW laser radar sensor and the focusing assembly, and includes a fiber coupler, an optical fiber, and a fiber coupling point; one end of the fiber coupler is connected to the FMCW laser radar sensor, and the other end is connected to the optical fiber, and includes a collimator and a focusing lens arranged in sequence along the emission direction of the measurement light to couple the measurement light into the optical fiber; the optical fiber extends to the optical fiber coupling point, and the measurement light is transmitted through the optical fiber and diverges to the focusing assembly at the optical fiber coupling point; The welding head module emits a welding laser to weld the workpiece, and the FMCW laser radar sensor emits a measuring light and feeds back a transmission signal to the control module. The measuring light hits the bottom of the molten pool and is reflected back to the FMCW laser radar sensor. The FMCW laser radar sensor feeds back an echo signal to the control module. The control module calculates and analyzes the penetration depth based on the time difference between the reflected signal and the echo signal, and issues corresponding control instructions to the laser processing module based on the penetration depth information, so that the penetration depth is always maintained within the set range during the welding process.

2. The laser welding device capable of real-time monitoring of welding penetration according to claim 1, characterized in that: The focusing assembly includes a manual focusing unit, which preliminarily adjusts the focus of the measuring light to the molten pool.

3. The laser welding device capable of real-time monitoring of welding penetration according to claim 2, characterized in that: The focusing assembly also includes an automatic focusing unit, which includes a focusing mirror and a moving part. The focusing mirror is connected to the moving part, and the moving part is connected to the control module. The control module controls the moving part to drive the focusing mirror to move, and positions the focus of the measuring light so that the focus of the measuring light is always located in the molten pool.

4. The laser welding device capable of real-time monitoring of welding penetration according to any one of claims 1 to 3, characterized in that: The welding head module includes a welding laser, a collimating component, a beam splitter and a focusing component; The welding laser is emitted along a first direction, and the collimating assembly is arranged in the first direction for converting the welding laser into a parallel beam; The beam splitter is arranged at a certain angle to the first direction to reflect the parallel light beam in the second direction; The focusing assembly is arranged in the second direction, and is used to focus the welding laser into a light spot on the workpiece; The measuring light enters the welding head module along the second direction, is transmitted to the focusing component through the beam splitter, and is emitted into the molten pool by the focusing component.

5. The laser welding device capable of real-time monitoring of welding penetration according to any one of claims 1 to 3, characterized in that: The welding head module includes a welding laser, a collimating component, a beam splitter, a reflecting unit and a focusing component; The welding laser is emitted along a second direction, and the collimating assembly is arranged in the second direction for converting the welding laser into a parallel beam; The beam splitter is arranged at a certain angle to the second direction to reflect the parallel light beam to the first direction, and the welding laser is reflected to the focusing assembly through the reflection unit; The focusing assembly is arranged in the second direction, and is used to focus the welding laser into a light spot on the workpiece; The measuring light enters the welding head module along a first direction, is transmitted to the reflecting unit through the spectroscope, and the reflecting unit reflects the measuring light and emits the measuring light into the molten pool through the focusing component.

6. The laser welding device capable of real-time monitoring of welding penetration according to claim 5, characterized in that: The reflection unit includes a reflector and a lens vibration assembly; the reflector is connected to the lens vibration assembly and is used to reflect the welding laser onto the focusing assembly; the lens vibration assembly can drive the reflector to swing to change the incident position of the welding laser on the workpiece.

7. The laser welding device capable of real-time monitoring of welding penetration according to claim 5, characterized in that: The reflection unit includes an X-galvanometer assembly and a Y-galvanometer assembly. The X-galvanometer assembly is used to deflect the welding laser in the X-axis direction, and the Y-galvanometer assembly is used to deflect the welding laser in the Y-axis direction, so as to deflect the welding laser onto the focusing assembly and change the incident position of the welding laser on the workpiece.

8. A laser welding method capable of real-time monitoring of weld penetration, comprising: performing welding using the laser welding device capable of real-time monitoring of weld penetration according to any one of claims 1 to 7, wherein: The steps include: (1) The welding head module continuously emits welding laser to the workpiece according to the set process parameters, and the motion module drives the welding head module to move along the welding direction and form a molten pool at the welding position; (2) The FMCW lidar sensor continuously emits measurement light into the molten pool and feeds back the emission signal to the control module; (3) The FMCW lidar sensor receives the echo signal of the measurement light and feeds it back to the control module; (4) The control module calculates and analyzes the depth of penetration in real time; when the depth of penetration exceeds the set range, the control module controls the laser processing module to stop working; when the depth of penetration is within the set range, the control module controls the laser processing module to adjust the process parameters in real time so that the depth of penetration is always close to the ideal target value; when the depth of penetration is close to the ideal target value, the laser processing module continues to weld the workpiece according to the current process parameters.

Images