阅读说明：本技术 利用高频/超高频微振动实现激光光斑动态调节的激光头 (Laser head for realizing dynamic regulation of laser facula by high-frequency/ultrahigh-frequency micro-vibration ) 是由 马修泉 许天宇 米高阳 周邵巍 邵新宇 于 2020-06-01 设计创作，主要内容包括：本发明公开了一种利用高频/超高频微振动实现激光光斑动态调节的激光头,包括激光传输装置、镜腔、特种机电模块和保护喷嘴,激光传输装置设置于镜腔的顶部,镜腔内由上到下依次设置有保护镜一和准直镜片,特种机电模块设置于镜腔的底部,通过外壳与镜腔连接,特种机电模块的外壳内还设置有一聚焦镜,且聚焦镜与特种机电模块之间设置有平面弹簧,特种机电模块能够带动聚焦镜超高频的微震荡,保护喷嘴设置于特种机电模块的底部；本发明中,输出的光斑直径随着聚焦镜振幅的变化而实时变化,可以实现光斑形态的高响应调节,以适应激光切割、激光焊接、激光增材加工等的工况要求。(The invention discloses a laser head for realizing dynamic adjustment of laser spots by utilizing high-frequency/ultrahigh-frequency micro-vibration, which comprises a laser transmission device, a mirror cavity, a special electromechanical module and a protective nozzle, wherein the laser transmission device is arranged at the top of the mirror cavity; according to the invention, the diameter of the output light spot changes in real time along with the change of the amplitude of the focusing mirror, so that the high-response adjustment of the light spot form can be realized, and the working condition requirements of laser cutting, laser welding, laser material increase processing and the like can be met.)

1. A laser head for realizing dynamic adjustment of laser spots by utilizing high-frequency/ultrahigh-frequency micro-vibration is characterized in that: including laser transmission device, mirror chamber, special electromechanical module and protection nozzle, laser transmission device set up in the top in mirror chamber, by the incident port that mirror chamber top set up to the laser is penetrated to the mirror intracavity, the mirror intracavity by last protective glass one and collimation lens of having set gradually under to, special electromechanical module set up in the bottom in mirror chamber, through the shell with the mirror chamber is connected, the shell top and the bottom of special electromechanical module are provided with the light trap respectively, still be provided with a focusing mirror in the shell of special electromechanical module, just the focusing mirror with be provided with the plane spring between the special electromechanical module, special electromechanical module can drive the micro-oscillation of focusing mirror hyperfrequency, the protection nozzle set up in the bottom of special electromechanical module.

2. The laser head for realizing dynamic adjustment of laser spots by using high frequency/ultrahigh frequency micro-vibration according to claim 1, wherein: an optical fiber end cap is arranged between the laser transmission device and the mirror cavity.

3. The laser head for realizing dynamic adjustment of laser spots by using high frequency/ultrahigh frequency micro-vibration according to claim 1, wherein: the special electromechanical module is a voice coil motor, a lens base of the focusing mirror is connected with an electrified coil of the voice coil motor, the planar spring is connected with a shell of the voice coil motor, when the electrified coil is under the action of high-frequency alternating current, a magnetic field generated by the electrified coil and a magnetic field of the permanent magnet interact to generate high-frequency periodic acting force to act on the focusing mirror, the focusing mirror is simultaneously under the acting force of the planar spring, and under the action of the two forces, the focusing mirror performs satellite rotation motion at ultrahigh frequency.

4. The laser head for realizing dynamic adjustment of laser spots by using high frequency/ultrahigh frequency micro-vibration according to claim 1, wherein: the special electromechanical module is a vibration exciter.

5. The laser head for realizing dynamic adjustment of laser spots by using high frequency/ultrahigh frequency micro-vibration according to claim 1, wherein: and a second protective mirror is also arranged at the bottom end in the special electromechanical shell.

6. The laser head for realizing dynamic adjustment of laser spots by using high frequency/ultrahigh frequency micro-vibration according to claim 1, wherein: the entrance port, the first protective mirror, the collimating lens, the light hole, the focusing lens and the second protective mirror are concentrically arranged.

7. The laser head for realizing dynamic adjustment of laser spots by using high frequency/ultrahigh frequency micro-vibration according to claim 1, wherein: the laser emitted by the laser transmission device is a Gaussian beam with the wavelength of 1030-1080 nm.

8. The laser head for realizing dynamic adjustment of laser spots by using high frequency/ultrahigh frequency micro-vibration according to claim 1, wherein: the diameter of the collimating optic is larger than the gaussian beam cross-sectional dimension at the location to wrap the entire beam within the refractive range.

Technical Field

The invention relates to the technical field of laser processing equipment, in particular to a laser head for realizing dynamic adjustment of laser spots by utilizing high-frequency/ultrahigh-frequency micro-vibration.

Background

The laser spot is the intersection surface of the laser beam and the workpiece to be operated, and directly determines the action position, size and energy density distribution of the laser. The realization of the dynamic adjustment of the laser light spot is a key for improving the laser processing level. The mode that the adoption installed device such as partial shipment light path, galvanometer additional in the laser head and realized facula regulation and control is comparatively common, has also gained certain effect. However, in a large number of working conditions, for example, the working condition that the requirement on the uniformity degree of the light spot energy is particularly high (such as large-format cleaning) and the working condition that the requirement on the movement speed of the light spot is particularly high (such as laser stirring welding), the traditional laser head internal light spot adjusting strategy is difficult to meet the high-speed and high-response adjusting requirement.

Analyzing in principle, realizing high-response intelligent controllability of light spots, and breaking through two key problems, wherein the first is to reduce the size of an original light spot, increase the concentration degree of a light beam as much as possible under the condition of the same power and reduce the light spots; secondly, the high-speed motion of the original light spot in any direction of the two-dimensional space is realized, so that the controllability of the output light spot is comprehensively improved. The first key issue is closely related to the laser, and as the laser technology is continuously developed, the issue will be gradually broken through. The second problem is to be overcome by adjusting the output beam.

The existing laser spot regulation and control method comprises three types: light spot direct amplification type, light spot beam splitting type and light spot sweeping type.

The direct light spot amplification type can realize the adjustment of the size of the light spot by directly adjusting the relative position of a lens in a light path, but the total power is constant, so that the power density is attenuated;

the light spot beam splitting type adopts the lens to realize light beam separation, thereby realizing a mode of changing a plurality of light spots, having good application in certain specific processing occasions, but the change effect is very limited because the number of the light spots can be changed only in a certain range;

the spot sweeping type can realize vibration frequency less than or equal to 500Hz at present, cannot realize ultrahigh frequency (vibration frequency is 1 kHz-30 kHz) motion, is realized by adopting a vibrating mirror structure mostly, and cannot bear laser power more than 1 ten thousand watts.

In conclusion, the current laser processing field has the problem that the dynamic adjustment of the light spot form is difficult, especially the dynamic adjustment with high response is difficult.

Disclosure of Invention

The invention aims to provide a laser head for realizing dynamic adjustment of laser spots by utilizing high-frequency/ultrahigh-frequency micro-vibration, which aims to solve the problems in the prior art. At the moment, the diameter of the output light spot changes in real time along with the change of the amplitude of the focusing mirror, and high-response adjustment of the light spot form can be realized. The laser welding device is suitable for working condition requirements of laser cutting, laser welding, laser additive processing and the like.

In order to achieve the purpose, the invention provides the following scheme:

the invention provides a laser head for realizing dynamic adjustment of laser spots by utilizing high-frequency/ultrahigh-frequency micro-vibration, which comprises a laser transmission device, a mirror cavity, a special electromechanical module and a protective nozzle, the laser transmission device is arranged at the top of the mirror cavity, laser is injected into the mirror cavity from an incident port arranged at the top of the mirror cavity, a first protective lens and a collimating lens are sequentially arranged in the lens cavity from top to bottom, the special electromechanical module is arranged at the bottom of the lens cavity, the special electromechanical module is connected with the mirror cavity through a shell, the top and the bottom of the shell of the special electromechanical module are respectively provided with a light hole, a focusing mirror is also arranged in the shell of the special electromechanical module, and a plane spring is arranged between the focusing mirror and the special electromechanical module, the special electromechanical module can drive the ultrahigh frequency micro oscillation of the focusing mirror, and the protection nozzle is arranged at the bottom of the special electromechanical module.

Preferably, an optical fiber end cap is arranged between the laser transmission device and the mirror cavity.

Preferably, the special electromechanical module is a voice coil motor, the lens base of the focusing mirror is connected with an electrified coil of the voice coil motor, the planar spring is connected with a housing of the voice coil motor, when the electrified coil is under the action of high-frequency alternating current, a magnetic field generated by the electrified coil interacts with a magnetic field of the permanent magnet to generate a high-frequency periodic acting force, the high-frequency periodic acting force acts on the focusing mirror, the focusing mirror is simultaneously under the acting force of the planar spring, and under the action of the two forces, the focusing mirror performs satellite rotation motion at ultrahigh frequency.

Preferably, the special electromechanical module is a vibration exciter.

Preferably, the bottom end in the special electromechanical shell is also provided with a second protective mirror.

Preferably, the entrance port, the first protective mirror, the collimating lens, the light-transmitting hole, the focusing mirror and the second protective mirror are concentrically arranged.

Preferably, the laser emitted by the laser transmission device is a Gaussian beam with the wavelength of 1030-1080 nm.

Preferably, the diameter of the collimating optic is larger than the gaussian beam cross-sectional dimension at the location to wrap the entire beam within the refractive range.

Compared with the prior art, the invention has the following beneficial technical effects:

1. the laser head for realizing dynamic adjustment of laser spots by utilizing high-frequency/ultrahigh-frequency micro-vibration provided by the invention can perform ultrahigh-frequency micro-vibration on any one of the focusing lens, the collimating lens and the optical fiber end cap. When the collimated laser passes through the focusing mirror, the laser can move along with the ultrahigh frequency micro-vibration of the focusing mirror after being focused, and at the moment, the equivalent spot diameter changes along with the change of the amplitude of the focusing mirror. The requirements for different materials and different laser processing technologies are met, the high-power processing occasions can be applied and adapted, and multi-occasion and multi-function processing of the laser can be realized in a real sense.

2. Compared with the laser head with the light spot directly amplified, the laser head with the dynamic adjustment of the laser light spot by utilizing the high-frequency/ultrahigh-frequency micro-vibration provided by the invention has the advantages that the size of the light spot is adjusted by driving the corresponding part to carry out the ultrahigh-frequency micro-vibration by adopting the special electromechanical module, and the power density attenuation is avoided. Compared with a light spot beam splitting type, the ultra-high frequency micro-vibration processing device has the advantages that the focusing lens, the collimating lens or the optical fiber end cap can drive the light spot to vibrate in an ultra-high frequency manner, a processing molten pool is more controllable, the adjustment flexibility is high, and the processing effect is improved. Compared with the spot sweeping type, the laser oscillation system adopts the special electromechanical module, the oscillation frequency of the laser oscillation system is between 1kHz and 30kHz and is higher than the frequency of the existing oscillating mirror motor, and the laser oscillation system is superior to the oscillating mirror laser oscillation system in the aspects of processing effect and processing efficiency.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

FIG. 1 is a schematic structural diagram of a laser head for dynamically adjusting laser spots by high-frequency/ultrahigh-frequency micro-vibration according to the present invention;

FIG. 2 is a schematic structural diagram of a voice coil motor according to the present invention;

FIG. 3 is a schematic diagram of the oscillating movement of the focusing lens according to the present invention;

FIG. 4 is a distribution diagram of spots formed on a focusing plane after laser focusing according to the present invention;

FIG. 5 is a schematic structural view of a flat spring according to the present invention;

in the figure: the system comprises a laser transmission device 1, an incident light 2, a collimating lens 3, a collimated light beam 4, a focusing lens 5, a planar spring 6, a special electromechanical module 7, a lens cavity 8, a protective lens I9, a laser focusing light beam 10, a protective lens II 11, a protective nozzle 12, a laser focusing plane 13, an optical fiber end cap 14, a voice coil motor shell 15, a coil 16 and a magnet 17.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The invention aims to provide a laser head for realizing dynamic adjustment of laser spots by utilizing high-frequency/ultrahigh-frequency micro-vibration so as to solve the problems in the prior art.

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in further detail below.

The laser head in the embodiment realizes the dynamic adjustment of laser spots by utilizing high-frequency/ultrahigh-frequency micro-vibration, as shown in fig. 1, the laser endoscope comprises a laser transmission device 1, a lens cavity 8, a special electromechanical module 7 and a protection nozzle 12, wherein the laser transmission device 1 is arranged at the top of the lens cavity 8, laser is injected into the lens cavity 8 from an entrance port arranged at the top of the lens cavity 8, a protection lens 9 and a collimating lens 3 are sequentially arranged in the lens cavity 8 from top to bottom, the special electromechanical module 7 is arranged at the bottom of the lens cavity 8, is connected with the mirror cavity 8 through a shell, the top and the bottom of the shell of the special electromechanical module 7 are respectively provided with a light hole, a focusing mirror 5 is also arranged in the shell of the special electromechanical module 7, and a plane spring 6 is arranged between the focusing mirror 5 and the special electromechanical module 7, the special electromechanical module 7 can drive the ultrahigh frequency micro oscillation of the focusing mirror 5, and the protection nozzle 12 is arranged at the bottom of the special electromechanical module 7.

In this embodiment, an optical fiber end cap 14 is disposed between the laser transmission device 1 and the mirror cavity 8, the optical fiber end cap 14 is a high-power device designed for processing the output end face of the high-power optical fiber laser and the amplifier, the optical power density of the output end is reduced by expanding the output light beam, and the echo reflection (better than-35 dB) of the end face is greatly reduced by adopting a special end face angle design. The fiber End Caps 14(End Caps) can be used at the output of lasers (amplifiers) with high power at high peak power or high average power with little distortion of the output beam.

The special electromechanical module 7 in this embodiment may be selected as a voice coil motor (as shown in fig. 2), the lens holder of the focusing lens 5 is connected to an energizing coil 16 of the voice coil motor, the planar spring 6 is connected to a housing 15 of the voice coil motor, when the energizing coil 16 is under the action of a high-frequency alternating current, a high-frequency periodic acting force is generated by interaction between a magnetic field generated by the energizing coil 16 and a magnetic field of the permanent magnet 17, and acts on the focusing lens 5, the focusing lens 5 is simultaneously subjected to the acting force of the planar spring 6, and under the action of the two forces, the focusing lens 5 performs satellite rotation motion at an ultrahigh frequency.

The special electromechanical module 7 in this embodiment may also be selected as a vibration exciter and other electromechanical devices capable of applying a high-frequency periodic acting force to other objects, and the function is to apply a high-frequency periodic acting force to the optical fiber end cap 14/focusing mirror 5/collimating mirror in the horizontal plane, so that the optical fiber end cap 14/focusing mirror 5/collimating mirror performs a high-frequency circular motion in the horizontal plane, and the optical fiber end cap 14/focusing mirror 5/collimating mirror does not rotate and revolves around the center.

In the embodiment, the bottom end in the special electromechanical shell is also provided with the second protective mirror 11, the specific thickness of the second protective mirror 11 is 1-6mm, and the special electromechanical module has the functions of preventing pollutants such as particles and the like from entering the specific electromechanical module and ensuring that the electromechanical module and the focusing mirror 5 work in a clean environment and are not polluted.

In the embodiment, the incident port, the first protective mirror 9, the collimating lens 3, the light hole, the focusing mirror 5 and the second protective mirror 11 are concentrically arranged; the collimated laser energy is just shot to the center of the static focusing mirror 5.

In this embodiment, the laser transmission device 1 can transmit continuous laser with specific power, the transmitted laser is a gaussian beam with a wavelength of 1030-1080nm, and the beam is an energy source for laser flexible processing.

A collimating lens 3, the diameter of the collimating lens 3 is larger than the Gaussian beam cross-sectional size at the position to wrap the whole beam in the refraction range. The collimating lens 3 can adjust the incident beam into a parallel beam, which is substantially not divergent during the transmission process and is transmitted to the focusing lens 5 in a parallel state. The lens belongs to a common high lens sheet and can bear at least 1.5 ten-thousand watts of laser power.

The diameter of the collimated light beam 4 depends on the NA value of the optical fiber generating the incident light 2 and the distance from the laser emitting point to the plane of the collimating mirror, and the diameter does not exceed the maximum diameter of the working surface of the collimating mirror and the focusing mirror 5.

The focusing mirror 5, whose oscillation schematic diagram is shown in fig. 3, performs ultrahigh frequency micro-vibration with frequency between 1kHz and 30kHz and amplitude between 0 and D (for example, D is 500 μm, but not limited to 500 μm) in X direction and Y direction under the combined action of the special electromechanical module 7 and the annular planar spring 6, and finally synthesizes circular motion, whose oscillation form is ultrahigh frequency revolution around an axis parallel to its own axis, and its own rotation does not.

The section of the plane spring 6 is shown in figure 5, the elastic coefficient K of the plane spring is more than 500N/m, and the plane spring can ensure that the focusing mirror 5 can quickly rebound after moving under the action of the special electromechanical module 7, so that the oscillation frequency of the focusing mirror 5 is between 1kHz and 30 kHz.

The first protective mirror 9 is 1-6mm thick and prevents particles from contacting the lens below the first protective mirror, and protects the lens and the mirror cavity 8 from being polluted.

The laser focusing beam 10, which oscillates at the same frequency as the focusing mirror 5, will eventually be focused into a spot of minimum diameter at the focal plane.

And the protective nozzle 12 is arranged right below the special electromechanical module 7 and is used for preventing splash generated when the laser acts on the workpiece from entering the lens cavity 8 and the electromechanical module above the protective nozzle, so that the protective nozzle can work in a clean environment.

The diameter of the laser focusing plane 13 when the laser spot is static is D (D is 10-100 μm), when the focusing mirror 5 works, the laser forms a laser spot as shown in fig. 4 on the plane after being focused, the equivalent diameter of the laser spot is changed into S (S is 0.5D + D), the power density of the formed laser spot is not reduced, but the equivalent diameter is increased, and the laser focusing plane can be suitable for flexible laser processing in various occasions.

The invention provides a new method for changing the equivalent spot diameter for the first time, which can ensure that the power density is not reduced basically, and can change the spot diameter in real time in the laser processing process, thereby realizing the intelligent processing of workpieces and obtaining good processing effect. The special electromechanical module 7 is adopted to drive any one of the focusing lens 5, the collimating lens and the optical fiber end cap 14 to perform ultrahigh frequency micro-oscillation between 0 and D (for example, D is 500 micrometers, but not limited to 500 micrometers), and the oscillation frequency is between 1kHz and 30 kHz. The system and the method are suitable for laser processing occasions needing the variable optical fiber core diameter, such as laser cutting, laser welding, laser material adding, material reducing manufacturing and the like. The oscillation mode of any one of the focusing mirror 5, the collimating mirror and the output optical fiber is that the ultrahigh frequency revolution is carried out around the axis parallel to the axis of the focusing mirror, and the focusing mirror does not rotate.

The principle and the implementation mode of the invention are explained by applying specific examples, and the description of the above examples is only used for helping understanding the method and the core idea of the invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, the specific embodiments and the application range may be changed. In summary, this summary should not be construed to limit the present invention.