Device and method for detecting curved surface laser processing optical path

Abstract

The present invention discloses a device and method for detecting the optical path of curved surface laser processing, which can realize that the optical path always enters the three-dimensional galvanometer unit during the movement of the three-dimensional motion platform; and combines with a laser displacement sensor to realize the laser focus recognition function during the curved surface processing process, and timely adjust the Z-axis moving mechanism; in addition, the present invention adopts laser induced breakdown spectroscopy technology to analyze the change of spectral information in real time, detect the surface quality of the processed component, and feed back the signal to the piezoelectric deflection module to compensate for the disturbance of the system movement on the light beam, thereby improving the efficiency and quality of curved surface processing.

Description

Technical Field

[0001] The present invention relates to the field of laser processing technology, and more specifically to a device and method for detecting a curved surface laser processing optical path. Background Art

[0002] Complex curved surfaces are a difficult part of laser processing. During the processing, due to the height changes of the curved surface, the laser head spot needs to be adjusted in real time according to the changes in the curved surface to ensure the processing quality.

[0003] At present, there are many studies on multi-axis processing of complex surface laser processing systems, but there is a lack of real-time detection and analysis of the processing surface quality and laser processing focus, and it is difficult to quickly determine whether the surface quality characteristics meet the process requirements during processing. For example, patent CN106563880B discloses a multi-light source, multi-function, multi-axis laser processing head and equipment. Although the above scheme has flexible processing methods, it lacks feedback functions for processing components and processing lasers. When the curvature of the processed surface is large, due to the lack of real-time monitoring of the processing process, the processing dimensional accuracy and quality are easily affected, so it needs to be improved. Summary of the invention

[0004] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a device and method for detecting the optical path of curved surface laser processing. By adopting a special design of multiple mobile platforms and multiple optical paths, the incidence of the optical path on the galvanometer is guaranteed, and laser induced breakdown spectroscopy technology and displacement sensors are used to perform real-time monitoring of the surface of the component during the processing process, thereby generating a feedback control signal to improve the efficiency of curved surface laser processing.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A device for detecting a curved surface laser processing optical path, comprising:

[0007] A first mobile platform, the first mobile platform is used to receive the component and drive the component to move along the Y axis;

[0008] A second mobile platform, on which a galvanometer processing head module is installed, and the second mobile platform is used to drive the galvanometer processing module to move in the Z axis;

[0009] A third mobile platform, the third mobile platform is connected to the second mobile platform and is used to drive the second mobile platform to move in the X-axis;

[0010] A laser beam shaping transmission module, the laser beam shaping transmission module comprising a laser and a piezoelectric deflection mirror, the laser being used to emit a picosecond pulse laser, the piezoelectric deflection mirror being arranged above a corresponding galvanometer processing head module and being fixed to a third movable platform, a first optical path being formed between the laser and the piezoelectric deflection mirror, the first optical path being parallel to a moving direction of the third movable platform, a second optical path being formed between the piezoelectric deflection mirror and the galvanometer processing head module, the second optical path being parallel to a moving direction of the second movable platform;

[0011] The galvanometer processing head module is provided with a laser displacement sensor, and the laser displacement sensor is used to detect the component processing surface.

[0012] As a further improvement of the present invention, a spectral analysis module is also included, which includes a spectrometer, a fiber coupler and a dichroic mirror. The spectrometer is connected to the fiber coupler via an optical fiber, and the dichroic mirror is arranged corresponding to the second optical path. The dichroic mirror is used to receive the radiation light generated by the component processing and reflect it to the fiber coupler.

[0013] As a further improvement of the present invention, a calculation module is also included, and the calculation module is used to receive and process the spectral information extracted by the spectrometer. The laser beam shaping transmission module also includes a piezoelectric controller. The calculation module is connected to the piezoelectric deflection mirror through the piezoelectric controller. The calculation module deflects and adjusts the table surface in the X and Y directions of the piezoelectric deflection mirror through the piezoelectric controller according to the spectral information.

[0014] As a further improvement of the present invention, the laser output end is provided with a beam expander, a diffractive optical element and a reflector group in sequence, and the laser passes through the beam expander, the diffractive optical element and the reflector group in sequence to the piezoelectric deflection mirror.

[0015] As a further improvement of the present invention, the galvanometer processing head module includes a galvanometer scanning head, a dynamic focusing unit is provided at an input end of the galvanometer scanning head, and a field lens is provided at an output end of the galvanometer.

[0016] As a further improvement of the present invention, the second movable platform is provided with an end reflector corresponding to the end of the second light path, and the end reflector is used to reflect the second light path to the dynamic focusing unit.

[0017] A method for detecting a curved surface laser processing optical path using the above-mentioned device comprises the following steps:

[0018] S1. Divide the component surface into regions and perform path planning according to the respective regions;

[0019] S2, turn on the laser, the light beam is reflected to the piezoelectric deflection mirror through the beam expander, the diffractive optical element and the reflector group, and then reflected to the galvanometer processing head module through the piezoelectric deflection mirror, and the surface of the component is laser processed through the galvanometer processing head module;

[0020] S3, the radiation light generated by the component during the processing is reflected by the galvanometer processing head module to the dichroic mirror, and then reflected by the dichroic mirror to the optical fiber coupler, and the optical signal is transmitted to the spectrometer through the optical fiber coupler;

[0021] S4, the spectrometer extracts the light signal to obtain spectral information, and transmits the information to the calculation module, the calculation module sends a signal to the piezoelectric controller according to the spectral information, and controls the piezoelectric deflection mirror through the piezoelectric controller to deflect and adjust the table in the X and Y directions to complete the deflection compensation control;

[0022] S5, the laser displacement sensor detects the component processing surface, and repeats steps S2-S4 if the processing quality standard is not met;

[0023] S6. Process the next area after the processing quality standard is met to complete the processing of all processing areas.

[0024] Step S1 includes the following steps for dividing the component surface area:

[0025] S11, obtaining geometric information of the curved surface element model, the geometric information including the spatial position of the point, the normal vector and the curvature radius of the curved surface;

[0026] S12, specifying the angle between the laser beam direction and the normal vector direction of the surface position as the laser incident angle, and dividing the surface into multiple blocks after analyzing and calculating the discrete point information based on the division algorithm and the scanning range of the galvanometer;

[0027] S13, based on the focus floating range of the galvanometer processing laser, each processing area is layered.

[0028] Beneficial effects of the present invention:

[0029] 1. Use the first mobile platform, the second mobile platform and the third mobile platform, and cooperate with the first optical path and the second optical path to achieve the requirement that the laser always enters the galvanometer processing head module during the processing;

[0030] 2. Use laser displacement sensors to detect processing quality in real time, so as to track the laser processing focus and adjust the Z axis in time, which is beneficial to the processing of complex curved surfaces with large curvature;

[0031] 3. The spectrometer is used to analyze the evolution of the spectral intensity, line shift, stability, etc. of the component processing surface, obtain the changes in the processing surface morphology, and realize the timely adjustment of the laser parameters in the system. By real-time control of the piezoelectric deflection mirror, the disturbance of the beam movement is compensated, the stability of the system and laser is improved, and the precision processing of complex curved surface components is realized. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic diagram of the overall optical path of the present invention;

[0033] Figure 2 This is a schematic diagram of the overall installation of the present invention;

[0034] Figure 3 The figure is a flow chart of the optical path processing method of the present invention.

[0035] Figure numerals: 1. laser; 2. beam expander; 3. diffractive optical element; 4. first reflector; 5. second reflector; 6. third reflector; 7. piezoelectric deflection mirror; 8. third moving platform; 9. third moving mechanism; 10. second moving platform; 11. second moving mechanism; 12. dichroic mirror; 13. end reflector; 14. dynamic focusing unit; 15. galvanometer scanning head; 16. field lens; 17. first moving platform; 18. first moving mechanism; 19. element; 20. fiber coupler; 21. optical fiber; 22. spectrometer; 23. piezoelectric controller; 24. computing module; 25. laser displacement sensor. DETAILED DESCRIPTION

[0036] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments, wherein the same components are represented by the same reference numerals.

[0037] like Figure 1-2 As shown, a curved surface laser processing optical path detection device includes a first movable platform 17, and the first movable platform 17 is used to receive a component 19. During the processing, the component 19 is placed on the first movable platform 17, and the first movable platform 17 drives the component 19 to move in the Y axis.

[0038] Specifically, a first moving platform 17 is provided with a first moving mechanism 18, which is any linear moving device in the prior art, and is specifically a guide rail slider in this embodiment. In other embodiments, a motor chain or gear drive method may also be adopted.

[0039] Preferably, the device includes a frame and a second mobile platform 10, a second mobile mechanism 11 on the second mobile platform 10, the second mobile mechanism 11 is connected to the second mobile platform 10 and drives the second mobile platform 10 to move in the Z axis, a galvanometer processing head module is installed on the second mobile platform 10, and the second mobile mechanism 11 drives the galvanometer processing head module to move in the Z axis through the second mobile platform 10.

[0040] Furthermore, a third moving mechanism 9 is provided on the frame and is connected to a third moving platform 8 through the third moving mechanism 9. The third moving mechanism 9 is used to drive the third moving platform 8 to move along the X-axis. The second moving platform 10 is located at the lower end of the third moving platform 8, and the second moving mechanism 11 is connected to the third moving platform 8.

[0041] During use, the third moving mechanism 9 simultaneously drives the third moving platform 8, the second moving mechanism 11 and the second moving platform 10 to move in the X-axis, and the second moving mechanism 11 further drives the second moving platform 10 to move in the Z-axis.

[0042] Specifically, in this embodiment, the second moving mechanism 11 is a cylinder, the cylinder is fixedly connected to the third moving platform 8, and the cylinder output end is fixed to the second moving platform 10. The third moving mechanism 9 can be selected as a linear drive mechanism such as a motor or a guide rail slider, and no specific restrictions are made here.

[0043] It also includes a laser beam shaping transmission module, which includes a laser 1 and a piezoelectric deflection mirror 7. The laser 1 is used to emit picosecond pulse laser. The piezoelectric deflection mirror 7 is arranged above the galvanometer processing head module and fixed to the third moving platform 8. A first optical path is formed between the laser 1 and the piezoelectric deflection mirror 7. The first optical path is parallel to the moving direction of the third moving platform 8, so that when the third moving platform 8 drives the second moving platform to move along the X-axis, the light beam can always be injected.

[0044] Furthermore, a second optical path is formed between the piezoelectric deflection mirror 7 and the galvanometer processing head module, and the second optical path is parallel to the moving direction of the second movable platform 10, so that when the second movable platform 10 moves in the Z axis, the light beam can always be kept incident on the galvanometer processing head module.

[0045] Preferably, a laser displacement sensor 25 is provided on the galvanometer processing head module, and the laser displacement sensor 25 is used to detect the processing surface of the component 19, so as to perform Z-axis adjustment in time.

[0046] It also includes a spectral analysis module, which includes a spectrometer 22, a fiber coupler 20 and a dichroic mirror 12. The spectrometer 22 is connected to the fiber coupler 20 via an optical fiber 21. The dichroic mirror 12 corresponds to the second optical path setting. The dichroic mirror 12 is used to receive the radiation light generated by the processing element 19 and reflect it to the fiber coupler 20.

[0047] Since the element 19 generates a certain amount of plasma during the processing, it will emit radiation light of a specific wavelength, so the radiation light can be naturally reflected along the laser processing optical path, and then screened and reflected to the fiber coupler 20 by the dichroic mirror 12. The input end of the fiber coupler 20 contains a lens, which can focus the light beam into a light spot with a smaller diameter, so that the light spot is hit on the end face of the optical fiber 21, ensuring that the subsequent light beam is transmitted in the optical fiber 21. Then the light beam is transmitted into the spectrometer 22, and the spectrum information is extracted by the spectrometer 22.

[0048] It also includes a calculation module 24, which is specifically a computer. The calculation module 24 is used to receive and process the spectral information extracted by the spectrometer 22. The laser beam shaping transmission module also includes a piezoelectric controller 23. The calculation module 24 is connected to the piezoelectric deflection mirror 7 through the piezoelectric controller 23. The calculation module 24 deflects and adjusts the table surface in the X and Y directions of the piezoelectric deflection mirror through the piezoelectric controller 23 according to the spectral information.

[0049] After extracting the spectral information, the spectrometer 22 transmits the information to the computer for processing. After screening the effective spectral information, the characteristic changes such as spectral line intensity and spectral line shift are analyzed, and then the changes in the surface quality characteristics of the workpiece are analyzed.

[0050] In addition, in order to prevent the laser beam from being disturbed after passing through multiple optical elements 19 and the influence of jitter caused by the movement of the system moving mechanism on the processing effect, during the operation of the galvanometer processing head, the calculation module 24 can apply a feedback signal to the piezoelectric controller 23 according to the detection quality, and then send an adjustment signal to the piezoelectric deflection mirror 7. The piezoelectric deflection mirror 7 can realize the table deflection in the X and Y directions of its surface, thereby realizing the adjustment of the angle of the reflected light beam and compensating for the deviation of the light beam caused by the system transmission process, so as to achieve ultra-high precision processing requirements. The deflection resolution can be lower than 0.01μrad.

[0051] Preferably, a beam expander 2, a diffractive optical element 3 and a reflector group are sequentially provided at the output end of the laser 1, and the laser passes through the beam expander 2, the diffractive optical element 3 and the reflector group to the piezoelectric deflection mirror 7 in sequence. In this embodiment, the reflector group includes a first reflector 4, a second reflector 5 and a third reflector 6, and the light beam passes through the first reflector 4, the second reflector 5 and the third reflector 6 in sequence to the piezoelectric deflection mirror 7, wherein the first optical path is the light beam between the third reflector 6 and the piezoelectric deflection mirror 7, and passes through the first reflector 4, the second reflector 5 and the third reflector 6. The three reflectors 6 can adjust the light beam emitted by the laser 1 to correspond to the position of the piezoelectric rotating mirror, and the direction of the light beam is the X-axis moving direction. At the same time, the beam expander 2 is a variable-power beam expander 2. The Gaussian light beam emitted by the laser 1 is shaped into a flat-top beam with uniform energy distribution through the beam expander 2 and the diffractive optical element 3. Specifically, the laser 1 emits picosecond pulse laser, and the magnification of the variable-power beam expander 2 is changed according to the spot diameter to optimize the Gaussian light beam diameter and divergence angle. After the light beam passes through the diffractive optical element 3, a flat-top beam with uniform spot energy distribution is formed.

[0052] Preferably, the galvanometer processing head module includes a galvanometer scanning head 15, and a dynamic focusing unit 14 is provided at the input end of the galvanometer scanning head 15. The dynamic focusing unit 14 is specifically a dynamic focusing mirror in the prior art, which will not be described in detail here. A field lens 16 is provided at the output end of the galvanometer.

[0053] Preferably, the second movable platform 10 is provided with an end reflector 13 corresponding to the end of the second optical path, and the end reflector 13 is used to reflect the second optical path to the dynamic focusing unit 14. The installation of the galvanometer scanning head 15 is adapted by the setting of the end reflector 13 to ensure that the light beam enters the dynamic focusing unit 14.

[0054] like Figure 3 As shown, a method for detecting the optical path of curved surface laser processing using the above-mentioned device comprises the following steps:

[0055] S1. Divide the surface of the component 19 into regions and perform path planning according to the respective regions.

[0056] S2, turn on the laser 1, the light beam is reflected by the beam expander 2, the diffractive optical element 3 and the reflector group to the piezoelectric deflection mirror 7, and then reflected by the piezoelectric deflection mirror 7 to the galvanometer processing head module, and the surface of the element 19 is laser processed by the galvanometer processing head module.

[0057] S3. The radiation light generated by the element 19 during the processing is reflected by the galvanometer processing head module to the dichroic mirror 12, and is reflected by the dichroic mirror 12 to the optical fiber 21 coupler 20, and the optical signal is transmitted to the spectrometer 22 through the optical fiber 21 coupler 20.

[0058] S4, the spectrometer 22 extracts the optical signal to obtain spectral information, and transmits the information to the calculation module 24. The calculation module 24 sends a signal to the piezoelectric controller 23 according to the spectral information, and controls the piezoelectric deflection mirror X, Y direction table to deflect and adjust to complete the deflection compensation control.

[0059] S5. The laser displacement sensor 25 detects the processing surface of the component 19. If the processing quality standard is not met, steps S2-S4 are repeated.

[0060] S6. Process the next area after the processing quality standard is met to complete the processing of all processing areas.

[0061] The step S1 includes the following steps for dividing the curved area of ​​the component 19:

[0062] S11. Obtaining geometric information of the curved surface element model, where the geometric information includes the spatial position of the point, the normal vector and the curvature radius of the surface.

[0063] S12. The angle between the laser beam direction and the normal vector direction of the surface position is defined as the laser incident angle. After analyzing and calculating the discrete point information based on the division algorithm and the galvanometer scanning range, the surface is divided into multiple blocks.

[0064] S13. Based on the focus floating range of the galvanometer processing laser, each processing area is layered to ensure layer-by-layer processing of components with complex surface heights.

[0065] The above is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

Claims

1. A device for detecting a curved surface laser processing optical path, characterized in that: include: A first movable platform (17), the first movable platform (17) is used to receive the component (19) and drive the component (19) to move along the Y axis; A second mobile platform (10), on which a galvanometer processing head module is installed, and the second mobile platform (10) is used to drive the galvanometer processing module to move in the Z axis; A third mobile platform (8), the third mobile platform (8) being connected to the second mobile platform (10) and used to drive the second mobile platform (10) to move along the X axis; A laser beam shaping transmission module, the laser beam shaping transmission module comprising a laser (1) and a piezoelectric deflection mirror (7), the laser (1) being used to emit picosecond pulse laser, the piezoelectric deflection mirror (7) being arranged above a corresponding galvanometer processing head module and being fixed to a third movable platform (8), a first optical path being formed between the laser (1) and the piezoelectric deflection mirror (7), the first optical path being parallel to a moving direction of the third movable platform (8), a second optical path being formed between the piezoelectric deflection mirror (7) and the galvanometer processing head module, the second optical path being parallel to a moving direction of a second movable platform (10); The galvanometer processing head module is provided with a laser displacement sensor (25), and the laser displacement sensor (25) is used to detect the processing surface of the element (19); The invention also comprises a spectrum analysis module, the spectrum analysis module comprising a spectrometer (22), a fiber coupler (20) and a dichroic mirror (12), the spectrometer (22) being connected to the fiber coupler (20) via an optical fiber (21), the dichroic mirror (12) being arranged corresponding to the second optical path, and the dichroic mirror (12) being used to receive radiation light generated by processing of the element (19) and reflect it to the fiber coupler (20); The invention also comprises a calculation module (24), wherein the calculation module (24) is used for receiving and processing spectral information extracted by the spectrometer (22); the laser beam shaping transmission module also comprises a piezoelectric controller (23); the calculation module (24) is connected to the piezoelectric deflection mirror (7) via the piezoelectric controller (23); and the calculation module (24) deflects and adjusts the table surface of the piezoelectric deflection mirror (7) in the X and Y directions via the piezoelectric controller (23) according to the spectral information.

2. The device for detecting curved surface laser processing optical path according to claim 1, characterized in that: The output end of the laser (1) is provided with a beam expander (2), a diffractive optical element (3) and a reflector group in sequence, and the laser light passes through the beam expander (2), the diffractive optical element (3) and the reflector group in sequence to the piezoelectric deflection mirror (7).

3. The device for detecting curved surface laser processing optical path according to claim 2, characterized in that: The galvanometer processing head module comprises a galvanometer scanning head (15), an input end of the galvanometer scanning head (15) is provided with a dynamic focusing unit (14), and an output end of the galvanometer is provided with a field lens (16).

4. The device for detecting curved surface laser processing optical path according to claim 3, characterized in that: The second movable platform (10) is provided with an end reflector (13) corresponding to the end of the second light path, and the end reflector (13) is used to reflect the second light path to the dynamic focusing unit (14).

5. A method for detecting the optical path of curved surface laser processing using the device described in claim 4, characterized in that: The following steps are involved: S1, dividing the surface of the component (19) into regions and performing path planning according to the respective regions; S2, turning on the laser (1), the light beam is reflected to the piezoelectric deflection mirror (7) through the beam expander (2), the diffractive optical element (3) and the reflector group, and is then reflected to the galvanometer processing head module through the piezoelectric deflection mirror (7), and the surface of the element (19) is laser processed through the galvanometer processing head module; S3, the radiation light generated by the element (19) during the processing is reflected by the galvanometer processing head module to the dichroic mirror (12), and is reflected by the dichroic mirror (12) to the optical fiber coupler (20), and the optical signal is transmitted to the spectrometer (22) through the optical fiber coupler (20); S4, the spectrometer (22) extracts the optical signal to obtain spectral information, and transmits the information to the calculation module (24), the calculation module (24) sends a signal to the piezoelectric controller (23) according to the spectral information, and controls the piezoelectric deflection mirror (7) to adjust the deflection in the X and Y directions through the piezoelectric controller (23) to complete the deflection compensation control; S5, the laser displacement sensor (25) detects the processing surface of the element (19), and repeats steps S2-S4 when the processing quality standard is not met; S6. Process the next area after the processing quality standard is met to complete the processing of all processing areas.

6. The method for detecting the optical path of curved surface laser processing according to claim 5, characterized in that: Step S1 includes the following steps for dividing the curved surface area of ​​the component (19): S11, obtaining geometric information of the curved surface element model, the geometric information including the spatial position of the point, the normal vector and the curvature radius of the curved surface; S12, specifying the angle between the laser beam direction and the normal vector direction of the surface position as the laser incident angle, and dividing the surface into multiple blocks after analyzing and calculating the discrete point information based on the division algorithm and the scanning range of the galvanometer; S13, based on the focus floating range of the galvanometer processing laser, each processing area is layered.

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