Multi-ray coaxial laser processing monitoring device based on active illumination

Abstract

This invention provides a multi-ray coaxial laser processing monitoring device based on active illumination. The device includes a laser welding head, a monitoring module, and an auxiliary light source unit. The monitoring module includes a beam reversing unit and a monitoring unit. The beam reversing unit includes a first beam bending module, a second beam bending module, an adjustment module, a third beam bending module, and a fourth beam bending module. The fourth beam bending module is located within the laser welding head. The first beam bending module is connected to the fourth beam bending module and the second beam bending module. The third beam bending module is horizontally connected to one end of the second beam bending module via the adjustment module. The monitoring unit includes a first monitoring unit, a second monitoring unit, and a third monitoring unit. This invention achieves multi-sensor integration and, by adding an auxiliary light source, increases the imaging clarity of the visual sensor, realizing multi-ray coaxial monitoring.

Description

Technical Field

[0001] This invention relates to the field of laser welding monitoring technology, and in particular to a multi-ray coaxial laser processing monitoring device based on active illumination. Background Technology

[0002] During laser welding, a complex physicochemical reaction occurs between the laser and the workpiece, generating various signals such as acoustic, optical, and electrical signals. These signals are collected to monitor the welding quality.

[0003] Currently, the common method for monitoring welding quality is visual monitoring. Visual monitoring mainly uses a camera to acquire light signals from the welding area. The visual sensor converts the single-band light signal into an electrical signal, ultimately presenting a welding image. To reduce the influence of other bands on monitoring, filters and attenuators are often added in front of the visual sensor, which leads to a problem of insufficient light transmission. This is usually solved by using an auxiliary light source. Currently, almost all of them use rangefinder light sources. This not only results in a loose structure, but also causes uneven beam distribution due to the angled illumination, leading to less clear images.

[0004] Furthermore, monitoring welding quality with a single sensor cannot achieve optimal results. Multi-sensor fusion based on vision sensors is the current development trend. Summary of the Invention

[0005] The purpose of this invention is to provide a multi-ray coaxial laser processing monitoring device based on active illumination, which integrates multiple sensors and adds an auxiliary light source to increase the imaging clarity of the visual sensor, thereby achieving multi-ray coaxial monitoring.

[0006] The technical solution of the present invention is: a multi-ray coaxial laser processing monitoring device based on active illumination, comprising a laser welding head for welding, a monitoring module for monitoring the welding process of the laser welding head, and an auxiliary light source unit for increasing the light transmission of the monitoring module and the laser welding head;

[0007] The monitoring module includes a beam reversing unit and a monitoring unit. The beam reversing unit includes a first beam bending module, a second beam bending module, an adjustment module, a third beam bending module, and a fourth beam bending module. The fourth beam bending module is located inside the laser welding head. The first beam bending module is horizontally connected to one end of the fourth beam bending module. The second beam bending module is vertically connected to the upper end of the first beam bending module. The third beam bending module is horizontally connected to one end of the second beam bending module through the adjustment module.

[0008] The monitoring unit includes a first monitoring unit connected to the first beam bending module, a second monitoring unit connected to the second beam bending module, and a third monitoring unit connected to the third beam bending module.

[0009] Preferably, the laser welding head includes a collimating lens, a welding body, a reflector, a focusing lens, and a focusing module. The collimating lens, the reflector, the focusing lens, and the focusing module are arranged sequentially from top to bottom within the welding body, and the reflector is located within the fourth beam bending module.

[0010] Preferably, the first beam bending module is provided with a first beam opening and a second beam opening, and a first beam splitter is provided in the first beam bending module for refracting the beam from the second beam opening to the first beam opening.

[0011] The second beam bending module is provided with a third beam port and a fourth beam port; the second beam bending module is provided with a second beam splitter for refracting the beam from the fourth beam port to the third beam port;

[0012] The third beam bending module is provided with a fifth beam port and a sixth beam port, and the third beam bending module is provided with a polarizing beam splitter for refracting the beam from the sixth beam port to the fifth beam port.

[0013] The fourth beam bending module is provided with a seventh beam port, an eighth beam port and a ninth beam port;

[0014] The ninth beam port is located at the upper end of the fourth beam bending module, the seventh beam port is located at the lower end of the fourth beam bending module, the eighth beam port is connected to the first beam port, the second beam port is connected to the third beam port, the fourth beam port is connected to one end of the adjustment module, and the other end of the adjustment module is connected to the fifth beam port.

[0015] Preferably, a photoelectric sensor for determining the moving position of the laser welding head is installed on one side of the first beam bending module.

[0016] Preferably, the first beam bending module is further provided with a first monitoring port; the second beam bending module is further provided with a second monitoring port; and the third beam bending module is further provided with a third monitoring port.

[0017] The first monitoring unit includes a mounting cabinet, a drawer, a connection module, and a first sensor. The drawer is embedded in the mounting cabinet. One end of the mounting cabinet is connected to the first monitoring port, and the other end is connected to the connection module. The first sensor is mounted on the connection module.

[0018] The second monitoring unit includes a mounting cabinet, a drawer, a connection module, and a second sensor; the drawer is embedded in the mounting cabinet, one end of the mounting cabinet is connected to the second monitoring port, and the other end is connected to the connection module; the second sensor is mounted on the connection module.

[0019] The third monitoring unit includes a mounting cabinet, a drawer, a connection module, and a third sensor; the drawer is embedded in the mounting cabinet, one end of the mounting cabinet is connected to the third monitoring port, and the other end is connected to the automatic zoom device, which is connected to the third sensor.

[0020] Preferably, the drawer has countersunk holes at both the top and bottom, the countersunk holes are internally connected, a filter and an attenuator are installed in the countersunk holes, and a buckle is also provided to limit the position of the filter and attenuator.

[0021] Preferably, the automatic zoom device includes a first housing, a first lens, a second lens, a sliding groove, a worm gear shaft, an upper end cover, an optical axis, a first lens sleeve, a third lens, a worm, a first motor, a support, a sealing cover, and a bearing;

[0022] The first housing contains a first lens and a third lens spaced axially inside. One end of the first housing with the first lens is connected to the third monitoring unit via an end cap, and the other end is axially fitted with a sealing cap. The end of the sealing cap is covered by the upper end cap. A worm gear shaft and an optical axis are provided inside the sealing cap. One end of the worm gear shaft and the optical axis are rotatably disposed in opposite side walls of the first housing, and the other end of the worm gear shaft and the optical axis are rotatably mounted to the upper end cap via bearings. A sliding groove is provided on two opposite side walls of the sealing cap. Both ends of the first lens sleeve are fitted into the sliding groove and connected to the worm gear shaft and the optical axis, respectively. The third lens is embedded inside the first lens sleeve. The worm is mounted on the sealing cap via a support. The first motor is driven by the worm, and the worm meshes with the worm gear shaft. The rotation of the worm gear shaft can drive the first lens sleeve and the third lens on it to move axially along the sealing cap.

[0023] Preferably, the auxiliary light source unit includes a coaxial auxiliary light source part and a paraxial auxiliary light source part. The coaxial auxiliary light source part is mounted on the third beam bending module, and the paraxial auxiliary light source part is mounted on the laser welding head.

[0024] Preferably, the coaxial auxiliary light source includes a connecting cover, a fourth lens, a third buckle, a second housing, a rotating shaft, a third housing, a second lens sleeve, a fifth lens, and a first auxiliary light source;

[0025] The second housing is docked with the third housing, and the rotating shaft is rotatably disposed between the second housing and the third housing. The connecting cover is placed on the end of the second housing away from the third housing, and the fourth lens is embedded in the interior of the second housing by a third buckle. The fifth lens is embedded on the second lens sleeve, and the second lens sleeve is fixed inside the rotating shaft. The end of the third housing away from the second housing is connected to the first auxiliary light source. The connecting cover is connected to the third beam bending module.

[0026] Preferably, the off-axis auxiliary light source includes a connecting rod, a fan-shaped plate, a second fiber collimating lens, a motor frame, a second motor, a clamping frame, a convex slider, and a lead screw;

[0027] One end of the connecting rod is connected to the laser welding head, and the other end is provided with a sliding groove. The lead screw is rotatably installed in the sliding groove. The convex slider is fitted on the lead screw and adapted to the sliding groove. One end of the lead screw is connected to the second motor, and the other end is provided with a second photoelectric sensor. The second motor is installed at one end of the connecting rod through a motor frame.

[0028] The sector plate is connected to the convex slider. The clamping frame is provided with the second fiber collimator. The sector plate is provided with an arc groove. One end of the clamping frame is hinged to the center of the sector plate, and the other end is provided with a column. The column passes through the arc groove and slides along the arc groove. The column is limited to its sliding position on the arc groove by a nut.

[0029] Compared with related technologies, the beneficial effects of the present invention are as follows:

[0030] First, the first beam bending module, the second beam bending module, and the third beam bending module are set up to achieve the integration of multiple beams in the same optical path. At the same time, the connection module is set up to facilitate the installation of different types of sensors and realize the replacement and integration of different types of sensors.

[0031] Second, the coaxial auxiliary light source, the quarter-wave plate, and the polarizing beam splitter are configured to ensure that the final beam is incident on the welding area in an approximately parallel manner, resulting in more uniform light and improved image clarity from the third sensor. The position of the fifth lens can be adjusted by rotating the axis to accommodate focusing lenses with different focal lengths. Common focal length values ​​are marked on the rotating axis, and by aligning these values ​​with the markings on the second housing, the fifth lens can be adjusted, further increasing the adaptability of the device.

[0032] Third, the automatic focusing device and the first photoelectric sensor are provided. The automatic focusing device includes a first lens, a second lens, a third lens, a first motor, a worm gear shaft, and a worm. The positions of the first lens and the second lens are fixed. The first photoelectric sensor determines the moving distance of the laser welding head, i.e., the defocus distance. According to the correspondence between different defocus distances and the position of the third lens, an electrical signal is sent to the first motor to control its rotation angle, thereby adjusting the position of the third lens and finally realizing automatic focusing. This allows the third sensor to accurately acquire light signals so that the monitoring effect can be optimized.

[0033] Fourth, the second photoelectric sensor and the off-axis auxiliary light source are set up. Due to the change in defocus, the horizontal position of the second fiber collimator needs to be adjusted so that the third sensor can acquire sufficient light signal during the welding process. The defocus signal transmitted by the first photoelectric sensor is used to calculate the position of the convex slider through the similar triangle theorem. The electrical signal is sent to the second motor, and the drive screw rotates to move the convex slider to the designated position. Finally, the position of the second fiber collimator is automatically adjusted to achieve the best detection effect. Attached Figure Description

[0034] Figure 1 A schematic diagram of the structure of the multi-ray coaxial laser processing monitoring device based on active illumination provided by the present invention;

[0035] Figure 2 for Figure 1 A cross-sectional view;

[0036] Figure 3 This is a schematic diagram of the automatic zoom device.

[0037] Figure 4 This is a cross-sectional schematic diagram of the automatic zoom device;

[0038] Figure 5 This is a schematic diagram of the coaxial auxiliary light source section.

[0039] Figure 6 This is a cross-sectional schematic diagram of the coaxial auxiliary light source section;

[0040] Figure 7 This is a schematic diagram of the rotating shaft in the coaxial auxiliary light source section.

[0041] Figure 8 A schematic diagram of the off-axis auxiliary light source section;

[0042] Figure 9 This is a rear view diagram of the auxiliary light source section of the rangefinder.

[0043] Figure 10 for Figure 9 A bottom view;

[0044] Figure 11 A schematic diagram of the adjustment module in the monitoring module;

[0045] Figure 12 This is a schematic diagram of the drawer structure;

[0046] Figure 13 This is a cross-sectional view of the drawer;

[0047] Figure 14 The optical path diagram of the third sensor;

[0048] Figure 15 Optical path diagram of a coaxial light source;

[0049] Figure 16 The optical path diagram of the first sensor;

[0050] Figure 17 This is the optical path diagram of the second sensor. Detailed Implementation

[0051] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other. For ease of description, the terms "upper," "lower," "left," and "right" used below only indicate that they correspond to the upper, lower, left, and right directions in the accompanying drawings and do not limit the structure.

[0052] like Figure 1-Figure 2 As shown, the multi-ray coaxial laser processing monitoring device based on active illumination provided in this embodiment includes a laser welding head 1 for welding, a monitoring module for monitoring the welding process of the laser welding head 1, and an auxiliary light source unit 3 for increasing the light transmission of the monitoring module and the laser welding head 1.

[0053] The laser welding head 1 includes a collimating lens 104, a welding body 101, a focusing lens 103, and a focusing module 106.

[0054] The monitoring module includes a beam reversing unit and a monitoring unit. The beam reversing unit includes a first beam bending module 201, a second beam bending module 202, an adjustment module 204, a third beam bending module 203, and a fourth beam bending module 105.

[0055] The welding body 101 has an internal cavity, with a welding head at the bottom end. Within the cavity, from top to bottom, are arranged the collimating lens 104, the fourth beam bending module 105, the focusing lens 103, and the focusing module 106. The focusing lens 103 has a retaining ring 107 at its upper end.

[0056] The first beam bending module 201 is horizontally connected to one end of the fourth beam bending module 105, the second beam bending module 202 is vertically connected to the upper end of the first beam bending module 201, and the third beam bending module 203 is horizontally connected to one end of the second beam bending module 202 through the adjustment module 204.

[0057] The monitoring unit includes a first monitoring unit 4 connected to the first beam bending module 201, a second monitoring unit 5 connected to the second beam bending module 202, and a third monitoring unit 6 connected to the third beam bending module 203.

[0058] The first beam bending module 201 is provided with a first beam port 2001, a second beam port 2002, and a first monitoring port 2008. The first beam port 2001 and the first monitoring port 2008 are horizontally located at both ends of the first beam bending module 201, and the second beam port 2002 is located at the upper end of the first beam bending module 201. A first beam splitter 211 is provided within the first beam bending module 201 for refracting the beam from the second beam port 2002 to the first beam port 2001.

[0059] The second beam bending module 202 is provided with a third beam port 2004, a fourth beam port 2005, and a second monitoring port 2009. The third beam port 2004 and the second monitoring port 2009 are vertically located at the upper and lower ends of the second beam bending module 202, and the fourth beam port 2005 is horizontally located at one end of the second beam bending module 202. The second beam bending module 202 is provided with a second beam splitter 221 for refracting the beam from the fourth beam port 2005 to the third beam port 2004.

[0060] The third beam bending module 203 is provided with a fifth beam port 2006, a sixth beam port 2007, and a third monitoring port 2010. The fifth beam port 2006 and the sixth beam port 2007 are horizontally located at both ends of the third beam bending module 203, and the third monitoring port 2010 is located at the upper end of the third beam bending module 203. The third beam bending module 203 is provided with a polarizing beam splitter 231 for refracting the beam from the sixth beam port 2007 to the fifth beam port 2006.

[0061] The fourth beam bending module 105 is provided with a seventh beam port 1001, an eighth beam port 1002, and a ninth beam port 1003. The fourth beam bending module 105 contains a reflector 102 capable of perpendicularly reflecting the beam from the eighth beam port 1002 to the seventh beam port 1001. The ninth beam port 1003 is located at the upper end of the fourth beam bending module 105, and a collimating lens 104 is disposed at its upper end. The seventh beam port 1001 is located at the lower end of the fourth beam bending module 105. The eighth beam port 1002 is connected to the first beam port 2001, the second beam port 2002 is connected to the third beam port 2004, the fourth beam port 2005 is connected to one end of the adjustment module 204, and the other end of the adjustment module 204 is connected to the fifth beam port 2006.

[0062] The first beam splitter 211 and the second beam splitter 221 split the light beam reflected by the reflector 102 in sequence, so that the first sensor 12 and the second sensor 13 can collect the light signal. The third beam bending module 203 is equipped with a polarizing beam splitter 231, which transmits the P light and reflects the S light at the same time. Compared with ordinary beam splitters, it can reduce the loss of the reflected useful light signal.

[0063] The first monitoring unit 4 includes a mounting cabinet 7, a drawer 8, a connection module 18, and a first sensor 12. The drawer 8 is embedded in the mounting cabinet 7. One end of the mounting cabinet 7 is connected to the first monitoring port 2008, and the other end is connected to the connection module 18. The first sensor 12 is disposed on the connection module 18.

[0064] The second monitoring unit 5 includes a mounting cabinet 7, a drawer 8, a connection module 18, and a second sensor 13; the drawer 8 is embedded in the mounting cabinet 7, one end of the mounting cabinet 7 is connected to the second monitoring port 2009, and the other end is connected to the connection module 18, and the second sensor 13 is disposed on the connection module 18.

[0065] The third monitoring unit 6 includes a mounting cabinet 7, a drawer 8, a connection module 18, and a third sensor 14; the drawer 8 is embedded in the mounting cabinet 7, one end of the mounting cabinet 7 is connected to the third monitoring port 2010, and the other end is connected to the automatic zoom device 15, which is connected to the third sensor 14.

[0066] The first sensor 12 and the second sensor 13 are both installed in the corresponding connection module 18 by means of threaded connection, which is convenient for installation and disassembly, and can be connected with different types of sensors. The appropriate sensor type can be selected for different welding materials and processes.

[0067] like Figure 12 , Figure 13As shown, the drawer 8 has countersunk holes 801 at both the top and bottom, which are through-holes, allowing for the simultaneous installation of two lenses (filter 9 and attenuator 10). The drawer-type installation method facilitates installation and disassembly. The countersunk holes 801 are threaded, and the filter 9 and attenuator 10 are installed in the countersunk holes of the drawer 8 to filter the optical signal bands, reducing interference from other optical signal bands. This helps the sensor to acquire optical signals more accurately. Both the filter 9 and attenuator 10 are limited by the first latch 11 to prevent them from shaking randomly during operation, which would affect the acquisition of the sensing signal.

[0068] The filter 9 transmits the same wavelength as the first sensor 12, the second sensor 13 and the third sensor 14, which are most sensitive to the wavelength, thus enabling effective monitoring of the welding process.

[0069] The third sensor 14 is an industrial camera, and an automatic zoom device 15 is installed between it and the connection module 18. For example... Figure 3 , Figure 4 As shown, the automatic zoom device 15 includes a first housing 1501, a first lens 1502, a second lens 1503, a sliding groove 1504, a worm gear shaft 1505, an upper end cover 1506, an optical axis 1507, a first lens sleeve 1508, a third lens 1509, a worm gear 1510, a first motor 1511, a support 1512, a sealing cover 1513, and a bearing 1514.

[0070] The first housing 1501 has a first lens 1502 and a third lens 1503 axially spaced inside. One end of the first housing 1501 with the first lens 1502 is connected to the third monitoring unit 6 via an end cap, and the other end is axially fitted with a sealing cover 1513. The end of the sealing cover 1513 is covered by an upper end cap 1506. A worm gear shaft 1505 and an optical axis 1507 are provided inside the sealing cover 1513. One end of the worm gear shaft 1505 and the optical axis 1507 are rotatably mounted in opposite side walls of the first housing 1501 via bearings. The other ends of the worm gear shaft 1505 and the optical axis 1507 are rotatably mounted to the upper end cover 1506 via bearing 1514; both ends of the first lens sleeve 1508 are adapted to the sliding groove 1504, and both ends of the first lens sleeve 1508 are respectively connected to the worm gear shaft 1505 and the optical axis 1507, and the third lens 1509 is embedded inside the first lens sleeve 1508; the worm 1510 is mounted on the sealing cover 1513 via support 1512, and the first motor 1511 is driven by the worm 1510, and the worm 1510 meshes with the worm gear shaft 1505. The rotation of the worm gear shaft 1505 can drive the first lens sleeve 1508 and the third lens 1509 on it to move.

[0071] The first motor 1511 drives the worm gear 1510 and the worm wheel shaft 1501 to rotate, thereby adjusting the third lens 1509 up and down through the principle of the lead screw and nut pair, thus achieving the purpose of adjusting the defocus.

[0072] The sealing cover 1513 can prevent natural light from interfering with the optical path and improve the accuracy of monitoring.

[0073] like Figure 11 As shown, the adjustment module 204 has a countersunk hole and is equipped with a quarter-wave plate 214 and a fourth latch 224. The countersunk hole has threads on its sidewall, and the adjustment module 204 and the fourth latch 224 are connected by threads. The quarter-wave plate 214 is installed between the adjustment module 204 and the fourth latch 224 to fix the quarter-wave plate 214 in place. The quarter-wave plate 214 converts the transmitted P-light into S-light, causing the polarizing beam splitter 231 to reflect more light signals and improve the conversion efficiency of the light signals.

[0074] like Figure 1 As shown, the auxiliary light source unit 3 includes a coaxial auxiliary light source part 3001 and a paraxial auxiliary light source part 3002. The coaxial auxiliary light source part 3001 is mounted on the third beam bending module 203, and the paraxial auxiliary light source part 3002 is mounted on the laser welding head 1.

[0075] like Figures 5-7 As shown, the coaxial auxiliary light source part 3001 includes a connecting cover 3011, a fourth lens 3121, a third buckle 3221, a second housing 3021, a rotating shaft 3031, a third housing 3041, a second lens sleeve 3131, a fifth lens 3231, and a first auxiliary light source 3051.

[0076] The second housing 3021 has a connecting cover 3011 at one end and a groove 3321 recessed axially at the other end. The third housing 3041 has a locking block 3141 protruding axially at one end. Two grooves 3321 and two locking blocks 3141 are arranged opposite each other. The locking block 3141 is inserted into the groove 3321 and then connected by screws. A rotating shaft 3031 is provided between the second housing 3021 and the third housing 3041. Specifically, both the second housing 3021 and the third housing 3041 have grooves, and both ends of the rotating shaft 3031 extend into the grooves and can rotate relative to them. A trapezoidal boss 3331 (e.g., ...) is provided in the middle of the rotating shaft 3031. Figure 7 (As shown).

[0077] The rotating shaft 3031 is a hollow cylindrical structure with internal threads on its inner cylindrical sidewall. The second lens sleeve 3131 is threadedly fixed inside the rotating shaft 3031. A fifth lens 3231 is embedded in the second lens sleeve 3131. The end of the third housing 3041 away from the second housing 3021 is threadedly connected to the first auxiliary light source 3051. The connecting cover 3011 is connected to the third beam bending module 203. The fourth lens 3121 is embedded inside the end of the second housing 3021 where the connecting cover 3011 is located via a third buckle 3221.

[0078] The first fiber collimating lens 3051 emits P-beams, which pass through the fifth lens 3231, the fourth lens 3121 and the focusing lens 103, and finally illuminate the welding area as a parallel beam. By rotating the rotating shaft 3031, the second lens sleeve 3131 can be moved along its axial direction, thereby adjusting the parallelism of the beam emitted by the first fiber collimating lens 3051.

[0079] The trapezoidal protrusion 3331 is marked with the focal length of a common focusing lens 103. The second housing 3021 has a positioning groove 20 at the top of the section near the rotating shaft 3031. The Zemax simulation software simulates different focusing lenses 103 to determine the position of the fifth lens 3231 corresponding to each focusing lens 103. The fifth lens 3231 is adjusted to the position of the corresponding focal length value by rotating the rotating shaft 3031.

[0080] like Figures 8-10 As shown, the off-axis auxiliary light source part 3002 includes a connecting rod 3012, a fan-shaped plate 3082, a second fiber collimating lens 3302, a motor frame 3062, a second motor 3052, a clamping frame 3102, a convex slider 3032, a lead screw 3022, and a T-block 3033.

[0081] One end of the connecting rod 3012 is connected to the laser welding head 1, and the other end is provided with a sliding groove 3034. The lead screw 3022 is rotatably mounted in the sliding groove 3034 via a bearing. The convex slider 3032 is fitted onto the lead screw 3022 and is adapted to the sliding groove 3034. One end of the lead screw 3022 is connected to the second motor 3052 via a coupling 3042, and the other end is provided with the second photoelectric sensor 16. The second motor 3052 is mounted on one end of the connecting rod 3012 via a motor frame 3062.

[0082] The second photoelectric sensor 16 emits a light signal to the convex slider 3032 and receives the signal to determine the position of the convex slider 3032. The first photoelectric sensor 17 determines the defocus amount, and then calculates the position of the convex slider 3032 using the similar triangle theorem. Then, it sends a signal to the second motor 3052 to move the convex slider 3032 a certain distance.

[0083] The sector plate 3082 is connected to the convex slider 3032 via a T-shaped block 3033. The second fiber collimating lens 3302 is fixed inside the clamping frame 3102 by screws 3202. The second fiber collimating lens 3302 is positioned towards the bottom working end of the laser welding head 1 (e.g., ...). Figure 1 (As shown).

[0084] The sector plate 3082 is provided with an arc-shaped groove 3092. One end of the clamping frame 3102 is hinged to the center of the sector plate 3082 (the hinge can be achieved by using a cylinder and bearing mounting method, with the cylinder fixed on the clamping frame 3102 and mounted on the sector plate 3082 via a bearing). The other end of the clamping frame 3102 is provided with a column 3112. The length of the column 3112 is greater than the thickness of the sector plate 3082. The column 3112 passes through the arc-shaped groove 3092 and slides along the arc-shaped groove 3092. The sliding position of the column 3112 on the arc-shaped groove 3092 is limited by a nut. The clamping frame 3102 is manually adjustable by tightening the nut to fix the angle of the clamping frame 3102.

[0085] The second motor 3052 rotates to drive the convex slider 3032, its fan-shaped plate 3082, clamping frame 3102, and second fiber optic collimating lens 3302 to move together along the slide groove 3034. Furthermore, by adjusting the angle of the clamping frame 3102, the position of the second fiber optic collimating lens 3302 is adjusted to prevent significant mirror reflection during welding and increase the amount of light entering the third sensor 14. Different welding materials require different angles for the second fiber optic collimating lens 3302.

[0086] like Figure 1 As shown, a photoelectric sensor 17 for determining the moving position of the laser welding head 1 is installed on one side of the first beam bending module 203. The sensor determines the moving position of the laser welding head 1 and then determines its defocus amount. Based on the relationship between the defocus amount and the automatic zoom device 15, the position of the third lens 1509 is adjusted to improve the imaging clarity of the third sensor 14.

[0087] The first sensor 12, the second sensor 13, the third sensor 14, and the coaxial auxiliary light source section 3001 share a common optical path.

[0088] like Figures 14-17 As shown, the working principle of the laser processing monitoring device provided by the present invention is as follows:

[0089] The laser is turned on, and the auxiliary light source is emitted from the first fiber collimator 3051 and the second fiber collimator 3102. The rotating clamp 3102 is rotated so that the polarized beam from the second fiber collimator 3302 illuminates the welding area. Welding parameters are set to start welding. The polarized beam in the P direction of the first fiber collimator 3051 passes through the polarizing beam splitter 231, and the polarization direction of the emitted beam from the quarter-wave plate 214 changes to the same direction as that of the second fiber collimator 3302. After passing through the beam expanding system composed of the fourth lens 3121, the fifth lens 3231, and the focusing lens 103, and the reflection effect of the second beam splitter 221, the first beam splitter 211, and the reflecting mirror 102, the beam is uniformly illuminated in the welding area.

[0090] Under the influence of reflection and diffuse reflection on the surface of the welded workpiece, the polarized light beam passes through the focusing lens 103, the reflecting mirror 102, the first beam splitter 211, the second beam splitter 221, the fifth lens 3231, and the fourth lens 3121. After passing through the quarter-wave plate 214, the polarization direction changes and becomes S-polarized light. This beam cannot directly pass through the cemented surface of the polarizing beam splitter and is reflected. The polarized light beam passes through the attenuator 10 and the filter 9. Under the action of the first lens 1502, the second lens 1503, and the third lens 1509, the polarized light beam illuminates the third sensor 14 and forms an image.

[0091] When welding begins, various radiation bands are generated in the welding area. These radiation bands pass through the focusing lens 103 and the reflecting mirror 102. Radiation bands identical to the coating bands on the first beam splitter 211 pass through the first beam splitter 211 and ultimately illuminate the first sensor 12. Bands that do not pass through 211 are reflected by 211 to the second beam splitter 221. Radiation bands identical to the coating bands on the second beam splitter 221 pass through the second beam splitter 221 and ultimately illuminate the second sensor 13. By capturing the changes in the intensity of the light signals from the first sensor 12, the second sensor 13, and the third sensor 14, and processing these signals, the welding process can be monitored.

[0092] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A multi-ray coaxial laser processing monitoring device based on active illumination, characterized in that, It includes a laser welding head (1) for welding, a monitoring module for monitoring the welding process of the laser welding head (1), and an auxiliary light source unit (3) for increasing the light transmission of the monitoring module and the laser welding head (1); The monitoring module includes a beam reversing unit and a monitoring unit. The beam reversing unit includes a first beam bending module (201), a second beam bending module (202), an adjustment module (204), a third beam bending module (203), and a fourth beam bending module (105). The fourth beam bending module (105) is located inside the laser welding head (1). The first beam bending module (201) is horizontally connected to one end of the fourth beam bending module (105). The second beam bending module (202) is vertically connected to the upper end of the first beam bending module (201). The third beam bending module (203) is horizontally connected to one end of the second beam bending module (202) through the adjustment module (204). The monitoring unit includes a first monitoring unit (4) connected to the first beam bending module (201), a second monitoring unit (5) connected to the second beam bending module (202), and a third monitoring unit (6) connected to the third beam bending module (203); A photoelectric sensor (17) for determining the moving position of the laser welding head (1) is installed on one side of the first beam bending module (201).

2. The multi-ray coaxial laser processing monitoring device based on active illumination according to claim 1, characterized in that, The laser welding head (1) includes a collimating lens (104), a welding body (101), a reflector (102), a focusing lens (103), and a focusing module (106). The collimating lens (104), the reflector (102), the focusing lens (103), and the focusing module (106) are arranged sequentially from top to bottom within the welding body (101). The reflector (102) is located within the fourth beam bending module (105).

3. The multi-ray coaxial laser processing monitoring device based on active illumination according to claim 1, characterized in that, The first beam bending module (201) is provided with a first beam port (2001) and a second beam port (2002), and a first beam splitter (211) is provided in the first beam bending module (201) for refracting the beam from the second beam port (2002) to the first beam port (2001); The second beam bending module (202) is provided with a third beam port (2004) and a fourth beam port (2005); the second beam bending module (202) is provided with a second beam splitter (221) for refracting the beam from the fourth beam port (2005) to the third beam port (2004); The third beam bending module (203) is provided with a fifth beam port (2006) and a sixth beam port (2007). The third beam bending module (203) is provided with a polarizing beam splitter (231) for refracting the beam from the sixth beam port (2007) to the fifth beam port (2006). The fourth beam bending module (105) is provided with a seventh beam port (1001), an eighth beam port (1002) and a ninth beam port (1003); The ninth beam port (1003) is located at the upper end of the fourth beam bending module (105), the seventh beam port (1001) is located at the lower end of the fourth beam bending module (105), the eighth beam port (1002) is connected to the first beam port (2001), the second beam port (2002) is connected to the third beam port (2004), the fourth beam port (2005) is connected to one end of the adjustment module (204), and the other end of the adjustment module (204) is connected to the fifth beam port (2006).

4. The multi-ray coaxial laser processing monitoring device based on active illumination according to claim 1, characterized in that, The first beam bending module (201) is also provided with a first monitoring port (2008); the second beam bending module (202) is also provided with a second monitoring port (2009); and the third beam bending module (203) is also provided with a third monitoring port (2010). The first monitoring unit (4) includes a mounting cabinet (7), a drawer (8), a connection module (18), and a first sensor (12). The drawer (8) is embedded in the mounting cabinet (7). One end of the mounting cabinet (7) is connected to the first monitoring port (2008), and the other end is connected to the connection module (18). The first sensor (12) is mounted on the connection module (18). The second monitoring unit (5) includes a mounting cabinet (7), a drawer (8), a connection module (18), and a second sensor (13); the drawer (8) is embedded in the mounting cabinet (7), one end of the mounting cabinet (7) is connected to the second monitoring port (2009), and the other end is connected to the connection module (18); the second sensor (13) is mounted on the connection module (18). The third monitoring unit (6) includes a mounting cabinet (7), a drawer (8), a connection module (18), and a third sensor (14); the drawer (8) is embedded in the mounting cabinet (7), one end of the mounting cabinet (7) is connected to the third monitoring port (2010), and the other end is connected to the automatic zoom device (15), which is connected to the third sensor (14).

5. The multi-ray coaxial laser processing monitoring device based on active illumination according to claim 4, characterized in that, The drawer (8) is provided with countersunk holes (801) at both the top and bottom. The countersunk holes (801) are internally connected. A filter (9) and an attenuator (10) are installed in the countersunk holes (801). A buckle (11) is also provided to limit the position of the filter (9) and the attenuator (10).

6. The multi-ray coaxial laser processing monitoring device based on active illumination according to claim 4, characterized in that, The automatic zoom device (15) includes a first housing (1501), a first lens (1502), a second lens (1503), a sliding groove (1504), a worm gear shaft (1505), an upper end cover (1506), an optical axis (1507), a first lens sleeve (1508), a third lens (1509), a worm (1510), a first motor (1511), a support (1512), a sealing cover (1513), and a bearing (1514). The first housing (1501) contains a first lens (1502) and a third lens (1509) spaced axially inside. One end of the first housing (1501) with the first lens (1502) is connected to the third monitoring unit (6) via an end cap, and the other end is axially fitted with a sealing cover (1513). The end of the sealing cover (1513) is covered by an upper end cap (1506). A worm gear shaft (1505) and an optical axis (1507) are provided inside the sealing cover (1513). One end of the worm gear shaft (1505) and the optical axis (1507) are rotatably disposed in opposite side walls of the first housing (1501), and the other end of the worm gear shaft (1505) and the optical axis (1507) are connected to the upper end cap (1506) via a bearing (1514). The first lens sleeve (1508) is rotated and installed; the sliding groove (1504) is provided on two opposite side walls of the sealing cover (1513), the two ends of the first lens sleeve (1508) are embedded in the sliding groove (1504) and connected to the worm gear shaft (1505) and the optical axis (1507) respectively, and the third lens (1509) is embedded inside the first lens sleeve (1508); the worm (1510) is mounted on the sealing cover (1513) through the support (1512), the first motor (1511) is driven and connected to the worm (1510), and the worm (1510) meshes with the worm gear shaft (1505); the rotation of the worm gear shaft (1505) can drive the first lens sleeve (1508) and the third lens (1509) on it to move axially along the sealing cover (1513).

7. The multi-ray coaxial laser processing monitoring device based on active illumination according to claim 1, characterized in that, The auxiliary light source unit (3) includes a coaxial auxiliary light source part (3001) and a paraxial auxiliary light source part (3002). The coaxial auxiliary light source part (3001) is mounted on the third beam bending module (203), and the paraxial auxiliary light source part (3002) is mounted on the laser welding head (1).

8. The multi-ray coaxial laser processing monitoring device based on active illumination according to claim 7, characterized in that, The coaxial auxiliary light source part (3001) includes a connecting cover (3011), a fourth lens (3121), a third buckle (3221), a second housing (3021), a rotating shaft (3031), a third housing (3041), a second lens cover (3131), a fifth lens (3231), and a first auxiliary light source (3051); The second housing (3021) is connected to the third housing (3041), and the rotating shaft (3031) is rotatably disposed between the second housing (3021) and the third housing (3041). The connecting cover (3011) is provided on the end of the second housing (3021) away from the third housing (3041), and the fourth lens (3121) is embedded in the interior of this end by a third buckle (3221). The fifth lens (3231) is embedded on the second lens sleeve (3131), and the second lens sleeve (3131) is fixed inside the rotating shaft (3031). The end of the third housing (3041) away from the second housing (3021) is connected to the first auxiliary light source (3051); the connecting cover (3011) is connected to the third beam bending module (203).

9. The multi-ray coaxial laser processing monitoring device based on active illumination according to claim 7, characterized in that, The off-axis auxiliary light source part (3002) includes a connecting rod (3012), a fan-shaped plate (3082), a second fiber collimating lens (3302), a motor frame (3062), a second motor (3052), a clamping frame (3102), a convex slider (3032), and a lead screw (3022); One end of the connecting rod (3012) is connected to the laser welding head (1), and the other end is provided with a slide groove (3034). The lead screw (3022) is rotatably installed in the slide groove (3034). The convex slider (3032) is fitted on the lead screw (3022) and adapted to the slide groove (3034). One end of the lead screw (3022) is connected to the second motor (3052), and the other end is provided with a second photoelectric sensor (16). The second motor (3052) is installed at one end of the connecting rod (3012) through a motor frame (3062). The sector plate (3082) is connected to the convex slider (3032). The second fiber collimating lens (3302) is provided in the clamping frame (3102). The sector plate (3082) is provided with an arc groove (3092). One end of the clamping frame (3102) is hinged to the center of the sector plate (3082), and the other end is provided with a column (3112). The column (3112) passes through the arc groove (3092) and slides along the arc groove (3092). The column (3112) is limited to its sliding position on the arc groove (3092) by a nut.

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