Switchable double-laser-head machining light path system and device

Abstract

According to the switchable double-laser-head machining light path system and device, a three-dimensional galvanometer and a cutting head assembly are integrated into a machining head assembly, a light path switching mechanism is adopted, two dichroscopes are horizontally moved through a sliding table, selective light splitting is conducted on wavelength setting of the two dichroscopes, and therefore the machining precision of the two dichroscopes is improved. Rapid seamless switching and light path multiplexing between a three-dimensional galvanometer machining mode and a cutting head machining mode are achieved, it is ensured that the lens angle does not need to be adjusted again or light path alignment does not need to be conducted after light path switching, coaxial CCD monitoring is adopted, according to the wavelength setting characteristics of the two dichroscopes, the wavelength differentiation design is conducted on the first illumination light source and the second illumination light source, and therefore the machining efficiency is improved. According to the multi-axis moving platform, the same CCD camera is shared by two machining modes, high-precision real-time monitoring under the double machining modes is achieved, a closed-loop control basis is provided for the laser machining process, and meanwhile, the multi-axis moving platform is matched with the two rotary table assemblies, so that laser machining can be flexibly conducted on a curved-surface workpiece within a large-format range.

Description

Technical Field

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

[0002] Laser direct writing machining usually includes a moving platform and a focusing lens. In laser machining, by moving the workpiece or the focusing lens in laser direct writing machining, it has the characteristics of simple structure and low cost, and can achieve a large laser machining range, mainly facing large-size and high-power machining objects. However, it cannot quickly adjust the laser focus position, and has weak ability to machine complex workpieces. At the same time, the machining speed and machining accuracy are also limited by the accuracy of the moving platform, lacking micron / nanometer-level machining accuracy. Using a three-dimensional galvanometer for laser machining, with a dynamically focused and highly deflected mirror, has the characteristics of high response speed and high accuracy. It can quickly adjust the position of the laser focus, and can machine complex three-dimensional workpieces without a moving mechanism, mainly applied to the precision machining of micron-level complex three-dimensional structure workpieces. However, the cost is relatively high, it is difficult to achieve machining in a large area, and it is difficult to process large-size workpieces or thick materials.

[0003] In high-end manufacturing fields such as consumer electronics, aerospace, and new energy vehicles, in the face of the machining requirements of complex parts, if the relationship between efficiency and cost can be balanced, and at the same time large-range cutting and the processing of complex structures can be achieved, it will help improve production efficiency and increase the added value of products.

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

[0005] The application document with the publication number CN119589163A discloses a dual-laser machining device, which reduces the absorption loss during the machining of two laser light sources through a mirror switching mechanism. However, this device only includes one machining head, which is difficult to meet the machining requirements of complex curved surface workpieces of various types and sizes. It uses two lasers to provide light sources, increasing the cost of the system. If other methods are used, such as splitting the laser into two beams, the laser power after splitting will decrease, affecting the laser machining quality.

[0006] Therefore, when facing workpieces with multiple processing requirements, using multiple processing platforms will occupy the processing site space, increase the processing cost, and there will be problems such as low efficiency and cumulative positioning errors because the same workpiece needs to be processed step by step by multiple devices. If the processing head assembly is continuously replaced according to the change of processing requirements, the time cost will be greatly increased. Moreover, using a three-dimensional galvanometer for processing on a multi-axis moving platform puts higher requirements on the multi-axis coordination ability. Summary of the Invention

[0007] In order to solve the problems that in the laser processing process, when facing the processing of large-size workpieces and local precision processing at the same time, a single type of processing platform is difficult to meet diverse processing requirements, and multi-platform processing increases space and time costs, etc., 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 single laser as the light source, and by switching the positions of two dichroic mirrors, ensures that the laser beam enters the cutting head assembly or the three-dimensional galvanometer. According to the processing requirements, the three-dimensional galvanometer processing or the cutting head processing can be switched in time, reducing the transfer cost of the workpiece, improving the processing efficiency, reducing the cost of the laser, and at the same time avoiding the problem of re-calibrating the optical path caused by 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: The present invention provides a switchable dual-laser-head processing optical path system, including a laser, a reflection optical path mechanism, and a processing head assembly. 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 at an inclination of 45°. The sliding drive mechanism is drivingly installed with 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 beam exit direction of the reflection optical path mechanism respectively. The sliding drive mechanism can be a pneumatic slide table, a precision slide table, or a rolling screw drive structure. For example, preferably, the precision cylinder in the precision slide table is adopted. The double-acting cylinder inside it realizes bidirectional movement by alternately supplying air. The piezoelectric proportional valve can be used to dynamically compensate the air pressure fluctuation and achieve micron-level precision control. Since the beam will also pass through the dynamic focusing unit of the three-dimensional galvanometer or the subsequent second beam expander for beam expansion after being reflected or transmitted by the dichroic mirror, as long as the two dichroic mirrors on the precision slide table can reach the specified positions and reflect or transmit the beam into the subsequent optical devices, the magnetic grating or grating feedback signal can also be combined to further improve the movement accuracy. If higher movement accuracy is required, a servo motor drive can be used to move the two dichroic mirrors with a ball screw or a linear motor, and the grating ruler is used to send a feedback signal to the controller. After calculating the error existing in the actual position, the position of the dichroic mirror is dynamically compensated; The laser beam emitted by the laser is reflected by the reflection 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-wave pass dichroic mirror, and the wavelength band of the laser beam emitted by the laser is higher than the cut-off wavelength of the first dichroic mirror. The second dichroic mirror is a long-wave 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 3D galvanometer, and then focused into a spot by the field lens and acts on the workpiece to be processed. The 3D galvanometer includes a dynamic focusing lens and two high-speed deflecting mirrors, so the focused beam output by the field lens can be adjusted in three dimensions for a certain distance; When the laser beam enters the second dichroic mirror, the beam passes through the second dichroic mirror downward and is transmitted to the cutting head assembly, and is converged by the focusing lens in the cutting head assembly and acts on the workpiece to be processed.

[0009] In specific applications, the wavelength of the laser beam emitted by the laser is 1030nm, and the power adjustment range needs to be set according to the maximum power that the 3D galvanometer and the cutting head assembly can withstand. The laser can select a short-pulse laser with a pulse width in nanoseconds or a quasi-continuous laser, or a laser that supports pulse / continuous mode switching, which is convenient for switching when processing workpieces with different thicknesses and effects.

[0010] In the overall optical path, mainly by switching the positions of the two dichroic mirrors in the processing head assembly and specifically designing the two dichroic mirrors, a rapid switch between the 3D galvanometer processing mode and the cutting head processing mode is achieved, without replacing the lens or recalibrating the optical path. Specifically, the first dichroic mirror is a short-wave pass dichroic mirror with high transmittance and high reflectivity characteristics. Its cut-off wavelength is 805nm, and it can reflect the beam with a wavelength higher than the cut-off wavelength (i.e., the laser beam with a wavelength of 1030nm), while transmitting the beam with a wavelength lower than the cut-off wavelength. The second dichroic mirror is a long-wave pass dichroic mirror with high transmittance and high reflectivity characteristics. Its starting wavelength is 605nm, and it can transmit the beam with a wavelength higher than the starting wavelength (i.e., the laser with a wavelength of 1030nm), while reflecting the beam with a wavelength lower than the starting wavelength. Through the above design, the laser beam is reflected by the first dichroic mirror to the 3D galvanometer and focused into a micron-level spot by the field lens for precision machining. The laser beam is transmitted through the second dichroic mirror to the cutting head assembly and converged into a beam with a diameter in the micron level by the focusing lens to achieve large-size cutting.

[0011] Further, it also includes a CCD camera. 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 cut-off 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, and it sequentially passes through the first dichroic mirror and the second dichroic mirror and is transmitted into the CCD camera.

[0012] Further, 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 into the CCD camera.

[0013] Through the cooperation of the first illumination light source, the second illumination light source and the two dichroic mirrors, a coaxial CCD monitoring system is formed, ensuring that the CCD camera can monitor the processing areas of the two processing modes in real time, realizing real-time monitoring of the processing surface and improving the processing accuracy.

[0014] The detection process of the CCD camera can be briefly summarized as follows: After the visible light emitted by the illumination light source irradiates on the surface of the workpiece to be processed, part of the reflected optical signal enters the CCD camera after propagating through the optical path. After the computer obtains the image information, it performs different processing according to different requirements. For example, if real-time monitoring of the processing trajectory is required, the image can be converted into a grayscale image. After filtering out the invalid noise information, feature extraction is performed on the processing area, and finally the processing trajectory is obtained by fitting. The illumination light source can be selected according to the cut-off wavelength and starting wavelength of the dichroic mirror, such as the first illumination light with a wavelength of 650 nm and the second illumination light with a wavelength of 525 nm. The photosensitive wavelength band of the CCD camera needs to cover the common visible light wavelength band of 400 - 780 nm to support more selectivity of the illumination light source and facilitate the replacement of the illumination light source for workpieces with different rough surfaces.

[0015] The specific working principle is as follows: 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. Since the wavelength band of the illumination light emitted by the first illumination light source (with a wavelength of 650 nm) is lower than the cut-off wavelength of the first dichroic mirror and higher than the starting wavelength of the second dichroic mirror, it will pass through the first dichroic mirror and the second dichroic mirror and be transmitted into the lens of the CCD camera. After the photosensitive target surface of the industrial CCD camera receives the illumination light information focused by the lens, real-time monitoring of the surface of the workpiece to be processed is realized.

[0016] Since the wavelength of the second illumination source (wavelength: 525 nm) is slightly lower than that of the first illumination source (wavelength: 650 nm), the visible light irradiated on the surface of the workpiece to be processed by the second illumination source 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 to the lens of the CCD camera after passing through the second dichroic mirror. The second illumination beam is also irradiated on the photosensitive surface of the CCD camera after being focused by the lens, realizing the monitoring of the surface of the workpiece by the CCD camera.

[0017] Further, the reflection 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 enters the first reflector at an angle of 45°. After being reflected, the beam enters the first beam expander. The first beam expander is a variable magnification beam expander. After expanding the beam spot diameter, the output collimated beam enters the second reflector at an angle of 45°. The beam reflected by the second reflector passes through the third reflector and the fourth reflector in sequence, and then enters the first dichroic mirror or the second dichroic mirror.

[0018] Further, when the laser beam enters the second dichroic mirror, the beam is transmitted downward through the second dichroic mirror to the second beam expander. After expanding the beam spot diameter, it is transmitted to the fifth reflector, and the reflected beam enters the cutting head assembly.

[0019] The reflectors are coated with a laser-induced damage threshold dielectric film with a reflectivity exceeding 99%. The first beam expander is a variable magnification beam expander with a magnification of 1 to 4 times. For example, the optimal incident beam diameter of a three-dimensional galvanometer is 5 mm. The first beam expander can expand a laser beam with a spot diameter of about 2.5 mm by 2 times to 5 mm. The laser beam expanded by the first beam expander is collimated parallel light. However, after multiple reflections and a long optical path, the laser beam has diverged to a certain extent when it reaches the processing head assembly. When performing three-dimensional galvanometer processing, since there is a dynamic focusing unit in the three-dimensional galvanometer, which changes the diameter of the beam entering the galvanometer through a movable lens group, it can essentially be equivalent to a beam expander, so the laser can be collimated again. When using the cutting head assembly for processing, on the one hand, since the collimation degree of the laser beam is reduced at this time and there is divergence, and on the other hand, since there is also an optimal incident beam diameter for the focusing lens in the cutting head assembly, the laser beam entering the cutting head assembly needs to be expanded. For example, the optimal incident beam diameter of the focusing lens is 10 mm. To prevent the knob of the variable magnification beam expander from loosening when the processing head assembly rotates, a second beam expander (a fixed magnification beam expander), such as a 2-fold beam expander, can be set in front of the fifth reflector.

[0020] The present invention also provides a switchable dual-laser head processing optical path device, which includes the above-mentioned processing optical path system, and also includes a base, an X-axis moving platform, a Y-axis moving platform, and a Z-axis moving plate; The top of the base is provided with an X-axis driving component and a Y-axis driving component. The X-axis driving component is drivingly connected to an X-axis moving platform, and the X-axis moving platform has a certain stroke in the X-axis direction. The Y-axis driving component is drivingly connected to a Y-axis moving platform, and the Y-axis moving platform has a certain stroke in the Y-axis direction. The side of the X-axis moving platform is provided with a Z-axis driving component, and the Z-axis driving component is drivingly connected to a Z-axis moving plate, and the Z-axis moving plate can move in the Z-axis direction; On the top of the X-axis moving platform, a laser, a first reflector, a first beam expander, and a second reflector are placed on the same horizontal plane. On the surface of the Z-axis moving plate, a third reflector, a fourth reflector, and a processing head assembly are installed on the same horizontal plane. The third reflector is directly below the second reflector. The Y-axis moving platform is located below the processing head assembly, and a workpiece to be processed is placed on the Y-axis moving platform.

[0021] Further, a first turntable assembly that can rotate around the Y-axis direction is installed on the Z-axis moving plate, and the processing head assembly is installed on the first turntable assembly. An incident hole for the laser beam to pass through is opened on the first turntable assembly. The first turntable assembly can carry the processing head assembly to rotate by a certain angle, realizing the change of the position of the beam output by the cutting head assembly, so as to perform laser processing on workpieces with complex surface shapes.

[0022] Further, a second turntable assembly that can rotate around 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, which drives the workpiece to be processed to rotate by a certain angle, so that the laser-irradiable area of the workpiece to be processed changes.

[0023] Further, a distance sensor is installed below the processing head assembly to assist in measuring the distance between the processing head assembly and the workpiece to be processed, preventing the bottom end of the cutting head assembly from touching the workpiece to be processed when the Z-axis moving plate moves in the Z-axis direction.

[0024] The specific working principle is as follows: When using the cutting head assembly to process large-sized workpieces, first, use the multi-axis moving platform (X-axis moving platform, Y-axis moving platform) to move the area to be processed of the workpiece directly below the cutting head assembly. At this time, after the slide on the precision slide moves a certain distance in the X direction, the second dichroic mirror can receive the laser beam reflected by the second mirror. The transmitted laser beam acts on the surface of the workpiece after passing through the second beam expander, the fifth mirror and the focusing head. After judging that a certain area of the workpiece has been processed according to the results monitored by the CCD camera, the position of the laser focus emitted by the cutting head assembly can be changed by using the X-axis moving platform, the Z-axis moving plate and the first turntable assembly as required. Or use the second turntable assembly and the Y-axis moving platform to displace or rotate the workpiece to process the next area of the workpiece. Repeat this process until it is necessary to switch to 3D galvanometer processing or all the processing areas of all workpieces are completed.

[0025] When precision machining is required on the surface of the workpiece, after adjusting the laser parameters of the laser according to the processing requirements and galvanometer requirements, use the multi-axis moving platform (X-axis moving platform, Y-axis moving platform) to move the area to be processed of the workpiece directly below the light output center of the field lens. At this time, after the slide on the precision slide moves to its initial position, the first dichroic mirror can receive the laser beam reflected by the second mirror and reflect the beam to the 3D galvanometer. The beam emitted by the 3D galvanometer acts on the surface of the workpiece through the field lens. Analyze the image monitored by the CCD camera. After processing an area on the surface of the workpiece, adjust the deflection angles of the dynamic focusing lens and the two mirrors of the 3D galvanometer to change the spatial position of the laser focus point and continue to process the next area on the surface of the workpiece. Repeat this process until it is necessary to switch to cutting head assembly processing or all the processing areas of all workpieces are completed.

[0026] Compared with the prior art, the present invention has the following beneficial effects: (1) In the present invention, an optical path switching mechanism is adopted. By translating two dichroic mirrors with a slide, selective beam splitting is performed on the wavelength settings of the two dichroic mirrors, realizing fast seamless switching and optical path multiplexing between the 3D galvanometer processing mode and the cutting head processing mode. Moreover, the cooperation between the slide and the two dichroic mirrors achieves high repeat positioning accuracy, short slide switching time, fast response, and ensures that the lens angles or optical path alignment do not need to be readjusted after the optical path is switched. The beam splitting characteristics of the dichroic mirror almost completely distribute the laser energy to the target processing head, avoiding the energy loss of the traditional beam splitter; (2) The present invention adopts coaxial CCD monitoring (the monitoring light is coaxial with the processing light). According to the wavelength setting characteristics of two dichroic mirrors, the wavelength of the first illumination source and the second illumination source is designed differently, enabling the two processing modes to share the same CCD camera, reducing the hardware cost and system complexity, achieving high-precision real-time monitoring in the dual processing mode, providing a basis for closed-loop control in the laser processing process, and significantly enhancing the versatility and processing quality of the equipment. (3) In a processing device, a multi-axis moving platform and two turntable components can be used to change the position of the workpiece or the laser focus, realizing large-area processing of large-sized workpieces. At the same time, a three-dimensional galvanometer can be used to perform further fine micro-processing on the surface of the workpiece, reducing the workpiece transfer time and improving the processing efficiency. Description of the Drawings

[0027] The present invention will be further described in detail below with reference to the drawings and specific embodiments.

[0028] Figure 1 It is a schematic diagram of the switchable dual-laser-head processing optical path system in Embodiment 1; Figure 2 It is a three-dimensional structure diagram of the switchable dual-laser-head processing optical path device in Embodiment 2; Figure 3 It is a right view of the switchable dual-laser-head processing optical path device in Embodiment 2; Figure 4 It is a top view of the processing head assembly in Embodiment 2; Among them, the specific reference numerals are: Laser 1, First Reflector 2, First Beam Expander 3, Second Reflector 4, Third Reflector 5, X-axis Moving Platform 6, X-axis Driving Component 7, Fourth Reflector 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 Source 906, Lens 907, CCD Camera 908, Second Beam Expander 909, Fifth Reflector 910, Cutting Head Assembly 911, Second Illumination Source 912, Distance Sensor 913, Z-axis Driving Component 10, Z-axis Moving Plate 11, First Turntable Component 12, Workpiece to be Processed 13, Second Turntable Component 14, Y-axis Moving Platform 15, Y-axis Driving Component 16, Base 17. Detailed Description of the Embodiment

[0029] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0030] Embodiment 1 This embodiment discloses a switchable dual-laser-head processing optical path system. As Figure 1 shown, it includes a laser 1, a reflection optical path mechanism, and a processing head assembly 9. The reflection 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. The processing head assembly 9 includes a first dichroic mirror 901, a second dichroic mirror 902, a three-dimensional galvanometer 904, and a cutting head assembly 911.

[0031] The first dichroic mirror 901 and the second dichroic mirror 902 are arranged side by side and inclined at 45°. The sliding drive mechanism is drivingly installed with 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 beam exit direction of the reflection optical path mechanism respectively. The sliding drive mechanism can be a pneumatic slide table, a precision slide table, or a rolling screw drive structure. In this embodiment, a precision slide table 903 is adopted. The precision cylinder in the precision slide table 903 has a double-acting cylinder inside that realizes bidirectional movement through alternating air supply. The piezoelectric proportional valve can be used to dynamically compensate for air pressure fluctuations and achieve micron-level precision control. Since after reflection or transmission by the dichroic mirror, it 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 table 903 only need to reach the specified positions and reflect or transmit the beam into the subsequent optical devices. The magnetic grating or grating feedback signal can also be combined to further improve the movement precision. If higher movement precision is required, a servo motor drive can be used to move the two dichroic mirrors with a ball screw or a linear motor, and the grating ruler is used to send a feedback signal to the controller. After calculating the error in the actual position, the position of the dichroic mirror is dynamically compensated.

[0032] The laser beam emitted by the laser 1 is incident on the first reflector 2 at an angle of 45°. After being reflected, the beam enters the first beam expander 3. The first beam expander 3 is a variable magnification beam expander. After expanding the diameter of the beam spot, the output collimated beam is incident on the second reflector 4 at an angle of 45°. The beam reflected by the second reflector 4 passes through the third reflector 5 and the fourth reflector 8 in sequence, and then is incident on the first dichroic mirror 901 or the second dichroic mirror 902. The first dichroic mirror 901 is a short-wave pass dichroic mirror, and the wavelength band of the laser beam emitted by the laser 1 is higher than the cut-off wavelength of the first dichroic mirror 901. The second dichroic mirror 902 is a long-wave pass dichroic mirror, and the wavelength band of the laser beam emitted by the 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 3D galvanometer 904, and then focused into a spot by the field lens 905 and acts on the workpiece 13 to be processed. The 3D galvanometer 904 includes a dynamic focusing lens and two high-speed deflecting reflectors. Therefore, the focused beam output by the field lens 905 can be adjusted in a certain distance in three dimensions; 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. After expanding the diameter of the beam spot, it is transmitted to the fifth reflector 910, and the reflected beam is incident on the cutting head assembly 911, and is converged by the focusing lens in the cutting head assembly 911 and acts on the workpiece 13 to be processed.

[0033] In specific applications, the wavelength of the laser beam emitted by the laser 1 is 1030 nm, and the power adjustment range needs to be set according to the maximum power that the 3D galvanometer 904 and the cutting head assembly 911 can withstand. The laser 1 can select a short-pulse laser with a pulse width in nanoseconds or a quasi-continuous laser, or a laser that supports pulse / continuous mode switching, which is convenient for switching when processing workpieces with different thicknesses and effects.

[0034] In the overall optical path, the rapid switching between the 3D galvanometer processing mode and the cutting head processing mode is achieved mainly by switching the positions of two dichroic mirrors in the processing head assembly 9 and specifically designing the two dichroic mirrors, without the need to replace the lenses or recalibrate the optical path. Specifically, the first dichroic mirror 901 is a short-wave pass dichroic mirror with high transmission and high reflection characteristics. Its cut-off wavelength is 805 nm, which can reflect light beams with wavelengths higher than the cut-off wavelength (i.e., the laser beam with a wavelength of 1030 nm) and transmit light beams with wavelengths lower than the cut-off wavelength at the same time. The second dichroic mirror 902 is a long-wave pass dichroic mirror with high transmission and high reflection characteristics. Its starting wavelength is 605 nm, which can transmit light beams with wavelengths higher than the starting wavelength (i.e., the laser with a wavelength of 1030 nm) and reflect light beams with wavelengths lower than the starting wavelength at the same time. Through the above design, the laser beam is reflected by the first dichroic mirror 901 to the 3D galvanometer 904 and focused into a micron-level spot by the field lens 905 for precision machining. The laser beam is transmitted through the second dichroic mirror 902 to the cutting head assembly 911 and converged into a beam with a diameter in the micron level to achieve large-size cutting.

[0035] The reflecting mirror 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 3D galvanometer 904 is 5 mm. The first beam expander 3 can expand the laser beam with a spot diameter of about 2.5 mm by 2 times to 5 mm. The laser beam expanded by the first beam expander 3 is collimated parallel light. However, after multiple reflections and with a long optical path, the laser has already diverged to a certain extent when it reaches the processing head assembly 9. When performing processing with the 3D galvanometer 904, since there is a dynamic focusing unit in the 3D galvanometer 904, which changes the diameter of the beam entering the galvanometer through a movable lens group, it can essentially be equivalent to a beam expander, so the laser can be collimated again. When using the cutting head assembly 911 for processing, on the one hand, since the collimation degree of the laser beam is reduced at this time and there is divergence, and on the other hand, since the focusing lens in the cutting head assembly 911 also has an optimal incident beam diameter, the laser entering the cutting head assembly 911 needs to be expanded. For example, the optimal incident beam diameter of the focusing lens is 10 mm. 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 2-fold beam expander, can be set in front of the fifth reflecting mirror 910.

[0036] Among them, 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 provided around the field lens 905. The wavelength band of the illumination light emitted by the first illumination light source 906 is lower than the cut-off wavelength of the first dichroic mirror 901 and higher 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 first illumination light source 906 is transmitted to the first dichroic mirror 901 after passing through the field lens 905 and the three-dimensional galvanometer 904, and then sequentially passes through the first dichroic mirror 901 and the second dichroic mirror 902 and is transmitted into the CCD camera 908.

[0037] 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 into the CCD camera 908.

[0038] Through the cooperation of the first illumination light source 906, the second illumination light source 912 and the two dichroic mirrors, a coaxial CCD monitoring system is formed to ensure that the CCD camera 908 can monitor the processing areas of the two processing modes in real time, realizing the real-time monitoring of the processing surface and improving the processing accuracy.

[0039] The detection process of the CCD camera 908 can be briefly summarized as follows: After the visible light emitted by the illumination light source irradiates on the surface of the workpiece 13 to be processed, part of the reflected optical signal enters the CCD camera 908 after passing through the optical path. After the computer obtains the image information, it performs different processing according to different requirements. For example, if it is necessary to monitor the processing trajectory in real time, the image can be converted into a grayscale image. After filtering out the invalid noise information, feature extraction is performed on the processing area, and finally the processing trajectory is obtained by fitting. The illumination light source can be selected according to the cut-off wavelength and starting wavelength of the dichroic mirror. For example, the first illumination light with a wavelength of 650 nm and the second illumination light with a wavelength of 525 nm. The photosensitive wavelength band of the CCD camera 908 needs to cover the common visible light wavelength band of 400 - 780 nm to support more selectivity of the illumination light source and facilitate the replacement of the illumination light source for workpieces with different rough surfaces.

[0040] The specific working principle is as follows: 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 through the field lens 905 and the three-dimensional galvanometer 904. Since the wavelength band (wavelength: 650 nm) of the illumination light emitted by the first illumination light source 906 is lower than the cut-off 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 the photosensitive target surface of the industrial CCD camera 908 receives the illumination light information focused by the lens 907, real-time monitoring of the surface of the workpiece 13 to be processed is realized.

[0041] Since the wavelength of the second illumination light source 912 (wavelength: 525 nm) is slightly lower than the wavelength of the first illumination light source 906 (wavelength: 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 through the cutting head assembly 911. Since the wavelength band 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 and transmitted to the lens 907 of the CCD camera 908. After the second illumination beam is focused by the lens 907, it also irradiates on the photosensitive surface of the CCD camera 908, realizing the monitoring of the surface of the workpiece by the CCD camera 908.

[0042] Embodiment 2 This embodiment discloses a switchable dual-laser head processing optical path device, as Figures 2 to 4 shown, which includes the processing optical path system in Embodiment 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; An X-axis driving component 7 and a Y-axis driving component 16 are provided on the top of the base 17. The X-axis driving component 7 is drivingly connected to the X-axis moving platform 6, and the X-axis moving platform 6 has a certain stroke in the X-axis direction. The Y-axis driving component 16 is drivingly connected to the Y-axis moving platform 15, and the Y-axis moving platform 15 has a certain stroke in the Y-axis direction. A Z-axis driving component 10 is provided on the side surface of the X-axis moving platform 6, and the Z-axis driving component 10 is drivingly connected to the Z-axis moving plate 11, and the Z-axis moving plate 11 can move in the Z-axis direction; The laser 1, the first reflector 2, the first beam expander 3, and the second reflector 4 are placed on the top of the X-axis moving platform 6 on the same horizontal plane. The third reflector 5, the fourth reflector 8, and the processing head assembly 9 are installed on the surface of the Z-axis moving plate 11 on 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 the workpiece 13 to be processed is placed on the Y-axis moving platform 15.

[0043] Among them, a first turntable assembly 12 capable of rotating around the Y-axis direction is installed on the Z-axis moving plate 11. The machining head assembly 9 is installed on the first turntable assembly 12. An incident hole for the laser beam to pass through is provided on the first turntable assembly 12. The first turntable assembly 12 can carry the machining head assembly 9 to rotate at a certain angle, realizing the change of the position of the beam output by the cutting head assembly 911, so as to perform laser processing on workpieces with complex surface shapes.

[0044] Among them, a second turntable assembly 14 capable of rotating around the Z-axis direction is installed on the Y-axis moving platform 15. The workpiece to be machined 13 is placed on the second turntable assembly 14, which drives the workpiece to be machined 13 to rotate at a certain angle, so that the laser-available area of the workpiece to be machined changes.

[0045] Among them, a distance sensor 913 is installed below the machining head assembly 9 to assist in measuring the distance between the machining head assembly 9 and the workpiece to be machined 13, preventing the bottom end of the cutting head assembly 911 from touching the workpiece to be machined 13 when the Z-axis moving plate 11 moves along the Z-axis direction.

[0046] The specific working principle is as follows: When using the cutting head assembly 911 to machine large-sized workpieces, first, use the multi-axis moving platform (X-axis moving platform 6, Y-axis moving platform 15) to move the area to be machined of the workpiece directly below the cutting head assembly 911. At this time, after the slide on the precision slide table 903 moves a certain distance in the X direction, the dichroic mirror 902 can receive the laser beam reflected by the second reflector 4. The transmitted laser beam acts on the surface of the workpiece after passing through the second beam expander 909, the fifth reflector 910 and the focusing head. After judging that a certain area of the workpiece has been machined according to the monitoring result of the CCD camera 908, the position of the laser focus emitted by the cutting head assembly 911 can be changed according to the needs by using the X-axis moving platform 6, the Z-axis moving plate 11 and the first turntable assembly 12. Or use the second turntable assembly 14 and the Y-axis moving platform 15 to displace or rotate the workpiece to process the next area of the workpiece. Repeat this process until it is necessary to switch to the three-dimensional galvanometer 904 for machining or all the machining areas of all the workpieces are completed.

[0047] When precise machining is required on the surface of the workpiece, after adjusting the laser parameters of the laser 1 according to the machining requirements and the requirements of the galvanometer, the multi-axis moving platform (X-axis moving platform 6, Y-axis moving platform 15) is used to move the area to be machined of the workpiece directly below the light-emitting center of the field lens 905. At this time, after the slide on the precision slide 903 moves to its initial position, the first dichroic mirror 901 can receive the laser beam reflected by the second mirror 4 and reflect the beam to the three-dimensional galvanometer 904. The beam emitted by the three-dimensional galvanometer 904 acts on the surface of the workpiece through the field lens 905. Analyze the image monitored by the CCD camera 908. After machining an area on the surface of the workpiece, adjust the dynamic focusing lens of the three-dimensional galvanometer 904 and the deflection angles of the two mirrors to change the spatial position of the laser focus point and continue machining the next area on the surface of the workpiece. Repeat this process until it is necessary to switch to machining with the cutting head assembly 911 or all the machining areas of all the workpieces are completed.

[0048] Although the embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present 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 reflection optical path mechanism, and a processing head assembly. 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 at an inclination of 45°. The sliding drive mechanism is drivingly installed with 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 beam exit direction of the reflection optical path mechanism respectively; The laser beam emitted by the laser is reflected by the reflection 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-wave pass dichroic mirror, and the wavelength band of the laser beam emitted by the laser is higher than the cut-off wavelength of the first dichroic mirror. The second dichroic mirror is a long-wave 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, and then focused into a 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, and is converged by the focusing lens in the cutting head assembly and acts on the workpiece to be processed.

2. The switchable dual-laser-head processing optical path system according to claim 1, wherein It further includes a CCD camera. 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 cut-off 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 through the field lens and the three-dimensional galvanometer, and it sequentially passes through the first dichroic mirror and the second dichroic mirror and is transmitted into the CCD camera.

3. The switchable dual-laser-head processing optical path system according to claim 2, wherein, 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 it is reflected by the second dichroic mirror into the CCD camera.

4. The switchable dual-laser-head processing optical path system according to claim 1, wherein, The reflection optical path structure includes a first reflecting mirror, a first beam expander, a second reflecting mirror, a third reflecting mirror, and a fourth reflecting mirror. The laser beam emitted by the laser is incident on the first reflecting mirror at 45°. After being reflected, the beam enters the first beam expander. 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 reflecting mirror at 45°. The beam reflected by the second reflecting mirror sequentially passes through the third reflecting mirror and the fourth reflecting mirror, and then is incident on the first dichroic mirror or the second dichroic mirror.

5. The switchable dual-laser head processing optical path system according to claim 4, wherein When the laser beam enters the second dichroic mirror, the beam passes downward through the second dichroic mirror and is transmitted to the second beam expander. After expanding the beam spot diameter, it is transmitted to the fifth reflecting mirror, and the reflected beam is incident on the cutting head assembly.

6. A switchable dual-laser-head processing optical path device, characterized in that, It includes the processing optical path system described in any one of claims 1 to 5, and further includes a base, an X-axis moving platform, a Y-axis moving platform, and a Z-axis moving plate; An X-axis driving component and a Y-axis driving component are provided on the top of the base. The X-axis driving component is drivingly connected to the X-axis moving platform, and the Y-axis driving component is drivingly connected to the Y-axis moving platform. A Z-axis driving component is provided on the side surface of the X-axis moving platform, and the Z-axis driving component is drivingly 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 moving platform at the same horizontal plane. A third reflector, a fourth reflector, and a processing head assembly are mounted on the surface of the Z-axis moving plate at the same horizontal plane. The third reflector is directly below the second reflector. The Y-axis moving platform is located below the processing head assembly, and a workpiece to be processed is placed on the Y-axis moving platform.

7. The switchable dual-laser-head processing optical path device according to claim 6, wherein, A first turntable assembly that can rotate around the Y-axis direction is mounted on the Z-axis moving plate, and the processing head assembly is mounted on the first turntable assembly. An incident hole for the laser beam to pass through is provided on the first turntable assembly.

8. The switchable dual-laser-head processing optical path device according to claim 7, wherein A second turntable assembly that can rotate around the Z-axis direction is mounted on the Y-axis moving platform, and the workpiece to be processed is placed on the second turntable assembly.

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

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