Focus drift detection and correction device and method and laser processing system and method

Abstract

The present invention discloses a detection and correction device and method for focus drift and a laser processing system and method, and belongs to the field of laser welding technology. The detection and correction device for focus drift includes a detection component and an adjustment component arranged corresponding to the laser processing component. The detection component allows the detection light emitted by the detection light module to be divided into monochromatic detection light with different wavelengths after being processed by a dispersion mirror through a second optical path, and after passing through the spectroscopic module, it is coaxially emitted into the focusing module with the processing light beam, and then coaxially emitted to the processing station with the processing light beam. Through the third optical path, the monochromatic detection light of a specific wavelength reflected back from the processing station can be transmitted to the photoelectric sensor and generate a corresponding electrical signal. Finally, the adjustment component obtains the actual focus position and focus drift value of the focusing module according to the electrical signal, and controls the focusing module to adjust the actual focus position to the theoretical focus position. The detection and correction device for focus drift has high adjustment accuracy and strong real-time performance, and is suitable for focus correction in various environments.

Description

Technical Field

[0001] The present invention belongs to the technical field of laser welding, and in particular relates to a focus drift detection and correction device and method, and a laser processing system and method. Background Art

[0002] With the development of automated manufacturing, laser equipment has gradually replaced traditional equipment for production operations. Its high operating precision, fast speed, high power and other characteristics have greatly improved production efficiency. However, when the laser equipment is working as the last process execution component, the collimator inside the focusing module needs to collimate the original light beam introduced by the laser fiber and focus it into a high-energy density spot before it can work. Due to the thermal lens surface distortion (thermal lens effect) of the collimator, the refractive index gradient distribution effect and the thermal deformation of the optical-mechanical assembly structure, the focus drift of the output focused beam and the decrease in beam quality. In addition, the flowing air medium in the equipment absorbs high-energy lasers and is heated. The turbulence and thermal halo effects generated will cause the broadening and intensity fluctuations of the laser beam, which will also affect the focus drift. Therefore, focus drift control has become a common key technology for high-power laser equipment.

[0003] Chinese Patent 202410180087.9 discloses a focus drift compensation system, an optical system, and a focus drift compensation method. The temperature rise of each lens of the optical system during the laser transmission process is judged by a temperature detector, so that the focus drift of the lens can be obtained, and then the temperature of the flat mirror is used to compensate the focus, so as to achieve real-time resetting of the focus drift of the conventional laser processing optical system, and effectively ensure the stability of the optical system during the laser processing process. Chinese Patent 202120519558.6 discloses a real-time automatic compensation and stabilization device and system for laser focus drift, the device includes a focus compensation module, a driver electrically connected to the focus compensation module, a feedback control module electrically connected to the driver, and a temperature sensor electrically connected to the feedback control module. The feedback control module adjusts the focus position of the outgoing laser by changing the distance between the concave lens and the convex lens according to the temperature data fed back by the temperature sensor and through the driver. By real-time detection of ambient temperature changes and adjustment of the focus compensation module, real-time automatic compensation of laser focus drift is achieved.

[0004] It can be seen that most laser devices on the market at this stage use temperature sensors to detect the temperature of optical lenses and adjust the focal position of laser devices by changing the distance between optical lenses. However, the method of using temperature sensors to detect the temperature of optical lenses has problems with temperature delay and measurement angle. There is a time difference between the temperature measured by the temperature sensor and the actual lens temperature, which will affect the real-time focus detection of the laser device. When using infrared temperature sensors, in order to reduce the measurement angle, it is necessary to add a lens that can filter out the influence of visible light and converge light to improve the measurement sensitivity. However, this lens will affect the accuracy and precision of the measurement, especially when measuring at long distances. This method has poor real-time performance, low accuracy, and has great limitations in the use environment. Summary of the invention

[0005] In response to one or more of the above-mentioned defects or improvement needs of the prior art, the present invention provides a focus drift detection and correction device and method and a laser processing system and method, which can detect the actual focal position of the focusing module of the laser processing component in real time and adjust it to be consistent with the theoretical focal position, thereby improving the accuracy of laser processing.

[0006] To achieve the above-mentioned object, the present invention provides a focus drift detection and correction device, which is arranged corresponding to a laser processing assembly, wherein the laser processing assembly comprises a laser, a light splitting module and a focusing module arranged in sequence along a first optical path, and a processing light beam emitted by the laser is transmitted along the first optical path and is emitted to a processing station after passing through the focusing module;

[0007] The detection and correction device includes a detection component and an adjustment component;

[0008] The detection assembly includes a detection light module, a coupler and a dispersion mirror arranged in sequence, and a photoelectric sensor arranged corresponding to the coupler; the coupler includes a first interface connected to the detection light module and a second interface connected to the photoelectric sensor;

[0009] The detection light module, the coupler, the dispersion mirror, the spectroscopic module, and the focusing module are arranged in sequence on the second optical path, so that the detection light emitted by the detection light module can be divided into monochromatic detection lights with different wavelengths after being processed by the dispersion mirror and can be coaxially emitted into the focusing module with the processing light beam after passing through the spectroscopic module;

[0010] The focusing module, the spectroscopic module, the dispersion mirror, the coupler and the photoelectric sensor are arranged in sequence on a third optical path, so that the monochromatic detection light of a specific wavelength reflected by the processing station can be transmitted along the third optical path to the photoelectric sensor, and the photoelectric sensor generates a corresponding electrical signal according to the specific wavelength;

[0011] The adjustment component includes a numerical control unit respectively connected to the photoelectric sensor and the focusing module signal, the numerical control unit is used to receive the electrical signal of the photoelectric sensor to obtain the actual focal position of the focusing module, and compare it with the preset theoretical focal position to obtain the focus drift value, and further the numerical control unit controls the focusing module according to the focus drift value to adjust the actual focal position to the theoretical focal position.

[0012] As a further improvement of the present invention, the detection light is white light;

[0013] and / or,

[0014] The detection light emitted by the detection light module is a fusion of light emitted by multiple light sources.

[0015] As a further improvement of the present invention, the detection light is light of a special wavelength band, or a filter is provided at any position between the detection light module and the spectroscopic module along the second optical path for transmitting light of a special wavelength band in the detection light.

[0016] As a further improvement of the present invention, a magnifier is provided at any position between the detection light module and the light splitting module along the second light path to increase the intensity of each monochromatic detection light so as to increase the maximum distance that can be detected by each monochromatic detection light.

[0017] A second aspect of the present invention further provides a method for detecting and correcting focus drift, wherein the method is implemented based on the self-detection and correction device for focus drift, and the focusing method comprises:

[0018] S1: Controlling the detection component to detect the actual focal position of the focusing module;

[0019] S2: The adjusting component controls the focusing module to adjust the actual focal position to a preset theoretical focal position according to the detection result.

[0020] A third aspect of the present invention further provides a laser processing system, the processing system comprising the above-mentioned self-detection and correction device for focus drift and a laser processing component, the laser processing component comprising a laser, a spectrometer module and a focusing module arranged in sequence along a first optical path, the processing light beam emitted by the laser is transmitted along the first optical path and emitted to the processing station via the focusing module;

[0021] A temperature sensor is provided corresponding to the focusing module for measuring the temperature of the focusing module. The numerical control unit is connected to the temperature sensor signal for recording the focus drift value of the focusing module at various temperatures.

[0022] As a further improvement of the present invention, the laser and the light splitting module are arranged above the focusing module in the vertical direction, and the processing station is arranged below the focusing module.

[0023] A fourth aspect of the present invention further provides a laser processing method, which is implemented using the above-mentioned laser processing system and includes the following process:

[0024] (1) Placing the workpiece to be processed on the processing station, and using S1 to S2 in the above-mentioned focus drift detection and correction method to focus the laser processing assembly on the workpiece to be processed;

[0025] (2) Controlling the laser processing assembly to process the workpiece to be processed, and controlling the temperature sensor to measure the temperature value of the focusing module, and simultaneously performing steps S1 to S2 in the above-mentioned self-detection and correction method for focus drift, until the workpiece to be processed is completely processed.

[0026] As a further improvement of the present invention, the laser processing method further includes the following process:

[0027] (3) The laser processing component stops emitting the processing light beam, and the numerical control unit obtains the corresponding change relationship between the focus drift value and the temperature value of the focusing module during the processing.

[0028] As a further improvement of the present invention, the laser processing method further includes the following process:

[0029] (4) The detection component detects the actual focal position of the focusing module after the processing is completed, and compares it with the theoretical focal position to obtain the focal drift value after the processing is completed;

[0030] (5) Determine whether the focus drift value after the processing is completed exceeds a threshold value. If so, stop the focusing module for inspection.

[0031] The above-mentioned improved technical features can be combined with each other as long as they do not conflict with each other.

[0032] In general, compared with the prior art, the above technical solution conceived by the present invention has the following beneficial effects:

[0033] (1) The focus drift detection and correction device of the present invention includes a detection component and an adjustment component arranged corresponding to the laser processing component. The detection component allows the detection light emitted by the detection light module to be divided into monochromatic detection lights of different wavelengths after being processed by a dispersion mirror through the second optical path, and after passing through the light splitting module, it is coaxially emitted into the focusing module with the processing light beam, and then coaxially emitted to the processing station with the processing light beam. Through the third optical path, the monochromatic detection light of a specific wavelength reflected back from the processing station can be transmitted to the photoelectric sensor and generate a corresponding electrical signal. Finally, the adjustment component obtains the actual focus position and focus drift value of the focusing module according to the electrical signal, and controls the focusing module to adjust the actual focus position to the theoretical focus position. The focus drift detection and correction device can detect the focus drift value of the focusing module and control the focusing module to make precise adjustments, so that the processing light beam reaches the best working state, has strong real-time performance, and is suitable for focus correction in various complex environments.

[0034] (2) The focus drift detection and correction method of the present invention completes the focusing of the focus module of the laser processing component through the above-mentioned focus drift detection and correction device, and can adjust the actual focus position of the focus module to be consistent with the preset theoretical focus position.

[0035] (3) The laser processing system of the present invention includes the above-mentioned focus drift detection and correction device and laser processing components. It is provided with a processing platform and a temperature sensor connected to the signal of the numerical control unit corresponding to the focusing module. It can record the corresponding change relationship between the focus drift value and the temperature value of the focusing module during the processing process, optimize the compensation value when correcting the focus drift of the focusing module in the next processing project, reduce the time of focus detection and correction, and improve the processing efficiency.

[0036] (4) The laser processing method of the present invention is implemented by using the above-mentioned laser processing system. It first focuses the laser processing component on the workpiece to be processed by using the above-mentioned focus drift detection and correction method, and then controls the laser processing component to process the workpiece to be processed. During the processing, the detection component always detects the actual focal position of the focusing module in real time and adjusts the actual focal position to be consistent with the theoretical focal position through the numerical control unit, which greatly improves the real-time and accuracy of the focus adjustment of the focusing module in a complex processing environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without paying creative work.

[0038] Figure 1is a schematic diagram of the overall structure of a laser processing system in an embodiment of the present invention;

[0039] Figure 2 1 is a schematic diagram comparing the thermal lens effect of the collimating mirror of the focusing module in an embodiment of the present invention;

[0040] Figure 3 is a schematic diagram of a coupler optical path channel in an embodiment of the present invention;

[0041] Figure 4 is a schematic diagram of a dispersive mirror decomposing detection light in an embodiment of the present invention;

[0042] Figure 5 is a flow chart of a method for detecting and correcting focus drift in an embodiment of the present invention;

[0043] Figure 6 4 is a flow chart of the laser processing method in an embodiment of the present invention.

[0044] In all the drawings, the same reference numerals represent the same technical features, specifically:

[0045] 1. Detection and correction device; 11. Detection component; 111. Detection light module; 112. Coupler; 1121. Second optical path channel; 1122. Third optical path channel; 113. Dispersion mirror; 114. Photoelectric sensor; 12. Adjustment component; 121. CNC unit; 2. Laser processing component; 201. Laser; 202. Spectral module; 203. Focusing module; 3. Processing station; 4. Detection light; 401. First monochromatic detection light; 402. Second monochromatic detection light; 403. Third monochromatic detection light. DETAILED DESCRIPTION

[0046] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0047] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0048] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0049] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0050] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0051] Example:

[0052] See also Figure 1The focus drift detection and correction device 1 in the preferred embodiment of the present invention is arranged corresponding to the laser processing component 2. The laser processing component 2 for laser processing includes a laser 201, a light splitting module 202, and a focusing module 203 arranged in sequence along a first optical path. The processing light beam emitted by the laser 201 is transmitted along the first optical path and is emitted to the processing station 3 after passing through the focusing module 203. Among them, the detection and correction device 1 includes a detection component 11 and an adjustment component 12.

[0053] Specifically, the detection component 11 includes a detection light module 111, a coupler 112 and a dispersion mirror 113 which are arranged in sequence, and a photoelectric sensor 114 which is arranged corresponding to the coupler 112; the coupler 112 includes a first interface connected to the detection light module 111 and a second interface connected to the photoelectric sensor 114; the detection light module 111, the coupler 112, the dispersion mirror 113, the spectroscopic module 202, and the focusing module 203 are arranged in sequence on the second optical path, so that the detection light emitted by the detection light module 111 can be divided into monochromatic detection lights with different wavelengths after being processed by the dispersion mirror 113 and can be coaxially emitted into the focusing module 203 with the processing light beam after passing through the spectroscopic module 202; the focusing module 203, the spectroscopic module 202, the dispersion mirror 113, the spectroscopic module 202, and the focusing module 203 can be arranged in sequence on the second optical path. The diffuser 113, the coupler 112 and the photoelectric sensor 114 are arranged in sequence on the third optical path, so that the monochromatic detection light of a specific wavelength reflected by the processing station 3 can be transmitted along the third optical path to the photoelectric sensor 114, and the photoelectric sensor 114 generates a corresponding electrical signal according to the specific wavelength; the adjustment component 12 includes a numerical control unit 121 respectively connected to the photoelectric sensor 114 and the spectrometer module 202, the numerical control unit 121 is used to receive the electrical signal of the numerical control unit 121 to obtain the actual focal position of the focusing module 203, and compare it with the preset theoretical focal position to obtain the focus drift value, and further the numerical control unit 121 controls the focusing module 203 according to the focus drift value to adjust the actual focal position to the theoretical focal position.

[0054] Please refer to Figure 2 The focusing module 203 generates thermal lens surface distortion (thermal lens effect), refractive index gradient distribution effect and thermal deformation of the optical-mechanical assembly structure in the internal collimator, and the flowing air medium in the optical path of the device absorbs high-energy laser and is heated. The generated turbulence and thermal blooming effect cause the broadening and intensity fluctuation of the laser beam, resulting in the focus drift of the output focused beam and the degradation of the beam quality. Figure 2 As shown, the same beam of light enters the focusing module 203. After the focus of the focusing module 203 drifts, the focus of the light after passing through the focusing module 203 changes from F1 to F2. If the processing light beam and the detection light pass through the focusing module 203 at the same time, the focus positions of both will drift. The present device adjusts the focus after drift to the preset theoretical focus position.

[0055] In a preferred embodiment, the theoretical focal position preset by the focusing module 203 can be at the processing station 3, or can be at the processing part of the workpiece to be processed located on the processing station 3. The theoretical focal position has a corresponding theoretical monochromatic detection light of a specific wavelength. The numerical control unit 121 can calculate the actual focal position of the focusing module 203 based on the single detection light of a specific wavelength reflected back from the processing station 3, and then compare it with the theoretical focal position to obtain the focus drift value of the focusing module 203.

[0056] Specifically, the detection light emitted by the detection light module 111 is dispersed into monochromatic detection lights with different wavelengths along the second optical path by the dispersion mirror 113. After passing through the spectroscopic module 202, each monochromatic detection light is coaxially emitted to the focusing module 203 and the processing light beam of the first optical path, and then emitted to the processing station 3. Since the monochromatic detection lights of different wavelengths have different focal lengths, the positions where the corresponding focal points are formed are different, such as Figure 3 As shown, only the monochromatic detection light of the characteristic wavelength whose focus is exactly on the processing station 3 can be reflected back along the reverse direction of the original second optical path, and transmitted to the photoelectric sensor 114 through the third optical path. The photoelectric sensor 114 converts the acquired light signal (the wavelength of the reflected monochromatic detection light) into an electrical signal and inputs it into the numerical control unit 121. The numerical control unit 121 can obtain the actual focal position of the focusing module 203 by analyzing and processing the reflected monochromatic detection light of the specific wavelength, and then compare it with the theoretical focal position set by the focusing module 203 to obtain the focus drift value of the focusing module 203. The numerical control unit 121 controls the focusing module 203 to adjust the focal length according to the focus drift value, and adjusts the actual focal position to the theoretical focal position. At this time, the monochromatic detection light of the specific wavelength reflected back from the processing station 3 is the theoretical monochromatic detection light of the specific wavelength corresponding to the theoretical focal position.

[0057] Preferably, if Figure 4 As shown, the coupler 112 is provided with two optical path channels, namely, the second optical path channel 1121 and the third optical path channel 1122. Among them, the two ends of the second optical path channel 1121 are coaxially connected to the detection light module 111 and the dispersion mirror 113 through optical fibers, respectively, to provide a channel for the detection light emitted by the detection light module 111 to be emitted to the dispersion mirror 113 along the second optical path, for transmitting the detection light, and ensuring the stability of the output of the detection light module 111; the two ends of the third optical path channel 1122 are connected to the dispersion mirror 113 and the photoelectric sensor 114 through optical fibers, respectively, to provide a channel for the monochromatic detection light of a characteristic wavelength reflected from the processing station 3 to enter the photoelectric sensor 114 along the third optical path, and to change the transmission direction of the monochromatic detection light of a specific wavelength reflected back, so that the monochromatic detection light of a specific wavelength reflected back from the processing station 3 can be stably and reliably transmitted to the photoelectric sensor 114.

[0058] Preferably, the dispersion mirror 113 disperses the detection light emitted by the detection light module 111 into a plurality of monochromatic detection lights with different wavelengths, which may be 3, 5, 7 or other monochromatic detection lights with different wavelengths without limitation.

[0059] For example, Figure 3 As shown, the detection light 4 is decomposed into three monochromatic detection lights with different wavelengths after passing through the dispersion mirror 113, namely, the first monochromatic detection light 401, the second monochromatic detection light 402, and the third monochromatic detection light 403, wherein the focus of the second monochromatic detection light 402 is just located on the processing station 3. Therefore, in this embodiment, the second monochromatic detection light 402 is a monochromatic detection light of a specific wavelength, which can be reflected back along the reverse direction of the second optical path and transmitted to the photoelectric sensor 114 along the third optical path, and the photoelectric sensor 114 obtains its wavelength, while the first monochromatic detection light 401 and the third monochromatic detection light 403 cannot be reflected back along the reverse direction of the second optical path.

[0060] Preferably, the detection light 4 is white light, which is a mixture of multiple colored lights and can be dispersed into monochromatic detection lights of various wavelengths, corresponding to multiple detection distances, and is suitable for detection and correction of focusing in complex processing situations.

[0061] Preferably, the detection light 4 emitted by the detection light module 111 is a fusion of lights emitted by multiple light sources, which can increase the light intensity of the detection light 4 .

[0062] Preferably, the detection light 4 is light of a special band, or a filter is provided at any position between the detection light module 111 and the focusing module 203 along the second optical path, which is used to transmit light of a special band in the detection light, corresponding to a special detection distance, and is suitable for detection and correction of focusing in simple processing conditions.

[0063] Preferably, a magnifier is provided at any position between the detection light module 111 and the focusing module 203 along the second optical path, for increasing the light intensity of each monochromatic detection light, so as to increase the maximum detectable distance of each monochromatic detection light, which is suitable for detection and correction of focusing when the focusing module 203 is far away from the processing station 3.

[0064] like Figure 5 As shown, the present invention also provides a method for detecting and correcting focus drift, which is implemented based on the above-mentioned device for detecting and correcting focus drift, and includes the following steps:

[0065] S1: Control the detection component 11 to detect the actual focus position of the focusing module 203;

[0066] Specifically, the detection light module 111 emits detection light through the second optical path to the processing station 3 or the workpiece to be processed at the processing station 3, and the processing station 3 or the workpiece to be processed reflects the monochromatic detection light of a specific wavelength to the photoelectric sensor 114, and the photoelectric sensor 114 generates a corresponding electrical signal.

[0067] S2: The adjustment component 12 controls the focus adjustment module 203 to adjust its actual focus position to a preset theoretical focus position according to the detection result.

[0068] Specifically, the numerical control unit 121 obtains the actual focal position of the focusing module 203 according to the received electrical signal, compares it with the preset theoretical focal position to obtain the focus drift value of the focusing module 203, and then controls the focusing module 203 to adjust the actual focal position to be consistent with the theoretical focal position.

[0069] like Figure 1 As shown, the present invention also provides a laser processing system, which includes the above-mentioned laser processing detection and correction device 1 and a laser processing component 2, the laser processing component 2 includes a laser 201, a spectrometer module 202, and a focusing module 203 arranged in sequence along a first optical path, and the processing light beam emitted by the laser 201 is transmitted along the first optical path and emitted to the processing station 3 via the focusing module 203.

[0070] Preferably, a temperature sensor is provided corresponding to the focusing module 203 for measuring the temperature of the focusing module 203 , and the numerical control unit 121 is connected to the temperature sensor signal for recording the focus drift value of the focusing module 203 at various temperatures.

[0071] The laser processing system in this embodiment improves the real-time performance of focus correction during the processing. The detection and correction speed of the laser processing system can reach thousands of measurements per second or even tens of thousands of measurements per second. Especially in the application scenario of continuous measurement, it has obvious advantages over the traditional method of measuring temperature with temperature sensors and judging the focus drift amount by temperature, and greatly improves the real-time performance of focus correction during the processing.

[0072] In actual setting, the laser 201 and the light splitting module 202 are preferably arranged above the focusing module 203 in the vertical direction, and the processing station 3 is preferably arranged below the focusing module 203. Figure 1 This is a layout diagram of the laser processing system in a vertical plane.

[0073] like Figure 6 As shown, the present invention also provides a laser processing method, which is implemented by using the above laser processing system, and includes the following process:

[0074] (1) Placing the workpiece to be processed on the processing station 3, and using S1-S2 in the above-mentioned self-detection and correction method of focus drift to perform focusing of the focusing module 203 on the workpiece to be processed;

[0075] (2) Controlling the laser processing assembly 2 to process the workpiece to be processed, and controlling the temperature sensor to measure the temperature value of the focusing module 203, and simultaneously performing steps S1 to S2 in the self-detection and correction method of focus drift until the workpiece to be processed is completed.

[0076] Further preferably, the laser processing method further comprises the following process:

[0077] (3) The laser processing assembly 2 stops emitting the processing light beam, and the numerical control unit 121 obtains the corresponding change relationship between the focus drift value and the temperature value of the focusing module 203 during the processing.

[0078] By recording the focus drift value of the focusing module 203 at each temperature, the corresponding change relationship between the focus drift value and the temperature value of the focusing module 203 during the processing is obtained. When correcting the focus drift of the focusing module 203 in the next processing project, the compensation value can be optimized, thereby reducing the time for focus detection and correction and improving processing efficiency.

[0079] Further preferably, the laser processing method further comprises the following process:

[0080] (4) The detection component 11 detects the actual focal position of the focusing module 203 after the processing is completed, and compares it with the theoretical focal position to obtain the focal drift value of the focusing module after the processing is completed;

[0081] (5) Determine whether the focus drift value of the focusing module 203 after the processing is completed exceeds a threshold value. If so, shut down the focusing module 203 for inspection.

[0082] In this embodiment, by detecting the focus of the focusing module 203 after the processing process is completed, it is determined whether the focusing module 203 produces a large focus drift. If the focus drift value is too large and exceeds the threshold, it is necessary to check the focusing module 203 more carefully. If the focus drift value is within the normal range, the inspection time can be reduced and the processing efficiency can be improved.

[0083] The focus drift detection and correction device of the present invention detects the specific wavelength monochromatic detection light reflected by the processing station 3 through the detection component 11, and the numerical control unit 121 analyzes the specific wavelength monochromatic detection light to quickly and accurately obtain the actual focus position and focus drift value of the focusing module 203. The wavelength of each monochromatic detection light corresponds to a fixed distance value, and the accuracy of the distance value can reach 10 nanometers, thereby controlling the focusing module 203 to more accurately adjust the actual focus position to the theoretical focus position, so that the processing light beam reaches the best working state. In addition, the detection and correction speed of the device can reach thousands of measurements per second or even tens of thousands of measurements per second, especially in the application scenario of continuous measurement, compared with the traditional method of measuring temperature with a temperature sensor and judging the focus drift amount by temperature, it has obvious advantages, which greatly improves the real-time performance of focus correction during the processing process. In addition, the device can be used for focus correction in a variety of complex working environments, whether it is the thermally induced lens surface distortion (thermal lens effect), the refractive index gradient distribution effect and the thermal deformation of the optical-mechanical assembly structure of the optical path system in the equipment that lead to the focus drift and beam quality degradation of the output focused light beam, or the turbulence and thermal blooming effect caused by the flowing air medium in the equipment absorbing high-energy lasers and being heated, which causes the broadening and intensity fluctuations of the laser beam and the drift of the focus, the focus can be detected and corrected.

[0084] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A laser processing method, characterized in that: It is realized by using a laser processing system, which includes a focus drift detection and correction device and a laser processing component; The laser processing assembly comprises a laser, a beam splitting module and a focusing module which are sequentially arranged along a first optical path, and a processing light beam emitted by the laser is transmitted along the first optical path and emitted to a processing station via the focusing module; The focus drift detection and correction device comprises a detection component and an adjustment component; The detection assembly includes a detection light module, a coupler and a dispersion mirror arranged in sequence, and a photoelectric sensor arranged corresponding to the coupler; the coupler includes a first interface connected to the detection light module and a second interface connected to the photoelectric sensor; The detection light module, the coupler, the dispersion mirror, the spectroscopic module, and the focusing module are arranged in sequence on the second optical path, so that the detection light emitted by the detection light module can be divided into monochromatic detection lights with different wavelengths after being processed by the dispersion mirror and can be coaxially emitted into the focusing module with the processing light beam after passing through the spectroscopic module; The focusing module, the spectroscopic module, the dispersion mirror, the coupler and the photoelectric sensor are arranged in sequence on a third optical path, so that the monochromatic detection light of a specific wavelength reflected by the processing station can be transmitted along the third optical path to the photoelectric sensor, and the photoelectric sensor generates a corresponding electrical signal according to the specific wavelength; The adjustment component includes a numerical control unit connected to the photoelectric sensor and the focusing module signal respectively, the numerical control unit is used to receive the electrical signal of the photoelectric sensor to obtain the actual focal position of the focusing module, and compare it with the preset theoretical focal position to obtain a focal drift value, and further the numerical control unit controls the focusing module to adjust the actual focal position to the theoretical focal position according to the focal drift value, so that the monochromatic detection light of the specific wavelength reflected back by the processing station is adjusted to the theoretical monochromatic detection light of the specific wavelength corresponding to the theoretical focal position; A temperature sensor is provided corresponding to the focusing module, and is used to measure the temperature of the focusing module. The numerical control unit is connected to the temperature sensor signal, and is used to record the focus drift value of the focusing module at various temperatures; The laser processing method comprises the following steps: (1) Placing a workpiece to be processed on the processing station, and using a focus drift detection and correction method to focus the focusing module on the workpiece to be processed, wherein the focus drift detection and correction method comprises: S1: Controlling the detection component to detect the actual focal position of the focusing module; S2: the adjusting component controls the focusing module to adjust the actual focal position to a preset theoretical focal position according to the detection result; (2) controlling the laser processing assembly to process the workpiece to be processed, and controlling the temperature sensor to measure the temperature value of the focusing module, and simultaneously performing steps S1 to S2 of the self-detection and correction method for focus drift described in step (1), until the workpiece to be processed is completely processed; (3) The laser processing component stops emitting the processing light beam, and the numerical control unit obtains the corresponding change relationship between the focus drift value and the temperature value of the focusing module during the processing, and optimizes the compensation value when correcting the focus drift of the focusing module during the next processing.

2. The laser processing method according to claim 1, characterized in that: The detection light emitted by the detection light module is white light; and / or, The detection light emitted by the detection light module is a fusion of light emitted by multiple light sources.

3. The laser processing method according to claim 1, characterized in that: The detection light is light of a special wavelength band, or a filter is provided at any position between the detection light module and the light splitting module along the second optical path for transmitting light of a special wavelength band in the detection light.

4. The laser processing method according to claim 1, characterized in that: A magnifier is provided at any position between the detection light module and the light splitting module along the second light path, for increasing the light intensity of each monochromatic detection light, so as to increase the maximum distance that can be detected by each monochromatic detection light.

5. The laser processing method according to claim 1, characterized in that: In the vertical direction, the laser and the light splitting module are arranged above the focusing module, and the processing station is arranged below the focusing module.

6. The laser processing method according to claim 1, characterized in that: It also includes the following processes: (4) The detection component detects the actual focal position of the focusing module after the processing is completed, and compares it with the theoretical focal position to obtain the focal drift value of the focusing module after the processing is completed; (5) Determine whether the focus drift value of the focusing module after the processing is completed exceeds a threshold value. If so, stop the focusing module for inspection.

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