Water-guided laser water-light coupling correction method

Abstract

The invention belongs to the technical field of water-guided laser processing, and relates to a water-guided laser water-light coupling correction method, which comprises the following steps of: dotting a light plate for the first time by laser, dotting for the second time after a focus lens module moves upwards, and calculating the deviation between secondary positions by a control system, then the control system adjusts the angle of the two-way mirror according to the deviation calculation result, and the nozzle adjusting module adjusts the angle of the nozzle according to the result fed back by the detection optical module, so that the water column is vertical; according to the invention, self-correction adjustment is carried out on the center of the nozzle and the vertical direction relative to the z axis, and meanwhile, vertical self-correction adjustment is carried out on the laser beam. Therefore, the problems existing between the focusing optical system and the nozzle can be solved, the coupling condition of the laser beam and the water beam is detected and adjusted, the structure is simpler in the aspects of adjustment and use, various introduced errors are few, the water guide laser machining quality is better, and the efficiency is higher.

Description

Technical Field

[0001] The invention belongs to the technical field of water-conducting laser processing and relates to a water-conducting laser water-light coupling correction method. Background Art

[0002] Water-jet guided laser (WJGL), also known as laser water jet processing, is a technology that couples laser to a high-pressure water beam for processing. Through this laser-water beam coupling processing method, a slit parallel to the cut section can be produced, which not only ensures precise processing accuracy, but also ensures that the processing area remains cool and clean. At the same time, there is no need to focus and control the distance of the laser during the processing process. It can be applied to the processing of various thickness ranges and difficult-to-process materials, and will not produce defects such as heat-affected zones and microcracks, meeting complex and precise processing requirements.

[0003] During the water-guided laser processing, the laser water jet nozzle is a necessary condition for forming a stable and reliable "water optical fiber". It is generally made of sapphire (red) sapphire material and has very high processing accuracy requirements. Since the nozzle is subjected to high water pressure and laser impact that does not enter the water beam, it is a conventional consumable part. Every time a new nozzle is replaced, there are processing differences between different nozzles, which not only include the processing error of the nozzle, but also cover the positioning error of the nozzle installation, the error caused by high-pressure water impact, etc., which will cause the geometric position and dimensional accuracy of the processed "water knife" to deviate. For example, the water beam may not be perpendicular to the workpiece coordinate system, and the water beam diameter may have different diameters under different water pressures.

[0004] To solve these problems, two methods are usually used in the prior art to correct the geometric relationship of the water beam. The first method is to manually measure and adjust the verticality of the water beam, but its correction accuracy and efficiency are low. The second method is to use the water beam to touch the sensor multiple times in the x and y directions and at different heights, determine the deviation angle through trigonometric functions, and control the micro-motion mechanism to drive the processing head to deflect, thereby performing water beam correction. Although this method has relatively high correction reliability and accuracy, the operation is relatively cumbersome, generally requiring multiple sampling and comparison operations, and the requirements for the sensor are also relatively high, resulting in higher costs.

[0005] Therefore, a method is now needed that can quickly and effectively locate and correct problems such as water beam deflection and water beam diameter change, so as to improve the accuracy and efficiency of water-guided laser processing. Summary of the invention

[0006] The present invention aims to provide an efficient and accurate water-guided laser water beam correction method to overcome the shortcomings of the prior art. By using the positive and negative electrodes to energize, the water beam can be corrected in real time and accurately, the performance and stability of the water-guided laser system can be improved, and its application in more fields can be expanded.

[0007] The technical solution adopted by the present invention to solve the technical problem is: a water-guided laser water-light coupling correction method, comprising the following steps:

[0008] Step S1, the light beam emitted by the laser is deflected by the dichroic mirror and then enters the focusing mirror module, the focusing mirror module focuses the deflected light beam and then propagates it in the water column by total reflection; the generated slender water column light beam is made to move relative to the workpiece to process the part;

[0009] Step S2: If the verticality of the light beam is poor and the light beam does not enter the center of the lens when entering the focusing lens module, resulting in poor depth of focus and image quality, which affects the coupling result, then proceed to step S3;

[0010] Step S3, the control system moves the aiming plate to the focal position formed by the focusing mirror module at a distance of δ1, turns on the laser to make the first dot on the aiming plate; uses the CCD detection system to perform the first position acquisition and position calibration, recorded as (x1, y1); then the focusing mirror module is moved upward by a distance of δ2 while maintaining the distance of δ1 from the aiming plate, and the laser makes the second dot on the aiming plate; uses the CCD detection system to perform the second position acquisition and position calibration, recorded as (x2, y2); the control system calculates the deviation between the two positions, and then adjusts the angle of the dichroic mirror according to the deviation calculation result, so that the lens angle reaches the value calculated by the system;

[0011] Step S4, when the system has adjusted the dichroic mirror, repeat the operation flow of step S3 to verify that the light beam is vertical and enters the center of the lens;

[0012] Step S5, passing water through the nozzle module to form a water column;

[0013] Step S6, detecting the light beam formed by the optical module to collect water columns at different heights, and repeating step S3 to calculate the vertical difference of the water column;

[0014] Step S7, the nozzle adjustment module adjusts the angle of the nozzle according to the test feedback result of the detection optical module, so that the water column reaches verticality; after the angle adjustment is completed, if there is no need to re-calibrate the beam center and the nozzle, go to step S14;

[0015] Step S14: The water-light debugging process is completed and product processing is carried out.

[0016] Preferably, in step S7, if it is necessary to recalibrate and adjust the beam center and the nozzle, go to the following steps:

[0017] Step S8, because the coupling cavity and the nozzle are assembled and manufactured, the center of the nozzle is not concentric with the center of the laser beam. As a result, position deviation occurs, which makes it impossible for the laser beam and the water column in the coupling cavity to produce total reflection and transmit the beam, which will cause the nozzle in the coupling cavity to be damaged or ablated; it is necessary to replace the new nozzle device, recalibrate the beam center and the nozzle, etc.; therefore, calibration adjustment is required based on the above situation; the position detection system is used for calibration adjustment; the light beam emitted by the detection light source passes through the 45° beam splitter and the focusing mirror module to irradiate the upper surface of the coupling cavity nozzle, and according to the reversibility of the optical path, the CCD detection system takes a picture of the center position of the nozzle and calculates the center position coordinates (x3, y3);

[0018] Step S9, the control system starts the focusing mirror micro-movement module to move the focusing mirror module to a position far away from the center of the nozzle, and at the same time controls the laser to emit light to process the marking point on the alignment plate;

[0019] Step S10, the control system starts the CCD detection system to take a picture of the marking coordinates to obtain the coordinates, and at the same time calculates the position coordinates (x4, y4) of the marking point;

[0020] Step S11, the control system detects and calculates the deviation value (δx, δy) of the laser beam relative to the center position of the nozzle by detecting the center position of the nozzle and the position of the laser beam in the coupling cavity;

[0021] Step S12, the control system starts the reflector micro-motion module and the focusing mirror module to move (δx, δy) on the basis of the plane (x4, y4), so that the center of the focusing beam overlaps with the center position of the nozzle, thus completing the position calibration;

[0022] Step S13, under the power meter, the control system controls the focusing mirror micro-motion module to adjust the focal position of the focusing mirror module to maximize the water-light coupling rate, that is, the laser power is more fully applied in the processing; after the adjustment is completed, go to step S14.

[0023] More preferably, in step S1, the angle between the light beam emitted by the laser and the normal of the incident surface of the dichroic mirror is in the range of 40° to 50°.

[0024] More preferably, in step S8, the angle between the light beam emitted by the detection light source and the normal line of the incident surface of the beam splitter is in the range of 43° to 48°.

[0025] More preferably, in step S8, the angle between the light beam emitted by the detection light source and the normal line of the incident surface of the beam splitter is 45°.

[0026] More preferably, in step S1, the focusing mirror module focuses the folded light beam into a light beam with a smaller diameter than the coupling cavity nozzle, a longer collimation range, and a smaller central spot.

[0027] The beneficial effects of the present invention are:

[0028] 1. The present invention can effectively solve the deviation and jitter of the water column and significantly improve the stability and consistency of the water column diameter.

[0029] 2. The present invention reduces the diameter of the water column to the greatest extent, greatly improves the cutting accuracy, and causes minimal material loss. It is suitable for extremely small aperture drilling or ultra-high precision laser cutting.

[0030] 3. The present invention uses positive and negative electrodes to change the flow direction of the water jet, thereby improving the overall performance of the water-guided laser system and broadening its application range in the fields of precision machining, medical treatment, etc.

[0031] 4. The present invention has a fast response speed and can correct the changes of water beams in real time to adapt to different working conditions and environmental changes.

[0032] 5. The present invention reduces the complexity and cost of the system and has higher cost performance and practicality compared to traditional correction methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 The present invention is a schematic diagram of the structure of an automatic adjustment coupling system of a water-guided laser water-light coupling correction method.

[0034] In the figure, 1. laser; 2. control system; 3. CCD detection system; 4. dichroic mirror; 5. focusing mirror module; 6. aiming plate; 7. nozzle module; 8. detection optical module; 9. micro-motion module; 10. water column. DETAILED DESCRIPTION

[0035] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the relevant technologies in the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] The present embodiment is described in detail below. The present invention is further described in detail in conjunction with a specific embodiment of the schematic diagram of the principle structure of the novel coupling optical path.

[0037] The water-guided laser water-light coupling correction system of this embodiment is composed of a laser 1, a control system 2, a CCD detection system 3, a dichroic mirror 4, a focusing mirror module 5, a light-aiming plate 6, a nozzle module 7, a detection optical module 8, a micro-movement module 9 (including: a reflector micro-movement module, a focusing mirror micro-movement module, a light-aiming plate micro-movement module, a nozzle adjustment module, a detection optical micro-movement module), a water column 10, etc. Figure 1 shown.

[0038] The water-guided laser water-light coupling calibration method of this embodiment comprises the following steps:

[0039] S1: The laser emits a beam that passes through a 45° dichroic mirror and deflects the beam into the center of the focusing mirror module. The focusing mirror module focuses the beam into a beam with a smaller diameter than the coupling cavity nozzle, a longer collimation range, and a smaller central spot, and then propagates through total reflection in the water column. The generated slender water column beam is made to move relative to the workpiece to process the part.

[0040] S2: When the laser beam is propagating, the verticality of the beam is relatively poor. When the beam enters the focusing lens module, it does not enter the center of the lens, resulting in poor depth of focus and imaging quality, which affects the coupling result. Therefore, the verticality of the beam needs to be adjusted.

[0041] S3: The control system moves the alignment plate to the focal position formed by the focusing mirror module at a distance of δ1, and turns on the laser to make the first dot on the alignment plate. The CCD detection system is used for the first position acquisition and position calibration, recorded as (x1, y1). Then the focusing mirror module is moved upward by a distance of δ2 while maintaining a distance of δ1 from the alignment plate, and the laser emits light to make a second dot on the alignment plate. The CCD detection system is used for the second position acquisition and position calibration, recorded as (x2, y2). The control system calculates the deviation between the two positions and adjusts the angle of the dichroic mirror so that the lens reaches the value calculated by the system.

[0042] S4: When the system has adjusted the dichroic mirror, repeat the operation flow of step S3 to verify, and finally make the light beam vertical.

[0043] S5: The nozzle module passes water to form a water column.

[0044] S6: The light beam formed by the detection optical module collects water columns at different heights, and the vertical difference of the water column is calculated in the same way as the S3 process.

[0045] S7: The nozzle adjustment module adjusts the angle of the nozzle according to the test feedback result of the detection optical module, so that the water column reaches a vertical state.

[0046] S8: When the coupling cavity and the nozzle are assembled and manufactured, the center of the nozzle is not concentric with the center of the laser beam. As a result, a position deviation occurs, which prevents the laser beam and the water column in the coupling cavity from being able to produce total reflection to propagate the beam, and will cause the nozzle in the coupling cavity to be damaged or ablated. It is necessary to replace a new nozzle device, recalibrate the beam center and the nozzle, etc. Therefore, based on the above situation, a position detection system is used for calibration and adjustment. It includes a detection light source and a CCD detection system. The light beam emitted by the detection light source passes through a 45° beam splitter and a focusing mirror module and directly irradiates the upper surface of the coupling cavity nozzle. According to the reversibility of the optical path, the CCD detection system takes a picture of the center position of the nozzle and calculates the center position coordinates (x3, y3).

[0047] S9: The control system starts the focusing mirror micro-motion module to move the focusing mirror module to a position farther away from the nozzle center, and at the same time controls the laser light to process the marking point on the alignment plate.

[0048] S10: The control system starts the CCD detection system in the detection system to take a picture of the marking coordinates to obtain the coordinates, and at the same time calculates the position coordinates (x4, y4) of the marking point.

[0049] S11: After detecting the nozzle center position and the position of the laser beam in the coupling cavity, the deviation value (δx, δy) of the laser beam relative to the nozzle center position is calculated.

[0050] S12: The control system starts the reflector module and the focusing mirror module in the micro-motion module to move (δx, δy) on the basis of the plane (x4, y4) so ​​that the center of the focusing beam overlaps with the center position of the nozzle to complete the position calibration.

[0051] S13: Under the power meter, the control system controls the height of the micro-motion module to adjust the focal position of the focusing mirror module, so that the water-light coupling rate reaches the maximum, so that the laser power can be more fully applied in the processing.

[0052] S14: Therefore, the entire water-light debugging process is completed, and product processing can be carried out.

[0053] Traditional water-guided lasers have many drawbacks during operation. In the optical system debugging, mechanical part alignment, and nozzle water-light coupling, manual control is relied on, and there is a lack of standard reference. This makes it difficult to ensure the consistency and repeatability of the installation and adjustment, and each debugging often takes a lot of time. In addition, during the water-light coupling process, the nozzle is easily burned due to the inability to accurately control it, which not only increases costs, but also affects the stability and service life of the equipment.

[0054] To address these issues, a water-guided laser-water-optical coupling correction method is now used. In the optical debugging stage, with the help of advanced automation technology and intelligent algorithms, the debugging of the optical system and the calibration of the verticality and position of the beam are streamlined and standardized, which greatly simplifies the difficulty of operation, reduces the interference of human factors, and improves the accuracy and speed of debugging. In terms of beam verticality and position calibration, automatic adjustment and calibration are achieved through high-precision sensors and feedback control systems to ensure the accuracy and consistency of each calibration, laying a solid foundation for the subsequent processing process.

[0055] The water-light coupling link is a key part of water-guided laser technology. The new correction method uses dynamic focus following technology, that is, the laser focused focus beam can automatically adjust the moving path according to the real-time changes in the nozzle position. This intelligent coupling method significantly improves the coupling efficiency, effectively solves the coupling problem under the traditional method, and reduces the energy loss and equipment failure caused by improper coupling. At the same time, each module uses high-precision electrical control and mechanical adjustment devices, and its control accuracy can be improved to the micron level or even higher compared to manual adjustment. For example, in the beam focusing module, the micro-nano displacement sensor and driver can accurately control the focus position and spot size of the beam to ensure the efficient transmission and precise effect of laser energy in the water beam.

[0056] In order to further ensure the stability and reliability of the processing, the system is equipped with a powerful optical detection module. This module uses advanced equipment such as high-speed cameras and spectrometers to perform real-time dynamic detection of parameters such as the shape, flow rate, and refractive index of the water beam. Through accurate monitoring and analysis of water beam changes, abnormal fluctuations in the water beam can be discovered in a timely manner, and relevant parameters can be adjusted through the feedback control system to ensure that the water beam is always in the best state during the entire processing process, ensuring the consistency and stability of the processing quality.

[0057] In terms of overall system operation, efficient linkage is achieved between the various modules of the waterline. Through the coordination and scheduling of the central control system, each module can adjust its own working parameters and operating status in real time according to the needs of the processing task. For example, when the processing materials or process requirements change, the optical system, water beam supply system and mechanical motion system can quickly respond in coordination and automatically optimize the configuration to ensure the efficiency and accuracy of the processing process. This linkage mechanism increases the processing efficiency to more than twice that of the traditional method, and greatly extends the debugging cycle and operation stability cycle from the previous days or weeks to months, significantly reducing the maintenance cost and downtime of the equipment, and improving production efficiency and the overall competitiveness of the equipment.

[0058] In summary, the present invention performs self-correction adjustment on the center of the nozzle and vertically relative to the z-axis, and at the same time makes the laser beam itself perform vertical self-correction adjustment. This will overcome the problems between the focusing optical system and the nozzle, detect and adjust the coupling of the laser beam and the water beam, and make the structure simpler in terms of adjustment and use. Therefore, the present invention introduces fewer errors, completes water-guided laser processing with better quality and higher efficiency.

[0059] It should be emphasized that the above are only preferred embodiments of the present invention and do not limit the present invention in any form. Any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A water-guided laser water-light coupling calibration method, characterized in that: The following steps are involved: Step S1, a beam emitted by a laser is deflected by a dichroic mirror and then enters a focusing mirror module, and the focusing mirror module focuses the deflected beam and then performs total reflection propagation in a water column; Step S2: If the verticality of the light beam is poor and the light beam does not enter the center of the lens when entering the focusing lens module, then proceed to step S3; Step S3, the control system moves the aiming plate to the focal position formed by the focusing mirror module at a distance of δ1, turns on the laser to make the first dot on the aiming plate; uses the CCD detection system to perform the first position acquisition and position calibration, recorded as (x1, y1); then the focusing mirror module is moved upward by a distance of δ2 while maintaining the distance of δ1 from the aiming plate, and the laser makes the second dot on the aiming plate; uses the CCD detection system to perform the second position acquisition and position calibration, recorded as (x2, y2); the control system calculates the deviation between the two positions, and then adjusts the angle of the dichroic mirror according to the deviation calculation result; Step S4, when the system has adjusted the dichroic mirror, repeat the operation flow of step S3 to verify that the light beam is vertical and enters the center of the lens; Step S5, passing water through the nozzle module to form a water column; Step S6, detecting the light beam formed by the optical module to collect water columns at different heights, and repeating step S3 to calculate the vertical difference of the water column; Step S7, the nozzle adjustment module adjusts the angle of the nozzle according to the test feedback result of the detection optical module, so that the water column reaches verticality; after the angle adjustment is completed, if there is no need to re-calibrate the beam center and the nozzle, go to step S14; Step S14: The water-light debugging process is completed and product processing is carried out.

2. A water-guided laser water-light coupling correction method according to claim 1, characterized in that: In step S7, if it is necessary to recalibrate and adjust the beam center and the nozzle, go to the following steps: Step S8, using the position detection system for calibration and adjustment; the light beam emitted by the detection light source passes through the beam splitter and the focusing lens module to illuminate the upper surface of the coupling cavity nozzle, and the CCD detection system takes a picture of the center position of the nozzle to calculate the center position coordinates (x3, y3); Step S9, the control system starts the focusing mirror micro-movement module to move the focusing mirror module to a position far away from the center of the nozzle, and at the same time controls the laser to emit light to process the marking point on the alignment plate; Step S10, the control system starts the CCD detection system to take a picture of the marking coordinates to obtain the coordinates, and at the same time calculates the position coordinates (x4, y4) of the marking point; Step S11, the control system detects and calculates the deviation value (δx, δy) of the laser beam relative to the center position of the nozzle by detecting the center position of the nozzle and the position of the laser beam in the coupling cavity; Step S12, the control system starts the reflector micro-motion module and the focusing mirror module to move (δx, δy) on the basis of the plane (x4, y4), so that the center of the focusing beam overlaps with the center position of the nozzle, thus completing the position calibration; Step S13, the control system controls the focusing mirror micro-motion module to adjust the focal position of the focusing mirror module so that the water-light coupling rate reaches the maximum; after the adjustment is completed, go to step S14.

3. A water-guided laser water-light coupling correction method according to claim 2, characterized in that: In the step S1, the angle between the laser light beam and the normal of the incident surface of the dichroic mirror is in the range of 40° to 50°.

4. A water-guided laser water-light coupling correction method according to claim 2, characterized in that: In the step S8, the angle between the light beam emitted by the detection light source and the normal line of the incident surface of the beam splitter is in the range of 43° to 48°.

5. A water-guided laser water-light coupling correction method according to claim 4, characterized in that: In step S8, the angle between the light beam emitted by the detection light source and the normal line of the incident surface of the beam splitter is 45°.

6. A water-guided laser water-light coupling correction method according to claim 2, characterized in that: In the step S1, the focusing mirror module focuses the folded light beam into a light beam with a smaller diameter than the coupling cavity nozzle, a longer collimation range, and a smaller central spot.

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