A tooth surface micro-texture ultrasonic auxiliary laser processing method and laser processing device

Abstract

The application discloses a tooth surface micro-texture ultrasonic auxiliary laser processing method and a laser processing device. The method comprises the following steps: obtaining a processing track of a to-be-processed tooth surface, a target ultrasonic phase window, a target laser gate window, a target aerosol covering window and a target dry gas clearing window, the target laser gate window covers the target ultrasonic phase window, the target aerosol covering window covers the target laser gate window and has an earlier starting time than the target laser gate window, and the starting time of the target dry gas clearing window is later than the ending time of the target laser gate window; performing micro-texture processing on the to-be-processed tooth surface based on the processing track and the target laser gate window, and emitting laser pulses in the target ultrasonic phase window; performing ultrasonic vibration auxiliary chip removal based on the target ultrasonic phase window; and controlling the opening and closing of an aerosol valve based on the target aerosol covering window and controlling the opening and closing of a dry gas valve based on the target dry gas clearing window to assist in chip removal. The application can break through the bottleneck of the depth-diameter ratio, improve the stability of chip removal, and reduce the risk of redeposition and recast layer.

Description

Technical Field

[0001] This application relates to the field of laser processing technology, and in particular to an ultrasonic-assisted laser processing method and laser processing device for microtexturing tooth surfaces. Background Technology

[0002] As a key component in the transmission system of high-end equipment, gears' load-bearing capacity, transmission efficiency, noise and vibration, and service life are increasingly limited by the micro-tribological state of the meshing interface. Under high-speed and high-power-density operating conditions, the macroscopic geometric accuracy and surface roughness obtained solely through traditional grinding and honing processes are often insufficient to simultaneously meet the comprehensive requirements of "low friction, anti-pitting, anti-scuffing, and low noise." Extensive tribological and surface engineering practices have shown that introducing microtextures with specific geometric morphologies, dimensions, and distribution patterns (such as micro-pit arrays, micro-grooves, herringbone patterns, etc.) at the contact interface can improve lubricant film load-bearing capacity, provide micro-oil reservoirs, capture abrasive particles, and regulate the contact state of the friction pair, thereby significantly improving the overall service performance of the gear pair without altering the material matrix.

[0003] Femtosecond lasers, due to their ultrashort pulse width and high peak power, exhibit small heat-affected zones in the removal of various engineering materials, making them a crucial technological approach for fabricating microtextures on tooth surfaces. Existing common ultrasonic-assisted laser processing methods include triggering emission near a fixed phase or processing under continuous ultrasonic superposition conditions; existing gas / mist / two-phase flow assisted methods include continuous jetting, constant flow cooling, and purging. While these methods are effective for planar or shallow texture processing, they still present challenges in machining deep microholes / microgrooves in complex curved gear surfaces, as it remains difficult to unify the favorable phase window for chip removal, the laser energy input window, and the flow field positioning window.

[0004] For complex curved surfaces such as gears, femtosecond laser microtexturing still faces the following common challenges:

[0005] 1. Aspect Ratio Bottleneck and Plasma / Debris Shielding: As micro-pits or micro-grooves gradually deepen, plasma plumes and nano-debris in the cavity are difficult to be discharged in time, leading to subsequent pulse energy attenuation, reduced removal rate or even saturation, and accompanied by defects such as redeposition of pore walls, recast layers and microcracks.

[0006] 2. Challenges in surface focal depth and dimensional consistency: Changes in tooth surface curvature cause local normals and focal positions to vary with position. Without high-bandwidth measurement and compensation strategies, texture dimensions, depth, and edge quality are prone to systematic drift in different tooth positions and different meshing zones.

[0007] 3. Efficiency versus quality: In order to control heat accumulation and redeposition, the common practice is to reduce the single pulse energy and use multi-layer scanning, which significantly reduces processing efficiency and makes it difficult to keep up with industrial cycle time.

[0008] 4. Lack of coordination between energy field, flow field and vibration field: Existing processes often adjust laser parameters, auxiliary gas / liquid and vibration assistance independently, resulting in insufficient process robustness.

[0009] Therefore, there is an urgent need for a femtosecond laser microtexturing precision machining method for complex curved surface gears that can achieve both improved aspect ratio and surface quality, and significantly improve consistency. Summary of the Invention

[0010] This application aims to address at least one of the technical problems existing in the prior art. To this end, this application proposes an ultrasonic-assisted laser processing method for microtexturing tooth surfaces, which can overcome the aspect ratio bottleneck, improve the stability of chip removal, and reduce the risk of redeposition and recasting layers.

[0011] This application also provides a laser processing apparatus, a control device, and a computer-readable storage medium.

[0012] According to a first aspect of this application, an ultrasonic-assisted laser processing method for microtexturing gear teeth is applied to a laser processing apparatus. The laser processing apparatus includes a five-axis motion platform, an ultrasonic rotary table, a clamping and positioning structure, a laser-processed part, an aerosol / drying device, and a control device. The ultrasonic rotary table is mounted on the five-axis motion platform. The clamping and positioning structure is mounted on the ultrasonic rotary table and used to position the gear workpiece. The laser-processed part is positioned above the gear workpiece for laser processing. The aerosol / drying device includes a coaxial annular nozzle, an aerosol pipeline, and a dry gas pipeline. The coaxial annular nozzle is positioned between the laser-processed part and the gear workpiece. The aerosol pipeline and the dry gas pipeline are respectively connected to the coaxial annular nozzle, and the aerosol pipeline and the dry gas pipeline are respectively provided with an aerosol valve and a dry gas valve. The control device is electrically connected to the five-axis motion platform, the ultrasonic rotary table, the laser-processed part, the aerosol valve, and the dry gas valve.

[0013] The ultrasonic-assisted laser processing method for microtexturing tooth surfaces includes:

[0014] The machining trajectory of the gear workpiece's tooth surface to be machined is obtained, as well as the target ultrasonic phase window, target laser gated window, target aerosol coverage window, and target dry gas clearing window; the target laser gated window covers the target ultrasonic phase window, the target aerosol coverage window covers the target laser gated window, and the start time of the target aerosol coverage window is earlier than the start time of the target laser gated window, while the start time of the target dry gas clearing window is later than the end time of the target laser gated window;

[0015] Based on the processing trajectory, the target ultrasonic phase window, and the target laser gate window, the five-axis motion platform and the laser processing workpiece are controlled to perform micro-textured processing on the tooth surface to be processed, and the laser pulse of the laser processing workpiece is emitted within the target ultrasonic phase window;

[0016] Based on the target ultrasonic phase window, the ultrasonic rotary table is controlled to perform ultrasonic vibration-assisted chip removal.

[0017] The aerosol valve is opened and closed based on the target aerosol coverage window, and the dry air valve is opened and closed based on the target dry air clearing window, so as to assist in chip removal from the tooth surface to be processed.

[0018] The ultrasonic-assisted laser processing method for microtexturing tooth surfaces according to the embodiments of this application has at least the following beneficial effects:

[0019] This application achieves spatiotemporal coupling of multiple physical fields—energy field, flow field, and vibration field—through precise timing planning and coordinated control of the target ultrasonic phase window, target laser gate window, target aerosol coverage window, and target dry gas cleaning window. The target laser gate window covers the target ultrasonic phase window, ensuring that the laser pulse is emitted within a specific advantageous phase of ultrasonic vibration, at which point the material is in its optimal removal state, and the ultrasonic vibration more effectively assists in the removal of debris from the processing area. The target aerosol coverage window covers the target laser gate window and its start time is earlier than the start time of the target laser gate window. This allows the aerosol to arrive in the processing area before laser processing begins, forming an effective aerosol environment. This prepares for chip removal and cooling during processing, avoiding initial chip accumulation or localized overheating due to delayed aerosol arrival. The target dry gas cleaning window starts later than the end time of the target laser gate window, ensuring that after laser processing, dry gas can promptly purge the processing area, removing residual aerosol, micro-debris, and possible redeposited substances, further optimizing the surface quality. Through this multi-window collaborative control, the periodic excitation of ultrasonic vibration can enhance the separation and discharge of debris during laser processing. Combined with the efficient cooling and lubrication of the mist and the precise clearing of the dry gas, the problem of debris shielding and redeposition in aspect ratio machining is effectively solved. This significantly improves the stability, consistency and surface quality of microtexture processing, and provides strong technical support for the high-performance microtexture preparation of complex curved surface gears.

[0020] According to some embodiments of this application, the target ultrasound phase window is obtained through the following steps:

[0021] Based on the machining trajectory, a short-time phase scan trial machining is performed on the tooth surface to be machined, and online signals during the trial machining process and geometric results after the trial machining are collected. The online signals are real-time measurable signals that reflect the machining status and the forming quality of the micro-weave structure.

[0022] Based on the online signals during the trial processing and the geometric results after the trial processing, the objective function corresponding to different ultrasonic phases is calculated. The objective function is used to evaluate the overall processing quality under different ultrasonic phases.

[0023] A staged parameter table for the ultrasonic phase window is determined based on the objective function corresponding to different ultrasonic phases. The staged parameter table includes different optimal phase centers and window widths corresponding to different processing stages.

[0024] The target ultrasound phase window is determined based on the aforementioned stage parameter table.

[0025] According to some embodiments of this application, the constraint formula for the objective function is as follows:

[0026] ;

[0027] in, Let the objective function be... The online signal, This is the normalized value of the average removal depth per unit pulse or unit pulse train. This is the normalized value of the redeposition risk index. This is the normalized value of the depth consistency index. , and The weighting coefficients are preset, wherein the normalized value of the average removal depth per unit pulse or unit pulse train, the normalized value of the redeposition risk index, and the normalized value of the depth consistency index are all calculated based on the geometric results after trial processing.

[0028] According to some embodiments of this application, the microtexturing process sequentially includes an initial forming stage, a deepening stage, and a finishing stage. The stage parameter table includes a first optimal phase center and a first window width corresponding to the initial forming stage, a second optimal phase center and a second window width corresponding to the deepening stage, and a third optimal phase center and a third window width corresponding to the finishing stage. The duration of the first window width is greater than the duration of the second window width, and the duration of the second window width is greater than the duration of the third window width.

[0029] According to some embodiments of this application, in the initial forming stage, based on the processing trajectory, the first optimal phase center, the first window width, and the target laser gate window, the five-axis motion platform and the laser processing workpiece are controlled to perform micro-texturing processing on the tooth surface to be processed. The laser pulse is emitted within the first window width and the starting time is the first optimal phase center. Based on the first optimal phase center and the first window width, the ultrasonic rotary table is controlled to perform ultrasonic vibration-assisted chip removal. Based on the target mist coverage window, the mist valve is controlled to open and close, and based on the target dry gas cleaning window, the dry gas valve is controlled to open and close to assist in chip removal on the tooth surface to be processed.

[0030] In the deepening stage, based on the machining trajectory, the second optimal phase center, the second window width, and the target laser gate window, the five-axis motion platform and the laser processing workpiece are controlled to perform micro-texturing on the tooth surface to be processed using a layer-by-layer cutting strategy of layered scanning, spiral cutting, or grid filling. The laser pulse is emitted within the second window width and the starting time is the second optimal phase center. The effective ultrasonic amplitude is enhanced, and the ultrasonic rotating stage is controlled according to the second optimal phase center and the second window width to perform ultrasonic vibration-assisted chip removal. The opening and closing of the aerosol valve is controlled based on the target aerosol coverage window, and the opening and closing of the dry gas valve is controlled based on the target dry gas clearing window. The dry gas valve is also controlled to open during the interlayer time period of the layer-by-layer cutting to assist in chip removal from the tooth surface to be processed.

[0031] During the finishing stage, the single-pulse energy of the laser pulse is reduced. Based on the machining trajectory, the third optimal phase center, the third window width, and the target laser gate window, the five-axis motion platform and the laser-processed workpiece are controlled to perform micro-texturing on the tooth surface to be processed. The laser pulse is emitted within the third window width and the starting time is the third optimal phase center. Based on the third optimal phase center and the third window width, the ultrasonic rotary table is controlled to perform ultrasonic vibration-assisted chip removal. Based on the target aerosol coverage window, the opening and closing of the aerosol valve is controlled in an intermittent spray mode with a low duty cycle. Based on the target dry gas cleaning window, the opening and closing of the dry gas valve is controlled to assist in chip removal on the tooth surface to be processed.

[0032] According to some embodiments of this application, the starting time of the target aerosol coverage window is determined by the following steps:

[0033] The following parameters are obtained: the jet distance from the outlet of the coaxial annular nozzle to the processing point, the average velocity of the carrier gas of the coaxial annular nozzle, the valve response delay of the aerosol valve, the control system delay of the control device, and the preset target arrival time, wherein the target arrival time is earlier than the start time of the target laser gate window.

[0034] The aerosol arrival delay is calculated based on the jet distance and the average velocity of the carrier gas.

[0035] Subtract the aerosol arrival delay, the valve response delay, and the control system delay from the target arrival time to obtain the start time of the target aerosol coverage window.

[0036] According to some embodiments of this application, the pulse energy of the laser pulse on the laser-processed part is obtained through the following steps:

[0037] The first compensation amount is calculated based on the incident angle energy compensation model. The first compensation amount is used to correct the change in the spot area and the material absorption loss caused by the incident angle.

[0038] The second compensation amount is calculated based on the ultrasonic displacement equivalent defocus energy compensation model. The second compensation amount is used to correct the energy density attenuation caused by the equivalent defocus induced by ultrasonic displacement.

[0039] After timing synchronization, the first compensation amount and the second compensation amount are superimposed to obtain the total compensation amount;

[0040] The reference energy of the laser pulse is adjusted according to the total compensation amount to obtain the pulse energy of the laser pulse on the laser-processed workpiece.

[0041] According to some embodiments of this application, after processing, the ultrasonic-assisted laser processing method for microtextured tooth surfaces further includes:

[0042] The machined texture of the gear workpiece is scanned to obtain the depth, diameter or width, edge accumulation height and array position deviation of the pits or grooves;

[0043] The measured depth distribution is determined based on the depth of the pit or trench, the diameter or width, the edge stacking height, and the array position deviation.

[0044] An error map is generated based on the measured depth distribution and the preset target depth distribution;

[0045] Based on the error map, the pulse energy of the laser pulse of the laser-processed part, the window width of the target ultrasonic phase window, the window width of the target aerosol coverage window, and the duty cycle of the intermittent spray mode are updated, and the tooth surface to be processed is supplemented and iterated until the error map is less than a preset error threshold.

[0046] According to some embodiments of this application, the laser processing apparatus further includes a suction and discharge device disposed on the side of the processing area; after processing, the ultrasonic-assisted laser processing method for microtexturing tooth surfaces further includes:

[0047] Start the ultrasonic rotary table to perform ultrasonic air vibration cleaning;

[0048] Open the dry gas valve to perform dry gas purging;

[0049] Open the extraction device to perform extraction.

[0050] A laser processing apparatus according to a second aspect embodiment of this application includes:

[0051] Five-axis motion platform;

[0052] An ultrasonic rotary table is mounted on the five-axis motion platform;

[0053] A clamping and positioning structure is mounted on the ultrasonic rotary worktable and used to position the gear workpiece.

[0054] A laser-processed part is positioned above the gear workpiece for laser processing.

[0055] The aerosol dry air device includes a coaxial annular nozzle, an aerosol pipeline, and a dry air pipeline. The coaxial annular nozzle is disposed between the laser-processed part and the gear workpiece. The aerosol pipeline and the dry air pipeline are respectively connected to the coaxial annular nozzle, and the aerosol pipeline and the dry air pipeline are respectively provided with an aerosol valve and a dry air valve.

[0056] The control device is electrically connected to the five-axis motion platform, the ultrasonic rotary table, the laser-processed part, the aerosol valve, and the dry gas valve, respectively. The control device is used to implement the ultrasonic-assisted laser processing method for microtexturing tooth surfaces as described in the first aspect above.

[0057] Since the laser processing device adopts all the technical solutions of the ultrasonic-assisted laser processing method for microtextured tooth surfaces described in the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments.

[0058] A control device according to a third aspect embodiment of this application includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the ultrasonic-assisted laser processing method for microtexturing tooth surfaces as described in the first aspect embodiment above. Since the control device employs all the technical solutions of the ultrasonic-assisted laser processing method for microtexturing tooth surfaces described in the above embodiments, it possesses at least all the beneficial effects brought about by the technical solutions of the above embodiments.

[0059] According to a fourth aspect embodiment of this application, a computer-readable storage medium stores computer-executable instructions for performing the ultrasonic-assisted laser processing method for microtexturing tooth surfaces as described in the first aspect embodiment. Since the computer-readable storage medium employs all the technical solutions of the ultrasonic-assisted laser processing method for microtexturing tooth surfaces described in the above embodiments, it possesses at least all the beneficial effects brought about by the technical solutions of the above embodiments.

[0060] Other features and advantages of this application will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing this application. Attached Figure Description

[0061] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0062] Figure 1 This is a schematic diagram of the structure of a laser processing apparatus according to an embodiment of this application;

[0063] Figure 2 This is a schematic diagram comparing the effects of ultrasonic-assisted and non-ultrasonic microtexturing of tooth surfaces according to an embodiment of this application;

[0064] Figure 3 This is a control logic block diagram of a control device according to an embodiment of this application;

[0065] Figure 4 This is a timing diagram showing the coordination of the ultrasonic phase window, laser gating window, aerosol coverage window, and dry gas clearing sub-window according to an embodiment of this application.

[0066] Figure 5 This is a schematic diagram of the objective function changing with phase offset and the determination of candidate window width in phase self-optimization phase-locked loop calibration according to an embodiment of this application;

[0067] Figure 6 This is a schematic diagram of confocal measurement, error map construction, and parameter write-back closed-loop correction according to an embodiment of this application;

[0068] Figure 7 This is a schematic diagram of the conformal mapping of texture from the parameter domain to the tooth surface according to an embodiment of this application;

[0069] Figure 8 This is a flowchart of an embodiment of the ultrasonic-assisted laser processing method for microtexturing tooth surfaces according to this application. Detailed Implementation

[0070] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0071] In the description of this application, the use of terms such as "first," "second," etc., is for the purpose of distinguishing technical features only and should not be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated or the order of the technical features indicated.

[0072] In the description of this application, it should be understood that the orientation descriptions, such as up, down, etc., are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0073] In the description of this application, it should be noted that, unless otherwise explicitly defined, terms such as "setup," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this application in conjunction with the specific content of the technical solution.

[0074] The following will combine Figures 1 to 8 The ultrasonic-assisted laser processing method for microtexturing tooth surfaces according to the embodiments of this application will be clearly and completely described. Obviously, the embodiments described below are some embodiments of this application, not all embodiments.

[0075] refer to Figures 1 to 8 , Figure 1 This is a schematic diagram of the structure of a laser processing apparatus according to an embodiment of this application. Figure 2 This is a schematic diagram comparing the effects of ultrasonic-assisted and non-ultrasonic microtexturing of tooth surfaces according to an embodiment of this application. Figure 3 This is a control logic block diagram of a control device according to an embodiment of this application. Figure 4 This is a timing diagram showing the coordination of the ultrasonic phase window, laser gating window, aerosol coverage window, and dry gas clearing sub-window according to an embodiment of this application. Figure 5 This is a schematic diagram illustrating the change of the objective function with phase offset and the determination of the candidate window width in phase self-optimization phase-locked loop calibration according to an embodiment of this application. Figure 6 This is a schematic diagram illustrating confocal measurement, error map construction, and parameter write-back closed-loop correction according to an embodiment of this application. Figure 7 This is a schematic diagram of the conformal mapping of texture from the parameter domain to the tooth surface according to an embodiment of this application. Figure 8 This is a flowchart of an embodiment of the ultrasonic-assisted laser processing method for microtexturing tooth surfaces according to this application.

[0076] According to the first aspect of this application, the ultrasonic-assisted laser processing method for microtexturing of gear surfaces is applied to a laser processing apparatus. The laser processing apparatus includes a five-axis motion platform, an ultrasonic rotary table, a clamping and positioning structure, a laser processing workpiece, an aerosol dry gas device, and a control device. The ultrasonic rotary table is mounted on the five-axis motion platform. The clamping and positioning structure is mounted on the ultrasonic rotary table and used to position the gear workpiece. The laser processing workpiece is placed above the gear workpiece for laser processing. The aerosol dry gas device includes a coaxial annular nozzle, an aerosol pipeline, and a dry gas pipeline. The coaxial annular nozzle is located between the laser processing workpiece and the gear workpiece. The aerosol pipeline and the dry gas pipeline are respectively connected to the coaxial annular nozzle, and aerosol valve and dry gas valve are correspondingly provided on the aerosol pipeline and the dry gas pipeline. The control device is electrically connected to the five-axis motion platform, the ultrasonic rotary table, the laser processing workpiece, the aerosol valve, and the dry gas valve.

[0077] Ultrasonic-assisted laser processing methods for microtexturing tooth surfaces include:

[0078] The machining trajectory of the gear workpiece's tooth surface to be machined is obtained, as well as the target ultrasonic phase window, target laser gated window, target aerosol coverage window, and target dry gas clearing window; the target laser gated window covers the target ultrasonic phase window, the target aerosol coverage window covers the target laser gated window, and the start time of the target aerosol coverage window is earlier than the start time of the target laser gated window, while the start time of the target dry gas clearing window is later than the end time of the target laser gated window;

[0079] Based on the machining trajectory, the target ultrasonic phase window, and the target laser gate window, the five-axis motion platform and the laser workpiece are controlled to perform micro-textured machining on the tooth surface to be machined, and the laser pulse of the laser workpiece is emitted within the target ultrasonic phase window;

[0080] Ultrasonic vibration-assisted chip removal is achieved by controlling an ultrasonic rotary table based on a target ultrasonic phase window.

[0081] The opening and closing of the aerosol valve is controlled based on the target aerosol coverage window, and the opening and closing of the dry air valve is controlled based on the target dry air clearing window, in order to assist in chip removal from the tooth surface to be machined.

[0082] like Figure 1 As shown, the laser-processed part includes a femtosecond laser, a beam expander, a dynamic focusing mirror, a galvanometer, and a laser beam expander connected in sequence. Field mirror: After the femtosecond laser output beam passes through a beam expander, dynamic focusing mirror, galvanometer, and... The field lens shapes and focuses the image onto the area to be machined on the tooth surface; the beam expander is used to match the optical aperture of the subsequent stage, the dynamic focusing lens is used to compensate for changes in surface height, clamping errors, and low-frequency drift, and the galvanometer is used to quickly complete the scanning of texture units within a small local area. Field lenses are used to convert galvanometer deflection into spatial scanning of machining points.

[0083] In terms of the mechanical linkage, the gear workpiece is mounted on the clamping and positioning structure of the ultrasonic rotary table. The clamping and positioning structure is coaxially connected to the C-axis output end, responsible for transmitting ultrasonic vibration and rotational motion to the gear workpiece. The A-axis is used to adjust the posture of the gear workpiece, making the local tooth surface normal as consistent as possible with the laser incident direction. The C-axis is used for tooth position switching, indexing rotation, and ultrasonic vibration loading. Figure 2 As shown, ultrasonic vibration can assist in chip removal.

[0084] The coaxial annular nozzle is preferably located at At the end of the machining head below the field lens, there is a through hole in the center for the laser to pass through, and an annular outflow channel on the outer periphery. The aerosol pipeline and the dry gas pipeline are controlled by the upstream aerosol valve and dry gas valve respectively, and then enter the nozzle's independent flow channel, or switch at the nozzle tip and act on the same annular outlet, so that the aerosol or dry gas surrounds the laser optical axis circumferentially and converges towards the machining point, covering the plume area above the hole / groove without obstructing the optical path. The coaxial annular nozzle moves synchronously with the machining head.

[0085] A suction and discharge device is also provided on the side of the processing area. The suction and discharge device has a suction and discharge port, which is preferably located on the rear side or diagonally above the processing area to form a co-current flow field with the coaxial jet.

[0086] The control device includes a path planning module, a motion controller, and a phase-locked loop controller. Specific connection methods and control signals are as follows: Figure 3 As shown. The ultrasonic rotary table is also equipped with a vibration reference sensor, which is used to collect reference signals characterizing the frequency, phase and amplitude stability of ultrasonic vibration, so that the phase-locked controller can calculate the instantaneous phase and determine whether laser gating is allowed.

[0087] The basic idea of ​​this application is to consider the processing area as a microscale cavity (micro-pits / micro-grooves) and its above-ground plume space during femtosecond laser microtexturing. The chip removal capacity, plasma density, and debris fallback probability of this space are not constant, but rather vary periodically due to the influence of ultrasonic vibration displacement and velocity. Simultaneously, the auxiliary aerosol (or two-phase gas-liquid flow) exhibits significant time-sensitivity to heat removal, debris carrying, and droplet impact / micro-explosion effects. If the arrival time of the aerosol is misaligned with the cavity's "easy chip removal phase," a mismatch will occur between "effective cooling but insufficient chip removal" and "a chip removal window appears but lacks flow field carrying capacity," leading to redeposition and surface quality fluctuations.

[0088] Therefore, as Figure 4 As shown, this application summarizes the key timing constraints of the processing into four "windows" and proposes a collaborative control strategy:

[0089] (1) Ultrasonic phase window : Characterizes the time interval within which ultrasonic vibration is more favorable for the discharge of plumes and debris within a specific phase range; when the ultrasonic instantaneous phase When falling within this phase range, the channel renewal capability within the hole / groove is enhanced, and the probability of debris falling back is reduced.

[0090] (2) Laser-controlled doors and windows Under real-time control unit gating, only when fall into Laser pulses (or pulse trains) are allowed to be output at certain times; Can be regarded as The time-domain gating of the light output interval allows for the scheduling of pulse energy, pulse interval, repetition frequency, and pulse train structure within this interval, thereby achieving shaping and consistent control of energy input per unit ultrasound cycle.

[0091] (3) Fog-covered window Considering the flight time from the coaxial annular nozzle to the machining point Valve response delay and control system delay Then, control the mist within the laser-controlled door window. The mist coverage reaches and continuously covers the processing area within the processing zone to provide cooling, impact, and auxiliary chip removal; the mist coverage window is synchronized with the processing cycle of the texture unit or trajectory segment, and is not required to be synchronized with the ultrasonic cycle cycle by cycle.

[0092] (4) Dry air cleaning window Dry gas cleaning is carried out after processing.

[0093] This application employs a coaxial annular nozzle to form an envelope flow field, possessing at least two switchable modes: Mode A: Pulsed aerosol: Carrier gas carries micro-droplets, providing cooling, impact, and auxiliary chip removal; Mode B: Dry air knife: Carrier gas only (can be compressed air or inert gas), used at higher speed / pressure for clearing and removing plumes and particles. The two modes can be switched via an electrically controlled valve assembly or a high-speed switching mechanism (aerosol valve and dry air valve) to achieve duty cycle control of "aerosol covering the processing section, dry air covering the clearing section" at the processing cycle scale of the texture unit / track segment; the switching frequency is not limited to being equal to the ultrasonic frequency, but is determined jointly by the response capability of the coaxial annular nozzle and the process cycle.

[0094] In some embodiments of this application, reference is made to Figure 4 The start time of the target aerosol coverage window is determined by the following steps:

[0095] Obtain the jet distance from the outlet of the coaxial annular nozzle to the machining point. Average velocity of carrier gas in coaxial annular nozzle Valve response delay of aerosol valve Control system delay of the control device and the preset target arrival time Among them, the moment the target arrives Earlier than the start time of the target laser gate window;

[0096] According to jet distance and average velocity of carrier gas Calculate the arrival delay of the aerosol ;

[0097] When the target is in place Subtract the aerosol arrival delay Valve response delay and control system delay The starting time of the target fog coverage window is obtained. .

[0098] ;Formula (1)

[0099] ;Formula (2)

[0100] in, The preferred setting is a safe lead time before the start time of the gated light-emitting section of a certain texture unit or trajectory segment, ensuring that the mist has covered the processing area when entering the gated light-emitting section. Because With the change of five-axis attitude, As flow rate and pressure change, therefore It can be updated in real time by trajectory segment or by zone calibration.

[0101] In a texture unit processing cycle Internally, it should meet the following requirements: laser-controlled doors and windows. Completely located within the mist-covered window Inside, and dry air cleaning window and Mutual exclusion and located at after; The start time needs to be considered , , , so that the mist is in In place before starting and Maintain an appropriate margin after the event.

[0102] Set the center of the ultrasonic phase window corresponding time set Therefore, the requirement is: laser-gated window cover Nearby light; mist-covered window cover Appropriate margins before and after (considering droplet retention and evaporation); dry gas clearing window cover The rebound phase after the event ends is to accelerate the expulsion process.

[0103] The timing can be simplified as follows (using a texture unit or a scan trajectory as the object): Define the texture unit processing cycle. , Includes multiple ultrasound cycles (e.g.) One ultrasound cycle, ), and in The internal sequence is as follows: (1) Pre-wetting section: Only the aerosol valve is opened, so that the aerosol reaches the processing area after taking into account flight time and system delay; (2) Processing section: The aerosol is kept open, and the phase window gated laser output is activated, so that the laser pulse is emitted only within the ultrasonic phase window; (3) Cleaning section: The aerosol valve is closed and the dry air valve is opened, for a duration of (or continue for several ultrasonic cycles) to remove plumes and debris and reduce the risk of droplet residue and redeposition.

[0104] In some embodiments, the aerosol liquid may be selected from ethanol, isopropanol, or deionized water, based on factors such as volatility, corrosiveness to materials, impact on oxidation, and risk of optical pollution. For gear materials such as carburized and quenched steel, a micro-atomizing medium with high volatility and low residue is preferred, and extraction should be used to reduce the risk of fire. It should be noted that the average droplet size of the aerosol in this application should preferably be controlled within the range of 2μm to 20μm to balance responsiveness and impact effect; the liquid mass flow rate should preferably be controlled at the "micro-lubrication" level to avoid the formation of a continuous liquid film that could lead to optical path instability.

[0105] This application improves the channel renewal efficiency within holes / grooves and reduces plasma and debris shielding by locking the laser energy input within the favorable chip removal phase window of ultrasonic vibration, ensuring that the pulsed aerosol is in place before the start of the processing section, continuously covering the processing area within the section, and clearing the area with a dry air knife after the processing section ends. This benefits the improvement of the depth-to-diameter ratio and removal stability. By employing a combined mechanism of "dry air knife clearing—atomization cooling—phase window gating," this application makes it easier to peel off and remove debris after formation, reducing redeposition of particles on the hole walls and edges. Simultaneously, the cooling and impact effects reduce local heat accumulation and the probability of melting and resolidification, significantly reducing the risk of redeposition and recast layers.

[0106] It should be noted that this application does not limit the specific machine tool structure and can be implemented in combination with equipment such as five-axis motion platforms, galvanometer scanning, dynamic focusing, and ultrasonic rotary tables, and has strong engineering adaptability and expandability.

[0107] According to the ultrasonic-assisted laser processing method for microtextured tooth surfaces in this application, the method achieves spatiotemporal coupling of multiple physical fields—energy field, flow field, and vibration field—by precisely planning and coordinating the timing of the target ultrasonic phase window, target laser gate window, target aerosol covering window, and target dry gas clearing window. The target laser gate window covers the target ultrasonic phase window, ensuring that the laser pulse is emitted within a specific advantageous phase of ultrasonic vibration, at which point the material is in its optimal removal state, and the ultrasonic vibration more effectively assists in the removal of debris from the processing area. The target aerosol covering window covers the target laser gate window and its start time is earlier than that of the target laser gate window. This allows the aerosol to arrive at the processing area before laser processing begins, forming an effective aerosol environment. This prepares for chip removal and cooling during processing, avoiding initial chip accumulation or localized overheating due to the aerosol not arriving in time. The start time of the target dry gas clearing window is later than the end time of the target laser gating window, ensuring that the dry gas can promptly purge the processing area after laser processing, removing residual mist, micro-debris, and potential redeposited materials, further optimizing the surface quality. Through this multi-window collaborative control, the periodic excitation of ultrasonic vibration during laser processing enhances the separation and removal of debris. Combined with the efficient cooling and lubrication of the mist and the precise clearing by the dry gas, this effectively solves the problems of debris shielding and redeposit in aspect ratio machining, significantly improving the stability, consistency, and surface quality of microtexture processing, providing strong technical support for the fabrication of high-performance microtextures for complex curved gear surfaces.

[0108] In some embodiments of this application, reference is made to Figure 5 The target ultrasound phase window is obtained through the following steps:

[0109] Based on the machining trajectory, a short-time phase scan trial machining is performed on the tooth surface to be machined, and online signals during the trial machining process and geometric results after the trial machining are collected. The online signals are real-time measurable signals that reflect the machining status and the forming quality of the micro-weave structure.

[0110] Based on the online signals during the trial processing and the geometric results after the trial processing, the objective function corresponding to different ultrasonic phases is calculated. The objective function is used to evaluate the overall processing quality under different ultrasonic phases.

[0111] The stage parameter table of the ultrasonic phase window is determined based on the objective function corresponding to different ultrasonic phases. The stage parameter table includes different optimal phase centers and window widths corresponding to different processing stages.

[0112] The target ultrasound phase window is determined based on the phase parameter table.

[0113] Short-time phase scan trial machining refers to selecting 3-5 texture units as samples in a representative area of ​​the tooth surface, keeping all parameters except phase offset constant, and setting the phase offset set. :

[0114] ;Formula (3)

[0115] in, Take 8~16. For phase, for each Perform short-term trial processing: launch One pulse or several pulse trains are collected, and online signals and geometric results after trial processing are acquired.

[0116] In some embodiments, the online signal may be one or more of the following: plasma / plume luminescence intensity, reflected light signal, acoustic emission / vibration response, rapid depth sounding results (confocal / white light, etc.).

[0117] In some embodiments of this application, an objective function is constructed to improve engineering feasibility. The constraint formula for the objective function, used to evaluate the overall machining quality under different phases, is as follows:

[0118] ;Formula (4)

[0119] in, Let be the objective function. For online signals, This is the normalized value of the average removal depth per unit pulse or unit pulse train. This is the normalized value of the redeposition risk index. This is the normalized value of the depth consistency index. , and The weighting coefficients are preset, where the normalized values ​​of the average removal depth per unit pulse or unit pulse train, the normalized values ​​of the redeposition risk index, and the normalized values ​​of the depth consistency index are all calculated based on the geometric results after trial processing.

[0120] In some embodiments, Divide the depth difference before and after trial processing by Obtain and normalize. It is constructed and normalized by the edge stacking height after processing, scattering intensity, or low-frequency drift of online optical signal. This is the normalized value of the depth standard deviation. , and Preferred satisfaction It can also be preset according to "depth-to-diameter ratio priority / quality priority / efficiency priority".

[0121] Optimal phase center ,in, Preferably, in nearby A finer scan is performed within a 30° range to obtain greater detail. .

[0122] Window width It can be determined according to the following rules: take the one that satisfies The phase interval is used as the candidate window width, where Take a value of 0.80~0.95; and... Limit the angle to a preset range (e.g., 20°~150°) to balance efficiency and consistency. For quality-priority scenarios, choose the smaller value. For efficiency-first scenarios, take the larger value. However, it must be verified in the subsequent online detection closed loop that it does not exceed the limits.

[0123] This application introduces a "phase self-optimization phase-locking" step, which does not rely on a fixed empirical phase, but establishes a target function based on the online signal in a short time, automatically selects the optimal phase and locks it, so that different materials / different textures / different tooth positions have better transferability and reproducibility.

[0124] In some embodiments of this application, the optimal phase can change with each stage due to the altered shielding and chip removal states within the cavity after texture deepening. The microtexturing process sequentially includes an initial forming stage, a deepening stage, and a finishing stage. The stage parameter table includes the first optimal phase center corresponding to the initial forming stage. and the width of the first window The second optimal phase center corresponding to the deepening stage Second window width And the third optimal phase center corresponding to the refinement stage. and the width of the third window The first window is wide The duration is greater than the width of the second window. Duration, second window width The duration is greater than the width of the third window Duration.

[0125] In some embodiments of this application, during the initial forming stage, based on the processing trajectory and the first optimal phase center... First window width The laser gate window controls a five-axis motion platform and a laser-machined workpiece to perform micro-texturing on the tooth surface to be processed. The laser pulse is applied in the first window width. Internal emission with the start time being the first optimal phase center Based on the first optimal phase center and the width of the first window Control the ultrasonic rotary table to perform ultrasonic vibration to assist chip removal; control the opening and closing of the mist valve based on the target mist coverage window, and control the opening and closing of the dry air valve based on the target dry air clearing window, so as to assist chip removal on the tooth surface to be machined.

[0126] During the augmentation stage, based on the processing trajectory and the second optimal phase center... Second window width With the target laser gate window, the five-axis motion platform and the laser-processed workpiece are controlled to perform micro-texturing on the tooth surface to be processed using a layer-by-layer cutting strategy of layer-by-layer scanning, helical cutting, or grid filling. The laser pulse is in the second window width. Internal emission with the start time being the second optimal phase center Enhance the effective amplitude of ultrasound, and follow the second optimal phase center. Second window width Control the ultrasonic rotating worktable to perform ultrasonic vibration to assist chip removal; control the opening and closing of the mist valve based on the target mist coverage window, control the opening and closing of the dry air valve based on the target dry air clearing window, and control the opening of the dry air valve during the interlayer period of layer-by-layer cutting to assist chip removal on the tooth surface to be machined.

[0127] During the finishing stage, the single-pulse energy of the laser pulse is reduced based on the machining trajectory and the third optimal phase center. The third window width The laser gate window controls a five-axis motion platform and the workpiece to perform micro-texturing on the tooth surface to be processed. The laser pulse is within the third window width. Internal emission with the start time being the third optimal phase center Based on the third optimal phase center and the width of the third window The ultrasonic rotary table is controlled to perform ultrasonic vibration to assist chip removal; based on the target mist coverage window, the mist valve is controlled to open and close in an intermittent spray mode with a low duty cycle, and the dry air valve is controlled to open and close based on the target dry air cleaning window, so as to assist chip removal on the tooth surface to be machined.

[0128] This application divides the microtexturing process into at least three stages: the initial forming stage, the deepening stage, and the finishing stage. Each stage corresponds to different processing objectives and constraints, and employs different phase window widths, gas mist duty cycles, effective ultrasonic amplitudes, and scanning strategies to suppress the plasma shielding and redeposition risks that increase with depth.

[0129] Stage I (Initial Forming Stage): A relatively wide phase window is preferred to improve throughput, and a section control of "pre-wetting - processing section air mist coverage - cleaning section dry air knife" is adopted to quickly form a stable inlet morphology.

[0130] Phase II (Deepening Phase): It is preferable to enable the phase table and narrow the phase window to enhance the effective ultrasonic amplitude and aerosol coverage intensity; a layer-by-layer cutting strategy of layered scanning, spiral cutting or grid filling can be adopted, and dry gas clearing sections are set between layers to reduce redeposition.

[0131] Phase III (Refinement Phase): Narrower phase windows and lower single-pulse energy are preferred, and sidewall and edge quality is improved through low-energy multiple passes and higher overlap rate; the aerosol maintains cooling with a low duty cycle, and the cleaning is mainly done with dry air knife to reduce residual contamination.

[0132] In some embodiments, after each texture unit or each tooth surface is processed, a short-term combination of "ultrasonic air vibration + dry air knife + extraction enhancement" can be performed to remove residual droplets and carry away particles. This action can significantly reduce optical contamination and consistency drift on subsequent tooth surfaces.

[0133] This application improves material removal efficiency and shortens the processing cycle of a single tooth surface or the entire gear by using a phased processing strategy (start-deepening-finishing) and pulse train / repetition frequency scheduling, while ensuring the quality of the hole / groove wall.

[0134] In some embodiments, the effective ultrasonic amplitude is the effective component of ultrasonic vibration in the direction of the texture hole / groove axis. By using five-axis attitude planning to make the laser incident direction at the processing point as consistent as possible with the local normal, the direction of the texture hole / groove axis can be approximated as the unit normal vector, thus making the definition of the effective ultrasonic amplitude consistent with the actual removal direction. If the effective ultrasonic amplitude is lower than a preset threshold (e.g., 0.6 times the target amplitude), one of the following actions must be performed: adjust the A-axis / five-axis attitude to reduce the angle between the ultrasonic displacement and the unit normal vector; or switch the texture direction and scanning strategy to make the hole axis direction closer to the projection direction of the ultrasonic displacement; or enable the compensation combination of "increased gas mist duty cycle + narrowed phase window + enhanced dry air knife" in this area. This ensures that the chip removal capability of different tooth positions / different areas will not be out of control due to attitude limitations.

[0135] In some embodiments of this application, the pulse energy of the laser pulse on the laser-processed part is obtained through the following steps:

[0136] The first compensation amount is calculated based on the incident angle energy compensation model. The first compensation amount is used to correct the change in the spot area and the material absorption loss caused by the incident angle.

[0137] The second compensation amount is calculated based on the ultrasonic displacement equivalent defocus energy compensation model. The second compensation amount is used to correct the energy density attenuation caused by the equivalent defocus induced by ultrasonic displacement.

[0138] After timing synchronization, the first compensation amount and the second compensation amount are superimposed to obtain the total compensation amount;

[0139] The reference energy of the laser pulse is adjusted according to the total compensation amount to obtain the pulse energy of the laser pulse for the laser-processed workpiece.

[0140] The gating triggering in this application can be implemented by a real-time control unit: acquiring ultrasonic reference signals (transducer electrical signals or accelerometer signals) and calculating the instantaneous ultrasonic phase. ,when Laser triggering is allowed when the laser is in a given state and prohibited otherwise. Gated triggering can be achieved in any of the following ways: (1) the real-time control unit outputs a trigger pulse to the external trigger interface of the laser; (2) the real-time control unit controls a pulse selector (such as an electro-optic / acousto-optic modulator or a Pockels cell) to achieve phase-based release; (3) a pulse train trigger signal is output to a laser that supports pulse trains. At least one of the above methods can achieve the gating requirement of "light output only within the allowed phase window".

[0141] For the One allowable pulse, its trigger time Must meet:

[0142] ;Formula (5)

[0143] And satisfy the laser triggering cycle constraints (e.g.) (Or defined by an external trigger). Wherein, The phase folding function is a prior art technique known to those skilled in the art, and will not be explained in detail here. This is the center of the phase window.

[0144] When the laser supports pulse train mode, this application allows for... Internally emits one or more pulse trains and can encode the pulse trains: (1) The start time is locked at (2) Number of sub-pulses Sub-pulse interval With energy distribution Set according to "removal efficiency priority / surface quality priority"; (3) In the deepening stage, a higher number of sub-pulses can be used to improve the removal rate, and in the finishing stage, the number of sub-pulses and energy are reduced to improve the sidewall. The essence of this strategy is to shape the "energy input per unit ultrasonic cycle" so that it is synchronized with the renewal of the channel inside the hole.

[0145] In some embodiments, for the decrease in effective energy density caused by oblique incidence, energy density compensation is preferably performed in the following manner:

[0146] ;Formula (6)

[0147] in, For energy density, For the target effective energy density, It is not a single constant fixed for all operating conditions, but rather a target effective energy density pre-given or determined through short-term calibration based on material type, texture type, processing stage, and quality objectives. Preferably, The process window should be set within a range that is above the effective material removal threshold and below the upper limit of significant recasting, burning, or strong redeposition; different settings can be applied to the initial forming, deepening, and finishing stages. It also allows for minor corrections based on the results of post-processing testing and testing errors. Set the energy density (or equivalent) for the laser side. / spot area), For single-pulse energy, To prevent the denominator from being too small, a safety threshold of 0.3 to 0.5 is preferred. The incident angle is the angle between the unit vector of the laser beam propagation direction (or the tool axis direction of the machining head) and the unit normal vector of any point on the tooth surface to be machined.

[0148] It should be noted that, in order to avoid the single-pulse energy exceeding the laser's allowable range or causing surface burns due to energy compensation, it is preferable to set an energy upper limit. , making When calculated Exceed In this case, equivalent compensation can be achieved by reducing the scanning speed, increasing the number of repetitions, or narrowing the phase window. The difference between this compensation and the original process is that the compensation is not just "statically calculated by angle," but can be dynamically corrected by combining curvature partitioning and online detection results.

[0149] In some embodiments, ultrasonic displacement This changes the instantaneous position of the focal point relative to the surface, thus altering the spot radius. Under the paraxial approximation:

[0150] ;Formula (7)

[0151] in, The waist radius is Rayleigh length, Let be the axial propagation distance. Then the instantaneous spot area is... :

[0152] ;Formula (8)

[0153] To maintain the target effective energy density Stable, this application proposes phase-related energy compensation (equivalent defocusing and energy compensation caused by ultrasonic displacement):

[0154] ;Formula (9)

[0155] in, The set pulse energy is calculated based on the gating time. This refers to the triggering time allowed by the gating. Through this compensation, an approximately consistent effective energy density can be maintained under different phases and curvature attitudes, thereby significantly improving texture consistency.

[0156] It is understandable that the single-pulse removal depth in femtosecond laser ablation... A logarithmic model can be used to approximate this:

[0157] ; Formula (10)

[0158] in, To effectively absorb depth or material constants, For effective energy density, The threshold energy density.

[0159] This application considers the synergistic effect of ultrasound and aerosol to be equivalent to a reduction in the threshold or an increase in the removal coefficient, which can be expressed empirically as follows:

[0160] ;Formula (11)

[0161] in The coupling factor is used to characterize the phase. Effective amplitude of ultrasound Related to aerosol parameters (carrier gas volumetric flow rate) aerosol liquid mass flow rate The overall impact on removal efficiency is used to guide the necessity of phase optimization and aerosol positioning compensation.

[0162] In some embodiments of this application, reference is made to Figure 6 After processing, the ultrasonic-assisted laser processing method for microtexturing tooth surfaces also includes:

[0163] The machined texture of the gear workpiece is scanned to obtain the depth, diameter or width, edge accumulation height and array position deviation of the pits or grooves.

[0164] The measured depth distribution is determined based on the depth, diameter or width of the pit or trench, the edge accumulation height, and the array position deviation.

[0165] An error map is generated based on the measured depth distribution and the preset target depth distribution;

[0166] Based on the error map, the pulse energy of the laser pulse, the window width of the target ultrasonic phase window, the window width of the target aerosol coverage window, and the duty cycle of the intermittent spray mode of the laser-processed part are updated, and the tooth surface to be processed is supplemented and iterated until the error map is less than the preset error threshold.

[0167] The objects to be tested may also include taper and surface roughness or equivalent scattering indices.

[0168] Error Map Defined as:

[0169] ;Formula (12)

[0170] in, For the preset target depth distribution, This represents the measured depth distribution.

[0171] For example, pulse energy can be corrected using a limiting ratio:

[0172] ;Formula (13)

[0173] in, The corrected pulse energy. The pulse energy before correction. For the amplitude limiting operator, This is a preset lower limit to prevent the denominator from being too small. This is for closed-loop gain correction.

[0174] It can also correct the window width of the target ultrasound phase window:

[0175] ;Formula (14)

[0176] in, To correct the window width of the target ultrasound phase window, To correct the window width of the target ultrasound phase window, To correct the gain in the closed loop. The preset depth dispersion allowable value, This is a measure of depth dispersion.

[0177] Set the maximum step size for a single update and set the iteration stopping condition: when ,and When to stop making corrections or move to the fine-tuning stage, among which, This is the preset error threshold.

[0178] It can also update the window width of the target mist coverage window and the duty cycle of the intermittent spray mode, and then generate gating trigger and valve control sequences for further processing.

[0179] In some embodiments, if an increased risk of redeposition or a significant decrease in removal rate is detected, a "rapid phase rescan" may be triggered: only when... around Local scan update at 20° This eliminates the need for full-range scanning, thus taking into account the beat.

[0180] In some embodiments, the depth, diameter or width of the pit or trench, the edge stacking height, and the array position deviation can be detected by a confocal sensor or by other optical measurement units with equivalent resolution, and should not be regarded as a limitation of this application.

[0181] The control device in this application embodiment also includes Figure 6 The controller in the system is used to correct the processing path data.

[0182] This application achieves adaptive consistency of texture depth, diameter / width, and form / position errors in curvature variation regions through pre-processing surface topography measurement and conformal mapping, phase-energy-defocus joint compensation during processing, and rapid post-processing metrological feedback. Preferably, the texture depth error and depth dispersion can be controlled within a preset threshold range through online metrological closed-loop control, thereby reducing systematic drift in different tooth positions and curvature regions.

[0183] In some embodiments of this application, reference is made to Figure 1 The laser processing apparatus also includes a suction and discharge device located on the side of the processing area; after processing, the ultrasonic-assisted laser processing method for microtexturing tooth surfaces further includes:

[0184] Start the ultrasonic rotary table to perform ultrasonic air vibration cleaning;

[0185] Open the dry air valve to purge with dry air;

[0186] Turn on the extraction device to extract the fluid.

[0187] This application also has a series of post-processing and security requirements:

[0188] 1. After the aerosol is used, dry gas purging and extraction must be performed to ensure that no flammable vapors accumulate in the cavity. Preferably, the aerosol carrier gas is an inert gas such as nitrogen, and anti-static and explosion-proof measures are set for the processing cavity to reduce the safety risks of volatile organic media in the laser processing environment.

[0189] 2. The processing area should be equipped with multi-stage filtration and anti-backflow structures to prevent microparticle contamination of optical components;

[0190] 3. Gear workpieces can be dried at low temperature or blown with clean gas to prevent residual droplets from affecting subsequent assembly and rust prevention;

[0191] 4. If the processed material is sensitive to corrosion, a suitable medium should be selected and humidity and residue should be controlled;

[0192] 5. After the process is completed, the cleanliness of the texture can be checked. If necessary, ultrasonic cleaning (non-processing ultrasonic) or solvent wiping can be used, but the edges of the texture should be avoided.

[0193] In one specific embodiment, for ease of engineering implementation, this application provides a feasible parameter range:

[0194] 1. Ultrasonic parameters: Frequency: 15 kHz~60 kHz (20 kHz~40 kHz is commonly used); Amplitude: 3μm~25μm (lower in the finishing stage and higher in the cleaning stage); Effective ultrasonic amplitude: It is recommended not to be less than 60% of the target value, otherwise attitude / process compensation should be performed.

[0195] 2. Laser parameters: Wavelength: preferably 1030nm or 1064nm, 515nm is also an option; Pulse width: 100fs~800fs; Repetition rate: 50 kHz~2 MHz; Single pulse energy: 1μJ~200μJ (matched to spot size and material threshold); If it is a pulse train: number of sub-pulses =2~50, the sub-pulse interval is set according to the equipment capacity.

[0196] 3. Ultrasonic phase window parameters: Phase center : Determined by self-optimization; Window width 20°~150° (scheduled according to stage and quality requirements); Allowable phase jitter: should be significantly less than (In engineering practice, the jitter index can be used to constrain the behavior).

[0197] 4. Aerosol / Dry Gas Parameters: Carrier Gas: Compressed air, nitrogen, or other inert gas; Aerosol Liquid: Ethanol / Isopropanol / Deionized water, etc. (selected according to material and safety requirements); Droplet Size: 2μm~20μm; Nozzle Arrival Time Real-time estimation based on attitude and distance, or zone calibration; Duty cycle: The duty cycle of the aerosol can be increased in the initial / deepening stage and decreased in the refinement stage.

[0198] It should be noted that the specific values ​​of the above parameters should not be regarded as limitations on this application, and can be adjusted according to the actual situation.

[0199] In some embodiments of this application, before acquiring the machining trajectory of the gear workpiece's tooth surface to be machined, and the target ultrasonic phase window, target laser gating window, target mist coverage window, and target dry gas clearing window, the ultrasonic-assisted laser machining method for tooth surface microtexturing further includes:

[0200] Workpiece preparation and clamping positioning: Clamp the gear workpiece on a clamping and positioning mechanism with ultrasonic vibration output capability, and establish the transformation relationship between the workpiece coordinate system and the machine tool coordinate system;

[0201] Tooth surface morphology acquisition and local normal calculation: Perform three-dimensional morphology measurement on the tooth surface to be machined or generate a surface parametric model based on the CAD model, and calculate the local normal, curvature and allowable attitude domain;

[0202] Texture design and conformal mapping: The texture array design is completed in the parameter domain, the texture points / lines are mapped to the tooth surface, and the "five-axis pose - galvanometer scanning - dynamic focusing" joint trajectory (i.e. machining trajectory) is generated.

[0203] Gear workpieces should ideally be clamped using a combination of end-face positioning and coaxial positioning of the inner hole / outer circle. This end-face positioning and coaxial positioning structure provides... Figure 1 The specific implementation method of the top clamping and positioning structure of the ultrasonic rotary table. Figure 1 For the sake of illustration, the details of the fixture are not shown. In practice, a positioning mandrel, expansion sleeve, or coaxial chuck can be installed at the output end of the ultrasonic rotary table, and a clamping and positioning structure can be formed in conjunction with the end face positioning step and the pressure cap. The reference end face of the gear workpiece fits against the end face positioning step, and the inner hole or outer circle is coaxially engaged with the positioning mandrel or chuck. Then, the pressure cap or locking device applies an axial clamping force, thereby keeping the gear reference axis coaxial with the C-axis rotation axis.

[0204] For high-precision micro-texture machining, it is preferable to perform a rotation axis runout measurement after clamping. Rotation axis runout refers to the periodic axial oscillation and radial offset of the actual reference end face or reference circle relative to the ideal rotation axis as the workpiece rotates with the C-axis. Preferably, during one revolution of the C-axis at low speed, the reference end face and reference circle can be simultaneously sampled using a contact probe, confocal sensor, or displacement sensor. An error function regarding the rotation angle is established by combining this with the encoder angle. This error function can be further decomposed into axial error and radial error. In subsequent trajectory planning, when the C-axis reaches the corresponding angle, the focus point height command is superimposed with the axial error to compensate for the Z-axis runout, and the pose command in the radial direction or local normal projection direction is superimposed with the radial error to compensate for eccentricity, thereby reducing texture depth drift and landing point deviation.

[0205] The establishment and calibration of the above coordinate system can be achieved using existing calibration methods such as coaxial vision, contact probes, or confocal sensors.

[0206] refer to Figure 7 , Figure 7This is a schematic diagram of conformal mapping of texture from the parameter domain to the tooth surface according to an embodiment of this application. It should be noted that the principles and processes of tooth surface topography acquisition and local normal calculation, as well as the principles and processes of texture design and conformal mapping, are all prior art known to those skilled in the art, and will not be described in detail here.

[0207] In addition, it should be noted that, since this application introduces the synergy between aerosol and femtosecond laser, the activation of aerosol requires that the extraction system be in an effective state, and the laser output must meet the conditions of access control, extraction, cooling, and ultrasonic stabilization phase locking; otherwise, the energy compensation step is prohibited.

[0208] Additionally, one embodiment of this application provides a control device comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor. The processor and the memory can be connected via a bus or other means.

[0209] Memory, as a non-transitory computer-readable storage medium, can be used to store non-transitory software programs and non-transitory computer-executable programs. Furthermore, memory may include high-speed random access memory, and may also include non-transitory memory, such as at least one disk storage device, flash memory device, or other non-transitory solid-state storage device. In some embodiments, memory may optionally include memory remotely located relative to the processor, and these remote memories can be connected to the processor via a network. Examples of such networks include, but are not limited to, the Internet, intranets, local area networks, mobile communication networks, and combinations thereof.

[0210] The non-transient software program and instructions required to implement the ultrasonic-assisted laser processing method for microtexturing tooth surfaces in the above embodiments are stored in the memory. When executed by the processor, the ultrasonic-assisted laser processing method for microtexturing tooth surfaces in the above embodiments is executed.

[0211] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0212] Furthermore, one embodiment of this application provides a computer-readable storage medium storing computer-executable instructions that are executed by a processor or controller, such as the processor of the aforementioned control device, causing the processor to perform the ultrasonic-assisted laser processing method for microtexturing tooth surfaces described in the above embodiment.

[0213] It will be understood by those skilled in the art that all or some of the steps and systems in the methods disclosed above can be implemented as software, firmware, hardware, and suitable combinations thereof. Some or all of the physical components can be implemented as software executed by a processor, such as a central processing unit, digital signal processor, or microprocessor, or as hardware, or as an integrated circuit, such as an application-specific integrated circuit. Such software can be distributed on a computer-readable medium, which can include computer storage media (or non-transitory media) and communication media (or transient media). As is known to those skilled in the art, the term computer storage media includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information (such as computer-readable instructions, data structures, program modules, or other data). Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technologies, CD-ROM, digital versatile disc (DVD) or other optical disc storage, magnetic cartridges, magnetic tape, disk storage or other magnetic storage devices, or any other medium that can be used to store desired information and is accessible to a computer. Furthermore, as is known to those skilled in the art, communication media typically contain computer-readable instructions, data structures, program modules, or other data in modulated data signals such as carrier waves or other transmission mechanisms, and may include any information delivery medium.

[0214] The embodiments of this application have been described in detail above with reference to the accompanying drawings. However, this application is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of this application.

Claims

1. A method for ultrasonic-assisted laser processing of microtextured tooth surfaces, characterized in that, This invention relates to a laser processing apparatus, comprising a five-axis motion platform, an ultrasonic rotary table, a clamping and positioning structure, a laser-processed workpiece, an aerosol / drying air device, and a control device. The ultrasonic rotary table is mounted on the five-axis motion platform. The clamping and positioning structure is mounted on the ultrasonic rotary table and used to position the gear workpiece. The laser-processed workpiece is positioned above the gear workpiece for laser processing. The aerosol / drying air device includes a coaxial annular nozzle, an aerosol pipeline, and a dry air pipeline. The coaxial annular nozzle is positioned between the laser-processed workpiece and the gear workpiece. The aerosol pipeline and the dry air pipeline are respectively connected to the coaxial annular nozzle, and the aerosol pipeline and the dry air pipeline are respectively equipped with an aerosol valve and a dry air valve. The control device is electrically connected to the five-axis motion platform, the ultrasonic rotary table, the laser-processed workpiece, the aerosol valve, and the dry air valve. The ultrasonic-assisted laser processing method for microtexturing tooth surfaces includes: The machining trajectory of the gear workpiece's tooth surface to be machined is acquired, along with a target ultrasonic phase window, a target laser gated window, a target aerosol coverage window, and a target dry gas clearing window. The target laser gated window covers the target ultrasonic phase window, and the target aerosol coverage window covers the target laser gated window. The start time of the target aerosol coverage window is earlier than the start time of the target laser gated window, and the start time of the target dry gas clearing window is later than the end time of the target laser gated window. The target ultrasonic phase window is obtained through the following steps: based on the machining trajectory, a short-time phase scan trial machining is performed on the tooth surface to be machined, and online signals during the trial machining process and geometric results after the trial machining are collected. The online signal is a real-time measurable signal reflecting the processing status and microtextile forming quality. Based on the online signal during the trial processing and the geometric results after the trial processing, an objective function corresponding to different ultrasonic phases is calculated. This objective function is used to evaluate the overall processing quality under different ultrasonic phases. A staged parameter table of the ultrasonic phase window is determined based on the objective function corresponding to different ultrasonic phases. This staged parameter table includes different optimal phase centers and window widths corresponding to different processing stages in the microtextile processing process, including the initial forming stage, the deepening stage, and the finishing stage. The target ultrasonic phase window is determined based on the staged parameter table. The constraint formula for the objective function is: ； in, Let the objective function be... The online signal, This is the normalized value of the average removal depth per unit pulse or unit pulse train. This is the normalized value of the redeposition risk index. This is the normalized value of the depth consistency index. , and The weighting coefficients are preset, wherein the normalized value of the average removal depth under a unit pulse or unit pulse train, the normalized value of the redeposition risk index, and the normalized value of the depth consistency index are all calculated based on the geometric results after trial processing. Based on the processing trajectory, the target ultrasonic phase window, and the target laser gate window, the five-axis motion platform and the laser processing workpiece are controlled to perform micro-textured processing on the tooth surface to be processed, and the laser pulse of the laser processing workpiece is emitted within the target ultrasonic phase window; Based on the target ultrasonic phase window, the ultrasonic rotary table is controlled to perform ultrasonic vibration-assisted chip removal. The aerosol valve is opened and closed based on the target aerosol coverage window, and the dry air valve is opened and closed based on the target dry air clearing window, so as to assist in chip removal from the tooth surface to be processed.

2. The ultrasonic-assisted laser processing method for microtexturing tooth surfaces according to claim 1, characterized in that, The stage parameter table includes the first optimal phase center and the first window width corresponding to the initial forming stage, the second optimal phase center and the second window width corresponding to the deepening stage, and the third optimal phase center and the third window width corresponding to the finishing stage. The duration of the first window width is greater than the duration of the second window width, and the duration of the second window width is greater than the duration of the third window width.

3. The ultrasonic-assisted laser processing method for microtexturing tooth surfaces according to claim 2, characterized in that, In the initial forming stage, based on the processing trajectory, the first optimal phase center, the first window width, and the target laser gate window, the five-axis motion platform and the laser processing workpiece are controlled to perform micro-texturing processing on the tooth surface to be processed. The laser pulse is emitted within the first window width and the starting time is the first optimal phase center. Based on the first optimal phase center and the first window width, the ultrasonic rotary table is controlled to perform ultrasonic vibration-assisted chip removal. Based on the target mist coverage window, the mist valve is controlled to open and close, and based on the target dry gas cleaning window, the dry gas valve is controlled to open and close to assist in chip removal from the tooth surface to be processed. In the deepening stage, based on the machining trajectory, the second optimal phase center, the second window width, and the target laser gate window, the five-axis motion platform and the laser processing workpiece are controlled to perform micro-texturing on the tooth surface to be processed using a layer-by-layer cutting strategy of layer-by-layer scanning, spiral cutting, or grid filling. The laser pulse is emitted within the second window width and the starting time is the second optimal phase center. The effective ultrasonic amplitude is enhanced, and the ultrasonic rotating stage is controlled according to the second optimal phase center and the second window width to perform ultrasonic vibration-assisted chip removal. The opening and closing of the aerosol valve is controlled based on the target aerosol coverage window, and the opening and closing of the dry gas valve is controlled based on the target dry gas clearing window. The dry gas valve is also controlled to open during the interlayer cutting period to assist in chip removal from the tooth surface to be processed. During the finishing stage, the single-pulse energy of the laser pulse is reduced. Based on the machining trajectory, the third optimal phase center, the third window width, and the target laser gate window, the five-axis motion platform and the laser-processed workpiece are controlled to perform micro-texturing on the tooth surface to be processed. The laser pulse is emitted within the third window width and the starting time is the third optimal phase center. Based on the third optimal phase center and the third window width, the ultrasonic rotary table is controlled to perform ultrasonic vibration-assisted chip removal. Based on the target aerosol coverage window, the opening and closing of the aerosol valve is controlled in an intermittent spray mode with a low duty cycle. Based on the target dry gas cleaning window, the opening and closing of the dry gas valve is controlled to assist in chip removal on the tooth surface to be processed.

4. The ultrasonic-assisted laser processing method for microtexturing tooth surfaces according to claim 1, characterized in that, The starting time of the target aerosol coverage window is determined through the following steps: The following parameters are obtained: the jet distance from the outlet of the coaxial annular nozzle to the processing point, the average velocity of the carrier gas of the coaxial annular nozzle, the valve response delay of the aerosol valve, the control system delay of the control device, and the preset target arrival time, wherein the target arrival time is earlier than the start time of the target laser gate window. The aerosol arrival delay is calculated based on the jet distance and the average velocity of the carrier gas. Subtract the aerosol arrival delay, the valve response delay, and the control system delay from the target arrival time to obtain the start time of the target aerosol coverage window.

5. The ultrasonic-assisted laser processing method for microtexturing tooth surfaces according to claim 1, characterized in that, The pulse energy of the laser pulse on the laser-processed part is obtained through the following steps: The first compensation amount is calculated based on the incident angle energy compensation model. The first compensation amount is used to correct the change in the spot area and the material absorption loss caused by the incident angle. The second compensation amount is calculated based on the ultrasonic displacement equivalent defocus energy compensation model. The second compensation amount is used to correct the energy density attenuation caused by the equivalent defocus induced by ultrasonic displacement. After timing synchronization, the first compensation amount and the second compensation amount are superimposed to obtain the total compensation amount; The reference energy of the laser pulse is adjusted according to the total compensation amount to obtain the pulse energy of the laser pulse on the laser-processed workpiece.

6. The ultrasonic-assisted laser processing method for microtexturing tooth surfaces according to claim 1, characterized in that, After processing, the ultrasonic-assisted laser processing method for microtexturing tooth surfaces further includes: The machined texture of the gear workpiece is scanned to obtain the depth, diameter or width, edge accumulation height and array position deviation of the pits or grooves; The measured depth distribution is determined based on the depth of the pit or trench, the diameter or width, the edge stacking height, and the array position deviation. An error map is generated based on the measured depth distribution and the preset target depth distribution; Based on the error map, the pulse energy of the laser pulse of the laser-processed part, the window width of the target ultrasonic phase window, the window width of the target aerosol coverage window, and the duty cycle of the intermittent spray mode are updated, and the tooth surface to be processed is supplemented and iterated until the error map is less than a preset error threshold.

7. The ultrasonic-assisted laser processing method for microtexturing tooth surfaces according to claim 1, characterized in that, The laser processing apparatus further includes a suction and discharge device located on the side of the processing area; after processing, the ultrasonic-assisted laser processing method for microtexturing tooth surfaces further includes: Start the ultrasonic rotary table to perform ultrasonic air vibration cleaning; Open the dry gas valve to perform dry gas purging; Open the extraction device to perform extraction.

8. A laser processing apparatus, characterized in that, include: Five-axis motion platform; An ultrasonic rotary table is mounted on the five-axis motion platform; A clamping and positioning structure is mounted on the ultrasonic rotary worktable and used to position the gear workpiece. A laser-processed part is positioned above the gear workpiece for laser processing. The aerosol dry air device includes a coaxial annular nozzle, an aerosol pipeline, and a dry air pipeline. The coaxial annular nozzle is disposed between the laser-processed part and the gear workpiece. The aerosol pipeline and the dry air pipeline are respectively connected to the coaxial annular nozzle, and the aerosol pipeline and the dry air pipeline are respectively provided with an aerosol valve and a dry air valve. The control device is electrically connected to the five-axis motion platform, the ultrasonic rotary table, the laser-processed part, the aerosol valve, and the dry gas valve, respectively. The control device is used to implement the ultrasonic-assisted laser processing method for microtexturing tooth surfaces as described in any one of claims 1 to 7.

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