Laser welding penetration detection device

Abstract

The utility model is applicable to the technical field of laser welding, and provides a laser welding penetration detection device which comprises a reference arm and a sample arm, the reference arm comprises a detection light source, an optical fiber coupler and a reflector, the sample arm comprises a scanning galvanometer, a first optical lens and a welding laser galvanometer, and detection light output by the detection light source is transmitted to the optical fiber coupler. After being input into the optical fiber coupler, the light is divided into reference light and scanning light, and the reference light returns to the optical fiber coupler through the reflector; the scanning light sequentially passes through the scanning galvanometer and the first optical lens and then irradiates the surface of a workpiece together with the welding laser through the welding laser galvanometer, the scanning galvanometer enables a first light spot to move with a second light spot as a reference system so that the scanning light can irradiate a key hole in the workpiece in real time, and the scanning light is reflected from the key hole and input into the optical fiber coupler. The optical fiber coupler generates an interference signal containing keyhole fusion depth data based on the scanning light reflected from the keyhole and the reference light returned by the reflector, and real-time detection of the keyhole fusion depth data in the welding process is achieved.

Description

Technical Field

[0001] The utility model belongs to the technical field of laser welding, and in particular relates to a laser welding penetration detection device. Background Art

[0002] As a non-contact welding method, laser welding has the characteristics of high efficiency, high precision and small heat-affected zone. It has wide applications and good development prospects in the industrial field.

[0003] During the laser welding process, the laser with extremely high energy density melts the surface material of the workpiece to form a molten pool. In the area with the highest energy density, the metal is rapidly heated and even produces metal vapor and metal plasma. The inside of the molten pool is molten liquid metal and gasified and plasmatized metal, and the outside of the molten pool is unmelted solid metal outside the heat-affected zone. As the laser beam moves, the molten pool after welding cools and solidifies to form a weld.

[0004] The depth of the molten pool is an important indicator for evaluating the quality of welds. If the molten pool is too shallow or too deep, it will lead to insufficient welding strength or damage other parts of the workpiece. Since the molten pool is only formed during the action of the laser, when the laser moves to other positions, the molten pool cools, closes and solidifies. At this time, in order to measure the depth of the molten pool, you can only cut the workpiece and grind the section, and then corrode the section with special potions. The melted metal and the unmelted metal have obvious differences under the corrosion of the potion. At this time, the depth of the molten pool is obtained by observing the workpiece section under a microscope. This method is a lossy measurement. The cut workpiece cannot be used later, and the whole process is very time-consuming. How to detect the keyhole penetration data in real time during the welding process has become a difficult problem that needs to be solved urgently in the laser welding industry. Utility Model Content

[0005] The utility model aims to provide a laser welding penetration detection device, aiming to realize real-time detection of keyhole molten pool data during welding.

[0006] The laser welding penetration detection device provided by the utility model comprises a reference arm and a sample arm;

[0007] The reference arm comprises a detection light source, a fiber coupler, and a reflector, wherein the detection light source is used to output detection light, the fiber coupler is used to receive the detection light, and output reference light to the reflector, output the first scanning light to the sample arm, and the reflector is used to reflect the reference light back to the fiber coupler;

[0008] The sample arm comprises a scanning galvanometer, a first optical mirror and a welding laser galvanometer, wherein the scanning galvanometer is used to receive the first scanning light and output the second scanning light to the first optical mirror, the first optical mirror is used to receive the second scanning light and the welding laser and output them to the welding laser galvanometer, and the welding laser galvanometer is used to output the received welding laser and the second scanning light to the workpiece;

[0009] The scanning galvanometer is also used to make the light spot of the second scanning light on the workpiece move with the light spot of the welding laser on the workpiece as a reference system;

[0010] The optical fiber coupler is further used to receive the second scanning light reflected by the workpiece, and output an interference signal based on the second scanning light and the reference light.

[0011] In one embodiment, the first optical mirror is a dichroic mirror or a beam combiner.

[0012] In one embodiment, the sample arm further includes a probe, and the probe is used to receive the first scanning light output by the optical fiber coupler, and output the first scanning light to the scanning galvanometer.

[0013] In one embodiment, the reference arm further includes a photosensitive device, and the photosensitive device is used to receive the interference signal output by the optical fiber coupler.

[0014] In one embodiment, the reference arm further comprises a collimator mirror, and the collimator mirror is located on the optical path between the optical fiber coupler and the photosensitive device.

[0015] In one embodiment, the reference arm further comprises a grating, and the grating is located on the optical path between the collimating mirror and the photosensitive device.

[0016] In one embodiment, the reference arm further comprises a focusing lens group, and the focusing lens group is located on the optical path between the grating and the photosensitive device.

[0017] In one embodiment, the focusing lens group includes 3 to 5 focusing lenses.

[0018] In one embodiment, the laser welding penetration detection device further includes a processor, which is communicatively connected to the photosensitive device, and the processor is used to generate keyhole penetration data based on the interference signal obtained by the photosensitive device.

[0019] In one embodiment, the reflector is a plane reflector or a spherical reflector.

[0020] The utility model provides a laser welding penetration detection device, comprising a reference arm and a sample arm, wherein the reference arm comprises a detection light source, a fiber coupler, and a reflector, and the sample arm comprises a scanning galvanometer, a first optical mirror, and a welding laser galvanometer. The detection light output by the detection light source is input into the fiber coupler and is divided into reference light and scanning light, and the reference light returns to the fiber coupler through the reflector along the original path; the scanning light sequentially passes through the scanning galvanometer and the first optical mirror, and is irradiated on the surface of a workpiece together with the welding laser through the welding laser galvanometer; the scanning galvanometer is also used to make the second scanning light move in the light spot of the workpiece with the light spot of the welding laser on the workpiece as a reference system, so as to realize that the scanning light is hit in a keyhole on the workpiece in real time, the scanning light is reflected from the keyhole and input into the fiber coupler, and the fiber coupler generates an interference signal containing keyhole penetration data based on the scanning light reflected from the keyhole and the reference light returned through the reflector, so that real-time keyhole molten pool data can be obtained from the interference signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0022] Figure 1 It is a structural schematic diagram of a laser welding penetration detection device provided by an embodiment of the utility model;

[0023] Figure 2 It is a partial structural schematic diagram of a reference arm provided by an embodiment of the utility model;

[0024] Figure 3 It is a structural schematic diagram of a focusing lens group provided by an embodiment of the utility model;

[0025] Figure Number:

[0026] Reference arm-1, detection light source-11, fiber coupler-12, reflector-13, collimator-14, grating-15, focusing lens group-16, first focusing lens-161, second focusing lens-162, third focusing lens-163, photosensitive device-17;

[0027] Sample arm-2, probe-21, scanning galvanometer-22, first optical mirror-23, welding laser mirror-24;

[0028] Welding laser source-3, workpiece-4. DETAILED DESCRIPTION

[0029] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application may also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present application.

[0030] It should be understood that when used in the present specification and the appended claims, the term "comprising" indicates the presence of described features, wholes, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or combinations thereof.

[0031] It should also be understood that the term “and / or” used in the specification and appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0032] In addition, in the description of the present application specification and the appended claims, the terms "first", "second", "third", etc. are only used to distinguish the descriptions and cannot be understood as indicating or implying relative importance.

[0033] References to "one embodiment" or "some embodiments" etc. described in the specification of this application mean that one or more embodiments of the present application include specific features, structures or characteristics described in conjunction with the embodiment. Therefore, the statements "in one embodiment", "in some embodiments", "in some other embodiments", "in some other embodiments", etc. that appear in different places in this specification do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "including", "comprising", "having" and their variations all mean "including but not limited to", unless otherwise specifically emphasized in other ways.

[0034] The utility model provides a laser welding penetration detection device, which is mainly used for laser welding. During the laser welding process, a scanning galvanometer is used to make the light spot of a second scanning light on the workpiece move with the light spot of the welding laser on the workpiece as a reference system, so that the scanning light is hit in the keyhole in real time, so as to obtain an interference signal containing the keyhole penetration data in real time.

[0035] like Figure 1 As shown, an embodiment of the present application provides a laser welding penetration detection device, including a reference arm 1 and a sample arm 2.

[0036] The reference arm 1 includes a detection light source 11, a fiber coupler 12, and a reflector 13. The detection light source 11 is used to output detection light, the fiber coupler 12 is used to receive the detection light, and output reference light to the reflector 13, output the first scanning light to the sample arm 2, and the reflector 13 is used to reflect the reference light back to the fiber coupler 12.

[0037] The sample arm 2 includes a scanning galvanometer 22, a first optical mirror 23 and a welding laser galvanometer 24. The scanning galvanometer 22 is used to receive the first scanning light and output the second scanning light to the first optical mirror 23. The first optical mirror is used to receive the second scanning light and the welding laser and output them to the welding laser galvanometer 24. The welding laser galvanometer 24 is used to output the received welding laser and the second scanning light to the workpiece 4.

[0038] The scanning galvanometer 22 is also used to make the light spot of the second scanning light on the workpiece 4 move with the light spot of the welding laser on the workpiece 4 as a reference system.

[0039] The optical fiber coupler 12 is also used to receive the second scanning light reflected by the workpiece 4, and output an interference signal based on the second scanning light and the reference light.

[0040] In applications, the detection light source 11 may be an optical coherence tomography (OCT) light source for outputting detection light.

[0041] In application, when laser welding reaches a certain power, the surface of the material melts and evaporates under the action of the welding laser, and the generated vapor recoil pressure is sufficient to overcome the surface tension of the liquid metal and the gravity of the liquid, thereby forming a concave pit in the molten pool. The welding laser beam directly acts on the bottom of the pit, causing the metal to further melt and vaporize. The high-pressure steam continues to force the liquid metal at the bottom of the pit to drain to the surroundings of the molten pool, further deepening the small hole, and finally forming a small hole similar to a keyhole, that is, a keyhole. The keyhole is in an unstable state, showing alternating expansion and necking. In particular, when the metal vapor inside the keyhole erupts outward, it will cause a steam vortex somewhere inside the keyhole, and the tail of the keyhole is very likely to neck and collapse. Therefore, the position of the keyhole changes in real time with the position of the welding laser, so the theoretical keyhole trajectory can be generated based on the welding laser trajectory with the spot of the welding laser on the workpiece as the reference system.

[0042] In application, the scanning galvanometer 22 can be controlled according to the theoretical keyhole trajectory and the working parameters of the welding laser so that the first light spot starts to move from the first preset point with the second light spot as the reference system. The working parameters of the welding laser include the speed of the welding laser, and the first preset point is any point on the theoretical keyhole trajectory. It can be understood that by controlling the first light spot to start from the first preset point, at a speed more than twice that of the welding laser, and moving with the second light spot as the reference system, the first light spot will meet the keyhole position after the catch-up time. The first light spot is the light spot of the second scanning light on the workpiece, and the second light spot is the light spot of the welding laser on the workpiece.

[0043] In application, the first penetration data at the first light spot is detected in real time during the process of controlling the scanning galvanometer 22 to make the first light spot move with the second light spot as the reference system. It can be understood that the keyhole will move dynamically with the welding laser, the penetration data at the keyhole position is the largest, and the penetration data at the position after the keyhole collapses will be smaller. Therefore, the first penetration data at the first light spot is detected in real time during the process of controlling the first light spot to move with the second light spot as the reference system, and it can be judged whether the first light spot meets the keyhole according to the size of the penetration data.

[0044] In the application, taking the motion trajectory of the welding laser as a circular motion at a first angular velocity as an example, the theoretical keyhole trajectory is a circle with the second light spot as the center and the first length as the radius, then the first light spot is controlled by the scanning galvanometer 22 to make a circular motion with the second light spot as the center and the first length as the radius from the first preset point at an angular velocity twice the first angular velocity, so that the first light spot catches up with the keyhole within a circle of circular motion, and there is a keyhole at the position of the scanning light spot at a certain moment. Within the first preset time, if the time from the first light spot starting to move from the first preset point to the detection of the first penetration data meeting the keyhole penetration condition is less than the second preset time, the position information of the first preset point with the second light spot as the reference system is set as the target position information of the keyhole with the second light spot as the reference system.

[0045] In the application, the first preset time is the time for the first light spot to complete a circular motion at the second angular velocity with the second light spot as the reference system. If the first melting depth data does not meet the preset keyhole melting depth condition within the first preset time, it means that with the radius of the theoretical keyhole trajectory as the radius, there is no keyhole at the position of the first light spot at all times, and the target radius should be adjusted.

[0046] In the application, the adjustment of the target radius can be increased within a range less than the maximum target radius, or decreased within a range greater than the minimum target radius; the two consecutive adjustments of the target radius can be opposite within a range greater than the minimum target radius and less than the maximum target radius. For example, the first adjustment of the target radius is to reduce the target radius on the basis of the first length. If the target radius needs to be adjusted for the second time after the first adjustment, the target radius should be increased on the basis of the first length; if the target radius needs to be adjusted for the third time after the second adjustment, the target radius should be reduced on the basis of the first adjustment; if the target radius needs to be adjusted for the fourth time after the third adjustment, the target radius should be increased on the basis of the second adjustment. The consecutive multiple adjustments of the target radius can also be to continuously reduce the target radius within a range greater than the minimum target radius, and if the target radius still needs to be adjusted, then the target radius is continuously increased within a range less than the maximum target radius; or to continuously increase the target radius within a range less than the maximum target radius, and if the target radius still needs to be adjusted, then the target radius is continuously reduced within a range greater than the minimum target radius.

[0047] In the application, if within the first preset time, it is detected that the first melt depth data meets the preset keyhole melt depth condition, but the time from the first light spot moving from the first preset point to the detection of the first melt depth data meeting the preset keyhole melt depth condition is greater than or equal to the second preset time, then it means that the target radius matches the target radius of the actual keyhole trajectory, and the first preset point is far away from the position of the keyhole at the start of laser welding. At this time, the first preset point can be adjusted relative to the azimuth angle of the second light spot to make the first preset point closer to the position of the keyhole at the start of laser welding, so that the keyhole melt depth data can be detected earlier.

[0048] In the application, after obtaining the target position information of the keyhole with the second light spot as the reference system, the second scanning light is made to move on the spot of the second scanning light on the workpiece with the spot of the welding laser on the workpiece as the reference system according to the target position information through the scanning galvanometer 22. For example, the scanning light spot is controlled to move in a circle with the welding laser spot as the center and the target radius as the radius from the first preset point at the first angular velocity, so as to achieve the real-time introduction of the scanning light into the keyhole. The scanning galvanometer 22 is realized to irradiate the first light spot in the keyhole in real time during the welding process, thereby ensuring the accuracy of the keyhole penetration data contained in the obtained interference signal.

[0049] In application, the detection light source 11 is connected to the fiber coupler 12 through an optical fiber, and the detection light propagates unidirectionally from the detection light source 11 to the fiber coupler 12. The optical path between the fiber coupler 12 and the reflector 13 and the optical path between the scanning galvanometer 22, the first optical mirror 23 and the welding laser galvanometer 24 are all bidirectionally conductive.

[0050] In application, the trajectory and speed of the second scanning light spot on the workpiece with the welding laser spot on the workpiece as the reference system depends on the trajectory and moving speed of the welding laser. For example, when the welding laser trajectory is a straight line and a circle, each time the welding laser draws a circle, the keyhole will appear at the rear and outside of the welding laser beam according to the change in the moving direction of the welding laser beam. With the second spot as the reference system, the theoretical keyhole trajectory is a circle with the second spot as the center and the first length as the radius. The angular velocity of the welding laser when drawing a circle is the first angular velocity. With the welding laser as the reference system, the angular velocity of the keyhole along the theoretical keyhole trajectory is also the first angular velocity. Therefore, the movement of the second scanning light spot on the workpiece with the welding laser spot on the workpiece as the reference system also moves in a circular motion with the second spot as the center and the first length as the radius at the first angular velocity.

[0051] In one embodiment, the first optical mirror 23 is a dichroic mirror or a beam combiner.

[0052] In application, the first optical mirror 23 may be a dichroic mirror or a beam combiner, or other optical mirrors capable of outputting the second scanning light from different directions and the welding laser together to the welding laser galvanometer.

[0053] In one embodiment, the sample arm 2 further includes a probe 21 , which is used to receive the first scanning light output by the fiber coupler 12 and output the first scanning light to the scanning galvanometer 22 .

[0054] In applications, the fiber coupler 12 and the probe 21 may be connected via an optical fiber.

[0055] In one embodiment, the reference arm 1 further includes a photosensitive device 17 , and the photosensitive device 17 is used to receive the interference signal output by the optical fiber coupler 12 .

[0056] In one embodiment, the reference arm 1 further includes a collimator 14 , which is located on the optical path between the fiber coupler 12 and the photosensitive device 17 .

[0057] In one embodiment, the reference arm 1 further includes a grating 15 , which is located on the optical path between the collimating mirror 14 and the photosensitive device 17 .

[0058] In one embodiment, the reference arm 1 further includes a focusing lens group 16 , which is located on the optical path between the grating 15 and the photosensitive device 17 .

[0059] In application, the interference signal output by the fiber coupler 12 has a certain divergence angle, so it needs to be collimated by the collimator 14 to become parallel light, then emitted at different angles after passing through the grating 15, and clearly focused on the photosensitive device through the focusing lens group 16.

[0060] like Figure 2 As shown, the collimator 14, the grating 15, and the focusing lens group 16 are sequentially arranged on the optical path between the fiber coupler 12 and the photosensitive device 17 to improve the quality of the interference signal.

[0061] In one embodiment, the focusing lens group 16 includes 3 to 5 focusing lenses.

[0062] In applications, such as Figure 3 As shown, the focusing lens group 16 includes three focusing lenses, which include a first focusing lens 161, a second focusing lens 162, and a third focusing lens 163. The first focusing lens 161, the second focusing lens 162, and the third focusing lens 163 are arranged in sequence on the optical path between the grating 15 and the photosensitive device 17.

[0063] In one embodiment, the laser welding penetration detection device further includes a processor, which is communicatively connected to the photosensitive device 17 , and the processor is used to generate keyhole penetration data based on the interference signal obtained by the photosensitive device 17 .

[0064] In the application, the photosensitive device 17 is an optical coherence tomography (OCT) sensor, and the processor obtains the interference signal through the OCT sensor; then the power spectrum density of the interference signal is inversely Fourier transformed to convert the interference signal in the time domain to the frequency domain, and the phase difference between the return light and the reference light is calculated, and the keyhole penetration data is obtained from the phase difference. The above process is carried out in real time during the laser welding process, so the keyhole penetration data during the welding process can be obtained in real time, and the real-time monitoring of the welding quality can be realized.

[0065] The processor 100 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor, etc.

[0066] In one embodiment, the reflector 13 is a plane reflector or a spherical reflector.

[0067] In one embodiment, the laser welding penetration detection device further includes a quality detection module, which is communicatively connected to the processor and is used to generate a warning signal indicating unqualified quality when the keyhole penetration data exceeds a preset penetration range.

[0068] In one embodiment, the laser welding penetration detection device further includes an alarm, which is connected to the quality detection module and is used to emit a warning sound signal and / or a warning light signal according to the warning signal.

[0069] In the application, the alarm can be a buzzer, a speaker, an indicator light, an audible and visual signal alarm, etc. The alarm sends out an audible and / or visual warning signal according to the warning signal, so as to make a prompt reminder in time when the welding quality is unqualified.

[0070] In application, the laser welding penetration detection device also includes an optimization feedback module, which is communicated with the processing module. The optimization feedback module is used to generate optimization instructions for adjusting welding laser processing parameters when the keyhole penetration data exceeds the preset penetration range.

[0071] In the application, the preset penetration range can be determined according to the characteristics of the workpiece to be processed, such as density, thickness, etc. If the keyhole penetration data exceeds the preset penetration range, a signal indicating that the welding is unqualified is generated to prompt the staff to handle it; at the same time, an optimization instruction for adjusting the welding laser processing parameters can also be generated, such as adjusting the welding laser power or the moving speed of the welding laser.

[0072] The laser welding detection device provided by the utility model uses a scanning galvanometer 22 to make the spot of the second scanning light on the workpiece move with the spot of the welding laser on the workpiece as a reference system, so that the first spot can be irradiated in the keyhole in real time during the welding process, thereby ensuring the accuracy of the keyhole penetration data contained in the interference signal obtained; by sequentially arranging the collimator 14, the grating 15, and the focusing lens group 16 on the optical path between the optical fiber coupler 12 and the photosensitive device 17, the quality of the interference signal output to the photosensitive device 17 is improved; the quality of welding can be detected in real time through the quality detection module, and the alarm can be used to make timely reminders when the welding quality is unqualified. In addition, through the optimization feedback module, when the keyhole penetration data exceeds the preset penetration range, an optimization instruction for adjusting the welding laser processing parameters is generated to achieve feedback to the welding system.

[0073] based on Figure 1The laser welding penetration detection device provided by the utility model is briefly explained in terms of use. The detection light source 11 outputs detection light, which is input into the fiber coupler 12 and then output as reference light and scanning light. The reference light is reflected by the reflector 13 and then input into the fiber coupler 12. The scanning light passes through the probe 21 and enters the sample arm. After passing through the scanning galvanometer 22 and the welding laser, it passes through the first optical mirror 23 and then hits the workpiece to be processed through the welding laser galvanometer 24. The scanning galvanometer 22 controls the scanning light to move with the welding laser as the reference system to accurately Hit the keyhole on the workpiece to be processed; after the scanning light hits the keyhole, it is reflected as return light, and the return light is sequentially input into the fiber coupler 12 through the welding laser galvanometer 24, the first optical mirror 23, the scanning galvanometer 22 and the probe 21, and the reference light and the return light interfere with each other in the fiber coupler 12 to generate an interference signal, and the interference signal sequentially passes through the collimator 14 and the grating 15 and then is focused on the photosensitive device 17 through the focusing lens group 16, and the processor processes the interference signal received by the photosensitive device 17 to obtain the keyhole melting depth data contained therein.

[0074] The utility model provides a laser welding penetration detection device, comprising a reference arm 1 and a sample arm 2, wherein the reference arm comprises a detection light source 11, a fiber coupler 12, and a reflector 13, and the sample arm 2 comprises a scanning galvanometer 22, a first optical mirror 23, and a welding laser galvanometer 24. The detection light output by the detection light source 11 is input into the fiber coupler 12 and is divided into a reference light and a scanning light, and the reference light returns to the fiber coupler 12 through the reflector 13; the scanning light sequentially passes through the scanning galvanometer 22 and the first optical mirror 23, and is irradiated on the surface of a workpiece together with the welding laser through the welding laser galvanometer 24, and the scanning galvanometer 22 is further used to make the light spot of the second scanning light on the workpiece move with the light spot of the welding laser on the workpiece as a reference system, so as to realize that the scanning light is hit in a keyhole on the workpiece in real time, the scanning light is reflected from the keyhole and input into the fiber coupler 12, and the fiber coupler 12 generates an interference signal containing keyhole penetration data based on the scanning light reflected from the keyhole and the reference light returned through the reflector, so that real-time keyhole molten pool data can be obtained from the interference signal.

[0075] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A laser welding penetration detection device, characterized in that: Includes a reference arm and a sample arm; The reference arm comprises a detection light source, a fiber coupler, and a reflector, wherein the detection light source is used to output detection light, the fiber coupler is used to receive the detection light, and output reference light to the reflector, output the first scanning light to the sample arm, and the reflector is used to reflect the reference light back to the fiber coupler; The sample arm comprises a scanning galvanometer, a first optical mirror and a welding laser galvanometer, wherein the scanning galvanometer is used to receive the first scanning light and output the second scanning light to the first optical mirror, the first optical mirror is used to receive the second scanning light and the welding laser and output them to the welding laser galvanometer, and the welding laser galvanometer is used to output the received welding laser and the second scanning light to the workpiece; The scanning galvanometer is also used to make the light spot of the second scanning light on the workpiece move with the light spot of the welding laser on the workpiece as a reference system; The optical fiber coupler is further used to receive the second scanning light reflected by the workpiece, and output an interference signal based on the second scanning light and the reference light.

2. The laser welding penetration detection device according to claim 1, characterized in that: The first optical mirror is a dichroic mirror or a beam combining mirror.

3. The laser welding penetration detection device according to claim 1, characterized in that: The sample arm further includes a probe, which is used to receive the first scanning light output by the optical fiber coupler and output the first scanning light to the scanning galvanometer.

4. The laser welding penetration detection device according to claim 1, characterized in that: The reference arm further includes a photosensitive device, and the photosensitive device is used to receive the interference signal output by the optical fiber coupler.

5. The laser welding penetration detection device according to claim 4, characterized in that: The reference arm further comprises a collimator, which is located on the optical path between the optical fiber coupler and the photosensitive device.

6. The laser welding penetration detection device according to claim 5, characterized in that: The reference arm further comprises a grating, and the grating is located on the optical path between the collimating mirror and the photosensitive device.

7. The laser welding penetration detection device according to claim 6, characterized in that: The reference arm further comprises a focusing lens group, and the focusing lens group is located on the optical path between the grating and the photosensitive device.

8. The laser welding penetration detection device according to claim 7, characterized in that: The focusing lens group includes 3 to 5 focusing lenses.

9. The laser welding penetration detection device according to claim 4, characterized in that: It also includes a processor, which is communicatively connected to the photosensitive device, and is used to generate keyhole penetration data based on the interference signal obtained by the photosensitive device.

10. The laser welding penetration detection device according to any one of claims 1 to 9, characterized in that: The reflector is a plane reflector or a spherical reflector.

Images