Apparatus for laser machining a groove in a PCD drill bit and method of controlling the same

Abstract

The application relates to a device for laser processing of a PCD drill bit groove and a control method thereof, and relates to the technical field of superhard material processing. The device comprises an XY moving guide rail platform, a rotating clamp, a laser lens, a water jet device, an auxiliary airflow device and a coaxial confocal displacement sensing device. The control method is as follows: a PCD round bar is clamped on the rotating clamp and the laser focal point is positioned; during processing, the water jet and the reverse auxiliary airflow jointly act to keep the light spot area locally water-free or covered with thin water, and a continuous dynamic water film is formed around the light spot area; the rotating clamp rotation and the platform axial feeding are synchronously controlled to obtain a spiral groove center processing track; the center track is taken as a reference to determine two side offset scanning tracks and corresponding target groove depths, the actual groove depth is measured after the device is moved to the current offset position, the laser power is corrected according to the depth deviation, the water jet flow and the auxiliary airflow flow are adjusted in linkage, and then scanning is carried out, so that the PCD drill bit spiral groove consistent with the preset groove type is finally formed.

Description

Technical Field

[0001] This invention relates to the field of superhard material processing technology, and more specifically, to an apparatus and control method for laser processing of PCD drill bit grooves. Background Technology

[0002] In high-end precision manufacturing fields such as aerospace and automotive electronics, polycrystalline diamond (PCD) is widely used in the manufacture of precision tools such as micro-drills and cutting tools due to its extremely high hardness, excellent wear resistance, and impact resistance. It is especially suitable for high-precision machining of difficult-to-machine materials such as silicon carbide and single-crystal silicon. As precision machining develops towards miniaturization, the spiral groove machining of PCD micro-drills has placed stringent requirements on dimensional accuracy, surface quality, and performance, requiring simultaneous compliance with standards for groove profile accuracy, low surface defects, and high machining consistency.

[0003] Traditional mechanical grinding methods for machining PCD materials suffer from low efficiency, severe wheel wear, easy chipping of cutting edges, and difficulty in controlling dimensional accuracy. Non-mechanical methods such as electrical discharge machining (EDM) and electrochemical machining have extremely low removal efficiency for diamond phase materials, failing to meet the high-efficiency, high-quality machining requirements for helical grooves in PCD micro-drills. Laser machining, with its advantages of non-contact operation, high precision, and high flexibility, can achieve complex groove shaping through motion trajectory control, making it a crucial technology for machining helical grooves in PCD micro-drills.

[0004] While conventional waterjet-assisted laser machining can suppress localized heat accumulation, reduce recast layer formation, and limit the heat-affected zone through water cooling, in the machining of microstructures, continuous water jets covering the laser's action area cause laser refraction, scattering, and energy attenuation. This reduces the actual laser energy acting on the workpiece surface, affecting machining stability and micromachining accuracy. This contradiction is particularly pronounced for complex microstructures like helical grooves in PCD micro-drills, which extend continuously along cylindrical surfaces. It's impossible to simultaneously achieve effective cooling and heat suppression while meeting high-precision forming requirements, directly leading to defects such as diamond graphitization, microcracks, and heat-affected zones, severely impacting the machining quality and performance of PCD micro-drills. Summary of the Invention

[0005] The present invention provides an apparatus and control method for laser processing of PCD drill bit grooves, which aims to improve at least one of the above-mentioned technical problems.

[0006] To address the aforementioned technical problems, this invention provides a control method for an apparatus for laser-processing PCD drill bit grooves. The apparatus includes an XY moving guide platform, a rotating fixture, a laser lens, a water jet device, an auxiliary airflow device, and a coaxial confocal displacement sensor.

[0007] The control method includes steps S1 to S4.

[0008] S1. Clamp the PCD round bar in the rotary fixture and position the laser focus at the starting position of the spiral groove machining on the outer cylindrical surface of the PCD round bar to be machined.

[0009] S2. During the laser processing, a water jet is supplied from one side of the PCD round bar by a water jet device, and a reverse auxiliary airflow is supplied from the opposite side by an auxiliary airflow device, so that the laser spot action area is kept locally dry or covered with a thin layer of water, and a continuous dynamic water film is maintained around the processing area.

[0010] S3. Control the rotary fixture to rotate around the central axis of the PCD round bar, and control the XY moving guide platform to feed axially, so that the axial displacement and rotation angle are synchronized to form the machining trajectory of the spiral groove center.

[0011] S4. Using the machining trajectory at the center of the spiral groove as a reference, determine the lateral offset scanning trajectories on both sides of the center machining trajectory and the target groove depth corresponding to each lateral offset position according to the preset groove shape. Move to the lateral offset of the current lateral offset scanning trajectory, obtain the actual groove depth at the current position through the coaxial confocal displacement sensor, and correct the laser power according to the deviation between the actual groove depth and the target groove depth. Then, adjust the water jet flow rate and auxiliary airflow flow rate in conjunction with the corrected laser power and start the current lateral offset scanning, so that multiple lateral offset scanning trajectories form a PCD drill bit spiral groove consistent with the preset groove shape.

[0012] As a further optimization, S1 specifically includes:

[0013] The PCD round bar is clamped and fixed on a rotating fixture, and the axis of the PCD round bar is kept coaxial with the rotation axis of the rotating fixture. Preferably, the PCD round bar is a composite material structure, the drill shank and drill rod are made of alloy material, the drill tip is made of polycrystalline diamond material, and the object to be laser processed is the polycrystalline diamond material part at the front end of the round bar.

[0014] The laser lens is calibrated for focal length and aligned for optical path, so that the laser focus is stably focused on the starting position of the center line of the outer cylindrical surface of the PCD bar to be processed, and this starting position of the center line is used as the starting reference point for subsequent center trajectory scanning and lateral offset scanning.

[0015] As a further optimization, S2 includes: The distance and spray angle of the water jet nozzle relative to the PCD round bar processing point are adjusted to ensure that the water jet acts stably around the laser processing area. Specifically, the water jet nozzle orifice diameter is 0.3 mm, the straight-line distance from the water jet nozzle to the PCD round bar is 12 mm, the water jet spray angle is 40 degrees to the horizontal direction, the reference water jet flow rate is 10 mL / min, and deionized water is used for the water jet.

[0016] After the water flow stabilizes, adjust the position and distance of the auxiliary airflow nozzle of the auxiliary airflow device to apply a reverse airflow from the side away from the regulating water jet device. The auxiliary airflow nozzle orifice diameter is 0.5 mm, the straight-line distance from the auxiliary airflow nozzle to the PCD round bar is 8 mm, the airflow injection angle is 30 degrees with the horizontal direction, and the reference auxiliary airflow flow rate is 9 L / min.

[0017] The water jet is sprayed from left to right, and the auxiliary airflow acts on the processing area from right to left. The auxiliary airflow can locally push aside the water near the laser spot without disturbing the rotational stability of the PCD rod, and blow away and discharge the molten slag and debris generated during the processing.

[0018] As a further optimization, S2 also includes: Once the water jet and auxiliary airflow have both reached a stable state, the laser beam is turned on and the spiral groove processing begins.

[0019] The stabilization time of the water jet, the airflow activation delay time, and the laser activation time are controlled to ensure that the water film forms first, the airflow disperses later, and the laser enters the processing state. The laser beam is formed by an infrared picosecond pulse laser with a pulse frequency of 1000 kHz and a pulse width of 10 ps, ​​and continuously performs point processing.

[0020] As a further optimization, S3 includes: The rotary fixture is controlled to rotate around the central axis of the PCD bar, and the XY moving guide platform is controlled to drive the PCD bar to perform linear feed along the axial direction, so that the axial feed speed and the angular velocity of the workpiece rotating around its own central axis maintain a fixed proportional relationship.

[0021] .

[0022] .

[0023] In the formula, This indicates the axial feed rate. This represents the angular velocity of the workpiece rotating around its own central axis. This indicates the diameter of the PCD drill bit. This indicates the helix angle of the drill bit. This indicates a fixed coefficient.

[0024] The real-time rotation angle of the rotary fixture is obtained based on the axial displacement of the XY moving guide rail platform.

[0025] .

[0026] .

[0027] In the formula, The axial displacement of the moving guide rail platform is... The real-time rotation angle of the rotating fixture. This indicates the initial rotation angle of the fixture. This indicates the lead of the helix angle. This indicates the axial displacement of the moving guide rail platform.

[0028] As a further optimization, S4 includes: The maximum depth of the groove bottom center relative to the highest point of the original round bar is defined as the machining depth, and a machining depth function is established according to the preset spiral groove cross-sectional shape to obtain the target spiral groove cross-sectional machining depth corresponding to each lateral offset position.

[0029] .

[0030] .

[0031] In the formula, This indicates the machining depth of the target spiral groove section. This represents the geometric subsidence of the original cylindrical outer contour relative to the highest point of the cylindrical rod. This indicates the width of the spiral groove. Indicates the lateral offset position. This indicates the radius of the PCD drill bit. This indicates the maximum groove depth of the spiral groove cross-section.

[0032] As a further optimization, S4 also includes: The lateral offset of each offset scanning trajectory is obtained based on the width of the spiral groove, so that each offset scanning trajectory is distributed sequentially on both sides of the central machining trajectory.

[0033] , .

[0034] In the formula, This indicates the total number of offset scan trajectories. Indicates the index of the offset scan trajectory. Indicates the first The lateral offset of the offset scan trajectory.

[0035] After the machining trajectory at the center of the spiral groove is completed, control the XY moving guide platform and the rotary fixture to return to the starting position, and control the XY moving guide platform to move to the next position. Lateral offset of the offset scan trajectory Then, the actual trench depth information at the current position is obtained through a coaxial confocal displacement sensor.

[0036] Based on the deviation between the actual groove depth at the current position and the machining depth of the target spiral groove section corresponding to the lateral offset position, the first... The laser power before processing the biased scanning trajectory, and the water jet flow rate and auxiliary airflow flow rate obtained based on the corrected laser power.

[0037] Subsequently, the rotary fixture and axial feed axis are controlled to perform the first step in a synchronous linkage relationship with the machining trajectory of the spiral groove center. Scanning processing of offset scan trajectories.

[0038] Pending After the offset scanning trajectory is processed, the XY moving guide platform and rotating fixture are controlled to return to the starting position, and then moved to the lateral offset of the next offset scanning trajectory and the actual groove depth acquisition, laser power correction, water jet flow rate adjustment, auxiliary airflow flow rate adjustment and scanning processing are repeated.

[0039] As a further optimization, the following was revised: The laser power before processing the offset scanning trajectory specifically includes: The actual groove depth information of the current position obtained by the coaxial confocal displacement sensor is compared with the processing depth of the target spiral groove section to obtain the correction coefficient, and the laser power is corrected according to the correction coefficient.

[0040] .

[0041] .

[0042] In the formula, This indicates the corrected laser power. Indicates the reference laser power. This represents the correction factor. This indicates the actual trench depth at the current location.

[0043] As a further optimization, the water jet flow rate and auxiliary airflow flow rate are obtained based on the corrected laser power, specifically including: The water jet flow rate corresponding to different lateral offset positions is obtained based on the corrected laser power, and the airflow flow rate corresponding to different lateral offset positions is obtained based on the water jet flow rate corresponding to different lateral offset positions. This is to simultaneously improve the water jet cooling capacity and the auxiliary airflow water-removing and slag-removing capacity when the laser power increases, and to correspondingly reduce the water jet flow rate and auxiliary airflow flow rate when the laser power decreases.

[0044] .

[0045] .

[0046] In the formula, This indicates the water jet flow rate corresponding to different lateral offset positions. This indicates the reference water jet flow rate. This indicates the corrected laser power. This indicates the maximum laser power. This indicates the minimum laser power. This indicates the airflow rate corresponding to different lateral offset positions. This indicates the reference airflow rate.

[0047] This application also provides an apparatus for laser processing of PCD drill bit grooves, which includes an XY moving guide platform, a rotary fixture, a laser lens, a water jet device, an auxiliary airflow device, a coaxial confocal displacement sensor, and a control device.

[0048] The rotary clamp is used to clamp the PCD round bar and drive the PCD round bar to rotate around its own central axis.

[0049] The XY moving guide rail platform is used to drive the PCD round bar to feed axially and move laterally with offset.

[0050] The water jet device and the auxiliary airflow device are respectively used to act on the processing area from opposite sides of the PCD round bar.

[0051] The coaxial confocal displacement sensing device is used to obtain the actual groove depth at the current position after the XY moving guide platform moves to the current lateral offset scanning trajectory by the lateral offset amount.

[0052] The control device is used for the control method of the aforementioned laser processing PCD drill bit groove device.

[0053] By adopting the above technical solution, the present invention can achieve the following technical effects: This invention utilizes the synergistic effect of water jets and auxiliary airflow to construct a continuous dynamic water film around the laser processing area, while simultaneously forming a localized waterless or thinly water-covered area at the laser spot's point of action. This achieves real-time cooling and stable protection of the processing area while ensuring effective laser energy transmission.

[0054] The coordinated control of the XY moving guide platform, rotary fixture, laser, water jet and auxiliary airflow device by the control device enables the axial feed motion and rotational motion to be synchronously linked according to the preset function relationship, and to perform lateral offset scanning processing according to the preset groove shape. Combined with online depth detection and laser power feedback correction, the smooth connection of multiple scanning trajectories is effectively guaranteed.

[0055] This method effectively suppresses local heat accumulation in PCD materials during laser processing, significantly reducing thermal damage defects such as diamond graphitization, heat-affected zones, microcracks, and recast adhesion layers. Simultaneously, it promotes the timely removal of molten slag and processing debris, minimizing the adverse effects of secondary residue adhesion on subsequent processing. By linking laser power with water / air flow rate according to the lateral offset position, sufficient cooling capacity of the water medium is ensured while avoiding interference from excessively thick local water layers or excessively strong airflow on laser energy transmission efficiency and processing stability. This significantly improves the groove shape accuracy, surface quality, and processing consistency of the spiral groove, obtaining a cross-sectional profile highly matched to the preset groove shape. It is particularly suitable for the high-precision, high-quality processing requirements of PCD micro-drilled spiral grooves. Attached Figure Description

[0056] To more clearly illustrate the technical solutions of the specific embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

[0057] Figure 1 A schematic diagram of the device for laser processing of PCD drill bit grooves using dynamic water film.

[0058] Figure 2 A schematic diagram of dynamic water film-assisted laser processing for PCD drill bit grooves.

[0059] Figure 3 Top view of dynamic water film-assisted laser processing of PCD drill bit grooves Figure 4 This is a schematic diagram of the cross-sectional profile of the PCD drill bit groove.

[0060] In the figure: 1-XY moving guide rail platform, 2-PCD round bar, 3-water jet device, 4-laser lens, 5-auxiliary airflow device, 6-control device, 7-rotating clamp, 8-coaxial confocal displacement sensing device. Detailed Implementation

[0061] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. It should be understood that the described embodiments are used to illustrate the technical solutions of the present invention and should not be construed as limiting the scope of protection of the present invention.

[0062] like Figures 1 to 4 As shown, this embodiment provides an apparatus and control method for laser processing of PCD drill bit grooves.

[0063] like Figure 1 As shown, the device includes an XY moving guide platform 1, a rotary fixture 7, a laser lens 4, a water jet device 3, an auxiliary airflow device 5, a coaxial confocal displacement sensor 8, and a control device 6. The rotary fixture 7 is used to clamp the PCD rod 2 and drive it to rotate around its central axis. The XY moving guide platform 1 is used to drive the PCD rod 2 axially and to perform lateral offset movement after the machining trajectory at the center of the spiral groove is completed. The water jet device 3 and the auxiliary airflow device 5 act on the machining area from opposite sides of the PCD rod 2. The coaxial confocal displacement sensor 8 is used to obtain the actual groove depth at the current position after the XY moving guide platform 1 moves to the lateral offset of the current lateral offset scanning trajectory. The control device 6 is used to coordinate the control of the XY moving guide platform 1, the rotary fixture 7, the laser lens 4, the water jet device 3, the auxiliary airflow device 5, and the coaxial confocal displacement sensor 8.

[0064] In this embodiment, the PCD rod 2 is a composite material structure, the drill shank and drill rod are made of alloy material, and the drill tip is made of polycrystalline diamond. The laser processing target is the polycrystalline diamond portion at the front end of the rod. In one embodiment, the PCD rod 2 has a diameter of 1 mm and a length of 1 mm for the polycrystalline diamond portion. The laser processing mainly acts on the polycrystalline diamond portion at the front end of the rod. Through the synergistic effect of the water jet and the auxiliary airflow, a continuous dynamic water film is formed around the laser processing area, and a locally waterless or thin water-covered state is formed in the laser spot area. This ensures effective transmission of laser energy while cooling and protecting the processing area and promoting the removal of molten slag and debris.

[0065] The coaxial confocal displacement sensing device 8 is a non-contact spectral confocal displacement sensing device, which includes a confocal measurement probe, a light source, a spectral receiving unit, and a signal processing unit. During measurement, the confocal measurement probe emits measurement light towards the position to be measured on the PCD rod 2, and the reflected light returns along the same optical axis. The signal processing unit determines the height position of the measured surface based on the reflected light signal at the confocal position, thereby obtaining the distance between the surface of the PCD rod 2 or the bottom of the machined groove and the measurement probe.

[0066] In this embodiment, the control device 6 first obtains the reference height of the unmachined outer cylindrical surface of the PCD round bar 2. When the XY moving guide platform 1 moves to the first... Lateral offset of the offset scan trajectory Subsequently, the coaxial confocal displacement sensor 8 measures the bottom or boundary of the processed groove at the current position, and the control device 6 obtains the actual groove depth information at the current position based on the difference between the reference height and the height measured at the current position. During measurement, laser emission can be paused, and auxiliary airflow can be used to blow away water film and debris in the measurement area to improve the actual trench depth information. Measurement stability.

[0067] The control method of this embodiment includes the following steps.

[0068] S1. Clamp the PCD round bar 2 in the rotating fixture 7 and position the laser focus at the starting position of the spiral groove machining on the outer cylindrical surface of the PCD round bar 2 to be machined.

[0069] Specifically, the PCD round bar 2 is clamped and fixed on the rotating fixture 7, ensuring that the axis of the PCD round bar 2 is coaxial with the rotation axis of the rotating fixture 7. This guarantees the positioning accuracy and rotational stability of the PCD round bar 2 during processing. After clamping, the laser lens 4 is calibrated for focal length and aligned for optical path, so that the laser focus is stably focused on the starting position of the center line of the outer cylindrical surface of the PCD round bar 2 to be processed. This starting position of the center line is used as the starting reference point for subsequent spiral groove center processing trajectory scanning and lateral offset scanning.

[0070] In practical implementation, the rotary fixture 7 can be angularly positioned according to the workpiece installation state, that is, the tilt angle with the horizontal plane can be adjusted to compensate for the influence of clamping errors on the machining accuracy of the spiral groove. In one embodiment, the tilt angle of the rotary fixture 7 with respect to the horizontal plane is 0 degrees, and the laser focus is positioned at the starting position of the spiral groove machining on the outer circular surface of the PCD round bar 2, so that the subsequent center machining trajectory and each lateral offset scanning trajectory have a unified starting reference.

[0071] S2. During the laser processing, a water jet is supplied from one side of the PCD rod 2 by the water jet device 3, and a reverse auxiliary airflow is supplied from the opposite side by the auxiliary airflow device 5, so that the laser spot action area is kept locally dry or covered with a thin layer of water, and a continuous dynamic water film is maintained around the processing area.

[0072] Specifically, such as Figures 1 to 3 As shown, the distance and spray angle of the water jet nozzle relative to the processing point of the PCD rod 2 are adjusted by the water jet device 3 to ensure that the water jet can stably act around the laser processing area. In one embodiment, the water jet nozzle orifice diameter is 0.3 mm, the straight-line distance from the water jet nozzle to the PCD rod 2 is 12 mm, the water jet spray angle is 40 degrees with the horizontal direction, the reference water jet flow rate is 10 mL / min, and deionized water is used for the water jet. Deionized water can reduce ion contamination and residual water stains on the workpiece surface and form a stable cooling medium around the laser processing area.

[0073] After the water flow stabilizes, adjust the position and distance of the auxiliary airflow nozzle of the auxiliary airflow device 5 to apply a reverse airflow from the side away from the water jet device 3. In one embodiment, the auxiliary airflow nozzle orifice diameter is 0.5 mm, the straight-line distance from the auxiliary airflow nozzle to the PCD round bar 2 is 8 mm, the airflow injection angle is 30 degrees with the horizontal direction, and the reference auxiliary airflow flow rate is 9 L / min.

[0074] During processing, a water jet is sprayed from left to right, while an auxiliary airflow acts on the processing area from right to left. Without disrupting the rotational stability of the PCD rod 2, the auxiliary airflow locally disperses the water near the laser spot, creating a locally waterless or thinly water-covered area. This prevents significant refraction, scattering interference, and energy attenuation of the laser beam, ensuring that the laser energy effectively acts on the surface of the PCD rod 2. Simultaneously, a continuous dynamic water film is maintained around the processing area for real-time cooling, suppressing localized heat accumulation in the PCD material under laser irradiation and reducing defects such as diamond graphitization, microcracks, heat-affected zone expansion, and recast adhesion layers.

[0075] The reverse auxiliary airflow can also promptly disperse and discharge the molten slag and processing debris generated during the processing, reducing the secondary adhesion of residues on the processing surface and improving the surface quality of the spiral groove and the consistency of subsequent scanning processing.

[0076] After both the water jet and the auxiliary airflow reach a stable state, the control device 6 activates the laser beam and begins spiral groove processing. The control device 6 can control the sequence of water jet stabilization time, airflow activation delay time, and laser activation time to ensure that the water film forms first, the airflow disperses later, and the laser enters the processing state, thereby improving the stability and repeatability of the dynamic water film state. In one embodiment, the laser beam is formed by an infrared picosecond pulse laser with a pulse frequency of 1000 kHz and a pulse width of 10 ps, ​​and continuously performs point processing.

[0077] S3. Control the rotary fixture 7 to rotate around the central axis of the PCD round bar 2, and control the XY moving guide rail platform 1 to feed axially, so that the axial displacement and rotation angle are synchronously linked to form the machining trajectory of the spiral groove center.

[0078] Specifically, the control device 6 controls the rotary fixture 7 to rotate around the central axis of the PCD rod 2, and controls the XY moving guide platform 1 to drive the PCD rod 2 to perform linear feed along the axial direction, so that the axial feed speed and the angular velocity of the workpiece rotating around its central axis maintain a fixed proportional relationship. The laser beam is fixedly applied to the predetermined processing area on the outer surface of the PCD rod 2, and under the synchronous linkage of axial feed and circumferential rotation, a machining trajectory for the center of the spiral groove is formed.

[0079] The relationship between the axial feed rate and the angular velocity is as follows: .

[0080] In the formula: This indicates the axial feed rate. This represents the angular velocity of the workpiece rotating around its own central axis. This indicates the diameter of the PCD drill bit. This indicates the helix angle of the drill bit. This indicates a fixed coefficient. This represents the tangent function.

[0081] The drill bit helix angle also satisfies: .

[0082] In the formula: This indicates the helix angle of the drill bit. This indicates the axial feed rate. This represents the angular velocity of the workpiece rotating around its own central axis. This indicates the radius of the PCD drill bit.

[0083] In one embodiment, It is 1mm. It is 0.5mm. It is 30 degrees Celsius. Approximately 0.29 mm. The control device 6 controls the axial feed speed of the XY moving guide platform 1 and the angular velocity of the rotating fixture 7 according to the above fixed proportional relationship, so that the machining trajectory of the helical groove center meets the predetermined helical angle requirement.

[0084] The real-time rotation angle of the rotary fixture 7 is obtained based on the axial displacement of the XY moving guide rail platform 1, and the real-time rotation angle is: .

[0085] In the formula: The axial displacement of the moving guide rail platform is... The real-time rotation angle of the rotating fixture 7. This indicates the initial rotation angle of the fixture. This indicates the lead of the helix angle. This indicates the axial displacement of the moving guide rail platform.

[0086] The helix angle lead is: .

[0087] In the formula: This indicates the lead of the helix angle. This indicates the diameter of the PCD drill bit. This indicates the helix angle of the drill bit.

[0088] In one embodiment, It is 0. The range is 0 to 1 mm. The control device 6 controls the rotation angle of the rotary fixture 7 in real time according to the above relationship, so that the axial displacement and the rotation angle are synchronized, thereby forming a continuous and stable machining trajectory for the center of the spiral groove.

[0089] S4. Using the machining trajectory at the center of the spiral groove as a reference, determine the lateral offset scanning trajectories on both sides of the center machining trajectory and the target groove depth corresponding to each lateral offset position according to the preset groove shape. Move to the lateral offset of the current lateral offset scanning trajectory, obtain the actual groove depth at the current position through the coaxial confocal displacement sensor 8, and correct the laser power according to the deviation between the actual groove depth and the target groove depth. Then, adjust the water jet flow rate and auxiliary airflow flow rate in conjunction with the corrected laser power before starting the current lateral offset scanning, so that multiple lateral offset scanning trajectories form a PCD drill bit spiral groove consistent with the preset groove shape.

[0090] Specifically, such as Figure 4 As shown, after completing the machining trajectory of the spiral groove center, the XY moving guide platform 1 and the rotating fixture 7 are controlled to return to the starting position. Subsequently, according to the groove width requirement of the preset groove type, the XY moving guide platform 1 is controlled to move laterally with an offset along the radial direction corresponding to the PCD round bar 2, and offset scanning is performed sequentially on both sides of the center machining trajectory to gradually cover the width area of ​​the target spiral groove. In this embodiment, the lateral offset of the current lateral offset scanning trajectory is moved first, and the actual groove depth at the current position is obtained through the coaxial confocal displacement sensor 8. In other embodiments, the actual groove depth can be measured first after the lateral offset scanning trajectory is completed, and then the trajectory is moved laterally.

[0091] The maximum depth of the groove bottom center relative to the highest point of the original round bar is defined as the machining depth. A machining depth function is established based on the preset spiral groove cross-sectional shape to obtain the target spiral groove cross-sectional machining depth corresponding to each lateral offset position. The target spiral groove cross-sectional machining depth is: .

[0092] In the formula: This indicates the machining depth of the target spiral groove section. This indicates the maximum groove depth of the spiral groove cross-section. Indicates the lateral offset position as The geometric subsidence of the original circular rod's outer contour relative to the highest point of the rod. This indicates the width of the spiral groove. Indicates the lateral offset position. This represents the geometric subsidence of the original cylindrical outer contour relative to the highest point of the cylindrical rod.

[0093] The geometric subsidence of the original cylindrical outer contour relative to the highest point of the cylindrical rod is: .

[0094] In the formula: This represents the geometric subsidence of the original cylindrical outer contour relative to the highest point of the cylindrical rod. This indicates the radius of the PCD drill bit. Indicates the lateral offset position.

[0095] In one embodiment, It is 0.35mm. The depth is 0.5mm. Using the aforementioned machining depth function, a larger machining depth can be assigned to the center position of the groove, and the machining depth can gradually change as the lateral offset position moves towards the groove edge, thus providing a target groove depth basis for subsequent multiple lateral offset scanning trajectories. Specifically, the groove center position... The maximum machining depth is at the edge of the groove. The processing depth is zero.

[0096] The lateral offset of each offset scanning trajectory is obtained based on the width of the spiral groove, so that each offset scanning trajectory is distributed sequentially on both sides of the central machining trajectory. The lateral offset is: .

[0097] In the formula: Indicates the first The lateral offset of the offset scan trajectory. Indicates the index of the offset scan trajectory. This indicates the width of the spiral groove. This indicates the total number of offset scan trajectories.

[0098] In practical implementation, the number of offset scan trajectories The more [number of] [scanning paths], the higher the fitting accuracy of the spiral groove cross-sectional profile, and the smoother the transition between adjacent scanning paths, thus improving the groove shape accuracy and surface quality of the spiral groove. Control device 6 [according to...] and Determine the corresponding offset scan trajectory And make each lateral offset scanning trajectory cover the width area of ​​the target spiral groove.

[0099] In the Before processing the offset scanning trajectory, control the XY moving guide platform 1 to move to the first... Lateral offset of the offset scan trajectory Then, the actual groove depth information at the current position is obtained through the coaxial confocal displacement sensor 8. Since the actual groove depth is obtained after the XY moving guide platform 1 reaches the current lateral offset position, the coaxial confocal displacement sensor 8 measures the groove depth state corresponding to the current position, which can more accurately reflect the deviation between the machined surface and the target groove depth at the current lateral offset position.

[0100] Control device 6 compares the actual groove depth information at the current position with the machining depth of the target spiral groove section corresponding to the lateral offset position, obtains the correction coefficient, and corrects the first... Laser power before processing the offset scanning trajectory. Corrected laser power is: .

[0101] In the formula: This indicates the corrected laser power. Indicates the lateral offset position. Indicates the reference laser power. This indicates exponentiation. This indicates the machining depth of the target spiral groove section. This represents the correction factor.

[0102] The correction factor is: .

[0103] In the formula: This represents the correction factor. This indicates the machining depth of the target spiral groove section. This indicates the actual trench depth at the current location.

[0104] In one embodiment, The value is 0.62W. Control device 6 uses the actual trench depth information at the current position... Machining depth of the target spiral groove section The deviation between them corrects the laser power, so that the first The processing energy of the offset scanning trajectory is matched with the amount of material to be removed at the current position, reducing the steps, overcutting or undercutting phenomena between multiple scans and improving the accuracy of the spiral groove cross-sectional profile.

[0105] The water jet flow rate and auxiliary airflow flow rate are obtained based on the corrected laser power. Specifically, the control device 6 obtains the water jet flow rate corresponding to different lateral offset positions based on the corrected laser power, and obtains the airflow flow rate corresponding to different lateral offset positions based on the water jet flow rate corresponding to different lateral offset positions, so as to simultaneously improve the water jet cooling capacity and the auxiliary airflow water-removing and slag-removing capacity when the laser power increases, and correspondingly reduce the water jet flow rate and auxiliary airflow flow rate when the laser power decreases.

[0106] The water jet flow rates corresponding to different lateral offset positions are: .

[0107] In the formula: This indicates the water jet flow rate corresponding to different lateral offset positions. Indicates the lateral offset position. This indicates the reference water jet flow rate. This indicates the corrected laser power. This indicates the minimum laser power. This indicates the maximum laser power.

[0108] The airflow rates corresponding to different lateral offset positions are: .

[0109] In the formula: This indicates the airflow rate corresponding to different lateral offset positions. Indicates the lateral offset position. This indicates the reference airflow rate. This indicates the water jet flow rate corresponding to different lateral offset positions. Indicates the operands defined by parentheses.

[0110] In one embodiment, The flow rate is 10 mL / min. The flow rate is 9 L / min. Through the above-mentioned linkage, the water jet flow rate is adjusted according to the modified laser power, and the auxiliary airflow flow rate is adjusted according to the water jet flow rate, so that the cooling capacity, water-repelling capacity, and slag removal capacity are matched with the laser processing energy at the current lateral offset position. This can avoid local heat accumulation caused by insufficient water medium cooling capacity, and can also avoid the impact of excessively thick local water layers or excessively strong airflow on laser energy transmission efficiency and the rotational stability of PCD rod 2.

[0111] After adjusting the laser power, water jet flow rate, and auxiliary airflow flow rate, control the rotary fixture 7 and the axial feed axis to perform the first synchronous linkage operation according to the same machining trajectory as the spiral groove center. Scanning processing of offset scan trajectories. (To be continued) After the offset scanning trajectory is processed, the XY moving guide platform 1 and the rotating fixture 7 are controlled to return to the starting position, and then moved to the lateral offset of the next offset scanning trajectory. The actual groove depth acquisition, laser power correction, water jet flow rate adjustment, auxiliary airflow flow rate adjustment and scanning process are repeated until multiple lateral offset scanning trajectories are processed.

[0112] In the above manner, each lateral offset scanning trajectory sequentially forms a corresponding processing depth on both sides of the machining trajectory at the center of the spiral groove, and gradually covers the entire width area of ​​the target spiral groove, so that the final PCD drill bit spiral groove cross-sectional profile is consistent with the preset groove shape.

[0113] Preferred, such as Figure 1 As shown, an apparatus for laser processing of PCD drill bit grooves according to this embodiment includes an XY moving guide platform 1, a rotating fixture 7, a laser lens 4, a water jet device 3, an auxiliary airflow device 5, a coaxial confocal displacement sensor 8, and a control device 6.

[0114] The rotary fixture 7 is used to clamp the PCD rod 2 and drive it to rotate around its own central axis. The XY moving guide platform 1 is used to drive the PCD rod 2 to feed axially and move laterally with an offset. The water jet device 3 and the auxiliary airflow device 5 are used to act on the processing area from opposite sides of the PCD rod 2, respectively. The coaxial confocal displacement sensor 8 is used to obtain the actual groove depth at the current position after the XY moving guide platform 1 moves to the lateral offset of the current lateral offset scanning trajectory. The control device 6 is used to execute the control method of the above-described laser processing PCD drill bit groove.

[0115] When the device is in operation, the control unit 6 uniformly controls the XY moving guide platform 1, the rotating fixture 7, the laser lens 4, the water jet device 3, the auxiliary airflow device 5, and the coaxial confocal displacement sensor 8, so that the axial feed, circumferential rotation, lateral offset, actual groove depth detection, laser power correction, water jet flow rate adjustment, and auxiliary airflow flow rate adjustment of the PCD round bar 2 form a closed-loop coordinated control. Thus, while ensuring that the laser spot action area is locally free of water or has a thin water coverage, a continuous dynamic water film is maintained around the processing area, and the slag discharge airflow is matched with the cooling state of the water film.

[0116] The technical solution of this embodiment can construct a continuous dynamic water film around the laser processing area and form a localized waterless or thinly water-covered area at the laser spot's point of action. This achieves real-time cooling and stable protection of the processing area while ensuring effective laser energy transmission. Simultaneously, the control device 6 synchronizes the axial feed motion and rotational motion according to a preset functional relationship and performs lateral offset scanning processing based on a preset groove shape. Combined with online depth detection and laser power feedback correction, it ensures smooth connection of multiple scanning trajectories, obtaining a cross-sectional profile highly matched to the preset groove shape.

[0117] This method effectively suppresses local heat accumulation in PCD materials during laser processing, reducing thermal damage defects such as diamond graphitization, heat-affected zones, microcracks, and recast adhesion layers. Simultaneously, it promotes timely removal of molten slag and processing debris, minimizing the adverse effects of secondary residue adhesion on subsequent processing. By linking laser power with water jet flow rate and auxiliary airflow flow rate according to the lateral offset position, sufficient cooling capacity of the water medium is ensured while avoiding excessively thick local water layers or excessively strong airflow that could interfere with laser energy transmission efficiency and processing stability. This improves the groove shape accuracy, surface quality, and processing consistency of the spiral groove, making it suitable for high-precision, high-quality processing of PCD micro-drilled spiral grooves.

[0118] Obviously, the above detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to describe preferred embodiments, not all embodiments, and is not intended to limit the invention. Various modifications and variations can be made to the invention by those skilled in the art. Based on the embodiments of the invention, any modifications, equivalent substitutions, improvements, etc., made by those skilled in the art to all other embodiments obtained without inventive effort are within the scope of protection of the invention.

Claims

1. A control method for an apparatus for laser processing PCD drill bit grooves, characterized in that, The device includes an XY moving guide rail platform, a rotary fixture, a laser lens, a water jet device, an auxiliary airflow device, and a coaxial confocal displacement sensor. Control methods include: S1. Clamp the PCD round bar in the rotary fixture and position the laser focus at the starting position of the spiral groove machining on the outer cylindrical surface of the PCD round bar to be machined; S2. During the laser processing, a water jet is supplied from one side of the PCD round bar by a water jet device, and a reverse auxiliary airflow is supplied from the opposite side by an auxiliary airflow device, so that the laser spot action area is kept in a local water-free state and a continuous dynamic water film is maintained around the processing area. S3. Control the rotary fixture to rotate around the central axis of the PCD round bar, and control the XY moving guide platform to feed axially, so that the axial displacement and rotation angle are synchronously linked to form the machining trajectory of the spiral groove center. S4. Using the machining trajectory at the center of the spiral groove as a reference, determine the lateral offset scanning trajectories on both sides of the center machining trajectory and the target groove depth corresponding to each lateral offset position according to the preset groove shape; move to the lateral offset of the current lateral offset scanning trajectory, obtain the actual groove depth at the current position through the coaxial confocal displacement sensor, and correct the laser power according to the deviation between the actual groove depth and the target groove depth. Then, adjust the water jet flow rate and the auxiliary airflow flow rate according to the corrected laser power and start the current lateral offset scanning, so that multiple lateral offset scanning trajectories form a PCD drill bit spiral groove consistent with the preset groove shape.

2. The control method of the device for laser processing PCD drill bit grooves according to claim 1, characterized in that, S4 include: The maximum depth of the groove bottom center relative to the highest point of the original round bar is defined as the machining depth, and a machining depth function is established according to the preset spiral groove cross-sectional shape to obtain the target spiral groove cross-sectional machining depth corresponding to each lateral offset position. ； ； In the formula, Indicates the machining depth of the target spiral groove section; This represents the geometric subsidence of the original cylindrical outer contour relative to the highest point of the cylindrical bar. Indicates the width of the spiral groove; Indicates the lateral offset position; Indicates the PCD drill bit radius; This indicates the maximum groove depth of the spiral groove cross-section.

3. The control method of the apparatus for laser processing PCD drill bit grooves according to claim 2, characterized in that, S4 also includes: The lateral offset of each offset scanning trajectory is obtained based on the width of the spiral groove, so that each offset scanning trajectory is distributed sequentially on both sides of the central machining trajectory. ， ； In the formula, Indicates the total number of offset scan trajectories; Indicates the index of the offset scan trajectory; Indicates the first Lateral offset of the offset scan trajectory; After the machining trajectory at the center of the spiral groove is completed, control the XY moving guide platform and the rotary fixture to return to the starting position, and control the XY moving guide platform to move to the next position. Lateral offset of the offset scan trajectory Then, the actual groove depth information at the current position is obtained through a coaxial confocal displacement sensor. Based on the deviation between the actual groove depth at the current position and the machining depth of the target spiral groove section corresponding to the lateral offset position, the first... The laser power before processing the offset scanning trajectory, and the water jet flow rate and auxiliary airflow flow rate obtained based on the corrected laser power; Subsequently, the rotary fixture and axial feed axis are controlled to perform the first step in a synchronous linkage relationship with the machining trajectory of the spiral groove center. Scanning processing of offset scan trajectories; Pending After the offset scanning trajectory is processed, the XY moving guide platform and rotating fixture are controlled to return to the starting position, and then moved to the lateral offset of the next offset scanning trajectory and the actual groove depth acquisition, laser power correction, water jet flow rate adjustment, auxiliary airflow flow rate adjustment and scanning processing are repeated.

4. The control method of the apparatus for laser processing PCD drill bit grooves according to claim 3, characterized in that, Amendment No. The laser power before processing the offset scanning trajectory specifically includes: The actual groove depth information of the current position obtained by the coaxial confocal displacement sensor is compared with the processing depth of the target spiral groove section to obtain the correction coefficient, and the laser power is corrected according to the correction coefficient. ； ； In the formula, This indicates the corrected laser power; Indicates the reference laser power; Indicates the correction factor; This indicates the actual trench depth at the current location.

5. The control method of the apparatus for laser processing PCD drill bit grooves according to claim 3, characterized in that, The water jet flow rate and auxiliary airflow flow rate are obtained based on the corrected laser power, specifically including: The water jet flow rate corresponding to different lateral offset positions is obtained based on the corrected laser power, and the airflow flow rate corresponding to different lateral offset positions is obtained based on the water jet flow rate corresponding to different lateral offset positions, so as to simultaneously improve the water jet cooling capacity and the auxiliary airflow water removal and slag removal capacity when the laser power increases, and reduce the water jet flow rate and auxiliary airflow flow rate accordingly when the laser power decreases. ； ； In the formula, This indicates the water jet flow rate corresponding to different lateral offset positions; Indicates the reference water jet flow rate; This indicates the corrected laser power; Indicates the maximum laser power; Indicates the minimum laser power; This indicates the airflow rate corresponding to different lateral offset positions; This indicates the reference airflow rate.

6. The control method for the apparatus for laser processing PCD drill bit grooves according to any one of claims 1 to 5, characterized in that, The PCD round bar has a composite material structure, the drill shank and drill rod are made of alloy material, the drill tip is made of polycrystalline diamond material, and the laser processing target is the polycrystalline diamond material part at the front end of the round bar. S1 specifically includes: The PCD round bar is clamped and fixed on the rotating fixture, and the axis of the PCD round bar is kept coaxial with the axis of rotation of the rotating fixture. The laser lens is calibrated for focal length and aligned for optical path, so that the laser focus is stably focused on the starting position of the center line of the outer cylindrical surface of the PCD bar to be processed, and this starting position of the center line is used as the starting reference point for subsequent center trajectory scanning and lateral offset scanning.

7. The control method of the apparatus for laser processing PCD drill bit grooves according to any one of claims 1 to 5, characterized in that, S2 include: The distance and spray angle of the water jet nozzle relative to the PCD round bar processing point are adjusted to ensure that the water jet acts stably around the laser processing area. The water jet nozzle orifice diameter is 0.3 mm, the straight-line distance from the water jet nozzle to the PCD round bar is 12 mm, the water jet spray angle is 40 degrees with the horizontal direction, the reference water jet flow rate is 10 mL / min, and deionized water is used for the water jet. After the water flow stabilizes, adjust the position and distance of the auxiliary airflow nozzle of the auxiliary airflow device to apply reverse airflow from the side away from the regulating water jet device; wherein, the diameter of the auxiliary airflow nozzle is 0.5mm, the straight distance from the auxiliary airflow nozzle to the PCD round bar is 8mm, the airflow injection angle is 30 degrees with the horizontal direction, and the reference auxiliary airflow flow rate is 9L / min; The water jet is sprayed from left to right, and the auxiliary airflow acts on the processing area from right to left. The auxiliary airflow can locally push aside the water near the laser spot without disturbing the rotational stability of the PCD rod, and blow away and discharge the molten slag and debris generated during the processing.

8. The control method of the apparatus for laser processing PCD drill bit grooves according to claim 7, characterized in that, S2 also includes: Once the water jet and auxiliary airflow have both reached a stable state, the laser beam is turned on and the spiral groove processing begins. The system controls the water jet stabilization time, the airflow activation delay time, and the laser activation time to ensure that the water film forms first, the airflow disperses later, and the laser enters the processing state. The laser beam is formed by an infrared picosecond pulse laser with a pulse frequency of 1000 kHz and a pulse width of 10 ps, ​​and it continuously performs point processing.

9. The control method of the apparatus for laser processing PCD drill bit grooves according to any one of claims 1 to 5, characterized in that, S3 include: The rotary fixture is controlled to rotate around the central axis of the PCD bar, and the XY moving guide platform is controlled to drive the PCD bar to perform linear feed along the axial direction, so that the axial feed speed and the angular velocity of the workpiece rotating around its own central axis maintain a fixed proportional relationship. ； ； In the formula, Indicates the axial feed rate; This indicates the angular velocity of the workpiece rotating around its own central axis; Indicates the diameter of the PCD drill bit; Indicates the helix angle of the drill bit; Indicates a fixed coefficient; The real-time rotation angle of the rotary fixture is obtained based on the axial displacement of the XY moving guide rail platform. ； ； In the formula, The axial displacement of the moving guide rail platform is... Real-time rotation angle of the rotating fixture; Indicates the initial rotation angle of the fixture; Indicates the lead of the helix angle; This indicates the axial displacement of the moving guide rail platform.

10. An apparatus for laser processing of PCD drill bit grooves, characterized in that, It includes an XY moving guide rail platform, a rotary fixture, a laser lens, a water jet device, an auxiliary airflow device, a coaxial confocal displacement sensor, and a control device; The rotary clamp is used to clamp the PCD round bar and drive the PCD round bar to rotate around its own central axis. The XY moving guide rail platform is used to drive the PCD round bar to feed along the axial direction and move laterally offset. The water jet device and the auxiliary airflow device are respectively used to act on the processing area from opposite sides of the PCD round bar; The coaxial confocal displacement sensing device is used to obtain the actual groove depth at the current position after the XY moving guide platform moves to the current lateral offset scanning trajectory by the lateral offset amount. The control device is used to execute the control method of the apparatus for laser processing PCD drill bit grooves as described in any one of claims 1 to 9.

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