Curved surface cutting processing equipment and processing method based on femtosecond laser high-speed scanning

Abstract

The present invention provides a surface cutting processing equipment and processing method based on high-speed scanning of femtosecond laser, which belongs to the field of laser processing technology, including a femtosecond laser, a moving reflector, a polygonal scanning galvanometer and a 3D scanning galvanometer, wherein a high-frequency pulse laser beam is generated by a femtosecond laser, each pulse is divided into a pulse train, and each pulse train contains a plurality of sub-pulses; the polygonal scanning galvanometer is installed on a first Z-axis slide, and a stepped step is formed on the surface of a processed workpiece by the polygonal scanning galvanometer; the 3D scanning galvanometer is installed on a second Z-axis slide, and the edge of the stepped step processed by the polygonal scanning galvanometer is etched by the 3D scanning galvanometer. The present invention can avoid the accumulation of plasma shielding clouds by dividing the pulse into pulse trains in the time domain, solve the problem of heat accumulation effect and improve the processing quality of the workpiece.

Description

Technical Field

[0001] The present invention belongs to the technical field of laser processing, and relates to a curved surface cutting processing equipment, in particular to a curved surface cutting processing equipment and a processing method based on femtosecond laser high-speed scanning. Background Art

[0002] Carbon fiber reinforced resin matrix composites (CFRP) and ceramic matrix composites (CMC) are typical difficult-to-process materials due to their unique properties. After the components of these materials are formed, some local installation features usually need to be processed. Although traditional machining methods are widely used in the processing of such composite materials, due to the characteristics of the composite materials themselves, such as low interlaminar shear strength and overall stiffness / strength, the presence of high-hardness fibers in the composite materials and the heterogeneity of the materials, the use of traditional mechanical cutting methods is prone to processing defects such as delamination, flash, burrs, and clamping deformation, which in turn affects the processing quality. In addition, due to the lack of cutting fluid, traditional mechanical cutting is also accompanied by large cutting forces, poor surface quality, low processing efficiency, and severe tool wear. More importantly, traditional machining methods are difficult to effectively process complex structural features such as tiny holes and deep narrow grooves in composite components. Although traditional femtosecond laser processing technology can achieve high-precision material removal, due to the low material removal rate, processing efficiency has become a key bottleneck restricting its engineering application.

[0003] Based on the above technical problems, in the prior art, high average power, high peak power, and high repetition frequency femtosecond lasers are used to improve material removal rates and achieve efficient and precise cold processing of difficult-to-process materials. However, excessive laser energy density input and long-term irradiation of materials will lead to the generation of severe plasma shielding clouds, which will affect the material's continued absorption of lasers and material areas. In addition, the high temperature of the plasma shielding cloud will cause heat accumulation and lead to uncontrollable thermal damage. In addition, the femtosecond laser beam driven by a polygonal scanning galvanometer can only process planar features, but cannot achieve curved surface processing of materials. Summary of the invention

[0004] The purpose of the present invention is to address the above-mentioned problems in the existing technology and to propose a surface cutting processing equipment that can overcome the shielding effect and heat accumulation effect caused by high-temperature plasma shielding cloud lock, solve the problem of thermal damage to the workpiece, and realize product surface processing.

[0005] The purpose of the present invention can be achieved by the following technical solutions: a curved surface cutting processing equipment based on high-speed scanning of femtosecond laser, comprising a femtosecond laser, a movable reflector, a polygonal scanning galvanometer and a 3D scanning galvanometer arranged on the path of laser propagation, and the high-frequency pulse laser beam generated by the femtosecond laser is transmitted to the polygonal scanning galvanometer or the 3D scanning galvanometer through the movable reflector, wherein:

[0006] A high-frequency pulsed laser beam with adjustable frequency and pulse width is generated by a femtosecond laser, each pulse is divided into a pulse train, and each pulse train contains multiple sub-pulses, a part of the sub-pulses are used as sub-pulses for ablating materials, and another part of the sub-pulses are used as sub-pulses for clearing plasma shielding clouds, wherein the high-frequency pulsed laser beam is guided by a multi-prism scanning galvanometer through a moving reflector to etch the XY plane on the workpiece layer by layer according to a preset trajectory;

[0007] The polygonal scanning galvanometer is installed on the first Z-axis slide. Each time a layer of material on the surface of the workpiece is etched, the polygonal scanning galvanometer is lowered by a thickness of the etched material under the action of the first Z-axis slide. After the polygonal scanning galvanometer is processed, a step-like step to be processed is formed on the XY plane of the workpiece.

[0008] The 3D scanning galvanometer is installed on the second Z-axis slide. The 3D scanning galvanometer is driven to rise and fall by the second Z-axis slide. The high-frequency pulse laser beam etches the edge of the stepped steps processed by the polygonal scanning galvanometer through the moving reflector under the guidance of the 3D scanning galvanometer.

[0009] In the above-mentioned curved surface cutting processing equipment based on high-speed scanning of femtosecond laser, among multiple sub-pulses, sub-pulses serving as ablative materials and sub-pulses serving as clearing plasma shielding clouds act alternately on materials in the XY plane of the workpiece being processed, and the pulse energy contained in the sub-pulse serving as ablative materials is greater than the pulse energy contained in the sub-pulse serving as clearing plasma shielding clouds.

[0010] In the above-mentioned surface cutting processing equipment based on high-speed scanning of femtosecond laser, the number of sub-pulses in the pulse train is an even number, or an odd number. When the number of sub-pulses in the pulse train is an even number, the number of sub-pulses used for ablating materials and the number of sub-pulses used for clearing plasma shielding clouds in each pulse train are exactly equal, forming a pulse cycle, wherein the first sub-pulse of each pulse train is a sub-pulse used for ablating materials, and the position layout of the sub-pulses used for ablating materials and the sub-pulses used for clearing plasma shielding clouds in each pulse train is the same; when the number of sub-pulses in the pulse train is an odd number, two adjacent pulse trains form a pulse cycle, wherein the first sub-pulse of one pulse train is a sub-pulse used for ablating materials, and the first sub-pulse of the other pulse train is a sub-pulse used for clearing plasma shielding clouds.

[0011] In the above-mentioned curved surface cutting processing equipment based on high-speed scanning of femtosecond laser, the time interval between the sub-pulse for ablating materials and the sub-pulse for clearing plasma shielding cloud is 1-30ns, and the interval time between two adjacent pulses is used as cooling time.

[0012] In the above-mentioned surface cutting processing equipment based on high-speed scanning of femtosecond laser, the polygonal scanning galvanometer includes a first reflector, a polygonal prism and a field lens in sequence along the propagation path of the laser, and the high-frequency pulse laser beam transmitted from the first reflector is rotated and emitted at different angles through the rotation of the polygonal prism, and a dot-matrix-arranged etching position is formed on the XY plane of the workpiece to be processed, and the high-frequency pulse laser beam is focused through the field lens.

[0013] In the above-mentioned curved surface cutting processing equipment based on high-speed scanning of femtosecond laser, the scanning speed of the high-frequency pulse laser beam is 200-1000m / s.

[0014] In the above-mentioned curved surface cutting processing equipment based on high-speed scanning of femtosecond laser, a beam collimation module and a beam shaping module are also arranged between the femtosecond laser and the movable reflector, wherein:

[0015] The beam collimation module is used to pre-process the high-frequency pulse laser beam, and the pre-processing includes collimation and beam expansion, and the spot distribution characteristic of the high-frequency pulse laser beam is Gaussian light distribution;

[0016] The beam shaping module is used to convert the pre-processed high-frequency pulse laser beam into a high-frequency pulse laser beam with a spot distribution characteristic of a flat-top light distribution.

[0017] In the above-mentioned curved surface cutting processing equipment based on femtosecond laser high-speed scanning, a 3D scanning galvanometer is sequentially provided with a second reflector, a first galvanometer and a second galvanometer along the propagation path of the laser, and the high-frequency pulsed laser beam is driven by the first galvanometer and the second galvanometer to move along the X-axis and Y-axis directions respectively, so as to etch the edge of the stepped steps processed by the polygonal scanning galvanometer.

[0018] In the above-mentioned surface cutting processing equipment based on femtosecond laser high-speed scanning, it also includes an XY dual-axis slide, and a rotation module is arranged on the XY dual-axis slide, wherein the processing workpiece is installed on the rotation module, and the rotation module and the XY dual-axis slide are used to realize the rotation of the processing workpiece and the movement along the horizontal X-axis and Y-axis directions.

[0019] The present invention also provides a curved surface cutting processing equipment based on high-speed scanning of a femtosecond laser, comprising a femtosecond laser, a movable reflector, a polygonal scanning galvanometer and a machining module arranged on the path of laser propagation, and transmitting the high-frequency pulse laser beam generated by the femtosecond laser to the polygonal scanning galvanometer or the machining module through the movable reflector, wherein:

[0020] A high-frequency pulsed laser beam with adjustable frequency and pulse width is generated by a femtosecond laser, each pulse is divided into a pulse train, and each pulse train contains multiple sub-pulses, a part of the sub-pulses are used as sub-pulses for ablating materials, and another part of the sub-pulses are used as sub-pulses for clearing plasma shielding clouds, wherein the high-frequency pulsed laser beam is guided by a multi-prism scanning galvanometer through a moving reflector to etch the XY plane on the workpiece layer by layer according to a preset trajectory;

[0021] The polygonal scanning galvanometer is installed on the first Z-axis slide. Each time a layer of material on the surface of the workpiece is etched, the polygonal scanning galvanometer is lowered by a thickness of the etched material under the action of the first Z-axis slide. After the polygonal scanning galvanometer is processed, a step-like step to be processed is formed on the surface of the workpiece.

[0022] The machining module is installed on the second Z-axis slide. The second Z-axis slide drives the machining module to rise and fall. The high-frequency pulse laser beam etches the edge of the stepped steps processed by the polygonal scanning galvanometer through the moving reflector under the guidance of the machining module.

[0023] In the above-mentioned surface cutting processing equipment based on femtosecond laser high-speed scanning, the machining module includes an electric spindle installed on the second Z-axis slide, and a tool connected to the output end of the electric spindle. The tool is driven to rotate by the electric spindle to cut the edge of the stepped step processed by the polygonal scanning galvanometer.

[0024] In the above-mentioned curved surface cutting processing equipment based on high-speed scanning of femtosecond laser, a beam collimation module and a beam shaping module are also arranged between the femtosecond laser and the movable reflector, wherein:

[0025] The beam collimation module is used to pre-process the high-frequency pulse laser beam, and the pre-processing includes collimation and beam expansion, and the spot distribution characteristic of the high-frequency pulse laser beam is Gaussian light distribution;

[0026] The beam shaping module is used to convert the pre-processed high-frequency pulse laser beam into a high-frequency pulse laser beam with a spot distribution characteristic of a flat-top light distribution.

[0027] The present invention also provides a processing method of a curved surface cutting processing device based on femtosecond laser high-speed scanning, comprising the steps of:

[0028] S1: A high-frequency pulsed laser beam with adjustable frequency and pulse width is generated by a femtosecond laser, and the pulse is divided into pulse trains in the time domain. Each pulse train contains multiple sub-pulses, some of which are used as sub-pulses for ablating materials, and the other sub-pulses are used as sub-pulses for clearing plasma shielding clouds.

[0029] S2: collimate and expand the high-frequency pulse laser beam through the beam collimation module;

[0030] S3: transforming the high-frequency pulse laser beam with Gaussian distribution into a high-frequency pulse laser beam with flat-top distribution through a beam shaping module;

[0031] S4: The high-frequency pulsed laser beam with flat top distribution is reflected to the polygonal scanning galvanometer by moving the reflector, and the irradiation area is switched in the spatial domain by rotating the polygonal prism in the polygonal scanning galvanometer to form etching positions arranged in a dot matrix;

[0032] S5: The high-frequency pulse laser beam is focused by the field mirror in the multi-prism scanning galvanometer. The focused high-frequency pulse laser beam etches the material on the XY plane of the workpiece. Each time a layer of material is etched, the multi-prism scanning galvanometer is driven by the first Z-axis slide table to move down a layer thickness to lower the position of the laser focus.

[0033] S6: After the processing of the XY plane is completed, the workpiece mounted on the rotating module is moved to the bottom of the 3D scanning galvanometer under the action of the XY dual-axis slide;

[0034] S7: The high-frequency pulsed laser beam with flat-top distribution is reflected by the second reflector and enters the 3D scanning galvanometer. The high-frequency pulsed laser beam is driven to move along the X-axis and Y-axis directions by the first galvanometer and the second galvanometer in the 3D scanning galvanometer respectively to etch the edge of the stepped steps processed by the polygonal scanning galvanometer to complete the processing of the workpiece.

[0035] The present invention also provides a processing method of a curved surface cutting processing device based on femtosecond laser high-speed scanning, comprising the steps of:

[0036] S1: A high-frequency pulsed laser beam with adjustable frequency and pulse width is generated by a femtosecond laser, and the pulse is divided into pulse trains in the time domain. Each pulse train contains multiple sub-pulses, some of which are used as sub-pulses for ablating materials, and the other sub-pulses are used as sub-pulses for clearing plasma shielding clouds.

[0037] S2: collimate and expand the high-frequency pulse laser beam through the beam collimation module;

[0038] S3: transforming the high-frequency pulse laser beam with Gaussian distribution into a high-frequency pulse laser beam with flat-top distribution through a beam shaping module;

[0039] S4: The high-frequency pulsed laser beam with flat top distribution is reflected to the polygonal scanning galvanometer by moving the reflector, and the irradiation area is switched in the spatial domain by rotating the polygonal prism in the polygonal scanning galvanometer to form etching positions arranged in a dot matrix;

[0040] S5: The high-frequency pulse laser beam is focused by the field mirror in the multi-prism scanning galvanometer. The focused high-frequency pulse laser beam etches the material on the XY plane of the workpiece. Each time a layer of material is etched, the multi-prism scanning galvanometer is driven by the first Z-axis slide table to move down a layer thickness to lower the position of the laser focus.

[0041] S6: After the processing of the XY plane is completed, the workpiece mounted on the rotating module is moved to the bottom of the machining module under the action of the XY dual-axis slide;

[0042] S7: The electric spindle in the machining module drives the tool to rotate at high speed to cut the edge of the stepped steps machined by the polygonal scanning galvanometer to complete the machining of the workpiece.

[0043] Compared with the prior art, the present invention has the following beneficial effects:

[0044] (1) The present invention provides a surface cutting processing equipment based on high-speed scanning of femtosecond laser, which can avoid the accumulation of plasma shielding cloud and solve the problem of heat accumulation effect by dividing the pulse into pulse trains in the time domain. In addition, the processing quality of the workpiece is improved by setting a 3D scanning galvanometer;

[0045] (2) Increasing the cooling time of the material between two adjacent pulses can further avoid thermal damage to the workpiece;

[0046] (3) In the spatial domain, a high-frequency pulse laser beam ultra-high-speed scanning strategy is realized through a rotating polygonal prism, that is, the target is changed immediately after shooting to prevent excessive heat accumulation in the local area and increase the rest time of the irradiated area. This rest time can be used as the dissipation time of the plasma shielding cloud, thereby avoiding thermal damage to the workpiece;

[0047] (4) The beam shaping module transforms the Gaussian-distributed high-frequency pulsed laser beam into a flat-top-distributed high-frequency pulsed laser beam. The more uniform energy distribution ensures consistent material removal and helps improve the roughness of the workpiece surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 It is a structural schematic diagram of the curved surface cutting processing equipment based on femtosecond laser high-speed scanning of the present invention.

[0049] Figure 2 It is a schematic diagram of etching a workpiece layer by layer in a preferred embodiment of the present invention.

[0050] Figure 3 It is a schematic diagram of processing a step area on the edge of a workpiece in a preferred embodiment of the present invention.

[0051] Figure 4It is a schematic diagram of converting a high-frequency pulse laser beam with a Gaussian distribution into a high-frequency pulse laser beam with a flat-top distribution in a preferred embodiment of the present invention.

[0052] Figure 5 It is a structural schematic diagram of another embodiment of the curved surface cutting processing equipment based on femtosecond laser high-speed scanning of the present invention.

[0053] In the figure, 10, femtosecond laser; 20, moving reflector; 30, polygonal prism scanning galvanometer; 31, first reflector; 32, polygonal prism; 33, field lens; 40, 3D scanning galvanometer; 41, second reflector; 42, first galvanometer; 43, second galvanometer; 50, first Z-axis slide; 60, second Z-axis slide; 70, beam collimation module; 80, beam shaping module; 90, XY dual-axis slide; 100, rotation module; 200, machining module; 210, electric spindle; 220, tool. DETAILED DESCRIPTION

[0054] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solution of the present invention, but the present invention is not limited to these embodiments.

[0055] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0056] In the existing technology, high average power, high peak power, and high repetition frequency femtosecond lasers are used to improve material removal rates and achieve efficient and precise cold processing of difficult-to-process materials. However, excessive laser energy density input and long-term irradiation of materials will lead to the generation of severe plasma shielding clouds, which will affect the material's continued absorption of lasers and material areas. In addition, the high temperature of the plasma shielding cloud will cause heat accumulation and lead to uncontrollable thermal damage. In addition, femtosecond lasers can only achieve planar processing of materials, but not curved surface processing of materials. Embodiment 1

[0057] like Figures 1 to 4 As shown, the present invention provides a surface cutting processing equipment based on high-speed scanning of femtosecond laser, including a femtosecond laser 10, a movable reflector 20, a polygonal scanning galvanometer 30 and a 3D scanning galvanometer 40 arranged on the path of laser propagation, and the high-frequency pulse laser beam generated by the femtosecond laser 10 is transmitted to the polygonal scanning galvanometer 30 or the 3D scanning galvanometer 40 through the movable reflector 20, wherein:

[0058] A high-frequency pulsed laser beam with adjustable frequency and pulse width is generated by a femtosecond laser 10, each pulse is divided into a pulse train, and each pulse train contains a plurality of sub-pulses, a part of the sub-pulses are used as sub-pulses for ablating materials, and another part of the sub-pulses are used as sub-pulses for clearing plasma shielding clouds, wherein the high-frequency pulsed laser beam is guided by a multi-prism scanning galvanometer 30 through a moving reflector 20 to etch the XY plane on the workpiece layer by layer according to a preset trajectory;

[0059] The polygonal scanning galvanometer 30 is mounted on the first Z-axis slide 50. Each time a layer of material on the surface of the workpiece is etched, the polygonal scanning galvanometer 30 is lowered by a thickness of the etched material under the action of the first Z-axis slide 50. After the polygonal scanning galvanometer 30 is processed, a step-like step to be processed is formed on the XY plane of the workpiece.

[0060] The 3D scanning galvanometer 40 is installed on the second Z-axis slide 60, and the 3D scanning galvanometer 40 is driven to rise and fall by the second Z-axis slide 60. The high-frequency pulse laser beam etches the edge of the stepped steps processed by the polygonal scanning galvanometer 30 under the guidance of the 3D scanning galvanometer 40 through the moving reflector 20.

[0061] It is worth mentioning that when a high-frequency pulse laser beam etches the material on the surface of the workpiece, a harmful plasma shielding cloud will be generated. That is, if the first pulse etches the surface of the workpiece, the laser beam generated by the second pulse will be absorbed by the plasma shielding cloud generated by the first pulse, resulting in the second pulse being unable to achieve the effect of etching the material. The second pulse will also generate a plasma shielding cloud, which will increase the content of the plasma shielding cloud and the etching effect of the material will become worse. At the same time, as the content of the plasma shielding cloud increases, a heat accumulation effect will be caused, thereby causing thermal damage to the workpiece.

[0062] Therefore, based on the above reasons, each pulse is divided into a pulse train, and the pulse train contains multiple sub-pulses, marked as n1, n2, n3, ..., among which a part of the sub-pulses are used as sub-pulses for ablating the workpiece material, and the other part of the sub-pulses are used as sub-pulses for clearing the plasma shielding cloud. This can avoid the accumulation of plasma shielding clouds and solve the problem of heat accumulation effect, thereby avoiding thermal damage to the workpiece.

[0063] The present invention provides a surface cutting processing equipment based on high-speed scanning of a femtosecond laser. By dividing the pulse into pulse trains in the time domain, the accumulation of plasma shielding clouds can be avoided and the problem of heat accumulation effect can be solved. In addition, the processing quality of the workpiece can be improved by setting a 3D scanning galvanometer 40.

[0064] It is further pointed out that among the multiple sub-pulses, the sub-pulses used for ablating materials and the sub-pulses used for clearing plasma shielding clouds act alternately on the materials in the XY plane of the workpiece, that is, the sub-pulse labeled n1 will produce a certain amount of harmful plasma shielding cloud when ablating the surface of the workpiece, the sub-pulse labeled n2 can completely or partially clear the plasma shielding cloud produced by the n1 sub-pulse, the sub-pulse labeled n3 continues to ablate the materials on the surface of the workpiece and produce a certain amount of harmful plasma shielding cloud, and the sub-pulse labeled n4 continues to clear the plasma shielding cloud produced by the n3 sub-pulse. Such a cycle can not only increase the depth of the ablated material, but also avoid the heat accumulation caused by the plasma shielding cloud, thereby avoiding thermal damage to the workpiece.

[0065] Furthermore, since each pulse is divided into a pulse train, the energy contained in the pulse is also divided into multiple parts, one part of the energy is used to ablate the material on the surface of the workpiece, and the other part of the energy is used to remove the plasma shielding cloud. Therefore, in order to improve the utilization rate of energy, the pulse energy contained in the sub-pulse used for ablating the material is greater than the pulse energy contained in the sub-pulse used for removing the plasma shielding cloud. This not only ensures the utilization rate of the pulse energy, but also realizes the effective removal of the plasma shielding cloud.

[0066] It is worth mentioning that the number of sub-pulses in a pulse train may be an even number or an odd number. When the number of sub-pulses in a pulse train is an even number, the number of sub-pulses used for ablating materials and the number of sub-pulses used for clearing plasma shielding clouds in each pulse train are exactly equal, forming a pulse cycle, wherein the first sub-pulse in each pulse train is a sub-pulse used for ablating materials, and the position layout of the sub-pulses used for ablating materials and the sub-pulses used for clearing plasma shielding clouds in each pulse train is the same. When the number of sub-pulses in a pulse train is an odd number, two adjacent pulse trains form a pulse cycle, wherein the first sub-pulse in one pulse train is a sub-pulse used for ablating materials, and the first sub-pulse in the other pulse train is a sub-pulse used for clearing plasma shielding clouds.

[0067] No matter whether the number of sub-pulses in the pulse train is an even number or an odd number, from the perspective of the entire high-frequency pulse laser beam, the sub-pulses for ablating materials and the sub-pulses for clearing the plasma shielding cloud always form a pulse cycle.

[0068] Further preferably, the time interval between the sub-pulse for ablating the material and the sub-pulse for clearing the plasma shielding cloud is 1-30 ns, and the interval time between two adjacent pulses is used as cooling time.

[0069] In this embodiment, increasing the cooling time of the material between two adjacent pulses can further avoid thermal damage to the processed workpiece.

[0070] Preferably, the polygonal scanning galvanometer 30 includes a first reflector 31, a polygonal prism 32 and a field lens 33 in sequence along the propagation path of the laser, and the high-frequency pulse laser beam transmitted from the first reflector 31 is rotated and emitted along different angles through the rotation of the polygonal prism 32, and a dot-matrix-arranged etching position is formed on the XY plane of the workpiece, and the high-frequency pulse laser beam is focused by the field lens 33.

[0071] It is worth mentioning that in the spatial domain, an ultra-high-speed scanning strategy of a high-frequency pulsed laser beam is realized by means of a rotating polygonal prism 32, that is, the target is replaced immediately after shooting, so as to prevent excessive heat accumulation in a local area and increase the rest time of the irradiated area, and the rest time can be used as the dissipation time of the plasma shielding cloud, thereby avoiding thermal damage to the workpiece.

[0072] It is further pointed out that the scanning speed of the high-frequency pulse laser beam is 200-1000 m / s.

[0073] Preferably, a beam collimation module 70 and a beam shaping module 80 are further provided between the femtosecond laser 10 and the movable reflector 20, wherein:

[0074] The beam collimation module 70 is used to pre-process the high-frequency pulse laser beam, and the pre-processing includes collimation and beam expansion, and the spot distribution characteristic of the high-frequency pulse laser beam is Gaussian light distribution;

[0075] The beam shaping module 80 is used to convert the pre-processed high-frequency pulse laser beam into a high-frequency pulse laser beam with a spot distribution characteristic of a flat-top light distribution.

[0076] In this embodiment, the high-frequency pulsed laser beam with Gaussian distribution is transformed into a high-frequency pulsed laser beam with flat-top distribution through the beam shaping module 80. The more uniform energy distribution can ensure consistent material removal and help improve the roughness of the workpiece processing surface.

[0077] Preferably, the 3D scanning galvanometer 40 is sequentially provided with a second reflector 41, a first galvanometer 42 and a second galvanometer 43 along the propagation path of the laser, and the high-frequency pulse laser beam is driven by the first galvanometer 42 and the second galvanometer 43 to move along the X-axis and Y-axis directions respectively, so as to etch the edge of the stepped steps processed by the polygonal scanning galvanometer 30.

[0078] It is worth mentioning that the edges of the stepped steps processed by the polygonal scanning galvanometer 30 etched by the 3D scanning galvanometer 40 , that is, the side surfaces of the processed workpiece, are the XZ plane and the YZ plane, respectively.

[0079] Preferably, the curved surface cutting processing equipment also includes an XY dual-axis slide 90, and a rotation module 100 is arranged on the XY dual-axis slide 90, wherein the processing workpiece is installed on the rotation module 100, and the rotation module 100 and the XY dual-axis slide 90 are used to realize the rotation of the processing workpiece and the movement along the horizontal X-axis and Y-axis directions.

[0080] The present invention also provides a processing method of a curved surface cutting processing device based on femtosecond laser high-speed scanning, comprising the steps of:

[0081] S1: generating a high-frequency pulse laser beam with adjustable frequency and pulse width by a femtosecond laser 10, and dividing the pulse into pulse trains in the time domain, each pulse train comprising a plurality of sub-pulses, wherein a part of the sub-pulses are used as sub-pulses for ablating materials, and another part of the pulses are used as sub-pulses for clearing plasma shielding clouds;

[0082] S2: collimating and expanding the high-frequency pulse laser beam through the beam collimation module 70;

[0083] S3: transforming the high-frequency pulse laser beam with Gaussian distribution into a high-frequency pulse laser beam with flat-top distribution through the beam shaping module 80;

[0084] S4: The high-frequency pulsed laser beam with flat top distribution is reflected to the polygonal scanning galvanometer 30 by moving the reflector 20, and the irradiation area is switched in the spatial domain by rotating the polygonal prism 32 in the polygonal scanning galvanometer 30 to form etching positions arranged in a dot matrix;

[0085] S5: The high-frequency pulse laser beam is focused by the field lens 33 in the multi-prism scanning galvanometer 30. The focused high-frequency pulse laser beam etches the material on the XY plane of the workpiece. Each time a layer of material is etched, the multi-prism scanning galvanometer 30 is driven by the first Z-axis slide 50 to move down a layer thickness to lower the position of the laser focus.

[0086] S6: After the processing of the XY plane is completed, the processed workpiece mounted on the rotating module 100 is moved to the bottom of the 3D scanning galvanometer 40 under the action of the XY dual-axis slide 90;

[0087] S7: The high-frequency pulsed laser beam with a flat-top distribution is reflected by the second reflector 41 and enters the 3D scanning galvanometer 40. The high-frequency pulsed laser beam is driven to move along the X-axis and Y-axis directions by the first galvanometer 42 and the second galvanometer 43 in the 3D scanning galvanometer 40, respectively, to etch the edge of the stepped steps processed by the polygonal scanning galvanometer 30, thereby completing the processing of the workpiece. Embodiment 2

[0088] like Figure 5As shown, the difference between this embodiment and the first embodiment is that in the first embodiment, the edge of the stepped step formed by the polygonal scanning galvanometer 30 is etched by the 3D scanning galvanometer 40, while in this embodiment, the edge of the stepped step formed by the polygonal scanning galvanometer 30 is etched by the machining module 200.

[0089] Further preferably, the machining module 200 is installed on the second Z-axis slide 60, and the machining module 200 is driven to rise and fall by the second Z-axis slide 60. The high-frequency pulse laser beam etches the edge of the stepped steps processed by the polygonal scanning galvanometer 30 under the guidance of the machining module 200 through the movable reflector 20.

[0090] It is further pointed out that the machining module 200 includes an electric spindle 210 installed on the second Z-axis slide 60, and a tool 220 connected to the output end of the electric spindle 210. The tool 220 is driven to rotate by the electric spindle 210 to cut the edge of the stepped step machined by the polygonal scanning galvanometer 30.

[0091] The present invention also provides a processing method of a curved surface cutting processing device based on femtosecond laser high-speed scanning, comprising the steps of:

[0092] S1: generating a high-frequency pulse laser beam with adjustable frequency and pulse width by a femtosecond laser 10, and dividing the pulse into pulse trains in the time domain, each pulse train comprising a plurality of sub-pulses, wherein a part of the sub-pulses are used as sub-pulses for ablating materials, and another part of the pulses are used as sub-pulses for clearing plasma shielding clouds;

[0093] S2: collimating and expanding the high-frequency pulse laser beam through the beam collimation module 70;

[0094] S3: transforming the high-frequency pulse laser beam with Gaussian distribution into a high-frequency pulse laser beam with flat-top distribution through the beam shaping module 80;

[0095] S4: The high-frequency pulsed laser beam with flat top distribution is reflected to the polygonal scanning galvanometer 30 by moving the reflector 20, and the irradiation area is switched in the spatial domain by rotating the polygonal prism 32 in the polygonal scanning galvanometer 30 to form etching positions arranged in a dot matrix;

[0096] S5: The high-frequency pulse laser beam is focused by the field lens 33 in the multi-prism scanning galvanometer 30. The focused high-frequency pulse laser beam etches the material on the XY plane of the workpiece. Each time a layer of material is etched, the multi-prism scanning galvanometer 30 is driven by the first Z-axis slide 50 to move down a layer thickness to lower the position of the laser focus.

[0097] S6: After the processing of the XY plane is completed, the workpiece mounted on the rotating module 100 is moved to the bottom of the machining module 200 under the action of the XY dual-axis slide 90;

[0098] S7: The electric spindle 210 in the machining module 200 drives the tool 220 to rotate at high speed to cut the edge of the stepped step machined by the polygonal scanning galvanometer 30, thereby completing the machining of the workpiece.

[0099] It should be noted that in the present invention, descriptions such as "first", "second", "one", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined. The terms "connected", "fixed", etc. should be understood in a broad sense. For example, "fixed" can be a fixed connection, a detachable connection, or an integral whole; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0100] In addition, the technical solutions between the various embodiments of the present invention can be combined with each other, but it must be based on the fact that ordinary technicians in the field can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0101] The specific embodiments described herein are merely examples of the spirit of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in similar ways, but they will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

Claims

1. A curved surface cutting equipment based on high-speed scanning of femtosecond laser, characterized in that: The invention comprises arranging a femtosecond laser, a movable reflector, a polygonal scanning galvanometer and a 3D scanning galvanometer on the path of laser propagation, and transmitting the high-frequency pulse laser beam generated by the femtosecond laser to the polygonal scanning galvanometer or the 3D scanning galvanometer through the movable reflector, wherein: A high-frequency pulsed laser beam with adjustable frequency and pulse width is generated by a femtosecond laser, each pulse is divided into a pulse train, and each pulse train contains multiple sub-pulses, a part of the sub-pulses are used as sub-pulses for ablating materials, and another part of the sub-pulses are used as sub-pulses for clearing plasma shielding clouds, wherein the high-frequency pulsed laser beam is guided by a multi-prism scanning galvanometer through a moving reflector to etch the XY plane on the workpiece layer by layer according to a preset trajectory; The polygonal scanning galvanometer is installed on the first Z-axis slide. Each time a layer of material on the surface of the workpiece is etched, the polygonal scanning galvanometer is lowered by a thickness of the etched material under the action of the first Z-axis slide. After the polygonal scanning galvanometer is processed, a step-like step to be processed is formed on the XY plane of the workpiece. The 3D scanning galvanometer is installed on the second Z-axis slide. The 3D scanning galvanometer is driven to rise and fall by the second Z-axis slide. The high-frequency pulse laser beam etches the edge of the stepped steps processed by the polygonal scanning galvanometer through the moving reflector under the guidance of the 3D scanning galvanometer.

2. The curved surface cutting processing equipment based on femtosecond laser high-speed scanning according to claim 1 is characterized in that: Among the multiple sub-pulses, the sub-pulses for ablating materials and the sub-pulses for clearing plasma shielding clouds act alternately on the materials in the XY plane of the workpiece, and the pulse energy contained in the sub-pulses for ablating materials is greater than the pulse energy contained in the sub-pulses for clearing plasma shielding clouds.

3. The curved surface cutting processing equipment based on femtosecond laser high-speed scanning according to claim 1 is characterized in that: The number of sub-pulses in a pulse train is an even number or an odd number. When the number of sub-pulses in a pulse train is an even number, the number of sub-pulses used for ablating materials and the number of sub-pulses used for clearing plasma shielding clouds in each pulse train are exactly equal, forming a pulse cycle, wherein the first sub-pulse in each pulse train is a sub-pulse used for ablating materials, and the position layout of the sub-pulses used for ablating materials and the sub-pulses used for clearing plasma shielding clouds in each pulse train is the same; when the number of sub-pulses in a pulse train is an odd number, two adjacent pulse trains form a pulse cycle, wherein the first sub-pulse in one pulse train is a sub-pulse used for ablating materials, and the first sub-pulse in the other pulse train is a sub-pulse used for clearing plasma shielding clouds.

4. The curved surface cutting processing equipment based on femtosecond laser high-speed scanning according to claim 1 is characterized in that: The time interval between the sub-pulse for ablating the material and the sub-pulse for clearing the plasma shielding cloud is 1-30ns, and the interval time between two adjacent pulses is used as cooling time.

5. The curved surface cutting processing equipment based on femtosecond laser high-speed scanning according to any one of claims 1 to 4, characterized in that: The polygonal scanning galvanometer includes a first reflector, a polygonal prism and a field lens in sequence along the propagation path of the laser. The high-frequency pulse laser beam transmitted from the first reflector is rotated and emitted at different angles through the rotation of the polygonal prism, and a dot-matrix-arranged etching position is formed on the XY plane of the workpiece to be processed, and the high-frequency pulse laser beam is focused through the field lens.

6. The curved surface cutting processing equipment based on femtosecond laser high-speed scanning according to claim 5 is characterized in that: The scanning speed of the high-frequency pulse laser beam is 200-1000m / s.

7. The curved surface cutting processing equipment based on femtosecond laser high-speed scanning according to claim 5 is characterized in that: A beam collimation module and a beam shaping module are also arranged between the femtosecond laser and the movable reflector. The beam collimation module is used to pre-process the high-frequency pulse laser beam, and the pre-processing includes collimation and beam expansion, and the spot distribution characteristic of the high-frequency pulse laser beam is Gaussian light distribution; The beam shaping module is used to convert the pre-processed high-frequency pulse laser beam into a high-frequency pulse laser beam with a spot distribution characteristic of a flat-top light distribution.

8. The curved surface cutting processing equipment based on femtosecond laser high-speed scanning according to claim 1 is characterized in that: The 3D scanning galvanometer is provided with a second reflector, a first galvanometer and a second galvanometer in sequence along the propagation path of the laser, and the high-frequency pulse laser beam is driven by the first galvanometer and the second galvanometer to move along the X-axis and Y-axis directions respectively, so as to etch the edge of the stepped steps processed by the polygonal scanning galvanometer.

9. The curved surface cutting processing equipment based on femtosecond laser high-speed scanning according to claim 1 is characterized in that: It also includes an XY dual-axis slide, and a rotation module is arranged on the XY dual-axis slide, wherein the processing workpiece is installed on the rotation module, and the processing workpiece is rotated and moved along the horizontal X-axis and Y-axis directions through the rotation module and the XY dual-axis slide.

10. A curved surface cutting processing equipment based on high-speed scanning of femtosecond laser, characterized in that: The invention comprises a femtosecond laser, a movable reflector, a polygonal scanning galvanometer and a machining module arranged on the path of laser propagation, and the high-frequency pulse laser beam generated by the femtosecond laser is transmitted to the polygonal scanning galvanometer or the machining module through the movable reflector, wherein: A high-frequency pulsed laser beam with adjustable frequency and pulse width is generated by a femtosecond laser, each pulse is divided into a pulse train, and each pulse train contains multiple sub-pulses, a part of the sub-pulses are used as sub-pulses for ablating materials, and another part of the sub-pulses are used as sub-pulses for clearing plasma shielding clouds, wherein the high-frequency pulsed laser beam is guided by a multi-prism scanning galvanometer through a moving reflector to etch the XY plane on the workpiece layer by layer according to a preset trajectory; The polygonal scanning galvanometer is installed on the first Z-axis slide. Each time a layer of material on the surface of the workpiece is etched, the polygonal scanning galvanometer is lowered by a thickness of the etched material under the action of the first Z-axis slide. After the polygonal scanning galvanometer is processed, a step-like step to be processed is formed on the surface of the workpiece. The machining module is installed on the second Z-axis slide. The second Z-axis slide drives the machining module to rise and fall. The high-frequency pulse laser beam etches the edge of the stepped steps processed by the polygonal scanning galvanometer through the moving reflector under the guidance of the machining module.

11. The curved surface cutting processing equipment based on femtosecond laser high-speed scanning according to claim 10, characterized in that: The machining module includes an electric spindle mounted on the second Z-axis slide, and a tool connected to the output end of the electric spindle. The tool is driven to rotate by the electric spindle to cut the edge of the stepped steps machined by the polygonal scanning galvanometer.

12. The curved surface cutting processing equipment based on femtosecond laser high-speed scanning according to claim 10, characterized in that: A beam collimation module and a beam shaping module are also arranged between the femtosecond laser and the movable reflector. The beam collimation module is used to pre-process the high-frequency pulse laser beam, and the pre-processing includes collimation and beam expansion, and the spot distribution characteristic of the high-frequency pulse laser beam is Gaussian light distribution; The beam shaping module is used to convert the pre-processed high-frequency pulse laser beam into a high-frequency pulse laser beam with a spot distribution characteristic of a flat-top light distribution.

13. A processing method using the curved surface cutting processing equipment based on femtosecond laser high-speed scanning according to claim 7, characterized in that: Includes steps: S1: A high-frequency pulsed laser beam with adjustable frequency and pulse width is generated by a femtosecond laser, and the pulse is divided into pulse trains in the time domain. Each pulse train contains multiple sub-pulses, some of which are used as sub-pulses for ablating materials, and the other sub-pulses are used as sub-pulses for clearing plasma shielding clouds. S2: collimate and expand the high-frequency pulse laser beam through the beam collimation module; S3: transforming the high-frequency pulse laser beam with Gaussian distribution into a high-frequency pulse laser beam with flat-top distribution through a beam shaping module; S4: The high-frequency pulsed laser beam with flat top distribution is reflected to the polygonal scanning galvanometer by moving the reflector, and the irradiation area is switched in the spatial domain by rotating the polygonal prism in the polygonal scanning galvanometer to form etching positions arranged in a dot matrix; S5: The high-frequency pulse laser beam is focused by the field mirror in the multi-prism scanning galvanometer. The focused high-frequency pulse laser beam etches the material on the XY plane of the workpiece. Each time a layer of material is etched, the multi-prism scanning galvanometer is driven by the first Z-axis slide table to move down a layer thickness to lower the position of the laser focus. S6: After the processing of the XY plane is completed, the workpiece mounted on the rotating module is moved to the bottom of the 3D scanning galvanometer under the action of the XY dual-axis slide; S7: The high-frequency pulsed laser beam with flat-top distribution is reflected by the second reflector into the 3D scanning galvanometer. The high-frequency pulsed laser beam is driven to move along the X-axis and Y-axis directions by the first galvanometer and the second galvanometer in the 3D scanning galvanometer respectively, so as to etch the edge of the stepped steps processed by the polygonal scanning galvanometer to complete the processing of the workpiece.

14. A processing method using the curved surface cutting processing equipment based on femtosecond laser high-speed scanning according to claim 12, characterized in that: Includes steps: S1: A high-frequency pulsed laser beam with adjustable frequency and pulse width is generated by a femtosecond laser, and the pulse is divided into pulse trains in the time domain. Each pulse train contains multiple sub-pulses, some of which are used as sub-pulses for ablating materials, and the other sub-pulses are used as sub-pulses for clearing plasma shielding clouds. S2: collimate and expand the high-frequency pulse laser beam through the beam collimation module; S3: transforming the high-frequency pulse laser beam with Gaussian distribution into a high-frequency pulse laser beam with flat-top distribution through a beam shaping module; S4: The high-frequency pulsed laser beam with flat top distribution is reflected to the polygonal scanning galvanometer by moving the reflector, and the irradiation area is switched in the spatial domain by rotating the polygonal prism in the polygonal scanning galvanometer to form etching positions arranged in a dot matrix; S5: The high-frequency pulse laser beam is focused by the field mirror in the multi-prism scanning galvanometer. The focused high-frequency pulse laser beam etches the material on the XY plane of the workpiece. Each time a layer of material is etched, the multi-prism scanning galvanometer is driven by the first Z-axis slide table to move down a layer thickness to lower the position of the laser focus. S6: After the processing of the XY plane is completed, the workpiece mounted on the rotating module is moved to the bottom of the machining module under the action of the XY dual-axis slide; S7: The electric spindle in the machining module drives the tool to rotate at high speed to cut the edge of the stepped steps machined by the polygonal scanning galvanometer to complete the machining of the workpiece.

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