Laser processing device

Abstract

The utility model provides a laser processing device. The laser processing device comprises a laser; a beam expander; the beam splitter is arranged on an emergent light path of the beam expander and used for splitting the laser beam into a transmission light beam and a reflection light beam, and the transmissivity of the beam splitter is larger than 99%; the light spot analyzer is arranged on a light path of the reflected light beam; the beam shaper is arranged on a light path of the transmission beam and is used for converting the Gaussian beam emitted by the laser into a flat-topped beam; the galvanometer is arranged on an emergent light path of the light beam shaper; the field lens is arranged on an emergent light path of the galvanometer; and the computer is respectively connected with the beam expander and the light spot analyzer. The device has the beneficial effects that the incident laser beam for 3D printing is monitored in real time by arranging the beam splitter and the light spot analyzer, and the computer controls the beam expander and adjusts the divergence angle of the laser beam to ensure that the light spot position of the flat-topped light beam does not change.

Description

Technical Field

[0001] The utility model relates to the technical field of laser rice polishing processing, in particular to a laser processing device. Background Art

[0002] Metal 3D printing mostly uses the Selective Laser Melting process, the principle of which is to quickly melt the preset metal powder through laser scanning to directly obtain parts of any shape. The density of the obtained parts can reach more than 99.9%.

[0003] The beam output by the existing laser is a Gaussian beam. Although it has high printing accuracy, it has a single form, a spot diameter of only about 90um, low working efficiency, and problems such as uneven energy distribution. The flat-top light printing technology based on DOE has the advantages of high beam energy uniformity, simple structure and easy installation, low cost, and high working efficiency. However, under the condition of large focal length, the obtained flat-top spot is very small. When the laser fiber head or beam expander causes the divergence angle of the laser beam to change due to temperature drift or mechanical problems, the position of the flat-top spot will also change, affecting the processing quality of parts. Utility Model Content

[0004] The utility model aims to provide a laser processing device to solve the problems existing in the prior art.

[0005] The utility model provides a laser processing device, comprising:

[0006] A laser for emitting a laser beam;

[0007] A beam expander, used to expand and collimate the laser beam;

[0008] A beam splitter, arranged on the outgoing light path of the beam expander, for splitting the laser beam into a transmitted beam and a reflected beam, wherein the transmittance of the beam splitter is greater than 99%;

[0009] A light spot analyzer, arranged on the optical path of the reflected light beam, for obtaining parameter information of the light spot;

[0010] A beam shaper, arranged on the optical path of the transmitted light beam, for converting the Gaussian beam emitted by the laser into a flat-top beam;

[0011] A galvanometer, arranged on an outgoing light path of the beam shaper, and used for deflecting the flat-top beam;

[0012] A field lens, arranged on the outgoing light path of the galvanometer, and used to focus the deflected flat-top beam on the printing plane;

[0013] The computer is connected to the beam expander and the spot analyzer respectively. The computer controls the beam expander to adjust the divergence angle of the laser beam based on the spot parameter information obtained by the spot analyzer.

[0014] Preferably, the beam splitter is tilted at 45°.

[0015] Preferably, the transmission-reflection ratio of the beam splitter is 99.9:0.1.

[0016] Preferably, the beam splitter is a high-transmittance lens.

[0017] Preferably, the beam shaper is a DOE type beam shaper.

[0018] The utility model is beneficial in that, by setting a beam splitter and a spot analyzer, the incident laser beam for 3D printing is monitored in real time, and the beam expander is controlled by a computer to adjust the divergence angle of the laser beam to ensure that the spot position of the flat-top beam does not change. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of the laser processing device of the utility model.

[0020] Component number description:

[0021] 1 Computer

[0022] 2 Beam Expander

[0023] 3 Spot Analyzer

[0024] 4 beam splitters

[0025] 5 Galvanometer

[0026] 6 Field Mirror

[0027] 7 Printing plane

[0028] 8 Beam Shaper

[0029] 9 Laser DETAILED DESCRIPTION

[0030] The following is a further detailed description of the specific implementations of the present invention in conjunction with the accompanying drawings. These implementations are only used to illustrate the present invention, but not to limit the present invention.

[0031] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0032] like Figure 1 As shown, the utility model provides a laser processing device, including a laser 9, a beam expander 2, a beam splitter 4, a spot analyzer 3, a beam shaper 8, a galvanometer 5, a field lens 6 and a computer 1. Among them, the laser 9 is used to emit a laser beam for processing parts. The beam expander 2 is used to expand and collimate the laser beam. The beam splitter 4 is arranged on the exit optical path of the beam expander 2, and is used to split the laser beam into a transmitted beam and a reflected beam, and the transmittance of the beam splitter 4 is greater than 99%. This arrangement can ensure that most of the laser beam passes through the beam splitter 4, while avoiding the problem of heating of optical components while avoiding affecting the printing quality. The spot analyzer 3 is arranged on the optical path of the reflected beam, and is used to obtain parameter information of the spot (including the image, size, and energy of the spot). The beam shaper 8 is arranged on the optical path of the transmitted beam, and is used to convert the Gaussian beam emitted by the laser into a flat-top beam. The galvanometer 5 is arranged on the exit optical path of the beam shaper 8, and is used to deflect the flat-top beam so that the printing plane 7 is located on the optical path of the flat-top beam. The field lens 6 is arranged on the outgoing light path of the galvanometer 5, and is used to focus the deflected flat-top beam on the printing plane 7. The computer 1 is connected to the beam expander 2 and the spot analyzer 3 respectively. The computer 1 adjusts the magnification of the beam expander 2 based on the spot parameter information obtained by the spot analyzer 3, and then adjusts the divergence angle of the laser beam.

[0033] In a specific embodiment of the utility model, the laser 9 can be a well-known laser light source such as a solid laser light source, a gas laser light source or a semiconductor laser light source, and its output, wavelength and other conditions can be appropriately set according to the type of processing and the object to be processed. The beam expander 2 is an electric beam expander, which can adjust the laser divergence angle and beam diameter under the control of the computer 1, and can also use its own buttons to achieve manual control. The beam expander driver and the motor are both integrated inside the electric beam expander, and the overall structure is compact and easy to use. The beam splitter 4 is tilted at 45°, and its transmission-reflection ratio is 99.9:0.1. Those skilled in the art can choose coated glass or high-transmittance lenses as the beam splitter 4 as needed. The beam shaper 8 is a DOE (diffraction optical element) type beam shaper, which can convert the peripheral shape of the beam into a quadrilateral. The aforementioned laser, electric beam expander, beam splitter and DOE type beam shaper are all prior art and will not be repeated here.

[0034] The working principle of the utility model is as follows:

[0035] The laser beam emitted by the laser 9 is collimated by the beam expander 2 and then divided into a 99.9% transmission beam and a 0.1% reflection beam by the beam splitter 4. The transmission beam enters the beam shaper 8 and is transformed into a flat-top beam. The galvanometer 5 allows the flat-top beam to enter the printing path. Finally, the field lens 6 focuses the flat-top beam on the printing plane 7 for printing. The reflected beam enters the spot analyzer 3, which analyzes the spot diameter d in real time. When the optical fiber head and the beam expander 2 of the laser 9 change the divergence angle of the laser beam due to temperature drift or mechanical problems, the spot size obtained by the spot analyzer 3 will change. This change data is sent back to the computer 1. The computer 1 adjusts the beam expander 2 according to the spot change logic to adjust the divergence angle of the laser beam to avoid changes in the spot position of the flat-top beam.

[0036] In the actual processing process, it was found that without monitoring and adjustment, under the focal length condition of F650, the spot area space of the flat-top light was only 500um. When the divergence angle of the laser beam changed slightly, it would affect the spot position of the flat-top light beam. Therefore, the laser processing device of the present invention can ensure the long-term reliability of the flat-top light in the 3D printing process.

[0037] The above are only preferred implementations of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principles of the present invention. These improvements and substitutions should also be regarded as the protection scope of the present invention.

Claims

1. A laser processing device, characterized in that: include: A laser for emitting a laser beam; A beam expander, used to expand and collimate the laser beam; A beam splitter, arranged on the outgoing light path of the beam expander, for splitting the laser beam into a transmitted beam and a reflected beam, wherein the transmittance of the beam splitter is greater than 99%; A light spot analyzer, arranged on the optical path of the reflected light beam, for obtaining parameter information of the light spot; A beam shaper, arranged on the optical path of the transmitted light beam, for converting the Gaussian beam emitted by the laser into a flat-top beam; A galvanometer, arranged on an outgoing light path of the beam shaper, and used for deflecting the flat-top beam; A field lens, arranged on the outgoing light path of the galvanometer, and used to focus the deflected flat-top beam on the printing plane; The computer is connected to the beam expander and the spot analyzer respectively. The computer controls the beam expander to adjust the divergence angle of the laser beam based on the spot parameter information obtained by the spot analyzer.

2. The laser processing device according to claim 1, characterized in that: The beam splitter is tilted at 45°.

3. The laser processing device according to claim 1, characterized in that: The transmission-reflection ratio of the beam splitter is 99.9:0.

1.

4. The laser processing device according to claim 1, characterized in that: The beam splitter is a high light transmittance lens.

5. The laser processing device according to claim 1, characterized in that: The beam shaper is a DOE type beam shaper.

Images