Three-dimensional curved surface laser adaptive conformal scanning processing system

Abstract

The utility model discloses a three-dimensional curved surface laser self-adaptive conformal scanning processing system which comprises a laser, a half-wave plate, a polarization splitting prism, a quarter-wave plate, a dynamic focus lens group and a galvanometer, a focusing lens and a photoelectric detector are sequentially arranged below the polarization splitting prism from top to bottom, and a small hole is formed between the focusing lens and the photoelectric detector; a voice coil motor capable of changing the focus height is arranged below the dynamic focus lens group; a lens is arranged between the galvanometer and the curved surface sample below the galvanometer; the laser, the photoelectric detector, the voice coil motor and the galvanometer are electrically connected with the analog-to-digital conversion and control module. A sample is scanned before laser processing, laser scanning processing on a curved-surface workpiece can be carried out without a model to realize self-adaption, scanning light and processing laser are coaxial and can be realized by adopting the same laser, and a laser track and a three-dimensional curved-surface model during scanning processing are completely overlapped, i.e., a cotype is formed; and the voice coil motor is used for zooming, so that rapid focusing is realized.

Description

Technical Field

[0001] The utility model relates to the technical field of laser processing, in particular to a three-dimensional curved surface laser adaptive conformal scanning processing system. Background Art

[0002] Laser processing is one of the most promising areas of laser application. Currently, more than 20 laser processing technologies have been developed both domestically and internationally, and some are relatively mature. In modern industrial processing, the surface of workpieces is gradually evolving from two-dimensional planes to three-dimensional curved surfaces. Traditional two-dimensional galvanometer systems are no longer able to meet this demand, and there is an urgent need for efficient and high-precision three-dimensional galvanometer systems. Traditional two-dimensional galvanometer systems use a field lens focusing method, which can produce a uniform focused light spot on the focal plane, but cannot effectively control the change in focal position. Dynamic focusing technology realizes a three-dimensional galvanometer system by adding a set of movable lenses in front of the galvanometer to change the focal plane of the optical path.

[0003] Existing laser processing methods for three-dimensional curved surfaces mainly include: a two-dimensional galvanometer linked with a multi-axis worktable to process the surface layer by layer from top to bottom. This method requires dividing the three-dimensional surface into multiple layers of two-dimensional planes. The process is cumbersome and time-consuming, and the workpiece needs to be constantly moved, resulting in low processing efficiency. The other method uses an automatically controlled three-dimensional galvanometer and a surface segmentation algorithm to calculate and plan the laser motion trajectory based on a pre-imported three-dimensional surface model for processing. This method significantly improves processing speed and can process most surfaces, but it requires a lot of time to calibrate the three-dimensional galvanometer and often leads to poor processing uniformity or even processing failure due to errors between the workpiece and the model. Utility Model Content

[0004] In view of the defects of the above-mentioned prior art, the technical problem to be solved by the present invention is to provide a three-dimensional surface laser adaptive conformal scanning processing system that can realize scanning and processing of a three-dimensional surface model using a laser.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions: a three-dimensional curved surface laser adaptive conformal scanning processing system, comprising a laser, a half-wave plate, a polarization beam splitter prism, a quarter-wave plate, a dynamic focusing lens group and a galvanometer mirror arranged in sequence from front to back; a focusing lens and a photodetector are arranged in sequence from top to bottom below the polarization beam splitter prism, and a small hole is provided between the focusing lens and the photodetector; a voice coil motor that can change the focal height is provided below the dynamic focusing lens group; a lens is provided between the galvanometer mirror and the curved surface sample below; the laser, photodetector, voice coil motor and galvanometer mirror are all electrically connected to the analog-to-digital conversion and control module.

[0006] Preferably, the dynamic focusing lens group consists of a concave lens and a convex lens, the concave lens is located on the voice coil motor, and the voice coil motor can change the height of the focus when the concave lens moves back and forth along the optical axis.

[0007] Preferably, the galvanometer is equipped with two motors, and both the galvanometer and the voice coil motor are controlled by a host computer to achieve three-dimensional conformal scanning processing of curved surface samples.

[0008] Preferably, the pinhole and the laser focus are a pair of conjugate points.

[0009] Preferably, the lens adopts an F-theta scanning lens, which can ensure that the size and shape of the light spot remain consistent during the entire scanning process, thereby improving processing accuracy and efficiency.

[0010] Preferably, the photodetector uses AD conversion for the detected light signal to improve the stability and reliability of the signal, is suitable for long-distance transmission and storage, and improves processing accuracy and flexibility.

[0011] The beneficial effects of the present invention are as follows: by scanning the sample before laser processing, laser scanning processing on curved workpieces can be performed without a model to achieve adaption, and the scanning light and the processing laser are coaxial, which can be achieved by using the same laser. The laser trajectory during scanning processing and the model of the three-dimensional curved surface are completely overlapped, that is, co-shaped, and zooming is performed through a voice coil motor to achieve fast focusing, which can match the speed of the galvanometer and complete high-speed three-dimensional scanning. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a structural diagram of the utility model;

[0013] In the figure: 1-laser, 2-half-wave plate, 3-polarization beam splitter, 4-quarter-wave plate, 5-concave lens, 6-convex lens, 7-galvanometer, 8-lens, 9-curved sample, 10-focusing lens, 11-pinhole, 12-photodetector, 13-voice coil motor, 14-analog-to-digital conversion and control module, 15-host computer. DETAILED DESCRIPTION

[0014] In order to better understand the improvements made by the present invention relative to the prior art, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments.

[0015] like Figure 1 As shown, a three-dimensional curved surface laser adaptive conformal scanning processing system mainly consists of a laser 1, a half-wave plate 2, a polarization beam splitter prism 3, a quarter-wave plate 4, a dynamic focusing lens group and a galvanometer 7 arranged along the optical path from front to back.

[0016] Below the polarizing beam splitter prism 3, from top to bottom, are a focusing lens 10 and a photodetector 12. A small aperture 11 is located between the focusing lens 10 and the photodetector 12. Based on the confocal principle, the small aperture 11 and the laser focal point form a pair of conjugate points. Below the dynamic focusing lens assembly, a voice coil motor 13 is located to adjust the focal height and enable movement along the Z axis. The dynamic focusing lens assembly consists of a concave lens 5 and a convex lens 6. The concave lens 5 is positioned on the voice coil motor 13, which adjusts the focal height as the concave lens moves back and forth along the optical axis. A galvanometer mirror 7 is equipped with two motors for movement along the X and Y axes. Both the galvanometer mirror 7 and the voice coil motor 13 are controlled by a host computer 15 to achieve three-dimensional conformal scanning of the curved sample 9. A lens 8 is located between the galvanometer mirror 7 and the curved sample 9 below. Lens 8 is preferably an F-theta scanning lens, which accurately focuses light onto a fixed plane in a laser cutting system, thereby improving cutting accuracy.

[0017] In the entire scanning processing system, the laser 1 , the photodetector 12 , the voice coil motor 13 and the galvanometer 7 are all electrically connected to the analog-to-digital conversion and control module 14 .

[0018] The working method of this scanning processing system is as follows: the linearly polarized laser emitted by the laser 1 passes through the half-wave plate 2 and enters the polarization beam splitter prism 3. The half-wave plate 2 is rotated to change the polarization direction of the laser so that it passes through the polarization beam splitter prism 3 and the quarter-wave plate 4. The quarter-wave plate 4 is rotated to convert the linearly polarized light into circularly polarized light and enter the dynamic focusing lens group. The concave lens 5 of the dynamic focusing lens group is located on the voice coil motor 13. When the voice coil motor 13 drives the concave lens to move back and forth along the optical axis, the height of the focal point can be changed. The circularly polarized laser is focused on the surface of the curved sample 9 through the galvanometer 7 and the lens 8. The reflected and scattered light of the curved sample 9 returns to the original path and becomes linearly polarized light perpendicular to the polarization direction of the incident light when passing through the quarter-wave plate 4 again. It is reflected by the polarization beam splitter prism 3, focused by the focusing lens 10, and reaches the detector 12 through the small hole 11. The light signal measured by the detector 12 is collected and analyzed by the host computer 15 after AD conversion. According to the confocal principle, the pinhole 11 and the laser focus are a pair of conjugate points. The strongest feedback light signal is generated only when the laser is focused on the surface of the curved sample 9. Continuously changing the position of the voice coil motor 13 determines the position with the strongest feedback signal, which represents the laser's focused state. The focal plane range at the initial position of the voice coil motor 13 is divided into a grid of points of a certain density. The position of the voice coil motor 13 during laser focus is obtained and stored at each grid point. Together with the adjusted positions of the two motors of the galvanometer mirror 7, a three-dimensional coordinate is obtained. This three-dimensional coordinate uniquely determines the location of the laser focus point. Because the position of the voice coil motor 13 and the focus changes are nearly linear, the motor positions corresponding to unscanned points can be determined by interpolation between adjacent points based on the linear variation. The three motors are then controlled by the host computer 15 to coordinate their motion, ultimately achieving conformal scanning of the 3D curved surface. During contour scanning, the beam power should be kept low, so as not to exceed the sample's damage threshold.

[0019] The above is only a preferred specific implementation method of the present invention, but the protection scope of the present invention is not limited to this. Any technician familiar with the technical field within the technical scope disclosed by the present invention can make equivalent replacements or changes based on the technical solution and utility model concept of the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A three-dimensional curved surface laser adaptive conformal scanning processing system, characterized by: The invention comprises a laser (1), a half-wave plate (2), a polarization beam splitter prism (3), a quarter-wave plate (4), a dynamic focusing lens group and a galvanometer (7) which are arranged in sequence from front to back; a focusing lens (10) and a photodetector (12) are arranged in sequence from top to bottom below the polarization beam splitter prism (3), and a small hole (11) is arranged between the focusing lens (10) and the photodetector (12); a voice coil motor (13) capable of changing the focal height is arranged below the dynamic focusing lens group; a lens (8) is arranged between the galvanometer (7) and a curved surface sample (9) below; the laser (1), the photodetector (12), the voice coil motor (13) and the galvanometer (7) are all electrically connected to an analog-to-digital conversion and control module (14).

2. The three-dimensional curved surface laser adaptive conformal scanning processing system according to claim 1, characterized in that: The dynamic focusing lens group consists of a concave lens (5) and a convex lens (6). The concave lens (5) is located on a voice coil motor (13). The voice coil motor can change the height of the focus when the concave lens moves forward and backward along the optical axis.

3. The three-dimensional curved surface laser adaptive conformal scanning processing system according to claim 1, characterized in that: The galvanometer (7) is equipped with two motors, and both the motors and the voice coil motor (13) are controlled by a host computer (15) to realize three-dimensional conformal scanning processing of the curved surface sample (9).

4. The three-dimensional curved surface laser adaptive conformal scanning processing system according to claim 1, characterized in that: The small hole (11) and the laser focus are a pair of conjugate points.

5. The three-dimensional curved surface laser adaptive conformal scanning processing system according to claim 1, characterized in that: The lens (8) is an F-theta scanning lens.

6. The three-dimensional curved surface adaptive conformal laser scanning processing system according to claim 1, characterized in that: The photodetector (12) performs AD conversion on the detected light signal.

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