Field lens and optical shaping system

Abstract

The utility model belongs to the field of additive manufacturing, and relates to a field lens and an optical forming system, and the shape of a working area of the field lens is the same as or similar to that of an available forming area of the field lens. The field lens and the optical forming system provided by the utility model can improve the large-format forming efficiency and quality.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the field of additive manufacturing, and relates to a field lens and optical forming system, in particular to a field lens and optical forming system for additive manufacturing. BACKGROUND

[0002] The field lens used by the optical forming system of the existing laser selective melting equipment is mostly circular, but the forming area is mostly rectangular, and the use schematic diagram of the field lens and the forming area is as shown in the figure. Figure 1 For the conventional circular field lens, in order to adapt to the rectangular forming area, the forming area of the circular field lens needs to be cut, and the forming ability of the field lens is lost. At the same time, the circular working area formed by the circular field lens is difficult to splice, and the splicing error is large, which affects the printing efficiency and printing quality in the large-format printing process. UTILITY MODEL CONTENT

[0003] In order to solve the above technical problems existing in the background art, the utility model provides a field lens and optical forming system capable of improving the large-format forming efficiency and quality.

[0004] In order to achieve the above purpose, the utility model adopts the following technical scheme:

[0005] A field lens, characterized in that: the shape of the working area of the field lens is the same as or similar to the shape of the available forming area of the field lens.

[0006] The shape of the working area of the above-mentioned field lens is non-circular.

[0007] The shape of the working area of the above-mentioned field lens is rectangular, triangular, trapezoidal or sector.

[0008] The above-mentioned field lens includes double-concave lenses, concave-convex lenses, double-convex lenses and protective lenses arranged in sequence from front to back; the light emitted through the protective lenses forms the working area of the field lens.

[0009] The above-mentioned field lens further includes a field lens shell covering the outside of the double-concave lenses, the concave-convex lenses, the double-convex lenses and the protective lenses.

[0010] An optical forming system, characterized in that: the optical forming system includes a galvanometer system and the above-mentioned field lens arranged in sequence from front to back.

[0011] The above-mentioned field lens is single or multiple groups; when the field lens is single, the shape of the working area of the single field lens is the same as or similar to the shape of the available forming area of the field lens; when the field lens is multiple, the shape formed after the working areas of the multiple field lenses are spliced is the same as or similar to the overall shape or partial shape of the area to be formed.

[0012] When the above-mentioned field lens is multiple, the multiple field lenses are arranged in an array.

[0013] The above-mentioned galvanometer system is a split structure or an integrated structure; when the galvanometer system is a split structure, the number of the galvanometer system matches the number of the field lens.

[0014] The utility model has the advantages of:

[0015] The utility model provides a field lens and optical forming system, wherein the shape of the working area of the field lens is same or similar to the shape of the available forming area of the field lens. The utility model discloses the shape of the working area of the field lens is same or similar to the shape of the available forming area of the field lens, reduces the area difference between the working area of the field lens and the available forming area as far as possible, reduces the light beam waste in the non-forming area and the volume waste of the field lens due to the matching of the circular field lens with different forming areas, and the multi-light-path forming system formed based on the field lens has better splicing quality, can improve the forming quality and efficiency in the large-format printing process. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 It is a schematic diagram of the circular field lens used in the prior art in use;

[0017] Figure 2 It is a schematic diagram of the field lens provided by the utility model in use;

[0018] Figure 3 It is a schematic diagram of the realization principle of the field lens provided by the utility model;

[0019] Figure 4 It is a schematic diagram of the sectional structure of the field lens provided by the utility model;

[0020] Figure 5 It is a schematic diagram of the three-dimensional structure of the field lens provided by the utility model;

[0021] Figure 6 It is a schematic diagram of the field lens provided by the utility model in splicing use (rectangular forming area);

[0022] Figure 7 It is a schematic diagram of the optical forming system (block integrated type) provided by the utility model in use;

[0023] Figure 8 It is a schematic diagram of the field lens provided by the utility model in splicing use (rectangular forming area);

[0024] Figure 9 It is a schematic diagram of the optical forming system (long strip integrated type) provided by the utility model in use;

[0025] Figure 10This is a schematic diagram of the field lens provided by this utility model when it is spliced ​​together (triangular forming area);

[0026] Figure 11 This is a schematic diagram of the optical shaping system (triangular splicing integrated type) provided by this utility model in use;

[0027] Figure 12 This is a schematic diagram of the field lens provided by this utility model when it is used in a splicing process (trapezoidal forming area);

[0028] Figure 13 This is a schematic diagram of the optical shaping system (ring-shaped integrated type) provided by this utility model in use;

[0029] Figure 14 These are schematic diagrams showing the use of a circular field lens in the prior art and the field lens provided by this utility model in a spliced ​​state (rectangular forming area);

[0030] Figure 15 These are schematic diagrams showing the use of a circular field lens in the prior art and the field lens provided by this utility model in a spliced ​​state (rectangular forming area);

[0031] Figure 16 This is a comparative schematic diagram of the use of the multi-path optical shaping system employed in the prior art and the optical shaping system provided by this utility model.

[0032] in:

[0033] 1-Biconcave lens; 2-Concave-convex lens; 3-Biconvex lens; 4-Protective lens; 5-Field lens housing; 6-Field lens; 7-Working area; 8-Usable forming area; 9-Galvanometer deflection motor assembly; 10-Galvanometer lens assembly; 11-Water cooling device; 12-Galvanometer controller; 13-Galvanometer encapsulation housing; 14-Laser beam; 15-Rotation axis; 16-Powder discharge cylinder; 17-Forming cylinder; 18-Integrated galvanometer system; 19-Unstitched area. Detailed Implementation

[0034] This invention provides a field lens whose working area 7 has the same or similar shape as the usable forming area 8. By setting the shape of the working area 7 to be the same or similar to the usable forming area 8, this invention minimizes the area difference between the working area and the usable forming area, thus reducing the area of ​​the unusable region and achieving a higher beam density per unit forming area, thereby improving forming quality. To achieve the aforementioned objective, the working area 7 of the field lens provided by this invention is non-circular; for example, the shape of the working area 7 can be rectangular (e.g.,...). Figure 2 As shown), triangle (as shown) Figure 10 (as shown), trapezoidal (as shown)Figure 12 (as shown) or sector.

[0035] For example, see Figure 2 This is a schematic diagram of the field lens provided by this utility model. The field lens has an overall rectangular structure. The working area 7 of the field lens and the usable shaping area 8 are similar in shape, both being rectangular. That is, the working area 7 and the usable shaping area 8 overlap as much as possible. Without changing the parameters of other optical shaping systems besides the field lens, the beam density within the shaping area can be significantly improved. See also... Figure 3 The field lens provided by this utility model represents the process of transforming an existing circular field lens into a non-circular field lens. After determining the forming area and forming parameter requirements, the existing conventional circular field lens is optically designed and verified. After confirming the shape characteristics of the non-circular field lens to meet the requirements, the existing conventional field lens is then... Figure 3 The processing shown involves inscribed rectangles on the lenses within the lens group inside the field lens, thereby increasing the number of beams per unit area and improving the layout density while meeting the forming requirements. Ultimately, this makes the working area 7 of the field lens have the same or similar shape as the available forming area 8.

[0036] To ensure that the working area 7 of the field lens has the same or similar shape to the available forming area 8, see [reference needed]. Figure 4 as well as Figure 5 This is the internal structure of the field lens 6 provided by this utility model. It includes a biconcave lens 1, a concave-convex lens 2, a biconvex lens 3, a protective mirror 4, and a field lens housing 5. The biconcave lens 1 is a negative lens that diverges light, expanding the scanning field of view; the concave-convex lens 2 is a negative lens that corrects aberrations such as field curvature, further expanding the field of view; the biconvex lens 3 converges light, further reducing the light spot; the protective mirror 4 protects the field lens without altering the optical path. Simultaneously, the biconcave lens 1, the concave-convex lens 2, the biconvex lens 3, and the protective mirror 4 can be installed inside the field lens housing 5. Exemplarily, the shapes of the biconcave lens 1, the concave-convex lens 2, the biconvex lens 3, and the protective mirror 4 are all the same as or similar to the shape of the usable forming area 8. Figure 5 For example, the field lens housing 5 is generally truncated trapezoidal in shape with a rectangular cross-section. The shapes of the biconcave lens 1, the concave-convex lens 2, the biconvex lens 3, and the protective lens 4 are respectively set into similar rectangular structures and finally encapsulated in the field lens housing 5. That is, the light emitted from the protective lens 4 forms a rectangular working area 7, which is the same as or similar in shape to the usable forming area 8. The field lens provided by this utility model is manufactured as follows: the scanning area of ​​the existing galvanometer and the rectangular field lens is confirmed, the field lens is designed according to the rectangle within the scanning area, the lens assembly inside the field lens is manufactured, the field lens housing is manufactured, and the lens assembly and the field lens housing are encapsulated. The manufacturing methods of the lens assembly, the housing, and the encapsulation methods of the lens assembly are all existing and conventional technologies, and will not be described in detail here.

[0037] Due to the special requirements of part additive manufacturing on forming parameters, a large-size special field lens must be used to achieve high forming precision. Therefore, based on the premise of using the large-size field lens, the field lens provided by the utility model can be spliced to form a forming area together when in use, that is, a large-size forming area is finally formed by reasonable splicing of a small-size available forming area 8, thereby meeting the use of different additive manufacturing. For example, referring to Figure 6 , based on Figure 2 , the field lens (the working area 7 is rectangular) is spliced by four groups of Figure 2 , the combination of multiple groups of field lenses is realized. The field lens combination shown in Figure 6 is used, so that the working area 7 of the field lens is similar in shape to the available forming area 8. In this spliced state, the demand for large-format forming can be met. Without changing other optical forming parameters except the field lens, the multi-path optical forming system meets the demand for large-format forming, and the beam density in the forming area is improved. At the same time, the closely arranged field lens groups increase the splicing overlap area between adjacent galvanometer mirrors, so that large-format forming can be realized while maintaining good splicing area forming quality. For example, for additive manufacturing of parts with obvious forming features, such as long strip-shaped parts, the field lens combination shown in Figure 8 can be used to realize complete forming area coverage, and the arrangement is more compact, and the splicing area of the forming area is larger. In the structure shown in Figure 8 , for example, six groups of field lenses shown in Figure 2 can be spliced to form a combination of long strip-shaped multiple groups of field lenses.

[0038] Referring to Figure 10 , the working area 7 of the field lens is triangular, and different types of forming area demands can be adapted by flexible combination of such field lenses. Referring to Figure 11 , for example, four groups of field lenses shown in Figure 10 , the working area 7 of which is triangular, are spliced to form a combination of linear multiple groups of field lenses. Referring to Figure 12 , the working area 7 of the field lens is trapezoidal or sector-shaped, and according to the forming demand, multiple Figure 12 , trapezoidal field lenses or sector-shaped field lenses can be spliced or combined into a field lens group to adapt to annular forming chambers. Referring to Figure 13 , for example, multiple groups of field lenses shown in Figure 12 , the working area 7 of which is trapezoidal, are spliced to finally form a combination of multiple groups of field lenses similar to a circular ring. Of course, according to actual needs, Figure 12The trapezoidal processing in the middle is processed into a fan shape, and through splicing, a plurality of groups of field mirrors in a circular ring shape can be directly formed. It should be noted that when splicing is performed, the forming area size needs to be confirmed, and a matching galvanometer field mirror combination is selected according to the forming precision requirement, the single galvanometer field mirror forming area is confirmed, the splicing area is confirmed, and the galvanometer field mirror group is spliced.

[0039] Referring to Figure 14 , Figure 15 and Figure 16 , it can be clearly seen that when the field mirror in the prior art is combined or spliced, an unspliced area 19 is formed at the periphery of the forming area and the center position, which is not conducive to the smooth forming of a large area; at the same time, when the field mirror adopted by the utility model is combined or spliced, the unspliced area 19 is reduced or even disappears, which well meets the forming requirement, and the closely arranged field mirror group increases the splicing overlap area between adjacent galvanometers, so that large-area forming can be realized while maintaining good splicing area forming quality.

[0040] On the basis of the foregoing field mirror, the utility model also provides an optical forming system formed based on the field mirror, which comprises a galvanometer system arranged in sequence from front to back and the field mirror 6 as described above, and further comprises a laser, a collimating mirror, a beam expander and other optical elements. According to actual forming requirements, the number of lasers, collimating mirrors, beam expanders, galvanometers and field mirrors can be increased respectively or simultaneously. The field mirror 6 is single or multiple groups. When the field mirror 6 is single, the shape of the working area 7 of the single field mirror 6 is the same as or similar to the overall shape of the available forming area 8, that is, the single field mirror 6 can be used to realize forming work. When the field mirror 6 is multiple, the shape of the working area 7 of the multiple field mirrors after splicing is the same as or similar to the overall shape or local shape of the area to be formed or the area to be formed, that is, the multiple field mirrors 6 complete the forming work of the area to be formed. When the field mirror 6 is multiple, the multiple field mirrors 6 are arranged in an array, as shown in Figure 6 , Figure 8 , Figure 11 , Figure 13 , Figure 14 and Figure 15 . Among them, Figure 13 The multiple field mirrors shown in are arranged in a circular array, Figure 6 , Figure 8 , Figure 11 , Figure 13 , Figure 14 and Figure 15 The multiple field mirrors are arranged in a linear array.

[0041] For example, in practical use, the field lens 6 and the galvanometer system can be packaged together to form a single integrated structure. Unifying and integrating optical components such as the galvanometer system, field lens 6, collimator, and beam expander can reduce unnecessary space requirements such as housings and packaging caused by multiple independent galvanometers, thereby reducing the relative volume of the multi-path shaping system, increasing the layout density of the shaping system, and improving the integration of the optical shaping system.

[0042] The galvanometer system used in this invention can be either a separate structure or an integrated structure; when the galvanometer system is a separate structure, the number of galvanometers matches the number of field lenses 6. Integrated packaging of the galvanometer system can meet the requirements of high system integration. See also Figure 7 This is an integrated galvanometer system 18, including a galvanometer lens assembly 10, a galvanometer deflection motor assembly 9, a galvanometer controller 12, a water-cooling device 11, and a galvanometer housing 13. By unifying and integrating multiple galvanometer lenses, deflection motors, and controllers into a single package, and by uniformly cooling this integrated package, the interfaces of multiple independent galvanometers of the same type are merged, reducing the number of external interfaces, increasing system integration, and reducing system size. It should be noted that the arrangement of the galvanometer lenses and deflection motors, the arrangement of the galvanometer controller, and the galvanometer housing are designed according to the arrangement of the field lens assembly. Simultaneously, thermal analysis of the galvanometer is performed, and the cooling design is based on the results of the thermal analysis. For example, using... Figure 8 Taking the field lens assembly shown as an example, the galvanometer system corresponding to the field lens assembly for this rectangular shaping area is further integrated. An integrated optical shaping system consisting of a rectangular field lens and an integrated galvanometer is used to achieve coverage of the entire rectangular shaping area, such as... Figure 9 As shown, this can significantly reduce the volume waste in the non-shaping area of ​​a conventional circular field lens's working area, greatly increase the integration of the system's optical shaping system, and reduce the number of parts. For example, see [link to example]. Figure 16 ,against Figure 2 The combination of field lenses shown (forming a rectangular shaping area) can integrate the galvanometer systems corresponding to the four field lenses, significantly reducing the volume waste in the non-shaping areas of conventional circular field lenses, reducing the number of parts, and further miniaturizing the galvanometer system. For another example, see... Figure 13 The integrated galvanometer system 18 can be connected to the rotating shaft 15 at the center of the annular forming chamber, which can realize various forming parameters such as forming spot size or power density. The laser can also be used for laser-assisted forming. Furthermore, multiple forming cylinders 17, powder dropping cylinders 16, and top powder cylinder groups as required are arranged at the bottom to further improve forming efficiency.

Claims

1. A field lens characterized in that: The shape of the working area (7) of the field lens is the same as or similar to the shape of the available shaping area (8) of the field lens.

2. The field lens of claim 1, wherein: The shape of the working area (7) of the field lens is non-circular.

3. The field lens of claim 2, wherein: The shape of the working area (7) of the field lens is rectangular, triangular, trapezoidal or sectorial.

4. Field lens according to claim 1 or 2 or 3, characterized in that: The field lens comprises, from front to back, a double-concave lens (1), a concave-convex lens (2), a double-convex lens (3) and a protective lens (4); the light emitted through the protective lens (4) forms the working area (7) of the field lens.

5. The field lens of claim 4, wherein: The field lens further comprises a field lens shell (5) covering the double-concave lens (1), the concave-convex lens (2), the double-convex lens (3) and the protective lens (4) from outside.

6. An optical shaping system characterized by: The optical shaping system comprises, from front to back, a galvanometer system and the field lens (6) according to any one of claims 1-5.

7. The optical shaping system of claim 6, wherein: The field lens (6) is single-group or multi-group; when the field lens (6) is single-group, the shape of the working area (7) of the single-group field lens (6) is the same as or similar to the shape of the available shaping area (8) of the field lens; when the field lens (6) is multi-group, the shape of the working area (7) of the multi-group field lens after splicing is the same as or similar to the overall shape or partial shape of the area to be shaped.

8. The optical shaping system of claim 7, wherein: When the field lens (6) is multi-group, the multi-group field lens (6) is arranged in an array.

9. The optical shaping system of claim 8, wherein: When the field lens (6) is multi-group, the multi-group field lens (6) is arranged in a circular array or in a linear array.

10. The optical shaping system of claim 7 or 8 or 9, wherein: The galvanometer system is of split structure or integrated structure; when the galvanometer system is of split structure, the number of the galvanometer system matches the number of the field lens (6).

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