Laser welding device and method capable of monitoring laser welding working distance

Abstract

The invention discloses a laser welding device and method capable of monitoring a laser welding working distance, and belongs to the technical field of laser welding, and the laser welding device comprises a laser processing module, a working distance monitoring module and a control module. Measurement light emitted by the working distance module and welding laser are coaxially arranged, so that the measurement light can accurately enter the surface of a workpiece and reflect echo signals, and measurement errors caused by light path deviation are avoided; through the high sensitivity of the laser radar system and the high-frequency signal transmission and processing capacity of the control system, echo signals reflected by the surface of a workpiece can be rapidly and accurately obtained and calculated and analyzed in real time, high-precision measurement of the working distance is achieved, the laser machining module is controlled in real time to adjust the working distance, and the working efficiency is improved. The working distance is always kept within a set range, high-precision real-time closed-loop feedback from measurement to control is realized, the stability and consistency of welding quality are greatly improved, the rejection rate is reduced, and the production efficiency is improved.

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 the laser welding working distance. 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 the laser welding process, the working distance between the laser head and the workpiece is a key parameter that affects the welding effect. Too large or too small will have a serious impact on the welding effect. If the working distance is too large, the energy density of the laser energy will be insufficient when it propagates to the surface of the workpiece, resulting in insufficient welding strength and insufficient weld penetration, which cannot meet the quality requirements of the product; on the contrary, if the working distance is too small, especially when it is in the zero focus position (the focus position of the welding laser is divided into three situations: 1. positive focus position, the workpiece is away from the laser focus position in the positive direction; 2. zero focus position, the laser focus is on the surface of the workpiece, and the energy density is the highest; 3. negative focus position, the workpiece is away from the laser focus position in the negative direction, and the energy density decreases as the distance increases), the laser energy is too concentrated on the surface of the workpiece, which can easily cause problems such as burn-through of the workpiece and poor weld formation. This not only wastes materials, but also increases production costs and may even cause the entire welded product to be scrapped. Therefore, it is necessary to monitor the working distance of laser welding in a timely manner during laser welding.

[0004] Existing methods for monitoring the working distance of laser welding generally include the following: 1) Monitoring using traditional tools such as mechanical measuring rulers requires manual operation before welding or during welding pauses, making it impossible to monitor changes in the working distance in real time during the welding process. Real-time changes in the working distance caused by factors such as thermal deformation and workpiece movement cannot be accurately grasped, making it impossible to achieve precise control of the welding process. 2) Monitoring using photoelectric sensors, while capable of achieving non-contact monitoring to a certain extent, in the complex environment of the welding site, factors such as strong light, high temperature, plasma, and welding smoke can seriously interfere with the photoelectric signal, resulting in inaccurate and unstable monitoring results. These existing monitoring methods struggle to provide reliable working distance data in actual industrial production and cannot guarantee the stability and consistency of welding quality. 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 laser welding working distance, which can improve the accuracy of measuring the laser welding working distance, ensure that the working distance of the welding head module is always within an appropriate range during the welding process, and improve the stability and reliability of the welding device.

[0006] To achieve the above-mentioned object, the present invention provides a laser welding device and method capable of monitoring the laser welding working distance, which includes a laser processing module, a working distance monitoring module and a control module; The laser processing module is connected to the control module and includes a motion module and a welding head module disposed on the motion module, wherein the welding head module is used to emit a welding laser; the motion module includes a horizontal motion unit and a vertical motion unit, wherein the horizontal motion unit is used to drive the welding head module to move along the welding direction of the workpiece, and the vertical motion unit is used to drive the welding head module to move vertically; The working distance monitoring 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 coaxially incident on the workpiece surface with the welding laser; The FMCW lidar sensor emits measuring light and feeds back a signal to the control module. The measuring light hits the surface of the workpiece and is reflected back to the FMCW lidar sensor. The FMCW lidar sensor feeds back the echo signal to the control module. The control module calculates and analyzes the distance from the welding head module to the workpiece based on the time difference between the reflected signal and the echo signal, and controls the vertical motion unit to drive the welding head module to move vertically based on the distance information, so that the distance between the welding head module and the workpiece is always maintained within the set range.

[0007] As a further improvement of the present invention, the working distance monitoring module also includes a focusing component, which is arranged between the FMCW lidar sensor and the laser processing module and is connected to the laser processing module to adjust the focus of the measuring light through the focusing component.

[0008] 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 the surface of the workpiece.

[0009] 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 on the surface of the workpiece.

[0010] As a further improvement of the present invention, the working distance monitoring module further includes a signal transmission unit, which is arranged between the FMCW lidar 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 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.

[0011] 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; 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 surface of the workpiece through the focusing component.

[0012] 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; 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 workpiece surface through the focusing assembly.

[0013] As a further improvement of the present invention, the reflecting unit includes a reflecting mirror and a lens vibration assembly; the reflecting mirror 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 reflecting mirror to swing to change the incident position of the welding laser on the workpiece; or, 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.

[0014] Another aspect of the present invention provides a laser welding method capable of monitoring the laser welding working distance, wherein welding is performed using the laser welding device capable of monitoring the laser welding working distance, comprising the following steps: (1) The horizontal motion unit drives the welding head module to move along the welding direction, and the FMCW laser radar sensor continuously emits measurement light to the workpiece surface and feeds back the emission signal to the control module; (2) The FMCW lidar sensor receives the echo signal of the measurement light and feeds it back to the control module; (3) The control module calculates and analyzes the distance information between the welding head module and the workpiece at each welding position; (4) The horizontal motion module drives the welding head module to return to the initial position and move again along the welding direction; (5) The welding head module continuously emits welding laser to the workpiece, and the control module controls the vertical motion module to adjust the working distance of the welding head module at each welding position to a set range until the welding work on the workpiece is completed.

[0015] Another aspect of the present invention provides a laser welding device capable of monitoring the laser welding working distance, wherein welding is performed using the laser welding device capable of monitoring the laser welding working distance, comprising the following steps: (1) The FMCW lidar sensor transmits measurement light to the surface of the workpiece and feeds back the transmission signal to the control module; (2) The FMCW lidar sensor receives the echo signal of the measurement light and feeds it back to the control module; (3) The control module calculates and analyzes the real-time distance information between the welding head module and the workpiece, and controls the vertical motion module to adjust the working distance of the welding head module to a set range; (4) The welding head module emits welding laser toward the workpiece; (5) Repeat the above steps continuously until the monitoring of the working distance of the welding head module during the welding process is completed.

[0016] The above-mentioned improved technical features can be combined with each other as long as they do not conflict with each other.

[0017] In general, the above technical solutions conceived by the present invention have the following beneficial effects compared with the prior art: (1) The laser welding device and method of the present invention can monitor the laser welding working distance. By arranging the measuring light and the welding laser coaxially, the measuring light can be accurately incident on the workpiece surface and reflect the echo signal, thereby avoiding the measurement error caused by the optical path deviation. Through the high sensitivity of the FMCW laser radar system and the high-frequency signal transmission and processing capability of the control system, the echo signal reflected from the workpiece surface can be quickly and accurately obtained and calculated and analyzed in real time, thereby achieving high-precision measurement of the working distance, and controlling the laser processing module in real time to adjust the working distance, so that the working distance is always kept within the set range, thereby achieving 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.

[0018] (2) The laser welding device and method of the present invention can monitor the laser welding working distance. A manual focusing unit and an automatic focusing unit are arranged in the focusing assembly to form an automatic and manual collaborative focusing mechanism. 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 shape or thickness of the workpiece surface, ensuring that the measuring light is always focused on the optimal position on the workpiece surface, thereby achieving high-precision measurement of the working distance and increasing the measurement range of the working distance measurement module, effectively avoiding welding quality problems caused by inaccurate working distance measurement.

[0019] (3) The laser welding device and method of the present invention, which can monitor the laser welding working distance, realizes long-distance transmission of the measuring light signal by setting a signal transmission unit in the working distance measuring module, thereby avoiding interference caused by environmental problems; by integrating the measuring light sensor, signal transmission unit and focusing component into the working distance measuring 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.

[0020] (4) The laser welding device and method of the present invention can monitor the laser welding working distance. Before the welding head module works, the working distance measurement module and the control module are used to measure the distance information of each continuous or discontinuous welding position along the welding direction. Then, when the welding head module works, the vertical position of the welding head module is adjusted accordingly according to the distance information monitored in advance, so that the working distance of the welding head module is always maintained within the set range, thereby improving the stability of the welding effect and welding quality.

[0021] (5) The laser welding device and method of the present invention can monitor the laser welding working distance. During the laser welding process, the device transmits and receives the measurement light signal in real time, and processes and analyzes it instantly through the control module, thereby achieving real-time dynamic monitoring of the working distance. The device can make corresponding adjustments at the moment when the working distance deviates. While ensuring the continuity of the welding process, the device maintains a high-quality welding effect, thereby greatly improving the controllability and stability of the welding quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] 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.

[0023] Figure 1 1 is a schematic structural diagram of a laser welding device capable of monitoring the laser welding working distance in the first embodiment of the present invention; Figure 2 2 is a schematic structural diagram of a laser welding device capable of monitoring the laser welding working distance in a second embodiment of the present invention; Figure 3 Schematic diagram of the structure of a laser welding device capable of monitoring the laser welding working distance in the third embodiment of the present invention; Figure 4 1 is a schematic structural diagram of a laser welding device capable of monitoring the laser welding working distance in a fourth embodiment of the present invention; Figure 51 is a schematic structural diagram of a laser welding device capable of monitoring the laser welding working distance in a fifth embodiment of the present invention; Figure 6 It is a structural schematic diagram of a laser welding device capable of monitoring the laser welding working distance in embodiment 6 of the present invention.

[0024] 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, working distance monitoring 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, collimator; 252, focusing mirror; 30, workpiece; 40, control module. DETAILED DESCRIPTION

[0025] 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.

[0026] 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.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] Example: See also Figures 1 to 6 The laser welding device capable of monitoring the laser welding working distance in a preferred embodiment of the present invention includes a laser processing module, a working distance monitoring module 20 and a control module 40, wherein the working distance monitoring module 20 is connected to the laser processing module, and the control module 40 is simultaneously connected to the laser processing module and the working distance monitoring module 20, so as to monitor the distance between the laser processing module and the workpiece 30 through the working distance monitoring module 20, and transmit the monitoring result to the control module 40, the control module 40 calculates and analyzes the monitoring result, and controls the laser processing module to adjust the processing position, so that the distance between the laser processing module and the workpiece is always maintained within the set range, thereby improving the welding effect and the stability of the welding quality.

[0031] 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 and is used to laser weld the workpiece 30, and the motion module drives the welding head module 10 to move relative to the workpiece 30. The motion module includes a horizontal motion unit and a vertical motion unit, so that the horizontal motion unit drives the welding head module 10 to move along the welding direction of the workpiece 30, and the vertical motion unit drives the welding head module 10 to move vertically to adjust the distance between the welding head module 10 and the workpiece 30.

[0032] Specifically, if Figure 1As 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.

[0033] 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 assembly 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.

[0034] 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.

[0035] 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, and the quality of the weld formed is better.

[0036] Preferably, if Figure 6In 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.

[0037] Furthermore, the output end of the working distance monitoring 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 on the surface of the workpiece 30 through the welding head module 10, and reflected back into the FMCW laser radar sensor 21 when it contacts the workpiece surface; 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 on the surface of the workpiece 30 and reflect the echo signal, effectively avoiding the monitoring error caused by the optical path deviation.

[0038] 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 to the surface of the workpiece 30 through the focusing component 14.

[0039] like Figures 4-6 As 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 to the surface of the workpiece 30 through the focusing component 14.

[0040] 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 .

[0041] At the same time, the FMCW lidar sensor 21 is connected to the control module 40 to feed back the transmission signal and echo signal of the measuring light 211 to the control module 40 in real time. The control module 40 calculates and analyzes the distance between the welding head module 10 and the workpiece 30 based on the time difference between the received transmission signal and the echo signal.

[0042] Accordingly, the control module 40 is connected to the laser processing module to control the motion module to adjust the position of the welding head module 10 according to the calculated distance information, so that the working distance 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.

[0043] Furthermore, the working distance monitoring 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 on the surface of the workpiece 30 through the focusing component; at the same time, the focusing component is connected to the welding head module 10 so that the output port of the working distance monitoring module 20 moves synchronously with the welding head module 10.

[0044] Preferably, if Figure 1 As 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 working distance monitoring 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 surface of the workpiece 30, thereby meeting the requirements of the working distance monitoring module 20 to adapt to different welding head modules 10 and improving the applicability of the working distance monitoring module 20.

[0045] 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 surface of the workpiece 30 .

[0046] 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 40. The control module 40 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 working distance, ensuring that the measuring light 211 is always focused on the optimal position on the surface of the workpiece 30, so that the echo signal captured by the FMCW lidar sensor 21 is stronger, thereby achieving high-precision working distance monitoring.

[0047] Preferably, the working distance monitoring module 20 further includes a signal transmission unit, which is arranged between the FMCW laser radar sensor 21 and the focusing assembly to transmit the measuring light 211 over a long distance.

[0048] Specifically, if Figure 3As 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 monitoring signal, thereby improving the environmental adaptability of the working distance monitoring module 20.

[0049] Furthermore, the present invention also provides a method for performing laser welding on the laser welding working distance using the laser welding device capable of monitoring the laser welding working distance, comprising the following steps: (1) The horizontal motion module drives the welding head module 10 to move along the welding direction, and the FMCW laser radar sensor 21 continuously emits measurement light 211 to the workpiece surface and feeds back the emission signal to the control module 40; (2) The FMCW lidar sensor 21 receives the echo signal of the measurement light 211 and feeds it back to the control module 50; (3) The control module 50 calculates and analyzes the distance information between the welding head module 10 and the workpiece at each welding position; (4) The horizontal motion module drives the welding head module 10 back to the initial position and moves again along the welding direction; (5) The welding head module 10 continuously emits the welding laser 11 toward the workpiece 30 , and the control module 50 controls the vertical motion module to adjust the working distance of the welding head module 10 at each welding position to a set range until the welding work on the workpiece is completed.

[0050] Furthermore, the present invention also provides a method for performing laser welding on the laser welding working distance using the laser welding device capable of monitoring the laser welding working distance, comprising the following steps: (1) The FMCW laser radar sensor 21 transmits measurement light 211 to the workpiece surface and feeds back the transmission signal to the control module 40; (2) The FMCW lidar sensor 21 receives the echo signal of the measurement light 211 and feeds it back to the control module 50; (3) The control module 50 calculates and analyzes the real-time distance information between the welding head module 10 and the workpiece, and controls the vertical motion module to adjust the working distance of the welding head module 10 to a set range; (4) The welding head module 10 emits a welding laser 11 toward the workpiece 30; (5) Repeat the above steps continuously until the welding of the workpiece is completed.

[0051] The laser welding device and monitoring method of the present invention can monitor the laser welding working distance. By coaxially arranging the welding laser focus and the measuring light focus, and cooperating with each component in the working distance monitoring module, it is possible to accurately obtain the reflected echo signal from the workpiece surface, thereby realizing high-precision monitoring of the working distance, and effectively avoiding welding quality problems caused by inaccurate working distance monitoring, such as insufficient strength of the welding joint or burning through the workpiece.

[0052] The laser welding device and monitoring method of the present invention, which can monitor the laser welding working distance, use a control system to accurately analyze the echo signal 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 working distance monitoring, making the monitoring data more reliable, and providing a solid data foundation for the precise control of the welding process.

[0053] The laser welding device and monitoring method of the present invention can monitor the laser welding working distance. The working distance monitoring module can emit measurement light and receive echo signals in real time during the welding process. The control module uses high-frequency signal transmission to quickly process this information, thereby realizing dynamic real-time monitoring of the working distance. It can detect the moment when a slight change in the working distance 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 working distance 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.

[0054] The laser welding device and monitoring method of the present invention can monitor the laser welding working distance. When facing complex welding conditions, such as rapid changes in working distance during high-speed welding and irregular shapes of working distance during swing welding, it uses a special optical path design and an adaptive signal processing mechanism to enable it to quickly adapt to changes in working distance 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.

[0055] The laser welding device and monitoring method of the present invention can monitor the laser welding working distance, and realize closed-loop feedback control of the laser processing module based on the monitored distance information through the control module. When the working distance exceeds the allowable range, the position of the welding head module can be adjusted in time or the welding head can be stopped, so that the working distance 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 working distance fluctuations, reducing equipment maintenance costs and labor costs, and at the same time extending the service life of the equipment, thereby improving the company's production efficiency and market competitiveness.

[0056] 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.

[0057] 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 monitoring the laser welding working distance, characterized in that: Includes laser processing module, working distance monitoring module and control module; The laser processing module is connected to the control module and includes a motion module and a welding head module disposed on the motion module, wherein the welding head module is used to emit a welding laser; the motion module includes a horizontal motion unit and a vertical motion unit, wherein the horizontal motion unit is used to drive the welding head module to move along the welding direction of the workpiece, and the vertical motion unit is used to drive the welding head module to move vertically; The working distance monitoring 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 coaxially incident on the workpiece surface with the welding laser; The FMCW lidar sensor emits measuring light and feeds back a signal to the control module. The measuring light hits the surface of the workpiece and is reflected back to the FMCW lidar sensor. The FMCW lidar sensor feeds back the echo signal to the control module. The control module calculates and analyzes the distance from the welding head module to the workpiece based on the time difference between the reflected signal and the echo signal, and controls the vertical motion unit to drive the welding head module to move vertically based on the distance information, so that the distance between the welding head module and the workpiece is always maintained within the set range.

2. The laser welding device capable of monitoring the laser welding working distance according to claim 1, characterized in that: The working distance monitoring module also includes a focusing component, which is arranged between the FMCW laser radar sensor and the laser processing module and is connected to the laser processing module to adjust the focus of the measuring light through the focusing component.

3. The laser welding device capable of monitoring the laser welding working distance according to claim 2, characterized in that: The focusing assembly includes a manual focusing unit, which preliminarily adjusts the focus of the measuring light to the surface of the workpiece.

4. The laser welding device capable of monitoring the laser welding working distance according to claim 3, 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 on the surface of the workpiece.

5. The laser welding device capable of monitoring laser welding working distance according to claim 2, characterized in that: The working distance monitoring 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; 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.

6. The laser welding device capable of monitoring the laser welding working distance according to any one of claims 1 to 5, 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 surface of the workpiece through the focusing component.

7. The laser welding device capable of monitoring the laser welding working distance according to any one of claims 1 to 5, 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 workpiece surface through the focusing assembly.

8. The laser welding device capable of monitoring laser welding working distance according to claim 7, characterized in that: The reflecting unit includes a reflecting mirror and a lens vibration assembly; the reflecting mirror 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 reflecting mirror to swing to change the incident position of the welding laser on the workpiece; or, 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.

9. A laser welding method capable of monitoring the laser welding working distance, comprising: performing welding using the laser welding device capable of monitoring the laser welding working distance according to any one of claims 1 to 8, wherein: The steps include: (1) The horizontal motion unit drives the welding head module to move along the welding direction, and the FMCW laser radar sensor continuously emits measurement light to the workpiece surface and feeds back the emission signal to the control module; (2) The FMCW lidar sensor receives the echo signal of the measurement light and feeds it back to the control module; (3) The control module calculates and analyzes the distance information between the welding head module and the workpiece at each welding position; (4) The horizontal motion module drives the welding head module to return to the initial position and move again along the welding direction; (5) The welding head module continuously emits welding laser to the workpiece, and the control module controls the vertical motion module to adjust the working distance of the welding head module at each welding position to a set range until the welding work on the workpiece is completed.

10. A laser welding method capable of monitoring the laser welding working distance, comprising: performing welding using the laser welding device capable of monitoring the laser welding working distance according to any one of claims 1 to 8, wherein: The steps include: (1) The FMCW lidar sensor transmits measurement light to the surface of the workpiece and feeds back the transmission signal to the control module; (2) The FMCW lidar sensor receives the echo signal of the measurement light and feeds it back to the control module; (3) The control module calculates and analyzes the real-time distance information between the welding head module and the workpiece, and controls the vertical motion module to adjust the working distance of the welding head module to a set range; (4) The welding head module emits welding laser toward the workpiece; (5) Repeat the above steps continuously until the welding of the workpiece is completed.

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