Self-feedback dual-wavelength laser cutting device for processing aramid fibers

Abstract

The utility model discloses a self-feedback dual-wavelength laser cutting device for processing aramid fibers. Comprising a laser, a power amplifier, a beam splitter, a first collimating lens, a second collimating lens, a polarization splitting prism, a half-wave plate, a first reflective mirror, a first concave mirror, a second concave mirror, a first frequency multiplier, a second reflective mirror, a beam combiner, a central control terminal, a second frequency multiplier, a first potentiometer, a second potentiometer, a third potentiometer, a data acquisition card, a camera and a lens group. An output port of the laser directly faces an input port of the power amplifier, and the power amplifier is connected with the central control end through the first potentiometer. The beam splitter, the first collimating lens, the polarization splitting prism, the half-wave plate, the second collimating lens, the first frequency multiplier and the first concave mirror are sequentially arranged from left to right and are aligned in optical axis. The optical axis of the beam splitter is aligned with the axis of the output port of the power amplifier. The second concave mirror, the second frequency multiplier, the beam combiner and the lens group are sequentially arranged and are aligned in optical axis, the second concave mirror directly faces the first concave mirror, and the distance between the two concave mirrors is adjustable; the first reflector is aligned with the beam splitter, the second reflector is aligned with the first reflector, and the second reflector is aligned with the beam combiner; and the data acquisition card, the camera and the lens group are connected with the central control end through the third potentiometer. And a good cutting effect can be achieved for aramid fibers with different thicknesses and components.

Description

TECHNICAL FIELD

[0001] The utility model belongs to aramid fiber processing technical field, specifically a kind of self-feedback dual-wavelength laser cutting device of aramid fiber processing. BACKGROUND

[0002] Aramid fiber is a kind of high modulus, excellent insulation high-performance fiber, has realized commercial application, plays a huge role in military defense, aerospace and other fields.Aramid fiber cutting mode is various, compared with traditional mechanical cutting, it is easy to produce burr, tear and delamination, water jet cutting operating cost is high, cutting precision and efficiency are low, and the shortcomings of manual cutting labor intensity and cutting difficulty are larger, laser cutting has the advantages of high precision, good quality, fast speed, strong flexibility and small material thermal damage, and is widely used in aramid fiber cutting.

[0003] Single laser cutting thermal damage is more obvious, processing heat-affected zone is large (generally in 50~1000 μm), and there are also cutting edge quality, material degradation, cutting speed, the need for repeated cutting and material thickness limit and other shortcomings, and dual-wavelength laser cutting uses different wavelengths of laser to penetrate the material heat depth and heat-affected degree, by reasonably selecting and controlling the wavelength of two kinds of laser, make the heat distribution in material more uniform, reduce the width and depth of heat-affected zone, avoid material deformation, crack and other defects due to overheating, have better cutting quality and effect, and can realize one-time cutting, improve production efficiency.

[0004] However, the existing dual-wavelength laser cutting aramid fiber still has the problems of large heat-affected zone, inaccurate wavelength matching and energy distribution, high equipment complexity and cost, difficult balance between cutting precision and speed, etc., which limits its effect and efficiency in practical application. Therefore, the present application proposes a self-feedback dual-wavelength laser cutting device for processing aramid fiber, which realizes more reasonable energy distribution and wavelength matching by controlling the power ratio of dual-wavelength laser, reduces the heat-affected zone, and realizes the balance between cutting precision and speed. SUMMARY

[0005] In view of the deficiencies of the prior art, the technical problem to be solved by the utility model is to provide a self-feedback dual-wavelength laser cutting device for processing aramid fiber.

[0006] The utility model solves the technical problem by adopting the following technical solution:

[0007] The utility model provides a kind of self-feedback dual-wavelength laser cutting device of processing aramid fiber, including laser, power amplifier, beam splitter, first collimating lens, second collimating lens, polarized light splitting prism, half wave plate, first mirror, first concave mirror, second concave mirror, first frequency doubler, second mirror, beam combiner, central control end, second frequency doubler, potentiometer, camera and data acquisition card, lens group;The output port of the laser is opposite the input port of power amplifier, and power amplifier is connected with central control end by potentiometer;Beam splitter, first collimating lens, polarized light splitting prism, half wave plate, second collimating lens, first frequency doubler and first concave mirror are sequentially arranged from left to right and the optical axis of each device is aligned, and the optical axis of beam splitter is aligned with the output port axis of power amplifier;Second concave mirror, second frequency doubler, beam combiner and lens group are sequentially arranged and the optical axis is aligned, and second concave mirror is opposite first concave mirror, and the distance between the two concave mirrors is adjustable;First mirror is located directly above or directly below beam splitter, and second mirror is opposite first mirror, and second mirror is located directly above or directly below beam combiner;Camera and data acquisition card are connected with central control end, and lens group is connected with central control end by potentiometer.

[0008] Further, the system further includes optical rotary translation stages, the first concave mirror and the second concave mirror are installed on the respective optical rotary translation stages to realize rotation and translation, and the optical rotary translation stages are connected with the central control end through the potentiometers.

[0009] Further, the first frequency doubler and the second frequency doubler have the same structure and each include a semiconductor refrigerator and a PPLN crystal, the PPLN crystal is used to convert the fundamental frequency laser into a frequency-doubled laser, and the semiconductor refrigerator is used to control the temperature of the PPLN crystal.

[0010] Further, the second concave mirror has a larger radius of curvature than the first concave mirror.

[0011] Further, the reflective surfaces of the first concave mirror and the second concave mirror are coated with high-reflection films having the same wavelengths as the fundamental frequency laser and the frequency-doubled laser.

[0012] Further, the beam splitter is inclined by 45° to the side of the power amplifier.

[0013] Compared with the prior art, the utility model has the following beneficial effects:

[0014] 1. In the frequency doubling process, the fundamental frequency laser is focused into a No. 1 frequency doubler for primary frequency doubling, and then focused into a No. 2 frequency doubler for secondary frequency doubling, thereby converting the fundamental frequency laser into frequency-doubled laser, and the frequency-doubled laser is combined with another fundamental frequency laser to form a dual-wavelength laser for cutting aramid fiber. By adjusting the distance between the two concave mirrors, the phase difference between the fundamental frequency laser and the frequency-doubled laser is adjusted, and then the power ratio of the fundamental frequency laser and the frequency-doubled laser is adjusted, so that the device can achieve high precision and low thermal damage cutting effect when cutting aramid fiber of different thickness or composition.

[0015] 2. The cutting image is fed back to the control end in real time, the control end analyzes and identifies the cutting quality after processing, dynamically adjusts the distance between the power amplifier and the two concave mirrors and the size of the focusing point of the lens group, optimizes the cutting parameters and the cutting process, and realizes self-feedback of the cutting effect. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 is a structural schematic diagram of the utility model;

[0017] Mark: 1, laser; 2, power amplifier; 3, beam splitter; 4, No. 1 collimating lens; 5, No. 2 collimating lens; 6, polarization beam splitter prism; 7, half-wave plate; 8, No. 1 reflector; 9, No. 1 concave mirror; 10, No. 2 concave mirror; 11, No. 1 frequency doubler; 12, No. 2 reflector; 13, beam combiner; 14, control end; 15, No. 2 frequency doubler; 16, No. 1 potentiometer; 17, camera and data acquisition card; 18, lens group; 19, No. 2 potentiometer; 20, No. 3 potentiometer. DETAILED DESCRIPTION

[0018] The specific embodiments are described below with reference to the drawings, and the specific embodiments are only used to specifically introduce the technical scheme of the utility model, and do not limit the protection scope of the application.

[0019] Referring to Figure 1 , the utility model provides a kind of self-feedback dual-wavelength laser cutting device of aramid fiber processing, including laser 1, power amplifier 2, beam splitter 3, No. 1 collimating lens 4, No. 2 collimating lens 5, polarization beam splitter prism 6, half-wave plate 7, No. 1 reflector 8, No. 1 concave mirror 9, No. 2 concave mirror 10, No. 1 frequency doubler 11, No. 2 reflector 12, beam combiner 13, control end 14, No. 2 frequency doubler 15, No. 1 potentiometer 16, camera and data acquisition card 17, lens group 18, No. 2 potentiometer 19 and No. 3 potentiometer 20;

[0020] The input port of the power amplifier 2 is aligned with the output port of the laser 1, ensuring that the laser beam emitted by the laser 1 can completely enter the power amplifier 2; the beam splitter 3, the first collimating lens 4, the polarization beam splitter prism 6, the half-wave plate 7, the second collimating lens 5, the first frequency doubler 11 and the first concave mirror 9 are arranged from left to right and the optical axes of each device are aligned, the optical axis of the beam splitter 3 is aligned with the output port axis of the power amplifier 2, the beam splitter 3 is inclined by 45° to the side of the power amplifier 2, ensuring that the laser beam incident on the beam splitter 3 can be divided into two paths, one laser beam is reflected and the other laser beam is refracted; the second concave mirror 10, the second frequency doubler 15, the beam combiner 13 and the lens group 18 are arranged in sequence, the optical axes of the four are aligned, and the second concave mirror 10 is directly opposite the first concave mirror 9, the distance between the two concave mirrors can be adjusted; the first mirror 8 is arranged directly above or below the beam splitter 3, the second mirror 12 is opposite the first mirror 8, and the second mirror 12 is directly above or below the beam combiner 13; the control end 14 is connected with the power amplifier 2 through the first potentiometer 16 to control the power amplification multiple of the power amplifier 2; the control end 14 and the camera are connected with the data acquisition card 17, the camera collects the cutting image and transmits it to the data acquisition card, and the data acquisition card transmits the cutting image to the control end; the control end 14 is connected with the lens group 18 through the third potentiometer 20 to adjust the size of the focus point.

[0021] The laser 1 emits base frequency laser with wavelength 1064nm and pulse width 120fs, which is power amplified by the power amplifier 2, then is incident on the beam splitter 3, and the base frequency laser is divided into two paths by the refraction and reflection of the beam splitter 3, the refracted base frequency laser is collimated by the first collimating lens 4, then forms linearly polarized base frequency laser by the polarization beam splitter prism 6, the linearly polarized base frequency laser adjusts the polarization direction by the half-wave plate 7, then is collimated by the second collimating lens 5 and is incident on the first frequency doubler 11, most of the base frequency laser is converted into frequency-doubled laser, then is reflected by the first concave mirror 9 to the second concave mirror 10, is reflected by the second concave mirror 10 to the second frequency doubler 15, the second frequency doubler 15 converts the remaining base frequency laser into frequency-doubled laser, then is incident on the beam combiner 13; the reflected base frequency laser is reflected by the first mirror 8 to the second mirror 12, and is reflected by the second mirror 12 to the beam combiner 13, and the frequency-doubled laser to form dual-wavelength laser, the dual-wavelength laser is focused by the lens group 18, and the focused dual-wavelength laser irradiates on the aramid fiber to cut it; the data acquisition card 17 collects the cutting image and transmits it to the control end 14, analyzes and identifies the cutting quality, controls the potentiometer 16 and then controls the power amplifier 2 according to the identification result, adjusts the distance between the two concave mirrors and the size of the focus point of the lens group 18 at the same time, and forms self-feedback.

[0022] The system further comprises an optical rotary translation stage and a second potentiometer 19; the first concave mirror 9 and the second concave mirror 10 are installed on the respective optical rotary translation stages, and the central control end 14 is connected with the two optical rotary translation stages through the second potentiometer 19, so as to control the rotation and / or translation of the optical rotary translation stages, so as to change the distance between the first concave mirror 9 and the second concave mirror 10, so as to adjust the power ratio of the fundamental frequency laser and the frequency-doubled laser, so that the device can obtain good cutting effect when cutting aramid fibers of different thicknesses and / or components.

[0023] It is found through research that more than 85% of light with wavelengths of 1064nm and 532nm is not effectively absorbed when passing through epoxy resin, although the purpose can be achieved by using nanosecond, picosecond and other short pulse lasers, but the ultrashort pulse laser has higher instantaneous power and frequency-doubling efficiency, so the laser 1 adopts a single-frequency seed source Nd:YAG single-block non-planar ring cavity laser with a wavelength of 1064nm, which is used to generate a fundamental frequency laser.

[0024] The first frequency doubler 11 and the second frequency doubler 15 have the same structure, which comprises a semiconductor refrigerator and a PPLN crystal, the PPLN crystal is used to convert the fundamental frequency laser into a frequency-doubled laser, and the semiconductor refrigerator is used to control the temperature of the PPLN crystal, so that it is consistent with the ambient temperature, so as to improve the frequency-doubling efficiency; when the power of the fundamental frequency laser is 9.2W, the power of the frequency-doubled laser obtained through the second frequency doubler 15 is 2.26W, and the highest frequency-doubling efficiency is 24.5%. The PPLN crystal doped with MgO can effectively improve the damage threshold of the PPLN crystal.

[0025] Due to the dispersion effect of air, the fundamental frequency laser and the frequency-doubled laser emitted by the first frequency doubler 11 continuously generate phase difference during air propagation, so by adjusting the distance between the first concave mirror 9 and the second concave mirror 10, the phase difference between the fundamental frequency laser and the frequency-doubled laser can be adjusted, so as to change the frequency-doubling efficiency, so as to adjust the power of the frequency-doubled light, and then adjust the power ratio of the fundamental frequency light and the frequency-doubled light, so that the device is suitable for cutting aramid fibers of different components or thicknesses.

[0026] Since the second frequency doubler 15 absorbs more frequency-doubled laser, the thermal effect of the second frequency doubler 15 is more serious, and thus the beam waist radius of the fundamental frequency laser in the second frequency doubler 15 is slightly larger than the beam waist radius of the fundamental frequency laser in the first frequency doubler 11, and the curvature radius of the second concave mirror 10 is larger than the curvature radius of the first concave mirror 9, and the curvature radius of the second concave mirror 10 can be selected as 250 mm, and the curvature radius of the first concave mirror 9 can be selected as 200 mm, and at this time, the beam waist radius of the fundamental frequency laser in the second frequency doubler 15 is about 25.46 μm. The reflecting surfaces of the first concave mirror 9 and the second concave mirror 10 are coated with high-reflection films with the same wavelength as the fundamental frequency laser and the frequency-doubled laser at the same time, so as to ensure that the fundamental frequency laser and the frequency-doubled laser can be effectively collected and output, reduce energy loss, and thus improve the frequency-doubling efficiency. In the embodiment, the wavelengths of the fundamental frequency laser and the frequency-doubled laser are 1064 nm and 532 nm respectively, and thus the reflecting surfaces of the first concave mirror 9 and the second concave mirror 10 are coated with high-reflection films with the wavelengths of 1064 nm and 532 nm at the same time.

[0027] The working principle and working process of the utility model are:

[0028] The laser 1 emits the fundamental frequency laser with the wavelength of 1064 nm, and after power amplification by the power amplifier 2, the fundamental frequency laser is incident to the beam splitter 3 and is divided into two paths. The refracted fundamental frequency laser is collimated by the first collimating lens 4, and then is collimated by the second collimating lens 5 after adjusting the polarization direction by the half-wave plate 7, and is incident to the first frequency doubler 11. The first frequency doubler 11 converts most of the fundamental frequency laser into the frequency-doubled laser with the wavelength of 532 nm, and then is reflected to the second concave mirror 10 by the first concave mirror 9, and is reflected to the second frequency doubler 15 by the second concave mirror 10. The second frequency doubler 15 converts the remaining fundamental frequency laser into the frequency-doubled laser with the wavelength of 532 nm, and then is incident to the beam combiner 13. The reflected fundamental frequency laser is reflected to the second mirror 12 by the first mirror 8, and is reflected to the beam combiner 13 by the second mirror 12, and is combined with the frequency-doubled laser to form the dual-wavelength laser. The dual-wavelength laser is focused by the lens group 18, and the focused dual-wavelength laser irradiates the aramid fiber surface. Since the surface layer of the epoxy resin has low laser absorption, the dual-wavelength laser passes through the epoxy resin and directly heats the aramid fiber. The surface layer of the epoxy resin is heated by the inner layer of the heated aramid fiber through the thermal effect. When the temperature of the aramid fiber exceeds the gasification and decomposition temperature, the aramid fiber is gasified to form an implosion force, so as to remove the matrix resin and realize the decomposition of the aramid fiber.

[0029] By changing the angle of the first concave mirror 9 and the angle and / or position of the second concave mirror 10, adjusting the distance between the two concave mirrors, and changing the propagation path of the laser between the first frequency doubler 11 and the second frequency doubler 15, the phase difference between the fundamental frequency laser and the frequency-doubled laser is adjusted, the power ratio of the fundamental frequency laser and the frequency-doubled laser is adjusted, and the device can obtain high precision and low thermal damage cutting effect when cutting aramid fiber of different thickness or composition through the synergistic effect of the fundamental frequency laser and the frequency-doubled laser; the data acquisition card 17 collects the cutting image in real time and transmits it to the central control end 14, the central control end 14 processes and analyzes the image, identifies the cutting quality, controls the first potentiometer 16 and then controls the power amplifier 2 according to the identification result, controls the two optical rotary translation stages through the second potentiometer 19 to adjust the distance between the two concave mirrors, controls the lens group 18 through the third potentiometer 20 to adjust the focusing point size, forms a self-feedback, and realizes real-time optimization of the cutting parameters and the cutting process.

[0030] The utility model is not described in the prior art.

Claims

1. A self-feedback dual-wavelength laser cutting device for processing aramid fibers, characterized in that, The device includes a laser, a power amplifier, a beam splitter, a collimating lens No. 1, a collimating lens No. 2, a polarizing beam splitter, a half-wave plate, a reflecting mirror No. 1, a concave mirror No. 1, a concave mirror No. 2, a frequency multiplier No. 1, a reflecting mirror No. 2, a beam combiner, a central control unit, a frequency multiplier No. 2, a potentiometer, a camera and data acquisition card, and a lens group. The output port of the laser is directly opposite the input port of the power amplifier, which is connected to the central control unit via a potentiometer. The beam splitter, collimating lens 1, polarizing beam splitter prism, half-wave plate, collimating lens 2, frequency multiplier 1, and concave mirror 1 are arranged sequentially from left to right with their optical axes aligned. The optical axis of the beam splitter is aligned with the output port axis of the power amplifier. The concave mirror 2, frequency multiplier 2, beam combiner, and lens group are arranged sequentially with their optical axes aligned. The concave mirror 2 faces the concave mirror 1, and the distance between the two concave mirrors is adjustable. The reflector 1 is located directly above or below the beam splitter, the reflector 2 faces the reflector 1, and the reflector 2 is located directly above or below the beam combiner. The camera is connected to the data acquisition card and the central control unit, and the lens group is connected to the central control unit via a potentiometer.

2. The self-feedback dual-wavelength laser cutting device for processing aramid fibers according to claim 1, characterized in that, The device also includes an optical rotation and translation stage. A first concave mirror and a second concave mirror are mounted on their respective optical rotation and translation stages to achieve rotation and translation. The optical rotation and translation stages are connected to the central control unit via potentiometers.

3. The self-feedback dual-wavelength laser cutting device for processing aramid fibers according to claim 1 or 2, characterized in that, The first and second frequency multipliers have the same structure, both including a semiconductor cooler and a PPLN crystal. The PPLN crystal is used to convert the fundamental frequency laser into a frequency-doubled laser, and the semiconductor cooler is used to control the temperature of the PPLN crystal.

4. The self-feedback dual-wavelength laser cutting device for processing aramid fibers according to claim 1, characterized in that, The radius of curvature of the second concave mirror is greater than that of the first concave mirror.

5. The self-feedback dual-wavelength laser cutting device for processing aramid fibers according to claim 1 or 4, characterized in that, The reflective surfaces of the first and second concave mirrors are simultaneously coated with a high-reflectivity film with the same wavelength as the fundamental frequency laser and the frequency-doubled laser.

6. The self-feedback dual-wavelength laser cutting device for processing aramid fibers according to claim 1, characterized in that, The beam splitter is tilted 45° toward the power amplifier side.

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