Light path system of additive manufacturing equipment

Abstract

The utility model discloses a light path system of additive manufacturing equipment, which comprises a laser, and a collimation beam splitting unit, a collimation beam expanding unit, a spatial light modulator, an optical focusing unit and a scanning galvanometer are sequentially arranged on an emergent light path of the laser; the beam combining unit is arranged on an emergent light path of the optical focusing unit and is used for combining a plurality of light beams and emitting the combined light beams to the scanning galvanometer; compared with the prior art, the light path system of the additive manufacturing equipment has the advantages that the quality of final finished products can be improved, the production efficiency is higher, and the cost of the whole structure is lower.

Description

Technical Field

[0001] This utility model relates to the field of additive manufacturing, and in particular to an optical path system for additive manufacturing equipment. Background Technology

[0002] Selective laser melting (SLM) is one of the most precise metal 3D printing methods currently available. It utilizes a high-density laser spot to rapidly scan a two-dimensional pattern within a protective atmosphere, causing molten metal powder to solidify into thin layers of 20μm to 30μm. These layers are then deposited to create precise 3D molded parts, widely used in the manufacture of precision components in aerospace and biomedical industries. However, existing technologies, such as the multi-beam structure disclosed in Chinese utility model patent CN216462460U, still present a split-beam laser onto the scanning galvanometer after beam splitting and other processing. This approach can negatively impact the final molding quality, potentially leading to less dense molding and relatively lower production efficiency.

[0003] Therefore, it is necessary to improve the optical path system of existing additive manufacturing equipment. Compared with existing technologies, this can improve the quality of the final product, increase production efficiency, and reduce overall structural costs. Summary of the Invention

[0004] In view of this, the purpose of this utility model is to provide an optical path system for additive manufacturing equipment, which can improve the quality of the final product, increase production efficiency, and reduce overall structural cost compared with the prior art.

[0005] The optical path system of the additive manufacturing equipment of this utility model includes a laser, and a collimating beam splitting unit, a collimating beam expanding unit, a spatial light modulator, an optical focusing unit and a scanning galvanometer are sequentially arranged on the output optical path of the laser.

[0006] It also includes a beam combining unit, which is disposed in the output optical path of the optical focusing unit, for combining multiple beams and projecting them onto the scanning galvanometer.

[0007] Furthermore, the collimation and beam splitting unit includes a collimation module and a beam splitter disposed on the output optical path of the collimation module. The beam splitter is used to split the laser beam modulated by the collimation module into m×n laser beams.

[0008] Furthermore, the collimating beam expanding unit includes prisms and beam expanders. The number of prisms is the same as the number of laser beams split by the beam splitter. Each prism is correspondingly disposed on the output optical path of a laser beam. The number of beam expanders is the same as the number of prisms and is correspondingly disposed on the output optical path of each prism.

[0009] Furthermore, it also includes a reflector I, which is disposed on the output optical path of the beam expander, and the number of reflectors I is the same as the number of beam expanders.

[0010] Furthermore, there are multiple spatial light modulators, and the number of spatial light modulators is the same as the number of laser beams split by the beam splitter. Each spatial light modulator corresponds to one laser beam, and each spatial light modulator is correspondingly set on the outgoing light path of each reflector I.

[0011] Furthermore, the optical focusing unit includes two focusing lenses arranged in sequence, which are positioned on the outgoing light path after passing through the spatial light modulator.

[0012] Furthermore, the beam combining unit includes multiple sets of mirror arrays and two lenses. The number of mirror arrays is the same as the number of split laser beams split by the beam splitter, and the two lenses are sequentially arranged on the outgoing light path of the mirror arrays.

[0013] Each array of mirrors consists of two mirrors II.

[0014] Furthermore, it also includes a beam homogenizer, which is disposed on the output optical path of the two lenses to combine the split laser beams, and the scanning galvanometer is disposed on the output optical path of the beam homogenizer.

[0015] Furthermore, the prism includes prism I and prism II, with prism I respectively disposed on the output optical paths of the two symmetrical split laser beams, and prism II respectively disposed on the output optical paths of the two symmetrical split laser beams.

[0016] Furthermore, prism I and prism II have a trapezoidal structure. Prism I is provided with an incident surface I and an exit surface I, and prism II is provided with an incident surface II and an exit surface II.

[0017] The beneficial effects of this utility model are as follows: The optical path system of the additive manufacturing equipment of this utility model uses a spatial light modulator to control and adjust the power of the separated beam, which can significantly improve the forming speed per unit area. At the same time, the beam combining unit is set up to combine the separated beam before it is incident on the scanning galvanometer, which can improve the energy distribution of the separated beam, making the beam more uniform, thereby improving the surface quality of the coating, increasing production efficiency, and helping to eliminate stress cracks, resulting in a dense finished product. Attached Figure Description

[0018] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0019] Figure 1 Optical path diagram of the collimation and beam splitting unit;

[0020] Figure 2Optical path diagram for collimation beam expander unit and spatial light modulator;

[0021] Figure 3 This is the optical path diagram of the beam combining unit;

[0022] Figure 4 This is a structural diagram of prism I from two different perspectives;

[0023] Figure 5 This is a structural diagram of Prism II from two different perspectives;

[0024] Figure 6 A schematic diagram of the prism structure when the split laser beam consists of four beams;

[0025] The above figures include the following reference numerals:

[0026] 1. Laser; 2. Collimation module; 3. Beam splitter; 4. Prism; 401. Prism I; 4011. Incident surface I; 4012. Exit surface I; 402. Prism II; 4021. Incident surface I; 4022. Exit surface II; 5. Beam expander; 6. Mirror I; 7. Spatial light modulator; 8. Focusing lens; 9. Mirror II; 10. Lens; 11. Beam homogenizer; 12. Scanning galvanometer. Detailed Implementation

[0027] Figure 1 This is the optical path diagram of the collimation and beam splitting unit. Figure 2 Optical path diagram of the collimation beam expander and spatial light modulator. Figure 3 This is the optical path diagram of the beam combining unit. Figure 4 This is a structural diagram of prism I from two different perspectives. Figure 5 This is a structural diagram of prism II from two different perspectives. Figure 6 A schematic diagram of the prism structure when the split laser beam is four beams is shown below. Figure 1-6 As shown: The optical path system of the additive manufacturing equipment in this embodiment includes a laser 1. The output optical path of the laser 1 is sequentially provided with a collimation beam splitting unit, a collimation beam expanding unit, a spatial light modulator 7, an optical focusing unit, and a scanning galvanometer 12. The laser 1 can be a high-power single-mode laser 1, through which an initial laser is emitted. The collimation beam splitting unit is used to adjust the angle of the laser emitted by the laser 1 and split the initial laser into multiple beams. It can use a combination of a collimating lens and a beam splitter 3 or other structures. The optical focusing unit can be a lens used to focus the laser. The collimation beam expanding unit can be a combination of a prism 4 and a beam expander 5 that can adjust the angle of the laser beam, or a collimation beam expanding mirror or other structures. The spatial light modulator 7 can be an electro-optic modulator or an acousto-optic modulator, etc. By setting the spatial light modulator 7, the separated laser beams can be controlled and the power adjusted, thereby improving the forming speed per unit area.

[0028] It also includes a beam combining unit, which is disposed on the output optical path of the optical focusing unit, for combining multiple beams and projecting them onto the scanning galvanometer 12. This structure also includes a control unit for controlling the scanning galvanometer and the spatial light modulator. The scanning galvanometer can be controlled by an existing galvanometer control RTC5 card, and the spatial light modulator can be controlled by an FPGA unit, etc., which are applications of existing technology and will not be described in detail here. The beam combining unit can be a combination of a beam homogenizer 11 and a lens 10, which combines multiple split laser beams modulated by the optical focusing unit, thereby improving the uniformity and energy of the beam and enhancing the forming quality.

[0029] In existing technologies, the optical path system of additive manufacturing equipment still projects the laser beam onto the scanning galvanometer 12 in the form of a split laser beam after a series of processing steps such as beam splitting. This method affects the final molding quality and may result in non-dense molding and relatively low production efficiency. The optical path system of the additive manufacturing equipment of this invention uses a spatial light modulator 7 to control and adjust the power of the split beam, which can significantly improve the molding speed per unit area. At the same time, a beam combining unit is set up to combine the split beam before it enters the scanning galvanometer 12, which can improve the energy distribution of the split beam, making the beam more uniform, thereby improving the surface quality of the coating, increasing production efficiency, and helping to eliminate stress cracks, resulting in a dense finished product.

[0030] In this embodiment, the collimation and beam splitting unit includes a collimation module 2 and a beam splitter 3 disposed on the output optical path of the collimation module 2. The beam splitter 3 is used to split the laser beam modulated by the collimation module 2 into m×n laser beams. In this structure, the collimation module 2 is a collimation lens or similar structure. By setting the collimation lens to collimate the initial laser beam emitted by the laser 1, the laser beam becomes more uniform and stable, which can improve the performance and accuracy of the optical path system. The beam splitter 3 splits the beam modulated by the collimation module 2. The number of split laser beams can be set according to the usage needs, such as splitting into 1×4 beams, thereby avoiding damage to the spatial light modulator 7.

[0031] In this embodiment, the collimating and beam expanding unit includes prisms 4 and beam expanders 5. The number of prisms 4 is the same as the number of laser beams split by the beam splitter 3. Each prism 4 is correspondingly disposed on the output optical path of one laser beam. The number of beam expanders 5 is the same as the number of prisms 4 and is correspondingly disposed on the output optical path of each prism 4. The prisms 4 are used to adjust the angle of the laser beams split by the beam splitter 3, so that the laser beams become parallel light. The number of prisms 4 is the same as the number of laser beams split by the beam splitter 3. For example, if the beam splitter 3 splits four laser beams, the corresponding number of prisms 4 is four and they are disposed on the output optical path of each laser beam. The number of beam expanders 5 is also the same as the number of laser beams split by the beam splitter 3 and they are correspondingly disposed on the output optical path of each prism 4. The use of beam expanders 5 to change the beam diameter of the laser beams is an application of existing technology and will not be described in detail here.

[0032] In this embodiment, a reflector I6 is also included. The reflector I6 is disposed on the output optical path of the beam expander 5, and the number of reflectors I6 is the same as the number of beam expanders 5. The number of reflectors I6 is the same as the number of split laser beams split by the beam splitter 3. By disposing of the reflector I6 between the beam expander 5 and the spatial light modulator 7, the incident direction of the split laser beam modulated by the beam expander 5 into the spatial light modulator 7 can be changed, thereby reducing the length of the optical path system in three-dimensional space, thus reducing the volume of the entire optical path system and saving space.

[0033] In this embodiment, there are multiple spatial light modulators 7, and the number of spatial light modulators 7 is the same as the number of laser beams split by the beam splitter 3. Each spatial light modulator 7 corresponds to one laser beam, and each spatial light modulator 7 is correspondingly set in the outgoing light path of each reflector I6. The number of spatial light modulators 7 is the same as the number of laser beams split by the beam splitter 3. By setting the spatial light modulators 7, the opening and closing of the laser beams or the direction and power of the laser beams can be controlled, thereby ensuring that the power of each laser beam is consistent and improving the quality of printing.

[0034] In this embodiment, the optical focusing unit includes two focusing lenses 8 arranged in sequence. The focusing lenses 8 are arranged in the outgoing light path after the spatial light modulator 7. In this structure, the two focusing lenses 8 have the same focal length and are arranged in the outgoing light path of the spatial light modulator 7. The split laser beam modulated by the spatial light modulator 7 passes through the two focusing lenses 8 in sequence to eliminate zero-order light, thereby improving the final imaging effect.

[0035] In this embodiment, the beam combining unit includes multiple sets of mirror arrays and two lenses 10. The number of mirror arrays is the same as the number of laser beams split by the beam splitter 3. The two lenses 10 are sequentially arranged in the output optical path of the mirror arrays. The number of mirror arrays is the same as the number of laser beams split by the beam splitter 3. The mirror arrays are arranged in the output optical path of the focusing lens 8 to change the angle of the laser beams modulated by the focusing lens 8, so that each laser beam becomes parallel light. The two lenses 10 are arranged after the mirror arrays. By setting two lenses 10 to converge the laser beams modulated by the mirror arrays, the volume of the optical path system can be reduced compared to setting a large lens 10 to converge the laser beams. Of course, the purpose can also be achieved by using a single lens 10.

[0036] Each set of mirror arrays includes two mirrors II9; the placement angle of the two mirrors II9 can be adjusted according to the angle of the incident split laser beam, so that each split laser beam modulated by the mirror array becomes parallel light.

[0037] In this embodiment, a beam homogenizer 11 is also included. The beam homogenizer 11 is disposed on the output optical path of the two lenses and is used to combine the split laser beams. The scanning galvanometer 12 is disposed on the output optical path of the beam homogenizer 11. In this structure, the scanning galvanometer 12 and the beam homogenizer 11 are applications of existing technology and will not be described in detail here. The beam homogenizer 11 is disposed on the output optical path of the two lenses 10 and is located between the lenses 10 and the scanning galvanometer 12. By setting the beam homogenizer 11 to converge the split laser beams modulated by the two lenses 10, the energy concentration and uniformity of the laser beam incident on the scanning galvanometer 12 can be improved, which is beneficial to improving the final molding quality. Compared with the prior art in which the split laser beams are directly incident on the scanning galvanometer 12, in this structure, the split laser beams are combined, which can eliminate stress cracks caused during the 3D printing process, improve the coating quality, produce dense materials, and at the same time improve energy utilization and reduce the waste of laser energy.

[0038] In this embodiment, the prism 4 includes prism I 401 and prism II 402. Prism I 401 is respectively disposed on the output optical path of two symmetrically split laser beams, and prism II 402 is respectively disposed on the output optical path of two symmetrically split laser beams. When the laser beam split by the beam splitter 3 is four beams, since the angles of the laser beams split by the beam splitter 3 are different, two types of prisms 4 are required. At the same time, prism I 401 and prism II 402 are respectively disposed on the output optical path of the four split laser beams. Among them, the two symmetrically distributed split laser beams can use one type of prism 4, that is, prism I 401 or prism II 402 can be used, so that the split laser beams can be modulated into parallel light at a lower cost.

[0039] In this embodiment, prism I 401 and prism II 402 are trapezoidal structures. Prism I 401 has an incident surface I 4011 and an exit surface I 4012, and prism II 402 has an incident surface II 4021 and an exit surface II 4022. Two laser beams that are relatively close to the center line of symmetry of the split laser beam use prism II 402. Prism I 401 has a larger volume than prism II 402. Prism I 401 and prism II 402 are trapezoidal structures, that is, polyhedral structures. Prism I 401 has an incident surface I 4011. The split laser beam enters prism I 401 from the incident surface I 4011 and exits through the exit surface I 4012. Prism II 402 has an incident surface II 4021. The split laser beam enters prism II 402 from the incident surface II 4021 and exits through the exit surface II 4022.

[0040] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model and are not intended to limit it. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of this utility model without departing from the spirit and scope of the technical solutions of this utility model, and all such modifications or substitutions should be covered within the scope of the claims of this utility model.

Claims

1. An optical path system of an additive manufacturing apparatus, characterized by: The laser includes a collimating beam splitter, a collimating beam expander, a spatial light modulator, an optical focusing unit, and a scanning galvanometer, which are sequentially arranged in the output optical path of the laser. It also includes a beam combining unit, which is disposed in the output optical path of the optical focusing unit, for combining multiple beams and projecting them onto the scanning galvanometer.

2. The light path system of an additive manufacturing apparatus according to claim 1, characterized in that: The collimation and beam splitting unit includes a collimation module and a beam splitter disposed on the output optical path of the collimation module. The beam splitter is used to split the laser beam modulated by the collimation module into m×n laser beams.

3. The light path system of an additive manufacturing apparatus according to claim 2, characterized in that: The collimation and beam expanding unit includes prisms and beam expanders. The number of prisms is the same as the number of laser beams split by the beam splitter. Each prism is correspondingly arranged in the output optical path of a laser beam. The number of beam expanders is the same as the number of prisms and is correspondingly arranged in the output optical path of each prism.

4. The light path system of an additive manufacturing apparatus according to claim 3, characterized in that: It also includes a reflector I, which is disposed in the output optical path of the beam expander, and the number of reflectors I is the same as the number of beam expanders.

5. The light path system of an additive manufacturing apparatus according to claim 4, characterized in that: There are multiple spatial light modulators, and the number of spatial light modulators is the same as the number of laser beams split by the beam splitter. Each spatial light modulator corresponds to one laser beam, and each spatial light modulator is set on the outgoing light path of each reflector I.

6. The light path system of an additive manufacturing apparatus according to claim 1, characterized in that: The optical focusing unit includes two focusing lenses arranged in sequence, which are positioned on the outgoing light path after passing through the spatial light modulator.

7. The light path system of an additive manufacturing apparatus according to claim 2, characterized by: The beam combining unit includes multiple sets of mirror arrays and two lenses. The number of mirror arrays is the same as the number of split laser beams split by the beam splitter. The two lenses are arranged sequentially on the outgoing light path of the mirror arrays. Each array of mirrors consists of two mirrors II.

8. The light path system of an additive manufacturing apparatus according to claim 7, characterized in that: It also includes a beam homogenizer, which is disposed on the output optical path of the two lenses to combine the split laser beams, and the scanning galvanometer is disposed on the output optical path of the beam homogenizer.

9. The light path system of an additive manufacturing apparatus according to claim 3, characterized in that: The prism includes prism I and prism II. Prism I is respectively disposed on the output optical path of two symmetrical split laser beams, and prism II is respectively disposed on the output optical path of two symmetrical split laser beams.

10. The light path system of an additive manufacturing apparatus according to claim 9, characterized in that: Prism I and prism II are trapezoidal structures. Prism I is provided with an incident surface I and an exit surface I, and prism II is provided with an incident surface II and an exit surface II.

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