A switchable dual laser head processing optical path system and device

Abstract

The present invention discloses a switchable dual-laser head processing optical path system and device, which integrates a three-dimensional galvanometer and a cutting head assembly into a processing head assembly, adopts an optical path switching mechanism, translates two dichroic mirrors through a slide, and selectively splits the wavelength settings of the two dichroic mirrors, thereby realizing fast and seamless switching and optical path multiplexing between the three-dimensional galvanometer processing mode and the cutting head processing mode, and ensuring that there is no need to readjust the lens angle or optical path alignment after the optical path is switched. Coaxial CCD monitoring is adopted, and the wavelengths of the first illumination light source and the second illumination light source are differentiated according to the wavelength setting characteristics of the two dichroic mirrors, so that the two processing modes share the same CCD camera, realizing high-precision real-time monitoring in the dual processing mode, and providing a closed-loop control basis for the laser processing process. At the same time, the multi-axis mobile platform is matched with two turntable assemblies, which can flexibly perform laser processing on curved surface workpieces within a large area.

Description

Technical Field

[0001] The present invention relates to the technical field of laser precision processing, and in particular to a switchable dual-laser head processing optical path system and device. Background Art

[0002] Laser direct writing processing usually includes a moving platform and a focusing lens. In laser processing, laser direct writing processing by moving the processing workpiece or focusing lens has the characteristics of simple structure and low cost. It can achieve a large laser processing range and is mainly aimed at large-sized and high-power processing objects. However, it cannot quickly adjust the laser focus position, and its ability to process complex workpieces is weak. At the same time, the processing speed and processing accuracy are also limited by the accuracy of the moving platform, lacking micron / nanometer-level processing accuracy. The use of a three-dimensional galvanometer for laser processing has the characteristics of high response speed and high precision due to dynamic focusing and high-speed deflection of the reflector. It can quickly adjust the position of the laser focus and can realize the processing of complex three-dimensional workpieces without a moving mechanism. It is mainly used for the precision processing of complex three-dimensional structure workpieces at the micron level, but the cost is high, and it is difficult to achieve processing within a large area, and it is difficult to handle large-sized workpieces or thick materials.

[0003] In high-end manufacturing fields such as consumer electronics, aerospace, and new energy vehicles, facing the processing needs of complex parts, if the relationship between efficiency and cost can be balanced, while achieving large-scale cutting and processing of complex structures, it will help improve production efficiency and increase product added value.

[0004] The application document with publication number CN119016860A discloses a multifunctional laser processing composite platform that realizes two types of multi-axis processing methods by switching the optical path. However, the four-axis processing area and the five-axis processing area of ​​the device are arranged on the front and back sides of the top of the base. The separation of the two processing areas increases the time cost of workpiece transfer.

[0005] Application publication number CN119589163A discloses a dual-laser processing device that uses a mirror switching mechanism to reduce absorption losses during processing using two laser light sources. However, this device, which only contains a single processing head, is unable to meet the processing needs of complex curved workpieces of various types and sizes. The use of two lasers as the light source increases system costs. Using other methods, such as splitting the laser into two beams, would result in a decrease in laser power after the split, affecting laser processing quality.

[0006] Therefore, when faced with workpieces with multiple processing requirements, using multiple processing platforms will occupy processing site space and increase processing costs. In addition, the same workpiece requires multiple devices to process in steps, resulting in low efficiency and accumulated positioning errors. If the processing head components are constantly replaced according to changes in processing requirements, the time cost will be greatly increased. In addition, the use of three-dimensional galvanometer processing on a multi-axis mobile platform places higher requirements on the ability of multi-axis collaboration. Summary of the Invention

[0007] In order to solve the problems in the laser processing process, when facing the simultaneous processing of large-sized workpieces and local precision processing, a single type of processing platform is difficult to meet diverse processing requirements, and multi-platform processing increases space and time costs. The present invention provides a switchable dual-laser head processing optical path system and device, which integrates a three-dimensional galvanometer and a cutting head assembly into a processing head assembly, uses a laser as a light source, and ensures that the laser beam enters the cutting head assembly or the three-dimensional galvanometer by switching the positions of two dichroic mirrors. According to the processing requirements, the three-dimensional galvanometer processing or cutting head processing can be switched in time, reducing the transfer cost of the workpiece, improving the processing efficiency, and reducing the cost of the laser. At the same time, it avoids the problem of recalibrating the optical path due to replacing the lens when the processing head is changed.

[0008] In order to achieve the above object, the present invention adopts the following technical solutions:

[0009] The present invention provides a switchable dual-laser head processing optical path system, comprising a laser, a reflective optical path mechanism and a processing head assembly, wherein the processing head assembly comprises a first dichroic mirror, a second dichroic mirror, a three-dimensional galvanometer and a cutting head assembly;

[0010] The first dichroic mirror and the second dichroic mirror are arranged side by side with an inclination of 45 degrees, and a sliding drive mechanism is installed to drive the first dichroic mirror and the second dichroic mirror. Under the action of the sliding drive mechanism, it drives the first dichroic mirror and the second dichroic mirror to move to positions corresponding to the light beam emission direction of the reflective light path mechanism. The sliding drive mechanism can choose a pneumatic slide, a precision slide or a rolling screw drive structure. For example, the precision cylinder in the precision slide is preferably used, and the double-acting cylinder inside it realizes bidirectional movement by alternating air supply, and can be dynamically compensated by a piezoelectric proportional valve. Compensate for air pressure fluctuations to achieve micron-level precision control. Since the light will be expanded by the dynamic focusing unit of the three-dimensional galvanometer or the subsequent second beam expander after reflection or transmission through the dichroic mirror, the two dichroic mirrors on the precision slide only need to reach the specified position and reflect or transmit the light beam into the subsequent optical device. The movement accuracy can also be further improved by combining magnetic grating or grating feedback signals. If higher movement accuracy is required, a servo motor drive with a ball screw or linear motor can be used to move the two dichroic mirrors, and a grating ruler can be used to send feedback signals to the controller to calculate the error in the actual position. Perform dynamic position compensation on the dichroic mirror.

[0011] The laser beam emitted by the laser is reflected by the reflective optical path mechanism, and after the beam spot diameter is expanded, it enters the first dichroic mirror or the second dichroic mirror in the processing head assembly, the first dichroic mirror is a short-wavelength pass dichroic mirror, and the wavelength band of the laser beam emitted by the laser is higher than the cutoff wavelength of the first dichroic mirror; the second dichroic mirror is a long-wavelength pass dichroic mirror, and the wavelength band of the laser beam emitted by the laser is higher than the starting wavelength of the second dichroic mirror;

[0012] When the laser beam enters the first dichroic mirror, it is reflected by the first dichroic mirror to the three-dimensional galvanometer mirror, and then focused into a light spot by the field lens and applied to the workpiece to be processed. The three-dimensional galvanometer mirror contains a dynamic focusing mirror and two high-speed deflection mirrors, so the focused beam output by the field lens can be adjusted a certain distance in the three-dimensional direction;

[0013] When the laser beam enters the second dichroic mirror, the beam passes downward through the second dichroic mirror and is transmitted to the cutting head assembly, converged by the focusing mirror in the cutting head assembly and acts on the workpiece to be processed.

[0014] In specific applications, the laser beam wavelength is 1030nm, and the power adjustment range is set according to the maximum power that the 3D galvanometer and cutting head assembly can withstand. The laser can be a short-pulse laser with a nanosecond pulse width or a quasi-continuous-wave laser. Lasers that support pulse / continuous mode switching can also be selected, facilitating switching when processing workpieces of varying thicknesses and finishes.

[0015] In the overall optical path, the switching of the two dichroic mirrors in the processing head assembly, along with their specific design, enables rapid switching between 3D galvanometer processing mode and cutting head processing mode, without the need for mirror replacement or optical path recalibration. Specifically, the first dichroic mirror is a short-wavelength-pass dichroic mirror with high transmittance and high reflectivity. Its cutoff wavelength is 805nm, reflecting beams above the cutoff wavelength (i.e., laser beams with a wavelength of 1030nm) while transmitting beams below the cutoff wavelength. The second dichroic mirror is a long-wavelength-pass dichroic mirror with high transmittance and high reflectivity. Its starting wavelength is 605nm, transmitting beams above the starting wavelength (i.e., laser beams with a wavelength of 1030nm) while reflecting beams below the starting wavelength. Through this design, the laser beam is reflected by the first dichroic mirror to the 3D galvanometer, where it is focused by the field lens into a micron-sized spot for precision machining. The laser beam is then transmitted by the second dichroic mirror to the cutting head assembly, where it is focused by the focusing lens into a beam with a micron diameter, enabling large-scale cutting.

[0016] Furthermore, it also includes a CCD camera, and the CCD camera and the first dichroic mirror are respectively located on the left and right sides of the second dichroic mirror. A first illumination light source is provided around the field lens, and the wavelength band of the illumination light emitted by the first illumination light source is lower than the cutoff wavelength of the first dichroic mirror and higher than the starting wavelength of the second dichroic mirror. The visible light irradiated by the first illumination light source on the surface of the workpiece to be processed is transmitted to the first dichroic mirror after passing through the field lens and the three-dimensional galvanometer, and is transmitted to the first dichroic mirror and the second dichroic mirror in turn and transmitted to the CCD camera.

[0017] Furthermore, a second illumination light source is provided around the cutting head assembly, and the wavelength band of the illumination light emitted by the second illumination light source is lower than the starting wavelength of the second dichroic mirror. The visible light irradiated by the second illumination light source on the surface of the workpiece to be processed is transmitted to the second dichroic mirror through the cutting head assembly, and is reflected by the second dichroic mirror to the CCD camera.

[0018] The first and second illumination light sources cooperate with two dichroic mirrors to form a coaxial CCD monitoring system, ensuring that the CCD camera monitors the processing areas of the two processing modes in real time, realizing real-time monitoring of the processing surface and improving processing accuracy.

[0019] The CCD camera inspection process can be briefly summarized as follows: visible light from an illumination source strikes the workpiece surface. Partially reflected light signals travel along the optical path and enter the CCD camera. A computer captures the image information and processes it based on specific needs. For example, if real-time monitoring of the machining trajectory is required, the image can be converted to grayscale, and after filtering out invalid noise, features of the machining area can be extracted, ultimately generating a fitting process trajectory. The illumination source can be selected based on the cutoff and starting wavelengths of the dichroic mirror, such as a first illumination light with a wavelength of 650nm and a second illumination light with a wavelength of 525nm. The CCD camera's sensitivity band should cover the common visible light band of 400 to 780nm to provide greater selectivity and facilitate the replacement of illumination sources for workpieces with varying surface roughness.

[0020] The specific working principle is as follows:

[0021] The visible light from the first illumination light source irradiates the surface of the workpiece to be processed and is transmitted to the first dichroic mirror after passing through the field lens and the three-dimensional galvanometer. Since the wavelength band of the illumination light emitted by the first illumination light source (wavelength is 650nm) is lower than the cutoff wavelength of the first dichroic mirror and higher than the starting wavelength of the second dichroic mirror, it will pass through the first and second dichroic mirrors and be transmitted to the lens of the CCD camera. After receiving the illumination light information focused by the lens, the photosensitive target surface of the industrial CCD camera realizes real-time monitoring of the surface of the workpiece to be processed.

[0022] Since the wavelength of the second illumination light source (525nm) is slightly lower than the wavelength of the first illumination light source (650nm), the visible light irradiated by the second illumination light source on the surface of the workpiece to be processed is transmitted to the second dichroic mirror through the cutting head assembly. Since the wavelength band of the second illumination light is lower than the starting wavelength of the second dichroic mirror, it is reflected into the lens of the CCD camera after passing through the second dichroic mirror. After being focused by the lens, the second illumination beam is also irradiated onto the photosensitive surface of the CCD camera, thereby enabling the CCD camera to monitor the surface of the workpiece.

[0023] Furthermore, the reflective optical path structure includes a first reflector, a first beam expander, a second reflector, a third reflector and a fourth reflector. The laser beam emitted by the laser is incident on the first reflector at 45°, and the beam enters the first beam expander after reflection. The first beam expander is a variable magnification beam expander. After the first beam expander expands the beam spot diameter, the output collimated beam is incident on the second reflector at 45°. The beam reflected by the second reflector passes through the third reflector and the fourth reflector in sequence, and then is incident on the first dichroic mirror or the second dichroic mirror.

[0024] Furthermore, when the laser beam enters the second dichroic mirror, the beam is transmitted downward through the second dichroic mirror to the second beam expander, the beam spot diameter is expanded and then transmitted to the fifth reflector, and the reflected beam is incident on the cutting head assembly.

[0025] The reflector is coated with a laser-induced damage threshold dielectric film with a reflectivity exceeding 99%. The first beam expander is an adjustable magnification beam expander with a magnification of 1 to 4 times. For example, the optimal incident beam diameter of the 3D galvanometer is 5mm. The first beam expander can expand a laser beam with a spot diameter of approximately 2.5mm by 2 times to 5mm. The laser beam expanded by the first beam expander is collimated parallel light, but after multiple reflections and a long optical path, the laser has already diverged to a certain extent when it reaches the processing head assembly. When performing 3D galvanometer processing, due to the presence of a dynamic focusing unit in the 3D galvanometer, it changes the diameter of the beam entering the galvanometer through a movable lens group, which is essentially equivalent to a beam expander, so the laser can be re-collimated. When using the cutting head assembly for processing, on the one hand, the laser beam is less collimated and divergent at this time; on the other hand, the focusing mirror in the cutting head assembly also has an optimal incident beam diameter. Therefore, the laser entering the cutting head assembly needs to be expanded. For example, the optimal incident beam diameter of the focusing mirror is 10 mm. In order to prevent the knob of the adjustable magnification beam expander from loosening when the processing head assembly rotates, a second beam expander (a fixed magnification beam expander), such as a 2x beam expander, can be set in front of the fifth reflector.

[0026] The present invention also provides a switchable dual-laser head processing light path device, comprising the above-mentioned processing light path system, and also comprising a base, an X-axis moving platform, a Y-axis moving platform, and a Z-axis moving plate;

[0027] An X-axis drive assembly and a Y-axis drive assembly are provided on the top of the base. The X-axis drive assembly is drivably connected to an X-axis movable platform, and the X-axis movable platform has a certain stroke in the X-axis direction. The Y-axis drive assembly is drivably connected to a Y-axis movable platform, and the Y-axis movable platform has a certain stroke in the Y-axis direction. A Z-axis drive assembly is provided on the side of the X-axis movable platform, and the Z-axis drive assembly is drivably connected to a Z-axis movable plate, and the Z-axis movable plate can move in the Z-axis direction.

[0028] A laser, a first reflector, a first beam expander and a second reflector are placed on the top of the X-axis movable platform, which are located in the same horizontal plane. A third reflector, a fourth reflector and a processing head assembly are installed on the surface of the Z-axis movable plate, which are located in the same horizontal plane. The third reflector is located directly below the second reflector. The Y-axis movable platform is located below the processing head assembly, and a workpiece to be processed is placed on the Y-axis movable platform.

[0029] Furthermore, a first turntable assembly that can rotate around the Y-axis direction is installed on the Z-axis movable plate, and the processing head assembly is installed on the first turntable assembly. The first turntable assembly is provided with an incident hole for the laser beam to pass through. The first turntable assembly can carry the processing head assembly to rotate at a certain angle to realize the change of the position of the output light beam of the cutting head assembly, thereby performing laser processing on workpieces with complex surface shapes.

[0030] Furthermore, a second turntable assembly that can rotate around the Z axis is installed on the Y-axis movable platform. The workpiece to be processed is placed on the second turntable assembly, which drives the workpiece to be processed to rotate at a certain angle, so that the laser area to be processed changes.

[0031] Furthermore, a distance sensor is installed under the processing head assembly to assist in measuring the distance between the processing head assembly and the workpiece to be processed, thereby preventing the bottom end of the cutting head assembly from touching the workpiece to be processed when the Z-axis moving plate moves along the Z-axis direction.

[0032] The specific working principle is as follows:

[0033] When using a cutting head assembly to process large workpieces, the multi-axis motion platform (X-axis and Y-axis) is first used to move the workpiece area to be processed directly below the cutting head assembly. The precision slide then moves a certain distance in the X direction, allowing the second dichroic mirror to receive the laser beam reflected by the second reflector. The transmitted laser beam passes through the second beam expander, the fifth reflector, and the focusing head before impinging on the workpiece surface. Once the CCD camera determines that a certain area of ​​the workpiece has been processed, the X-axis motion platform, the Z-axis plate, and the first turntable assembly can be used to adjust the focal position of the laser beam emitted by the cutting head assembly as needed. Alternatively, the second turntable assembly and Y-axis motion platform can be used to shift or rotate the workpiece to process the next area. This process repeats until it is necessary to switch to 3D galvanometer processing or until all workpiece areas have been processed.

[0034] When the workpiece surface requires precision machining, the laser parameters are adjusted according to the machining requirements and the galvanometer requirements. The multi-axis mobile platform (X-axis mobile platform, Y-axis mobile platform) is then used to move the workpiece area to be machined directly below the light output center of the field lens. At this point, after the slide on the precision slide moves to its initial position, the first dichroic mirror receives the laser beam reflected by the second reflector and reflects it to the 3D galvanometer. The beam emitted by the 3D galvanometer acts on the workpiece surface through the field lens. The CCD camera monitors the image. After machining one area of ​​the workpiece surface, the 3D galvanometer's dynamic focusing mirror and the deflection angles of the two reflectors are adjusted to change the spatial position of the laser focus point and continue machining the next area of ​​the workpiece surface. This process repeats until it is necessary to switch to the cutting head assembly for machining, or until all machining areas of all workpieces are completed.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] (1) The present invention adopts an optical path switching mechanism, which selectively splits the wavelength settings of the two dichroic mirrors by translating the two dichroic mirrors through the slide, thereby realizing fast and seamless switching and optical path multiplexing between the three-dimensional galvanometer processing mode and the cutting head processing mode. In addition, the cooperation between the slide and the two dichroic mirrors realizes high repeatability positioning accuracy, short slide switching time, fast response, and ensures that there is no need to readjust the lens angle or optical path alignment after the optical path is switched. The dichroic mirror's spectroscopic characteristics enable almost all of the laser energy to be distributed to the target processing head, avoiding the energy loss of the traditional spectrometer.

[0037] (2) The present invention adopts coaxial CCD monitoring (monitoring light and processing light are coaxial), and according to the wavelength setting characteristics of the two dichroic mirrors, the wavelengths of the first illumination light source and the second illumination light source are designed to be differentiated, so that the two processing modes can share the same CCD camera, reducing hardware costs and system complexity, and realizing high-precision real-time monitoring in dual processing modes, providing a closed-loop control basis for the laser processing process, and significantly improving the versatility and processing quality of the equipment;

[0038] (3) In a processing device, a multi-axis moving platform and two turntable assemblies can be used to change the position of the workpiece or the laser focus, thereby realizing large-scale processing of large-size workpieces. At the same time, a three-dimensional galvanometer can be used to perform further fine micro-processing on the workpiece surface, reducing the workpiece transfer time and improving the processing efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0040] Figure 1 Schematic diagram of the switchable dual laser head processing optical path system in Example 1;

[0041] Figure 2 A three-dimensional structural diagram of the switchable dual laser head processing optical path device in Example 2;

[0042] Figure 3 This is a right side view of the switchable dual laser head processing optical path device in Example 2;

[0043] Figure 4 is a top view of the processing head assembly in Example 2;

[0044] Among them, the specific drawings are marked as follows:

[0045] Laser 1, first reflecting mirror 2, first beam expander 3, second reflecting mirror 4, third reflecting mirror 5, X-axis moving platform 6, X-axis drive assembly 7, fourth reflecting mirror 8, processing head assembly 9, first dichroic mirror 901, second dichroic mirror 902, precision slide 903, three-dimensional galvanometer 904, field lens 905, first illumination light source 906, lens 907, CCD camera 908, second beam expander 909, fifth reflecting mirror 910, cutting head assembly 911, second illumination light source 912, distance sensor 913, Z-axis drive assembly 10, Z-axis moving plate 11, first turntable assembly 12, sample to be processed 13, second turntable assembly 14, Y-axis moving platform 15, Y-axis drive assembly 16, base 17. DETAILED DESCRIPTION

[0046] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0047] Example 1

[0048] This embodiment discloses a switchable dual laser head processing optical path system, such as Figure 1 As shown, it includes a laser 1, a reflective optical path mechanism and a processing head assembly 9,

[0049] The reflective optical path mechanism includes a first reflector 2, a first beam expander 3, a second reflector 4, a third reflector 5 and a fourth reflector 8 for reflecting the laser multiple times to the processing head assembly 9;

[0050] The machining head assembly 9 includes a first dichroic mirror 901 , a second dichroic mirror 902 , a three-dimensional galvanometer mirror 904 and a cutting head assembly 911 .

[0051] The first dichroic mirror 901 and the second dichroic mirror 902 are arranged side by side with an inclination of 45 degrees. The sliding drive mechanism is installed to drive the first dichroic mirror 901 and the second dichroic mirror 902. Under the action of the sliding drive mechanism, it drives the first dichroic mirror 901 and the second dichroic mirror 902 to move to positions corresponding to the light beam emission direction of the reflective light path mechanism. The sliding drive mechanism can choose a pneumatic slide, a precision slide or a rolling screw drive structure. In this embodiment, a precision slide 903 is used. The precision cylinder in the precision slide 903 realizes bidirectional movement through alternating air supply, and the piezoelectric proportional valve can be used to move the pneumatic slide. Dynamic compensation for air pressure fluctuations achieves micron-level precision control. Since the light beam, after reflection or transmission through the dichroic mirror, will also pass through the dynamic focusing unit of the three-dimensional galvanometer 904 or the subsequent second beam expander 909 for beam expansion, the two dichroic mirrors on the precision slide 903 only need to reach the specified position and reflect or transmit the light beam into the subsequent optical device. The movement accuracy can also be further improved by combining magnetic or optical grating feedback signals. If higher movement accuracy is required, a servo motor drive with a ball screw or linear motor can be used to move the two dichroic mirrors. A grating ruler can be used to send feedback signals to the controller to calculate the actual position error. Dynamic position compensation of the dichroic mirrors is performed.

[0052] The laser beam emitted by laser 1 is incident on the first reflector 2 at a 45° angle. After reflection, the beam enters the first beam expander 3, which is a variable-magnification beam expander. After expanding the beam spot diameter, the output collimated beam is incident on the second reflector 4 at a 45° angle. The beam reflected by the second reflector 4 passes through the third reflector 5 and the fourth reflector 8 in sequence before entering the first dichroic mirror 901 or the second dichroic mirror 902. The first dichroic mirror 901 is a short-wavelength pass dichroic mirror, and the wavelength of the laser beam emitted by laser 1 is higher than its cutoff wavelength. The second dichroic mirror 902 is a long-wavelength pass dichroic mirror, and the wavelength of the laser beam emitted by laser 1 is higher than the starting wavelength of the second dichroic mirror 902. When the laser beam enters the first dichroic mirror 901, the beam is reflected by the first dichroic mirror 901 to the three-dimensional galvanometer mirror 904, and then focused into a light spot by the field lens 905 and acts on the workpiece 13 to be processed. The three-dimensional galvanometer mirror 904 includes a dynamic focusing mirror and two high-speed deflection mirrors, so the focused beam output by the field lens 905 can be adjusted a certain distance in the three-dimensional direction; when the laser beam enters the second dichroic mirror 902, the beam is transmitted downward through the second dichroic mirror 902 to the second beam expander 909, and the beam spot diameter is expanded and then transmitted to the fifth reflector 910. The reflected beam is incident on the cutting head assembly 911, converged by the focusing mirror in the cutting head assembly 911 and acts on the workpiece 13 to be processed.

[0053] In specific applications, the laser beam emitted by Laser 1 has a wavelength of 1030nm, and the power adjustment range is set based on the maximum power that the 3D galvanometer 904 and cutting head assembly 911 can withstand. Laser 1 can be a short-pulse laser or a quasi-continuous-wave laser with a nanosecond pulse width, or a laser that supports pulse / continuous mode switching, facilitating switching when processing workpieces of varying thicknesses and finishes.

[0054] In the overall optical path, rapid switching between 3D galvanometer processing mode and cutting head processing mode is achieved primarily by switching the positions of the two dichroic mirrors in the processing head assembly 9 and specifically designing these mirrors, without the need for lens replacement or recalibration of the optical path. Specifically, the first dichroic mirror 901 is a short-wavelength dichroic mirror with high transmittance and high reflectivity. Its cutoff wavelength is 805nm, and it can reflect light beams above the cutoff wavelength (i.e., laser beams with a wavelength of 1030nm) while transmitting light beams below the cutoff wavelength. The second dichroic mirror 902 is a long-wavelength dichroic mirror with high transmittance and high reflectivity. Its starting wavelength is 605nm, and it can transmit light beams above the starting wavelength (i.e., laser beams with a wavelength of 1030nm) while reflecting light beams below the starting wavelength. Through this design, the laser beam is reflected by the first dichroic mirror 901 to the 3D galvanometer mirror 904, where it is focused into a micron-sized spot by the field lens 905 for precision processing. The laser beam is transmitted to the cutting head assembly 911 through the second dichroic mirror 902 and converged into a beam with a diameter at the micron level through the focusing mirror, thereby achieving large-scale cutting.

[0055] The reflector is coated with a laser-induced damage threshold dielectric film with a reflectivity exceeding 99%. The first beam expander 3 is an adjustable magnification beam expander with a magnification of 1 to 4 times. For example, the optimal incident beam diameter of the three-dimensional galvanometer 904 is 5 mm. The first beam expander 3 can expand a laser beam with a spot diameter of approximately 2.5 mm by 2 times to 5 mm. The laser light expanded by the first beam expander 3 is collimated parallel light, but after multiple reflections and a long optical path, the laser light has already diverged to a certain extent when it reaches the processing head assembly 9. When the three-dimensional galvanometer 904 is processed, due to the presence of a dynamic focusing unit in the three-dimensional galvanometer 904, it changes the diameter of the light beam entering the galvanometer through a movable lens group, which is essentially equivalent to a beam expander, so the laser light can be re-collimated. When using the cutting head assembly 911 for processing, on the one hand, the degree of collimation of the laser beam is reduced and there is divergence. On the other hand, the focusing mirror in the cutting head assembly 911 also has an optimal incident beam diameter. Therefore, the laser entering the cutting head assembly 911 needs to be expanded. For example, the optimal incident beam diameter of the focusing mirror is 10 mm. In order to prevent the knob of the adjustable magnification beam expander from loosening when the processing head assembly 9 rotates, a second beam expander 909 (a fixed magnification beam expander), such as a 2x beam expander, can be set in front of the fifth reflector 910.

[0056] It also includes a CCD camera 908. The CCD camera 908 and the first dichroic mirror 901 are respectively located on the left and right sides of the second dichroic mirror 902. A first illumination light source 906 is arranged around the field lens 905. The wavelength band of the illumination light emitted by the first illumination light source 906 is lower than the cutoff wavelength of the first dichroic mirror 901 and higher than the starting wavelength of the second dichroic mirror 902. The visible light irradiated by the first illumination light source 906 on the surface of the workpiece 13 to be processed is transmitted to the first dichroic mirror 901 after passing through the field lens 905 and the three-dimensional galvanometer 904. It is then transmitted through the first dichroic mirror 901 and the second dichroic mirror 902 in turn and transmitted to the CCD camera 908.

[0057] A second illumination light source 912 is provided around the cutting head assembly 911. The wavelength band of the illumination light emitted by the second illumination light source 912 is lower than the starting wavelength of the second dichroic mirror 902. The visible light irradiated on the surface of the workpiece 13 to be processed by the second illumination light source 912 is transmitted to the second dichroic mirror 902 through the cutting head assembly 911, and is reflected by the second dichroic mirror 902 to the CCD camera 908.

[0058] The first illumination light source 906, the second illumination light source 912 cooperates with two dichroic mirrors to form a coaxial CCD monitoring system, ensuring that the CCD camera 908 monitors the processing areas of the two processing modes in real time, realizing real-time monitoring of the processing surface and improving processing accuracy.

[0059] The detection process of CCD camera 908 can be briefly summarized as follows: After visible light from an illumination source strikes the surface of the workpiece 13 to be processed, the partially reflected light signal propagates along the optical path and enters CCD camera 908. A computer then captures the image information and processes it according to specific requirements. For example, if real-time monitoring of the processing trajectory is required, the image can be converted to a grayscale image, invalid noise information filtered out, and features of the processing area are extracted. Finally, the processing trajectory is obtained by fitting. The illumination source can be selected based on the cutoff and starting wavelengths of the dichroic mirror, such as a first illumination light with a wavelength of 650 nm and a second illumination light with a wavelength of 525 nm. The CCD camera 908's sensitivity band should cover the common visible light band of 400 to 780 nm to provide greater selectivity in the illumination source and facilitate the replacement of the illumination source for workpieces with varying surface roughness.

[0060] The specific working principle is as follows:

[0061] The visible light emitted by the first illumination light source 906 and irradiated onto the surface of the workpiece 13 to be processed is transmitted to the first dichroic mirror 901 after passing through the field lens 905 and the three-dimensional galvanometer mirror 904. Since the wavelength band (wavelength of 650nm) of the illumination light emitted by the first illumination light source 906 is lower than the cutoff wavelength of the first dichroic mirror 901 and higher than the starting wavelength of the second dichroic mirror 902, it will pass through the first dichroic mirror 901 and the second dichroic mirror 902 and be transmitted to the lens 907 of the CCD camera 908. After receiving the illumination light information focused by the lens 907, the photosensitive target surface of the industrial CCD camera 908 realizes real-time monitoring of the surface of the workpiece 13 to be processed.

[0062] Since the wavelength of the second illumination light source 912 (525 nm) is slightly lower than the wavelength of the first illumination light source 906 (650 nm), the visible light irradiated by the second illumination light source 912 on the surface of the workpiece 13 to be processed is transmitted to the second dichroic mirror 902 via the cutting head assembly 911. Since the wavelength of the second illumination light is lower than the starting wavelength of the second dichroic mirror 902, it is reflected by the second dichroic mirror 902 to the lens 907 of the CCD camera 908. After being focused by the lens 907, the second illumination light beam is also irradiated onto the photosensitive surface of the CCD camera 908, thereby enabling the CCD camera 908 to monitor the surface of the workpiece.

[0063] Example 2

[0064] This embodiment discloses a switchable dual laser head processing optical path device, such as Figures 2 to 4 As shown, it includes the processing optical path system in Example 1, and also includes a base 17, an X-axis moving platform 6, a Y-axis moving platform 15, and a Z-axis moving plate 11;

[0065] An X-axis drive assembly 7 and a Y-axis drive assembly 16 are provided on the top of the base 17. The X-axis drive assembly 7 is drivably connected to the X-axis mobile platform 6. The X-axis mobile platform 6 has a certain stroke in the X-axis direction. The Y-axis drive assembly 16 is drivably connected to the Y-axis mobile platform 15. The Y-axis mobile platform 15 has a certain stroke in the Y-axis direction. A Z-axis drive assembly 10 is provided on the side of the X-axis mobile platform 6. The Z-axis drive assembly 10 is drivably connected to the Z-axis mobile plate 11. The Z-axis mobile plate 11 can move in the Z-axis direction.

[0066] A laser 1, a first reflector 2, a first beam expander 3 and a second reflector 4 are placed on the top of the X-axis moving platform 6, which are located in the same horizontal plane. A third reflector 5, a fourth reflector 8 and a processing head assembly 9 are installed on the surface of the Z-axis moving plate 11, which are located in the same horizontal plane. The third reflector 5 is located directly below the second reflector 4. The Y-axis moving platform 15 is located below the processing head assembly 9, and a workpiece 13 to be processed is placed on the Y-axis moving platform 15.

[0067] Among them, a first turntable assembly 12 that can rotate around the Y-axis direction is installed on the Z-axis moving plate 11, and the processing head assembly 9 is installed on the first turntable assembly 12. The first turntable assembly 12 is provided with an incident hole for the laser beam to pass through. The first turntable assembly 12 can carry the processing head assembly 9 to rotate at a certain angle, thereby realizing the change in the position of the output light beam of the cutting head assembly 911, thereby performing laser processing on workpieces with complex surface shapes.

[0068] Among them, a second turntable assembly 14 that can rotate around the Z axis is installed on the Y-axis moving platform 15. The workpiece 13 to be processed is placed on the second turntable assembly 14, which drives the workpiece 13 to be processed to rotate at a certain angle, so that the laser area to be processed changes.

[0069] Among them, a distance sensor 913 is installed under the processing head assembly 9 to assist in measuring the distance between the processing head assembly 9 and the workpiece to be processed 13, to prevent the bottom end of the cutting head assembly 911 from touching the workpiece to be processed 13 when the Z-axis moving plate 11 moves along the Z-axis direction.

[0070] The specific working principle is as follows:

[0071] When using the cutting head assembly 911 to process large workpieces, the multi-axis motion platform (X-axis motion platform 6 and Y-axis motion platform 15) is first used to move the workpiece area to be processed directly below the cutting head assembly 911. At this point, the slide on the precision slide 903 moves a certain distance in the X direction, allowing the second dichroic mirror 902 to receive the laser beam reflected by the second reflector 4. The transmitted laser beam passes through the second beam expander 909, the fifth reflector 910, and the focusing head before impinging on the workpiece surface. After the CCD camera 908 determines that a certain area of ​​the workpiece has been processed, the X-axis motion platform 6, the Z-axis motion plate 11, and the first turntable assembly 12 can be used to adjust the focal position of the laser beam emitted by the cutting head assembly 911 as needed. Alternatively, the second turntable assembly 14 and the Y-axis motion platform 15 can be used to displace or rotate the workpiece to process the next area. This process repeats until processing is switched to the 3D galvanometer 904 or all workpiece areas have been processed.

[0072] When precision machining of a workpiece surface is required, the laser parameters of laser 1 are adjusted according to the machining requirements and the requirements of the galvanometer mirror. The multi-axis motion platform (X-axis motion platform 6 and Y-axis motion platform 15) is then used to move the workpiece area to be machined directly below the beam output center of field lens 905. At this point, after the slide on precision slide 903 has moved to its initial position, the first dichroic mirror 901 receives the laser beam reflected by the second reflector 4 and reflects it to the three-dimensional galvanometer mirror 904. The beam emitted by the three-dimensional galvanometer mirror 904 then passes through the field lens 905 and impacts the workpiece surface. The image captured by CCD camera 908 is analyzed. After machining one area of ​​the workpiece surface, the dynamic focusing lens of the three-dimensional galvanometer mirror 904 and the deflection angles of its two reflectors are adjusted to change the spatial position of the laser focus point, allowing machining to continue to the next area of ​​the workpiece surface. This process repeats until machining is switched to the cutting head assembly 911 or all workpiece areas have been machined.

[0073] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A switchable dual laser head processing optical path system, characterized in that: It includes a laser, a reflective optical path mechanism and a processing head assembly, wherein the processing head assembly includes a first dichroic mirror, a second dichroic mirror, a three-dimensional galvanometer and a cutting head assembly; The first dichroic mirror and the second dichroic mirror are arranged side by side and tilted at 45 degrees. A sliding drive mechanism is installed to drive the first dichroic mirror and the second dichroic mirror. Under the action of the sliding drive mechanism, the first dichroic mirror and the second dichroic mirror are driven to move to positions corresponding to the light beam exit direction of the reflective optical path mechanism. The laser beam emitted by the laser is reflected by the reflective optical path mechanism, and after the beam spot diameter is expanded, it enters the first dichroic mirror or the second dichroic mirror in the processing head assembly, the first dichroic mirror is a short-wavelength pass dichroic mirror, and the wavelength band of the laser beam emitted by the laser is higher than the cutoff wavelength of the first dichroic mirror; the second dichroic mirror is a long-wavelength pass dichroic mirror, and the wavelength band of the laser beam emitted by the laser is higher than the starting wavelength of the second dichroic mirror; When the laser beam enters the first dichroic mirror, the beam is reflected by the first dichroic mirror to the three-dimensional galvanometer mirror, and then focused into a light spot by the field lens and acts on the workpiece to be processed; When the laser beam enters the second dichroic mirror, the beam passes downward through the second dichroic mirror and is transmitted to the cutting head assembly, where it is converged by the focusing mirror in the cutting head assembly and acts on the workpiece to be processed; The machine tool further includes a CCD camera, wherein the CCD camera and the first dichroic mirror are respectively located on the left and right sides of the second dichroic mirror. A first illumination light source is provided around the field lens. The wavelength band of the illumination light emitted by the first illumination light source is lower than the cutoff wavelength of the first dichroic mirror and higher than the starting wavelength of the second dichroic mirror. The visible light irradiated on the surface of the workpiece to be processed by the first illumination light source is transmitted to the first dichroic mirror after passing through the field lens and the three-dimensional galvanometer. The visible light is transmitted through the first dichroic mirror and the second dichroic mirror in turn and is transmitted to the CCD camera.

2. The switchable dual laser head processing optical path system according to claim 1, characterized in that: A second illumination light source is provided around the cutting head assembly. The wavelength band of the illumination light emitted by the second illumination light source is lower than the starting wavelength of the second dichroic mirror. The visible light irradiated on the surface of the workpiece to be processed by the second illumination light source is transmitted to the second dichroic mirror through the cutting head assembly, and is reflected by the second dichroic mirror to the CCD camera.

3. The switchable dual laser head processing optical path system according to claim 1, characterized in that: The reflective optical path structure includes a first reflector, a first beam expander, a second reflector, a third reflector and a fourth reflector. The laser beam emitted by the laser is incident on the first reflector at 45°, and the beam enters the first beam expander after reflection. The first beam expander is a variable magnification beam expander. After the first beam expander expands the beam spot diameter, the output collimated beam is incident on the second reflector at 45°. The beam reflected by the second reflector passes through the third reflector and the fourth reflector in sequence, and then is incident on the first dichroic mirror or the second dichroic mirror.

4. The switchable dual laser head processing optical path system according to claim 3, characterized in that: When the laser beam enters the second dichroic mirror, the beam is transmitted downward through the second dichroic mirror to the second beam expander, the beam spot diameter is expanded and then transmitted to the fifth reflector, and the reflected beam is incident on the cutting head assembly.

5. A switchable dual laser head processing optical path device, characterized in that: The processing optical path system according to any one of claims 1 to 4 further comprises a base, an X-axis moving platform, a Y-axis moving platform, and a Z-axis moving plate; An X-axis drive assembly and a Y-axis drive assembly are provided on the top of the base, the X-axis drive assembly is drivably connected to the X-axis moving platform, the Y-axis drive assembly is drivably connected to the Y-axis moving platform, a Z-axis drive assembly is provided on the side of the X-axis moving platform, and the Z-axis drive assembly is drivably connected to the Z-axis moving plate; A laser, a first reflector, a first beam expander and a second reflector are placed on the top of the X-axis movable platform, which are located in the same horizontal plane. A third reflector, a fourth reflector and a processing head assembly are installed on the surface of the Z-axis movable plate, which are located in the same horizontal plane. The third reflector is located directly below the second reflector. The Y-axis movable platform is located below the processing head assembly, and a workpiece to be processed is placed on the Y-axis movable platform.

6. The switchable dual laser head processing optical path device according to claim 5, characterized in that: A first turntable assembly rotatable about the Y-axis direction is mounted on the Z-axis movable plate, the processing head assembly is mounted on the first turntable assembly, and an incident hole for the laser beam to pass through is provided on the first turntable assembly.

7. The switchable dual laser head processing optical path device according to claim 6, characterized in that: A second turntable assembly that can rotate about the Z-axis direction is installed on the Y-axis moving platform, and the workpiece to be processed is placed on the second turntable assembly.

8. The switchable dual laser head processing optical path device according to claim 7, characterized in that: A distance sensor is installed below the processing head assembly.

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