A method and system for laser processing of stepped blind via based on double helix scanning strategy
Patent Information
- Application Number
- CN202610900343.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-06-22
- Publication Date
- 2026-10-30
AI Technical Summary
[0004]目前已有通过控制激光沿同心圆轨迹进行扫描，以在CFRP构件上制备盲孔的方案，但由于同心圆路径不连续，因此在高速扫描过程中激光光斑需要频繁跳转，无法保证多层阶梯孔加工深度的一致性，同时，当阶梯盲孔每层台阶的直径从上至下逐步减小时，由于同心圆扫描路径在扫描间距确定后，其轨迹恒定，随着加工深度增加，工件上可供激光束射入的入口逐步减小，激光束沿同心圆轨迹扫描时的激光束能量无法有效作用至底部的工件表面上，因此导致底部材料残余较多，使得最终形成的盲孔无法满足质量要求
[0028]按照本发明中的双螺旋扫描策略进行扫描时，可基于双螺旋扫描轨迹连续、平滑的特性，避免激光器出光时间早于或晚于振镜扫描时间而导致的材料过加工或未加工现象，同时，在单次扫描过程中避免激光光斑频繁跳转，可有效缓解高速扫描过程中镜振扫描失真问题，可有效提高扫描效率与激光加工精度；
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Figure CN123000284A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of laser processing technology, and in particular to a method and system for laser processing of stepped blind holes based on a double helix scanning strategy. Background Technology
[0002] Carbon fiber reinforced polymer / plastic (CFRP) components that have been in service for a long time under extreme conditions inevitably develop defects such as cracks, delamination, and pits. To repair the damaged areas of CFRP components, the current approach is to remove the damaged areas layer by layer on the CFRP component to obtain a bondable multi-layer stepped blind hole structure, and then fill and solidify the blind hole areas [SE Fujimoto, H. Sekine, Identification of crack and disbond fronts in repaired aircraft structural panels with bonded FRP composite patches, Compos. Struct. 77(4) (2007) 533–545.].
[0003] Therefore, high-precision machining of stepped blind holes is key to accurately removing damaged areas of components and performing high-performance repairs.
[0004] Currently, there are schemes to prepare blind holes on CFRP components by controlling the laser to scan along a concentric circle trajectory. However, due to the discontinuity of the concentric circle path, the laser spot needs to jump frequently during high-speed scanning, which cannot guarantee the consistency of the processing depth of multi-layer stepped holes. At the same time, when the diameter of each step of the stepped blind hole gradually decreases from top to bottom, since the trajectory of the concentric circle scanning path is constant after the scanning interval is determined, as the processing depth increases, the entrance on the workpiece that can be entered by the laser beam gradually decreases. The laser beam energy when scanning along the concentric circle trajectory cannot be effectively applied to the bottom workpiece surface, resulting in more material residue at the bottom, which makes the final blind hole unable to meet the quality requirements. Summary of the Invention
[0005] To address the aforementioned issues, this invention proposes a stepped blind hole laser processing method and system based on a double-helix scanning strategy. When scanning based on the unique double-helix scanning strategy, it can effectively improve scanning efficiency and laser processing quality based on the characteristics of the double-helix scanning trajectory.
[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:
[0007] On the one hand, a method for laser processing of stepped blind holes based on a double-helix scanning strategy is provided, which includes the following steps:
[0008] like Figure 2-3 As shown, by adjusting the focal plane position of the laser beam, the laser beam is sequentially applied to k processing planes of the same workpiece 100 (k≥3 and are positive integers). After the laser beam is applied to the current processing plane, the laser beam is controlled to scan the current processing plane according to the double helix scanning trajectory corresponding to the current processing plane, so as to form the step of the stepped blind hole on the current processing plane.
[0009] Among them, k processing planes are distributed in the height direction (i.e., z-direction) of the workpiece 100 to be processed, and all of them are xy planes that are perpendicular to the z-direction and parallel to each other. At the same time, there are also k double helix scanning trajectories, and each processing plane has only one double helix scanning trajectory 200 that corresponds to it.
[0010] Preferred, such as Figure 2 As shown, the double-helix scanning trajectory 200 corresponding to each processing plane is a trajectory similar to a Fermat spiral, and includes:
[0011] The first spiral s1 and the second spiral s2 are symmetrical about the origin O, and the starting points of the first spiral s1 and the second spiral s2 coincide with the origin O, that is, the first spiral s1 and the second spiral s2 intersect at the origin O.
[0012] Furthermore, the first spiral s1 and the second spiral s2 rotate in the same direction (e.g., both are clockwise or counterclockwise), and the pitch d between adjacent spirals is the same.
[0013] Preferably, the pitch d of the double helix scanning trajectory corresponding to each processing plane is the same. Since a pitch d that is too small will result in a long scanning time and excessive material heat input, while a pitch d that is too large will result in a low material removal rate and material residue on the surface, making the blind hole quality unacceptable, in order to simultaneously consider processing quality and processing efficiency, the pitch d in this invention is in the range of 0.04mm-0.12mm (preferably 0.08mm).
[0014] Preferably, the maximum radius R of the double helix scanning trajectory 200 corresponding to the t-th processing plane is... t Greater than the maximum radius R of the double helix scanning trajectory corresponding to the (t+1)th processing plane t+1 The maximum radius R of the double helix scanning trajectory 200 refers to the radius of the outermost helix, t=1,2,3...,k-1, the t-th processing plane and the t+1-th processing plane are two adjacent processing planes in the height direction, and the t-th processing plane is above the t+1-th processing plane.
[0015] Preferably, the number of scans on the t-th processing plane is less than the number of scans on the (t+1)-th processing plane.
[0016] Preferably, the laser beam scans the t-th processing plane according to the first scanning method, and scans the t+1-th processing plane according to the second scanning method;
[0017] The first scanning method is as follows: the laser beam starts from the origin O of the double helix scanning trajectory 200 corresponding to the t-th processing plane, moves along the first helix s1 to the end point s11 of the first helix s1, and the laser beam starts from the origin O of the double helix scanning trajectory 200 corresponding to the t-th processing plane, moves along the second helix s2 to the end point s21 of the second helix s2.
[0018] The second scanning method is as follows: the laser beam starts from the end point s11 of the first spiral line s1 of the double spiral scanning trajectory 200 corresponding to the t+1th processing plane, moves along the first spiral line s1 to the origin O, and the laser beam starts from the end point s21 of the second spiral line s2 of the double spiral scanning trajectory 200 corresponding to the t+1th processing plane, moves along the second spiral line s2 to the origin O.
[0019] Alternatively, the first scanning method is as follows: the laser beam starts from the end point s11 of the first spiral line s1 of the double spiral scanning trajectory 200 corresponding to the t-th processing plane, moves along the first spiral line s1 to the origin O, and the laser beam starts from the end point s21 of the second spiral line s2 of the double spiral scanning trajectory 200 corresponding to the t+1-th processing plane, moves along the second spiral line s2 to the origin O.
[0020] The second scanning method is as follows: the laser beam starts from the origin O of the double helix scanning trajectory 200 corresponding to the (t+1)th processing plane, moves along the first helix s1 to the end point s11 of the first helix s1, and the laser beam starts from the origin O of the double helix scanning trajectory 200 corresponding to the (t+1)th processing plane, moves along the second helix s2 to the end point s21 of the second helix s2.
[0021] Preferably, controlling the laser beam to scan the current processing plane according to a double-helix scanning trajectory corresponding to the current processing plane includes the following steps:
[0022] Each time the laser beam completes one scan along the double helix scanning trajectory corresponding to the current processing plane, the focal plane is controlled to descend by a height h along the z-direction.
[0023] On the other hand, a stepped blind hole laser processing system is also provided, which includes:
[0024] Industrial control computers;
[0025] A laser, a reflector, a beam expander, a dynamic focusing unit, a scanning galvanometer, and a focusing field lens are arranged sequentially along the laser beam path. The industrial control computer is connected to the laser, the scanning galvanometer, and the dynamic focusing unit, and is used to control the output laser beam of the laser, control the deflection motion of the scanning galvanometer, and control the operation of the dynamic focusing unit.
[0026] And, a flue gas collection device.
[0027] Compared with the prior art, the beneficial effects of the present invention are as follows:
[0028] When scanning according to the double helix scanning strategy of the present invention, the continuous and smooth characteristics of the double helix scanning trajectory can avoid the phenomenon of over-processing or under-processing of materials caused by the laser emission time being earlier or later than the galvanometer scanning time. At the same time, the frequent jumping of the laser spot is avoided in a single scan, which can effectively alleviate the problem of mirror galvanometer scanning distortion in high-speed scanning and effectively improve scanning efficiency and laser processing accuracy.
[0029] Meanwhile, this invention takes advantage of the variable curvature characteristics of the double helix scanning trajectory and adopts a strategy of gradually decreasing the maximum radius of the double helix scanning trajectory from top to bottom and gradually increasing the number of scans. This can effectively remove workpiece material, avoid material residue, and significantly improve processing efficiency while ensuring processing quality. Attached Figure Description
[0030] Figure 1 This is a schematic diagram of the process of the stepped blind hole laser processing method based on the double helix scanning strategy in this invention;
[0031] Figure 2 This is a schematic diagram of the double-helix scanning trajectory in this invention;
[0032] Figure 3 This is a schematic diagram of the laser beam scanning on different processing planes according to a double helix scanning trajectory in this invention;
[0033] Figure 4 This is a schematic diagram of the stepped blind hole laser processing system of the present invention;
[0034] Figure 5 The image shows the longitudinal profile depth curve of a five-layer stepped blind hole prepared by the stepped blind hole laser processing method of the present invention.
[0035] Figure 6 The image shows the depth of a five-layer stepped blind hole prepared by the stepped blind hole laser processing method of the present invention.
[0036] Figure 7 The image shows a microscopic image of a single-layer step blind hole prepared by the laser processing method for stepped blind holes based on the present invention and the existing concentric circle scanning method. Detailed Implementation
[0037] To make the objectives, technical solutions, and advantages of this technical solution clearer, the following detailed description, in conjunction with specific embodiments, further illustrates this technical solution. It should be understood that these descriptions are merely exemplary and not intended to limit the scope of this technical solution.
[0038] Example 1:
[0039] This embodiment uses a 2mm thick carbon fiber composite material as the workpiece 100 to be processed, and takes the processing of a stepped blind hole with 5 steps on the workpiece as an example to illustrate the steps of the stepped blind hole laser processing method based on the dual-helix scanning strategy in this embodiment. Figure 1 As shown, the stepped blind hole laser processing method includes the following steps:
[0040] S1. Fix the workpiece 100 to be processed on the worktable 10, and the workpiece 100 to be processed has 5 processing planes from top to bottom in its height direction (i.e., z-direction), that is... Figure 5 Planes 1, 2, 3, 4, and 5 are defined, and a unique double-helix scanning trajectory 200 is set for each processing plane, namely, double-helix scanning trajectories 200-1, 200-2, 200-3, 200-4, and 200-5 corresponding to planes 1, 2, 3, 4, and 5 respectively.
[0041] Among them, the five double-helix scanning trajectories 200 are all similar to Fermat spirals, and the pitch d of the five double-helix scanning trajectories is 0.08mm. At the same time, the maximum radii R of double-helix scanning trajectories 200-1, 200-2, 200-3, 200-4, and 200-5 are R1=18.75mm, R2=15mm, R3=11.25mm, R4=7.5mm, and R5=3.75mm, respectively.
[0042] S2, such as Figure 4 As shown, laser 1 is activated to output a laser beam, and the laser beam is reflected by mirror 4 to adjust the incident and exit directions of the laser beam.
[0043] The laser beam reflected by the reflector 4 is further expanded by the beam expander 5 to increase the beam waist radius of the laser beam. The expanded laser beam is then adjusted by the dynamic focusing unit 6 to adjust the focal plane position of the laser beam.
[0044] Simultaneously, the industrial control computer 2 controls the movement of the scanning galvanometer 7 to deflect the laser beam output by the dynamic focusing unit 6. The deflected laser beam is further focused by the focusing field lens 9 onto the first processing plane of the workpiece to be processed, i.e., plane 1, and scans according to the double helix scanning trajectory corresponding to the first processing plane, i.e., double helix scanning trajectory 200-1, to form the first step of the stepped blind hole. After the first step is formed, the laser 1 stops emitting light.
[0045] The laser beam scans on plane 1 according to the first scanning method, which is as follows: the laser beam starts from the origin O of the double helix scanning trajectory 200-1, moves along the first helix s1 to the end point s11 of the first helix s1, and then starts from the origin O of the double helix scanning trajectory 200-1 and moves along the second helix s2 to the end point s21 of the second helix s2.
[0046] Furthermore, after each scan of the laser beam, the dynamic focusing unit 6 controls the position of the laser beam focal plane to decrease by a height h1=0.016mm along the z-direction, so that the laser spot can always be focused on the processing plane. Then, the first scanning method is repeated to complete the next scan until the predetermined number of scans is completed, such as 8 times.
[0047] Step S3: Control the laser 1 to output a laser beam again, and control the scanning galvanometer 7 to move through the industrial control computer 2, so as to deflect the laser beam output by the dynamic focusing unit 6 through the scanning galvanometer 7, and the deflected laser beam is further focused by the focusing field lens 9 onto the second processing plane of the workpiece to be processed, i.e., plane 2, and scanned according to the double helix scanning trajectory corresponding to the second processing plane, i.e., double helix scanning trajectory 200-2, to form the second step of the stepped blind hole, and the laser 1 stops emitting light after the second step is formed;
[0048] The laser beam scans the plane 2 according to the second scanning method, which is as follows: the laser beam starts from the end point s11 of the first spiral line s1 of the double spiral scanning trajectory 200-2 and moves along the first spiral line s1 to the origin O; and the laser beam starts from the end point s21 of the second spiral line s2 of the double spiral scanning trajectory 200-2 and moves along the second spiral line s2 to the origin O.
[0049] Furthermore, after each scan of the laser beam, the position of the focal plane of the laser beam is controlled by the dynamic focusing unit 6 to decrease by a height h2=0.014mm along the z direction, and then the second scan method is repeated to complete the next scan until the predetermined number of scans is completed, such as 9 times;
[0050] Step S4: Repeat step S2, so that the deflected laser beam is focused by the focusing field lens 9 onto the third processing plane of the workpiece to be processed, i.e., plane 3, and scanned according to the double helix scanning trajectory 200-3 to form the third step of the stepped blind hole. After the third step is formed, the laser 1 stops emitting light and scans according to the first scanning method.
[0051] Furthermore, after each scan of the laser beam, the focal plane position of the laser beam is controlled by the dynamic focusing unit 6 to decrease by a height h3 = 0.010 mm along the z direction, and then the first scan method is repeated to complete the next scan until the predetermined number of scans is completed, such as 13 times.
[0052] Step S5: Repeat step S3 so that the deflected laser beam is focused by the focusing field lens 9 onto the fourth processing plane of the workpiece to be processed, i.e., plane 4, and scanned according to the double helix scanning trajectory 200-4 to form the fourth step of the stepped blind hole. After the fourth step is formed, the laser 1 stops emitting light and scans according to the second scanning method.
[0053] Furthermore, after each scan of the laser beam, the position of the focal plane of the laser beam is controlled by the dynamic focusing unit 6 to decrease by a height h4 = 0.008 mm along the z direction, and then the second scan method is repeated to complete the next scan until the predetermined number of scans is completed, such as 15 times.
[0054] Step S5: Repeat step S2, so that the deflected laser beam is focused by the focusing field lens 9 onto the fifth processing plane of the workpiece to be processed, i.e. plane 5, and scanned according to the double helix scanning trajectory 200-5 to form the fifth step of the stepped blind hole. After the fifth step is formed, the laser 1 stops emitting light and scans according to the first scanning method.
[0055] Furthermore, after each scan of the laser beam, the position of the focal plane of the laser beam is controlled by the dynamic focusing unit 6 to decrease by a height h5 = 0.008 mm along the z direction. Then, the first scan method is repeated to complete the next scan until the predetermined number of scans is completed, such as 16 times.
[0056] like Figure 5-6 As shown, the same depth machining of each layer of the stepped blind hole can be completed through the above steps, thus finally obtaining a stepped blind hole with 5 steps, each step height of 125±15μm and a machining accuracy of about 14.7μm.
[0057] The laser processing parameters during the laser scanning process can be set by the industrial control computer 2 according to the specific workpiece material and the step blind hole size requirements. The laser processing parameters mainly include one or more of the following parameters: laser power, pulse width, repetition frequency, scanning speed, and number of scans.
[0058] Figure 7 The images show five-stage stepped blind holes prepared using the traditional concentric circle scanning strategy and the double helix scanning strategy in this embodiment, respectively. At observation scales of 1 mm and 20 μm, it can be clearly seen that the stepped blind hole prepared by the method of this embodiment (i.e., "double helix scanning") has no obvious material residue, while the stepped blind hole prepared by the concentric circle scanning strategy (i.e., "concentric circle scanning") has obvious material residue.
[0059] The reason is that, in this embodiment, the maximum radius of the double helix scanning trajectory corresponding to the processing plane from top to bottom gradually decreases, but the number of scans gradually increases. This ensures that after the focal plane of the laser beam moves down and focuses on the next processing plane, the laser beam energy can still be fully applied to the next processing plane, so as to ensure that the surface material of this layer can be completely removed without any residual material, thereby ensuring the processing quality.
[0060] Therefore, the double-helix scanning trajectory in this embodiment is continuous and smooth. When the laser beam scans along the double-helix scanning trajectory, the problem of switching light response delay, which is difficult to eliminate during laser scanning, can be solved. This avoids the phenomenon of over-processing or under-processing of materials caused by the laser beam emission time being earlier or later than the galvanometer scanning time. At the same time, during a single scan, due to the continuity of the double-helix scanning trajectory, the scanning process can avoid frequent laser spot jumping, which can effectively alleviate the galvanometer scanning distortion problem during high-speed scanning and effectively improve scanning efficiency and laser processing accuracy.
[0061] Meanwhile, compared to the concentric circle scanning strategy in the prior art, due to the variable curvature characteristics of the double helix scanning trajectory in this embodiment, and the strategy of gradually decreasing the maximum radius of the double helix scanning trajectory from top to bottom and gradually increasing the number of scans, the laser beam energy can be fully applied to each processing plane to effectively remove workpiece material and improve processing efficiency. For example, to complete the processing of a 5-level step blind hole of the same specification, the existing concentric circle scanning strategy takes about 145.65 seconds (because there is material residue, more scans are needed, resulting in a longer processing time), while this embodiment only takes 93.74 seconds, which can improve the processing efficiency by 35.6%.
[0062] Example 2:
[0063] This embodiment also provides a stepped blind hole laser processing system, which can implement the stepped blind hole laser processing method described in Embodiment 1, such as... Figure 4 As shown, it includes:
[0064] 2 industrial control computers;
[0065] The laser 1, mirror 4, beam expander 5, dynamic focusing unit 6, scanning galvanometer 7, and focusing field mirror 9 are arranged along the laser beam path.
[0066] And, flue gas collection device 8;
[0067] Wherein, the laser 1 is a picosecond laser or a 355nm nanosecond laser;
[0068] The industrial control computer 2 is connected to the laser 1, the dynamic focusing unit 6, and the scanning galvanometer 7. It is used to control the output laser beam of the laser 1, control the deflection motion of the scanning galvanometer 7, and control the action of the dynamic focusing unit 6 according to the set laser processing parameters. For example, the laser processing parameters in this embodiment can be set as laser power 10W, pulse width 14ns, repetition frequency 80kHz, and scanning speed 1000mm / s.
[0069] The dynamic focusing unit 6 is used to adjust the position of the focal plane; the focusing field lens 9 is used to focus the laser beam so that the beam is focused on the processing plane to obtain the maximum energy density.
[0070] The flue gas collection device 8 is used to collect and process the flue gas and material chips generated by the thermal ablation of materials during the processing.
[0071] Start laser 1 to output a laser beam, and reflect the laser beam through mirror 4;
[0072] The laser beam is reflected by the reflector 4 and enters the beam expander 5, where it is expanded. The expanded laser beam is then focused by the dynamic focusing unit 6 to determine the focal plane position. The laser beam output from the dynamic focusing unit 6 is deflected by the scanning galvanometer 7. The deflected laser beam is further focused by the focusing field lens 9 onto the processing plane of the workpiece. The laser beam is controlled to scan the current processing plane according to a double helix scanning trajectory corresponding to the current processing plane, so as to form a step of the stepped blind hole on the current processing plane.
[0073] In summary, when scanning based on the double helix scanning strategy of this invention, the continuous and smooth characteristics of the double helix scanning trajectory can avoid the phenomenon of over-processing or under-processing of materials caused by the laser emission time being earlier or later than the galvanometer scanning time. At the same time, it can avoid frequent laser spot jumping during a single scan, effectively alleviate the galvanometer scanning distortion problem during high-speed scanning, and effectively improve scanning efficiency and laser processing accuracy.
[0074] Meanwhile, this invention takes advantage of the variable curvature characteristics of the double helix scanning trajectory and adopts a strategy of gradually decreasing the maximum radius of the double helix scanning trajectory from top to bottom and gradually increasing the number of scans, so that the laser beam energy can be fully applied to each processing plane to effectively remove workpiece material and avoid material residue. This can significantly improve processing efficiency while ensuring processing quality.
[0075] The above content is only a preferred embodiment of the present invention. For those skilled in the art, many changes can be made in the specific implementation and application scope based on the ideas of the present invention. As long as these changes do not depart from the concept of the present invention, they all fall within the protection scope of this patent.
Claims
1. A method for laser processing of stepped blind holes based on a double-helix scanning strategy, characterized in that, Includes the following steps: The laser beam is applied sequentially to k processing planes of the same workpiece. After the laser beam is applied to the current processing plane, the laser beam is controlled to scan the current processing plane according to the double helix scanning trajectory corresponding to the current processing plane, so as to form the step of the stepped blind hole on the current processing plane. Furthermore, each processing plane has only one unique double-helix scanning trajectory corresponding to it.
2. The laser processing method for stepped blind holes as described in claim 1, characterized in that, The double-helix scanning trajectory corresponding to each processing plane includes: The first spiral s1 and the second spiral s2 are symmetrical about the origin O, and the starting points of the first spiral s1 and the second spiral s2 both coincide with the origin O. Furthermore, the first helix s1 and the second helix s2 rotate in the same direction, and the pitch d between adjacent helixes is the same.
3. The laser processing method for stepped blind holes as described in claim 1, characterized in that, The pitch d of the double helix scanning trajectory corresponding to each machining plane is the same.
4. The laser processing method for stepped blind holes as described in claim 1, characterized in that, The pitch d ranges from 0.04mm to 0.12mm.
5. The laser processing method for stepped blind holes as described in claim 1, characterized in that, The maximum radius R of the double helix scanning trajectory corresponding to the t-th machining plane t Greater than the maximum radius R of the double helix scanning trajectory corresponding to the (t+1)th processing plane t+1 .
6. The laser processing method for stepped blind holes as described in claim 1, characterized in that, The number of scans on the t-th machining plane is less than the number of scans on the (t+1)-th machining plane.
7. The laser processing method for stepped blind holes as described in claim 2, characterized in that, The laser beam scans the t-th processing plane according to the first scanning method, and scans the (t+1)-th processing plane according to the second scanning method; The first scanning method is as follows: the laser beam starts from the origin O of the double helix scanning trajectory corresponding to the t-th processing plane, moves along the first helix s1 to the end point s11 of the first helix s1, and the laser beam starts from the origin O of the double helix scanning trajectory corresponding to the t-th processing plane, moves along the second helix s2 to the end point s21 of the second helix s2. The second scanning method is as follows: the laser beam starts from the end point s11 of the first spiral line s1 of the double spiral scanning trajectory corresponding to the (t+1)th processing plane, moves along the first spiral line s1 to the origin O, and the laser beam starts from the end point s21 of the second spiral line s2 of the double spiral scanning trajectory corresponding to the (t+1)th processing plane, moves along the second spiral line s2 to the origin O. Alternatively, the first scanning method is as follows: the laser beam starts from the end point s11 of the first spiral line s1 of the double spiral scanning trajectory corresponding to the t-th processing plane, moves along the first spiral line s1 to the origin O, and the laser beam starts from the end point s21 of the second spiral line s2 of the double spiral scanning trajectory corresponding to the t+1-th processing plane, moves along the second spiral line s2 to the origin O. The second scanning method is as follows: the laser beam starts from the origin O of the double helix scanning trajectory corresponding to the (t+1)th processing plane, moves along the first helix s1 to the end point s11 of the first helix s1, and the laser beam starts from the origin O of the double helix scanning trajectory corresponding to the (t+1)th processing plane, moves along the second helix s2 to the end point s21 of the second helix s2.
8. The laser processing method for stepped blind holes as described in claim 1, characterized in that, Controlling the laser beam to scan the current processing plane according to a double-helix scanning trajectory corresponding to the current processing plane includes the following steps: Each time the laser beam completes one scan along the double helix scanning trajectory corresponding to the current processing plane, the focal plane is controlled to descend by a height h along the z-direction.
9. The laser processing method for stepped blind holes as described in claim 1, characterized in that, The workpiece to be processed includes carbon fiber composite material.
10. A stepped blind hole laser processing system for implementing the stepped blind hole laser processing method according to any one of claims 1-9, characterized in that, include: Industrial control computers; In addition, the laser, mirror, beam expander, dynamic focusing unit, scanning galvanometer, and focusing field mirror are arranged sequentially along the laser beam path; The industrial control computer is connected to the laser, scanning galvanometer, and dynamic focusing unit, and is used to control the laser beam output by the laser, control the deflection motion of the scanning galvanometer, and control the operation of the dynamic focusing unit.