A method and apparatus for laser processing to inhibit wall damage

Abstract

The present application relates to a kind of laser processing wall damage inhibition method and device, belong to laser processing technical field, method includes: S1: before the high-energy laser pulse of processing laser output, the laser pulse synchronization signal of processing laser is collected;Wherein, the frequency of laser pulse synchronization signal is synchronized with high-energy laser pulse;S2: according to the acquisition cycle of laser pulse synchronization signal, output detection laser beam;S3: according to acquisition cycle, the detection laser beam reflected by processing position is collected, and detection light signal is obtained;S4: according to detection light signal, it is judged to penetrate state, and laser pulse control signal is obtained, and according to laser pulse control signal, the next pulse output of high-energy laser pulse is controlled.The present application utilizes the pulse interval of the high-energy laser pulse of the output of processing laser to detect and decide control the output of high-energy laser pulse of processing laser, realizes the effect of inhibiting laser from root wall damage.

Description

Technical Field

[0001] This invention belongs to the field of laser processing technology, specifically relating to a method and apparatus for suppressing wall damage during laser processing. Background Technology

[0002] Due to its high peak power density and short pulse duration, ultrafast lasers can effectively avoid the influence of thermal effects on surrounding materials during processing, achieving industrial-grade "cold processing." At the same time, when combined with the process route, it can achieve precision processing of materials without thermal effects, recast layers, or microcracks. These significant advantages have led to the widespread application of ultrafast lasers in the aerospace field.

[0003] Aero-engine turbine blades are the most critical heat-receiving components in the engine combustion chamber. To extend the service life of blades and combustion chambers under extreme operating environments such as high temperature and high pressure, numerous micropores are typically designed on the surface of aero-engine turbine blades. Cooling gases ejected from the cooling zone pass through these micropores, forming a film of gas on the blade surface; hence, these micropores are called blade film-forming holes. However, because aero-engine turbine blades are generally hollow cavities with small distances to the walls, wall damage is easily generated during laser processing of the film-forming holes. This damage causes stress concentration at the points of damage, leading to uneven stress during operation and ultimately affecting the service life of the aero-engine turbine blade. Therefore, wall protection is one of the most critical technologies that urgently needs to be addressed in the laser processing of blade film-forming holes.

[0004] Existing laser-to-material protection technologies mainly include: cavity material filling technology, pre-planning technology based on solid models, and online monitoring technology for laser processing. Cavity material filling technology uses material to fill the cavity to block or weaken laser energy, thus reducing damage to the material wall; this is a passive protection technology. Pre-planning technology based on solid models plans the scanning trajectory based on theoretical data from the solid model, and simultaneously uses laser modulation pre-planning to prevent laser energy from acting on non-processing locations during processing. Online monitoring technology for laser processing uses a charge-coupled device (CCD) to collect the reflected light from the interaction between the laser and the material. Based on the reflected light, a monitoring image is obtained, and the changes in the monitoring image before and after laser penetration are observed manually through a viewing hole, enabling timely laser shut-off to reduce damage to the material wall.

[0005] However, existing wall protection technologies all have significant drawbacks. For example, due to the extremely narrow and complex cavities of aero-engine turbine blades, cavity material filling techniques struggle to address issues of uneven filling and incomplete cleaning. Pre-planning techniques based on solid models rely heavily on the degree of matching between the theoretical model and external factors such as actual workpiece precision, clamping accuracy, and material properties. These external factors are often uncontrollable, leading to unstable protection effects in practical applications. Laser processing online monitoring technology is currently limited by the speed of image acquisition and processing, making accurate real-time judgment impossible. Furthermore, when processing microholes at an angle, the removed portion does not penetrate simultaneously, making it extremely difficult to achieve wall damage protection and interpretation based on laser processing online monitoring technology.

[0006] Therefore, when using laser processing for air film cooling holes, a method and device are needed to achieve accurate real-time monitoring of wall damage. Summary of the Invention

[0007] To address the aforementioned problems in the prior art, this invention provides a method and apparatus for suppressing wall damage during laser processing. The technical problem to be solved by this invention is achieved through the following technical solution:

[0008] This invention provides a method for suppressing wall damage during laser processing, comprising:

[0009] S1: Before the processing laser outputs a high-energy laser pulse, a laser pulse synchronization signal of the processing laser is acquired; wherein, the laser pulse synchronization signal is synchronized with the frequency of the high-energy laser pulse;

[0010] S2: Obtain the acquisition period based on the laser pulse synchronization signal and output the probe laser beam;

[0011] S3: Acquire the detection laser beam reflected from the processing position according to the acquisition cycle to obtain the detection light signal;

[0012] S4: Based on the detection light signal, determine the penetration state, obtain the laser pulse control signal, and control the next pulse output of the high-energy laser pulse according to the laser pulse control signal.

[0013] In one embodiment of the present invention, the high-energy laser pulse and the probe laser beam are coaxially arranged in the optical path, and the high-energy laser pulse and the probe laser beam have the same frequency.

[0014] In one embodiment of the present invention, the detection laser beam is a pulsed beam or a continuous beam.

[0015] In one embodiment of the present invention, when the probe laser beam is a pulsed beam, S2 includes:

[0016] S2.1: Obtain the acquisition period based on the laser pulse synchronization signal;

[0017] S2.2: Set the delay time of the detection control signal according to the acquisition cycle;

[0018] S2.3: The detection control signal after setting a delay time controls the output detection laser beam.

[0019] In one embodiment of the present invention, when the probe laser beam is a continuous beam, S3 includes:

[0020] S3.1: Set the acquisition delay time according to the acquisition cycle;

[0021] S3.2: Acquire the probe laser beam reflected from the processing position according to the set acquisition delay time to obtain the probe optical signal. In one embodiment of the present invention, S4 includes:

[0022] S4.1: Set a penetration threshold based on the intensity of reflected light after penetration at the processing location;

[0023] S4.2: Determine the penetration state based on the penetration threshold and the probe light signal to obtain a laser pulse control signal;

[0024] S4.3: Control the output of the next pulse of the high-energy laser pulse according to the laser pulse control signal;

[0025] Specifically, when the intensity of the probe light signal is higher than the penetration threshold, the next pulse of the high-energy laser pulse is output through the laser pulse control signal; when the intensity of the probe light signal is lower than the penetration threshold, the next pulse of the high-energy laser pulse is stopped through the laser pulse control signal.

[0026] In one embodiment of the present invention, after S4, the following is also included:

[0027] S5: Using the laser pulse synchronization signal as the period, repeat S1 to S4 until the laser processing is completed.

[0028] The present invention also provides a device for suppressing wall damage during laser processing, using the above-mentioned method for suppressing wall damage during laser processing. The device includes: a processing laser, a detection laser, a photodetector, and a controller.

[0029] The processing laser is used to output high-energy laser pulses and to output a laser pulse synchronization signal synchronously with the high-energy laser pulses.

[0030] The detection laser is used to output a detection laser beam;

[0031] The photodetector is used to detect the detection laser beam reflected from the processing position;

[0032] The controller is used to acquire the laser pulse synchronization signal and control the detector laser to output a detection laser beam according to the laser pulse synchronization signal; the controller is also used to acquire the detection result of the photodetector, obtain the detection light signal, and determine the penetration state according to the detection light signal, so as to control the high-energy laser pulse to output the next pulse.

[0033] In one embodiment of the present invention, the laser processing wall damage suppression device further includes: a shaping and modulation system, a beam splitter, a beam combining system, a scanning system, and a focusing system;

[0034] The shaping and modulation system, the beam splitter, the beam combining system, the scanning system, and the focusing system are arranged in sequence. The high-energy laser pulse output from the processing laser passes through the shaping and modulation system and then enters the beam splitter and the beam combining system together with the probe laser beam output from the probe laser to combine the high-energy laser pulse and the probe laser beam.

[0035] The combined high-energy laser pulse and the probe laser beam are sequentially focused onto the same processing position by the scanning system and the focusing system.

[0036] In one embodiment of the present invention, the photodetector includes: an APD sensor, a PIN sensor, a PSD sensor, or a QDS sensor.

[0037] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0038] The present invention provides a method for suppressing wall damage in laser-processed gas film cooling holes. By utilizing the pulse interval of the high-energy laser pulses output by the processing laser, detection is performed during the gap time of the pulse interval. The penetration status is judged by comparing the detection light signal with the penetration threshold, and the output of the high-energy laser pulses of the processing laser is controlled according to the judgment result. This avoids the problem of excessive dependence on physical models and clamping accuracy in existing wall protection technologies, and also solves the problem of slow response in online monitoring technology for laser processing, thus achieving the effect of suppressing laser wall damage from the root.

[0039] The device for suppressing wall damage in laser-processed air film cooling holes of the present invention introduces a probe laser and a photodetector during the laser processing. The probe laser beam output by the probe laser and the high-energy laser pulse output by the processing laser are combined and coaxial. After scanning and focusing, the same-position penetration state detection of the processing position is realized during the processing. Then, based on the real-time detection of the probe laser beam returned from the workpiece to be processed by the photodetector, the probe light signal is collected by the controller, and the output of the next pulse of the high-energy laser pulse is controlled by the controller. This realizes accurate real-time monitoring of wall damage, thereby suppressing laser wall damage.

[0040] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention, it can be implemented according to the contents of the specification. In order to make the above and other objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0041] Figure 1 This is a flowchart of a laser processing method for suppressing wall damage, provided in an embodiment of the present invention.

[0042] Figure 2 This is a flowchart of step S2 in the laser processing wall damage suppression method provided in this embodiment of the invention;

[0043] Figure 3 This is a flowchart of step S3 in the laser processing wall damage suppression method provided in the embodiments of the present invention;

[0044] Figure 4 This is a flowchart of step S4 in the laser processing wall damage suppression method provided in this embodiment of the invention;

[0045] Figure 5 This is an optical path diagram of a laser processing wall damage suppression device provided in an embodiment of the present invention;

[0046] Figure 6 This is a schematic diagram illustrating the working principle of the laser processing wall damage suppression device provided in this embodiment of the invention.

[0047] Figure 7 This is a schematic diagram illustrating the working principle of another laser processing wall damage suppression device provided in this embodiment of the invention.

[0048] Figure 8 This is a flowchart of another laser processing wall damage suppression device provided in an embodiment of the present invention;

[0049] Figure 9 This is a schematic diagram illustrating the working principle of another laser processing wall damage suppression device provided in this embodiment of the invention;

[0050] Figure 10 This is a flowchart of another laser processing wall damage suppression device provided in an embodiment of the present invention.

[0051] Icons: 1-Processing laser; 2-Shaping and modulation system; 3-Beam splitter; 4-Beam combining system; 5-Scanning system; 6-Focusing system; 7-Detector laser; 8-Photodetector; 9-Processing position; 10-Controller. Detailed Implementation

[0052] To further illustrate the technical means and effects adopted by the present invention to achieve the intended purpose, the following detailed description of a laser processing wall damage suppression method and apparatus proposed according to the present invention is provided in conjunction with the accompanying drawings and specific embodiments.

[0053] The foregoing and other technical contents, features, and effects of the present invention will be clearly presented in the following detailed description of specific embodiments in conjunction with the accompanying drawings. Through the description of the specific embodiments, a more in-depth and concrete understanding can be gained of the technical means and effects adopted by the present invention to achieve its intended purpose. However, the accompanying drawings are for reference and illustration only and are not intended to limit the technical solutions of the present invention.

[0054] Example 1

[0055] like Figures 1 to 4 As shown, Figure 1 This is a flowchart of a laser processing method for suppressing wall damage, provided in an embodiment of the present invention. Figure 2 This is a flowchart of step S2 in the laser processing wall damage suppression method provided in this embodiment of the invention; Figure 3 This is a flowchart of step S3 in the laser processing wall damage suppression method provided in the embodiments of the present invention; Figure 4 This is a flowchart of step S4 in the laser processing wall damage suppression method provided in the embodiments of the present invention.

[0056] This embodiment provides a method for suppressing wall damage during laser processing, including:

[0057] S1: Before the processing laser outputs a high-energy laser pulse, the laser pulse synchronization signal of the processing laser is acquired; wherein, the laser pulse synchronization signal is synchronized with the frequency of the high-energy laser pulse;

[0058] S2: Obtain the acquisition period based on the laser pulse synchronization signal and output the probe laser beam.

[0059] In one alternative implementation, the high-energy laser pulse and the probe laser beam are coaxially arranged in the optical path, and the high-energy laser pulse and the probe laser beam have the same frequency.

[0060] In one alternative implementation, the probe laser beam is a pulsed beam or a continuous beam.

[0061] like Figure 2 As shown, in an optional implementation, when the probe laser beam is a pulsed beam, S2 includes:

[0062] S2.1: The acquisition period is obtained based on the laser pulse synchronization signal;

[0063] S2.2: Set the delay time of the detection control signal according to the acquisition cycle;

[0064] S2.3: Control the output of the detection laser beam by setting the detection control signal after the delay time.

[0065] It is worth noting that since detection requires utilizing the pulse interval of high-energy laser pulses—that is, completing the detection and penetration status judgment process before the arrival of the high-energy laser pulse to achieve advanced detection—a suitable delay time needs to be set. This is necessary to control the error within the allowable range, improve stability, and fundamentally suppress laser damage to the wall. For the case where the detection laser beam is a pulsed beam, the delay time of the detection control signal (in μs / ns) is set, and then the delayed detection control signal is used to trigger the detection laser beam. Furthermore, the reflected detection laser beam is simultaneously acquired after the detection laser beam is triggered and output.

[0066] S3: Collect the probe laser beam reflected from the processing position according to the acquisition cycle to obtain the probe light signal.

[0067] like Figure 3 As shown, in an optional implementation, when the probe laser beam is a continuous beam, S3 includes:

[0068] S3.1: Set the acquisition delay time according to the acquisition cycle;

[0069] S3.2: Acquire the probe laser beam reflected from the processing position according to the set acquisition delay time to obtain the probe light signal.

[0070] It should be noted that since the detection is performed using the pulse interval of high-energy laser pulses, a delay time needs to be set to control the error. However, when the detection laser beam is a continuous beam, there is no need to control the output of the detection laser beam through a detection control signal. Therefore, the acquisition delay time can be set according to the acquisition period, and the acquisition of the reflected detection laser beam can be started synchronously after the acquisition delay time is set.

[0071] like Figure 4 As shown, in one optional implementation, S4 includes:

[0072] S4.1: Set the penetration threshold based on the intensity of reflected light after penetration at the processing location;

[0073] S4.2: Determine the penetration status based on the penetration threshold and the probe light signal to obtain the laser pulse control signal;

[0074] S4.3: Control the output of the next high-energy laser pulse according to the laser pulse control signal;

[0075] Specifically, when the intensity of the probe light signal is higher than the penetration threshold, the next pulse of the high-energy laser pulse is controlled by the laser pulse control signal; when the intensity of the probe light signal is lower than the penetration threshold, the next pulse of the high-energy laser pulse is stopped by the laser pulse control signal.

[0076] It is worth noting that in the laser processing wall damage suppression method of this embodiment, the output control of the probe laser beam, the acquisition of the probe light signal, and the judgment of the penetration state are all completed in real time within the pulse period of a high-energy laser pulse. By utilizing the pulse interval of the high-energy laser pulse output by the processing laser, the detection is performed during the gap time of the pulse interval, thereby achieving the effect of suppressing laser wall damage from the source.

[0077] For example, when determining the penetration status, the power intensity can be compared with the intensity of the probe light signal and the penetration threshold.

[0078] It should be noted that the penetration threshold is influenced by various factors such as the power, frequency, scanning speed, and scanning trajectory of the processing laser. It can be determined through trial processing using a test fixture with a specific wall-to-wall distance and partial penetration. Furthermore, the delay time can also be determined based on actual trial processing. During trial processing, the intensity of the probe laser beam and the sampling signal of the photodetector are gradually adjusted, and the signal intensity changes of the penetrated and non-penetrated parts of the test fixture are monitored in real time to determine the optimal threshold for judging signal changes. Then, the processing laser is turned on, and the optimal delay time is gradually found using a binary search method based on the degree of wall damage. In other words, both the penetration threshold and the delay time can be determined with reference to relevant existing technologies, and this embodiment does not impose any limitations on this.

[0079] In an optional implementation, after S4, the following is also included:

[0080] S5: Repeat S1 to S4 with the laser pulse synchronization signal as the cycle until the laser processing is completed.

[0081] The present invention provides a method for suppressing wall damage in laser-processed gas film cooling holes. By utilizing the pulse interval of the high-energy laser pulses output by the processing laser, detection is performed during the gap time of the pulse interval. The penetration status is judged by comparing the detection light signal with the penetration threshold, and the output of the high-energy laser pulses of the processing laser is controlled according to the judgment result. This avoids the problem of excessive dependence on physical models and clamping accuracy in existing wall protection technologies, and also solves the problem of slow response in online monitoring technology for laser processing, thus achieving the effect of suppressing laser wall damage from the root.

[0082] Example 2

[0083] like Figure 5 and Figure 6 As shown, Figure 5 This is an optical path diagram of a laser processing wall damage suppression device provided in an embodiment of the present invention; Figure 6 This is a schematic diagram illustrating the working principle of the laser processing wall damage suppression device provided in this embodiment of the invention.

[0084] This embodiment provides a laser processing wall damage suppression device, using a laser processing wall damage suppression method as described in Embodiment 1. The device includes: a processing laser 1, a detection laser 7, a photodetector 8, and a controller 10. The processing laser 1 outputs high-energy laser pulses and synchronously outputs a laser pulse synchronization signal along with the high-energy laser pulses. The detection laser 7 outputs a detection laser beam. The photodetector 8 detects the detection laser beam reflected from the processing position 9. The controller 10 acquires the laser pulse synchronization signal and controls the detection laser 7 to output the detection laser beam based on the laser pulse synchronization signal. The controller 10 also acquires the detection result from the photodetector 8, obtains the detection light signal, and determines the penetration state based on the detection light signal to control the high-energy laser pulse to output the next pulse.

[0085] For example, the processing laser 1 uses an ultrafast laser to output a high-energy laser pulse with a repetition frequency.

[0086] It should be noted that the laser energy of the probe laser beam is low, much lower than the high-energy laser pulse output by the processing laser 1, and will not cause damage to the surface of the processing position 9.

[0087] The principle is as follows: the processing laser 1 prepares to output a high-energy laser pulse (the pulse has not yet been output) and simultaneously outputs a laser pulse synchronization signal. The controller 10 outputs a detection control signal according to the laser pulse synchronization signal. Under the trigger of the detection control signal, the detection laser 7 outputs several detection laser beams with a width of μs. The controller 10 simultaneously collects the detection results of the photodetector 8 to obtain the detection light signal, and then judges the penetration state according to the detection light signal. When the intensity of the detection light signal is higher than the penetration threshold, the next pulse of the high-energy laser pulse is allowed to be output. When the intensity of the detection light signal is lower than the penetration threshold, the processing laser 1 is immediately turned off to stop the next pulse of the high-energy laser pulse from being output.

[0088] Furthermore, the laser processing wall damage suppression device also includes: a shaping and modulation system 2, a beam splitter 3, a beam combining system 4, a scanning system 5, and a focusing system 6; the shaping and modulation system 2, beam splitter 3, scanning system 5, beam combining system 4, and focusing system 6 are arranged sequentially, wherein the high-energy laser pulse output from the processing laser 1, after passing through the shaping and modulation system 2, enters the beam splitter 3 and beam combining system 4 together with the probe laser beam output from the probe laser 7; so as to combine the high-energy laser pulse and the probe laser beam; the combined high-energy laser pulse and the probe laser beam are then focused onto the same processing position by the scanning system and the focusing system in sequence.

[0089] In an optional embodiment, the laser processing wall damage suppression device further includes: a detection lens; wherein a photodetector 8 is disposed behind the detection lens for detecting the detection laser beam reflected by the processing position 9.

[0090] The working principle of the laser processing wall damage suppression device in this embodiment is as follows: a laser processing optical path and an online detection optical path are coaxially arranged within the device. The processing laser 1 prepares to output a high-energy laser pulse (e.g., 100kHz repetition rate). The high-energy laser pulse passes through the beam splitter 3 and enters the scanning system 5 and focusing system 6 to form the laser processing optical path. The focal point is located at the processing position 9 of the workpiece to be processed, and scanning processing is performed by the high-energy laser pulse. Simultaneously, the detection laser 7 outputs a detection laser beam. After passing through the beam splitter 3, the detection laser beam enters the scanning system 5 and focusing system 6 to form the online detection optical path.

[0091] To ensure that the high-energy laser pulse used for processing and the probe laser beam used for detection act on the same processing position 9 of the workpiece, the high-energy laser pulse and the probe laser beam are combined in the beam combining system 4. Simultaneously, the combined high-energy laser pulse and probe laser beam are focused onto the same processing position 9 of the material. After reflection, the probe laser beam passes through the detection lens and enters the photodetector 8. The detection result returned by the photodetector 8 contains power and position information. The controller 10 collects the detection result to obtain the detection light signal. When the currently returned power is lower than the penetration threshold, it indicates that the position has been penetrated. At this time, the controller 10 outputs a laser pulse control signal to shut down the processing laser 1 and promptly stop the next pulse output of the high-energy laser pulse, thereby achieving the effect of suppressing laser damage to the wall from the source.

[0092] In one alternative implementation, the photodetector 8 includes, but is not limited to, an APD sensor, a PIN sensor, a PSD sensor, or a QDS sensor.

[0093] Understandably, both APD and PIN sensors have adjustable sensitivity, while both PSD and QDS sensors offer continuous signal strength measurement, allowing for selection based on the specific processing object and application scenario. Furthermore, the probe laser beam output from the probe laser 7 can be a pulsed beam or a continuous beam, and can be used in conjunction with any type of photodetector 8.

[0094] For example, an APD sensor or PIN sensor that does not contain position information can be set to improve response speed and detection sensitivity. Alternatively, a PSD sensor or QDS sensor that contains position information can be set to reconstruct and predict the processing in conjunction with real-time scanning, thereby achieving a more complete effect and control of wall damage suppression.

[0095] The device for suppressing wall damage in laser-processed air film cooling holes of the present invention introduces a probe laser and a photodetector during the laser processing. The probe laser beam output by the probe laser and the high-energy laser pulse output by the processing laser are combined and coaxial. After scanning and focusing, the same-position penetration state detection of the processing position is realized during the processing. Then, based on the real-time detection of the probe laser beam returned from the workpiece to be processed by the photodetector, the probe light signal is collected by the controller, and the output of the next pulse of the high-energy laser pulse is controlled by the controller. This realizes accurate real-time monitoring of wall damage, thereby suppressing laser wall damage.

[0096] Example 3

[0097] like Figure 7 and Figure 8 As shown, Figure 7 This is a schematic diagram illustrating the working principle of another laser processing wall damage suppression device provided in this embodiment of the invention. Figure 8 This is a flowchart of another laser processing wall damage suppression device provided in an embodiment of the present invention.

[0098] In this embodiment, the detection laser beam output by the detection laser 7 is a pulsed beam, and the photodetector 8 uses an APD sensor or a PIN sensor as an example.

[0099] Specifically, after processing begins, the processing laser 1 prepares to output a high-energy laser pulse. Simultaneously, the controller 10 acquires a laser pulse synchronization signal that is synchronized with the frequency of the high-energy laser pulse. After acquiring the laser pulse synchronization signal, the controller 10 obtains the acquisition period based on the laser pulse synchronization signal. The controller 10 then sets the delay time of the detection control signal according to the acquisition period. After a certain delay (at the μs / ns level), the controller 10 outputs the detection control signal. Triggered by the detection control signal, the detection laser 7 outputs several μs-width detection laser beams. During the output of the detection control signal, the controller 10 synchronously acquires the detection results output by the photodetector 8 to obtain the detection light signal. The controller then judges the penetration status based on the detection light signal. When the intensity of the detection light signal is higher than the penetration threshold, the next pulse of the high-energy laser pulse is allowed to be output for material removal. When the intensity of the detection light signal is lower than the penetration threshold, the next pulse of the high-energy laser pulse is immediately stopped to suppress damage to the wall.

[0100] It should be noted that during laser processing, the controller 10 can continuously control the output of the next high-energy laser pulse using the laser pulse synchronization signal as a cycle until the laser processing is completed. For example, the determination of the completion of laser processing can be performed through pre-setting, or through background task processing via the controller 10 or an external control device.

[0101] It is worth noting that the detection results obtained by APD sensors or PIN sensors do not contain position information, so they are suitable for applications that require improved response speed and detection sensitivity.

[0102] For example, the high-energy laser pulse is output by the processing laser 1 and is used to remove material. After the high-energy laser pulse is combined with the probe laser beam, it acts on the same processing position 9 of the workpiece to be processed. Since the laser energy of the probe laser beam is low, it will not cause damage to the surface of the processing position 9.

[0103] For example, the laser pulse synchronization signal (SYNC) is generated by the processing laser 1 itself. Since its frequency is synchronized with the frequency of the high-energy laser pulse, that is, each laser pulse synchronization signal corresponds to a high-energy laser pulse in terms of frequency, and the laser pulse synchronization signal is output regardless of whether the corresponding high-energy laser pulse is output. Therefore, the laser pulse synchronization signal is used as a synchronization reference signal to control the working cycle of the controller 10.

[0104] For example, the detection control signal (CTRL) is output by the controller 10. When the time for detection arrives, the controller 10 sends this signal to the detection laser 7, which then outputs a detection laser beam. Here, the slight timing difference between the detection control signal and the actual detection laser beam can be ignored; that is, they can be considered equivalent in the measurement and control timing. The detection light signal is the result signal obtained by acquiring the detection signal output by the photodetector 8. When no penetration occurs at the detected position, a relatively large signal is output; conversely, when penetration occurs at the detected position, a smaller signal is output.

[0105] For example, the laser pulse control signal (GATE / TIRGGER) is a control signal output by the controller 10, used to control the processing laser 1 to output high-energy laser pulses. The laser pulse control signal determines whether the processing laser 1 emits light, and its control granularity can reach 1 laser pulse.

[0106] Example 4

[0107] like Figure 9 and Figure 10 As shown, Figure 9 This is a schematic diagram illustrating the working principle of another laser processing wall damage suppression device provided in this embodiment of the invention; Figure 10 This is a flowchart of another laser processing wall damage suppression device provided in an embodiment of the present invention.

[0108] In this embodiment, the detection laser beam output by the detection laser 7 is a continuous beam, and the photodetector 8 uses a PSD sensor or a QDS sensor as an example.

[0109] Specifically, after processing begins, the processing laser 1 prepares to output a high-energy laser pulse, while the probe laser 7 emits a continuous probe beam throughout the processing. The controller 10 acquires a laser pulse synchronization signal that is synchronized with the frequency of the high-energy laser pulse. After acquiring the laser pulse synchronization signal, the controller 10 obtains the acquisition period based on the laser pulse synchronization signal. The controller 10 then sets the acquisition delay time based on the acquisition period. After setting the delay time, the controller 10 synchronously acquires the probe laser beam reflected from the processing position to obtain the probe light signal. The controller 10 then judges the penetration status based on the probe light signal. When the intensity of the probe light signal is higher than the penetration threshold, the next pulse of the high-energy laser pulse is allowed to be output for material removal. When the intensity of the probe light signal is lower than the penetration threshold, the next pulse of the high-energy laser pulse is immediately stopped to suppress damage to the wall.

[0110] It should be noted that during laser processing, the controller 10 can continuously control the output of the next high-energy laser pulse using the laser pulse synchronization signal as a cycle until the laser processing is completed. For example, the determination of the completion of laser processing can be performed through pre-setting, or through background task processing via the controller 10 or an external control device.

[0111] Furthermore, since the output control of the probe laser beam, the acquisition of the probe light signal, and the judgment of the penetration state all need to be completed in real time within the pulse period of a high-energy laser pulse, the laser pulse frequency of the high-energy laser pulse output by the processing laser 1 is used as the working period, so as to make real-time judgment on the wall damage of each pulse of the high-energy laser pulse.

[0112] For example, since the probe laser 7 is a continuous beam, the output of the probe laser 7 can be controlled without the probe control signal. Instead, the delay time can be set by the acquisition cycle of the controller 10, and the probe light signal can be acquired within the acquisition cycle.

[0113] It is worth noting that the detection results obtained by PSD or QDS sensors contain position information, which can be combined with real-time scanning to reconstruct and predict the processing process, thereby achieving a more effective suppression and control of wall damage.

[0114] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations are intended to cover non-exclusive inclusion, such that an article or device comprising a list of elements includes not only those elements but also other elements not expressly listed. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the article or device comprising said element. Terms such as "connected" or "linked" are not limited to physical or mechanical connections but can include electrical connections, whether direct or indirect. The orientations or positional relationships indicated by terms such as "upper," "lower," "left," and "right" are based on the orientations or positional relationships shown in the accompanying drawings and are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as limiting the invention.

[0115] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the scope of protection of the present invention.

Claims

1. A method for suppressing wall damage during laser processing, characterized in that, include: S1: Before the processing laser outputs a high-energy laser pulse, a laser pulse synchronization signal of the processing laser is acquired; wherein, the laser pulse synchronization signal is synchronized with the frequency of the high-energy laser pulse; S2: Obtain the acquisition period based on the laser pulse synchronization signal and output the detection laser beam; the high-energy laser pulse and the detection laser beam are coaxially arranged in the optical path, and the high-energy laser pulse and the detection laser beam have the same frequency; S3: Acquire the detection laser beam reflected from the processing position according to the acquisition cycle to obtain the detection light signal; S4: Based on the detection light signal, determine the penetration state, obtain the laser pulse control signal, and control the next pulse output of the high-energy laser pulse according to the laser pulse control signal; The S4 includes: S4.1: Set a penetration threshold based on the intensity of reflected light after penetration at the processing location; S4.2: Determine the penetration state based on the penetration threshold and the probe light signal to obtain a laser pulse control signal; S4.3: Control the output of the next pulse of the high-energy laser pulse according to the laser pulse control signal; Specifically, when the intensity of the probe light signal is higher than the penetration threshold, the next pulse of the high-energy laser pulse is output through the laser pulse control signal; when the intensity of the probe light signal is lower than the penetration threshold, the next pulse of the high-energy laser pulse is stopped through the laser pulse control signal.

2. The method for suppressing wall damage during laser processing according to claim 1, characterized in that, The detection laser beam is a pulsed beam or a continuous beam.

3. The method for suppressing wall damage during laser processing according to claim 1, characterized in that, When the probe laser beam is a pulsed beam, S2 includes: S2.1: Obtain the acquisition period based on the laser pulse synchronization signal; S2.2: Set the delay time of the detection control signal according to the acquisition cycle; S2.3: The detection control signal after setting a delay time controls the output detection laser beam.

4. The method for suppressing wall damage during laser processing according to claim 1, characterized in that, When the probe laser beam is a continuous beam, S3 includes: S3.1: Set the acquisition delay time according to the acquisition cycle; S3.2: Acquire the detection laser beam reflected from the processing position according to the set acquisition delay time to obtain the detection light signal.

5. The method for suppressing wall damage during laser processing according to claim 1, characterized in that, Following S4, it also includes: S5: Using the laser pulse synchronization signal as the period, repeat S1 to S4 until the laser processing is completed.

6. A device for suppressing wall damage during laser processing, characterized in that, The apparatus for suppressing wall damage during laser processing as described in any one of claims 1 to 5 includes: a processing laser, a detection laser, a photodetector, and a controller; The processing laser is used to output high-energy laser pulses and to output a laser pulse synchronization signal synchronously with the high-energy laser pulses. The detection laser is used to output a detection laser beam; The photodetector is used to detect the detection laser beam reflected from the processing position; The controller is used to acquire the laser pulse synchronization signal and control the detector laser to output a detection laser beam according to the laser pulse synchronization signal; the controller is also used to acquire the detection result of the photodetector, obtain the detection light signal, and determine the penetration state according to the detection light signal, so as to control the high-energy laser pulse to output the next pulse.

7. The laser processing wall damage suppression device according to claim 6, characterized in that, It also includes: a shaping and modulation system, a beam splitter, a beam combiner, a scanning system, and a focusing system; The shaping and modulation system, the beam splitter, the beam combining system, the scanning system, and the focusing system are arranged in sequence. The high-energy laser pulse output from the processing laser passes through the shaping and modulation system and then enters the beam splitter and the beam combining system together with the probe laser beam output from the probe laser to combine the high-energy laser pulse and the probe laser beam. The combined high-energy laser pulse and the probe laser beam are sequentially focused onto the same processing position by the scanning system and the focusing system.

8. The laser processing wall damage suppression device according to claim 7, characterized in that, The photodetector includes: an APD sensor, a PIN sensor, a PSD sensor, or a QDS sensor.

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