Laser scanning device based on light spot switching, additive manufacturing equipment and method thereof

Abstract

The invention discloses a laser scanning device based on light spot switching, additive manufacturing equipment and a method of the laser scanning device. The laser scanning device comprises a laser device, a collimator and a galvanometer system, wherein the power of the laser device can be adjusted within the range of 5w-30000w; an optical diffraction device is arranged between the collimator and the galvanometer system and used for achieving rapid switching of a first light spot and a second light spot so as to print a workpiece, the first light spot is a Gaussian light spot and used for printing the outer contour of the workpiece, the corresponding printing layer thickness is h1, the second light spot is a shaping light spot and used for printing a filling area of the workpiece, and the corresponding printing layer thickness is h2; the switching speed of the first light spot and the second light spot does not exceed 200 milliseconds. The optical diffraction device is arranged between the collimator and the galvanometer, rapid switching between the high-power shaping light spot and the low-power Gaussian light spot is achieved, the Gaussian light spot is adopted for printing the small-layer-thickness contour, the shaping light spot is adopted for printing the large-layer-thickness filling, and therefore on the premise that the printing quality of a workpiece is guaranteed, the production efficiency is improved. And the printing efficiency is greatly improved.

Description

Technical Field

[0001] The present application relates to the field of additive manufacturing technology, and in particular to a laser scanning device based on spot switching, additive manufacturing equipment and a method thereof. Background Art

[0002] Additive manufacturing technology is a rapid manufacturing technology that forms three-dimensional objects by controlling the laser to scan layer by layer and stacking layer by layer. The process flow is as follows: first, the three-dimensional model of the workpiece is sliced ​​to obtain the contour information of each layer of the workpiece; the powdered material is evenly spread on the surface of the work platform, and the laser selectively melts the powder according to the system instructions; after a section is completed, a new layer of material is spread, and the scanning continues to be selective according to the section information corresponding to the three-dimensional object; according to this method, the next section is scanned for powder spreading, and finally a three-dimensional object is obtained.

[0003] Powder bed additive manufacturing generally uses laser scanning technology, and uses a Gaussian spot of fixed diameter for printing at a fixed layer thickness. This process is usually limited by the spot size and has low efficiency. In order to increase efficiency, the general method is to use a larger diameter spot, obtain a larger spot by replacing the field lens, collimator, and galvanometer, and match it with a higher-power laser, but this method cannot guarantee printing accuracy and resolution, because a large spot with a large diameter has lower printing accuracy than a small spot with a small diameter. The three-axis galvanometer system can also achieve real-time switching of the spot size, with a typical switching diameter between 80μm and 300μm. Because it is a Gaussian spot, the galvanometer has poor tolerance to lasers and its maximum power is severely limited. In addition, the molten pool formed by the Gaussian spot is more prone to overheating in the middle, which can easily cause uneven heat in specific details of the workpiece.

[0004] In the field of welding, there are many ways to switch the spot, such as dual light source reflection switching, using two different collimation paths through electric reflectors to switch the spot size; for example, the coaxial automatic switching lens group can complete the conversion of the beam diameter before the light is emitted. However, they all have common problems, such as slow switching speed, large structural inertia, poor compatibility with the galvanometer, and poor optical quality. This series of problems limits the application of the concept of spot switching in the field of additive manufacturing.

[0005] In summary, spot switching devices have been used in the field of welding, but are not suitable for the field of additive manufacturing. Although three-axis dynamic focusing technology has been used in additive manufacturing, its Gaussian spot is not suitable for use under high power. This situation needs to be broken through urgently. Summary of the invention

[0006] In order to solve the above-mentioned technical problems existing in the prior art, the present invention provides a laser scanning device based on spot switching, an additive manufacturing device and a method thereof. The laser scanning device based on spot switching realizes rapid switching between a shaped spot and a Gaussian spot by deploying an optical diffraction device between a collimator and a galvanometer, and adopts a Gaussian spot to print a small layer thickness contour, and adopts a shaped spot to print a large layer thickness filling. Under the premise of ensuring the printing quality of the workpiece, the printing efficiency is greatly improved, and the shaped spot can make the molten pool state more stable to a certain extent, thereby reducing defects such as warping of the workpiece.

[0007] In order to achieve the above-mentioned object, the present invention provides a laser scanning device based on spot switching, including a laser, a collimator and a galvanometer system, wherein:

[0008] The laser is one, the power is adjustable within the range of 5W-30000W, and the adjustment accuracy at each gear is ±5W;

[0009] An optical diffraction device is provided between the collimator and the galvanometer system, which is used to generate at least a first light spot and a second light spot and realize rapid switching between the first light spot and the second light spot to print the workpiece, wherein the first light spot is a Gaussian light spot, which is used to print the outer contour of the workpiece, and the corresponding printing layer thickness is h1, and the second light spot is a shaping light spot, which is used to print the filling area of ​​the workpiece, and the corresponding printing layer thickness is h2; the switching speed between the first light spot and the second light spot does not exceed 200 milliseconds, the power of the first light spot is less than the power of the second light spot, the diameter of the first light spot is less than the diameter of the second light spot, and h1≦h2.

[0010] As a further preferred embodiment of the present invention, the power range of the first light spot is 5W to 3000W, and the power range of the second light spot is 10W to 30000W.

[0011] As a further preferred embodiment of the present invention, the optical diffraction device includes a vortex phase plate, a conical lens, a spiral phase plate, an optical rotator, a transmission optical grating, a transmission spatial light modulator, a Fresnel lens or a Fresnel grating device.

[0012] As a further preferred embodiment of the present invention, the shaped light spot is an annular light spot, an annular plus dotted light spot, a flat-top light spot, an optical spiral light spot, a honeycomb light spot or a star-shaped light spot.

[0013] As a further preferred embodiment of the present invention, the h1 is 10 μm to 500 μm, and the h2 is 10 μm to 8000 μm.

[0014] As a further preferred embodiment of the present invention, h2 is an integer multiple of h1, and h2 is 2-9 times of h1.

[0015] The present invention also provides an additive manufacturing device, including a powder spreading device, a control system, and a laser scanning device based on spot switching as described in any of the above items.

[0016] The present invention further provides a method for manufacturing an additive manufacturing device, characterized by comprising:

[0017] The control system controls the powder spreading device to spread powder on the working area according to the layer thickness h1. After each layer of powder is spread, the optical diffraction device is controlled to move to form a first light spot to print the outer contour of the workpiece; after each N layers of powder are spread, the optical diffraction device is controlled to move to form a second light spot to print the filling area of ​​the workpiece; wherein N=h2 / h1.

[0018] As a further preferred embodiment of the present invention, after the outer contour of the workpiece is printed using the first light spot, the first light spot is continued to be used to perform a supplementary scan around the outer contour for at least one circle.

[0019] As a further preferred embodiment of the present invention, the number of circles of the nested scan is 1-9 circles.

[0020] The laser scanning device, device and additive manufacturing equipment based on spot switching of the present invention have the following beneficial effects by adopting the above technical solution:

[0021] 1. The present invention adopts a laser with adjustable power in the range of 5W-30000W, and the adjustment accuracy is controlled within ±5W, and an optical diffraction device is deployed between the collimator and the galvanometer, so that the fast switching between the high-power shaping spot and the low-power Gaussian spot can be realized, and the Gaussian spot is used to print the small layer thickness contour, and the shaping spot is used to print the large layer thickness filling, thereby greatly improving the printing efficiency under the premise of ensuring the printing quality of the workpiece, and the shaping spot can make the molten pool state more stable to a certain extent, thereby reducing defects such as warping of the workpiece;

[0022] 2. The present invention only needs to use a set of optical path systems (including a laser, a collimator, a galvanometer system, etc.) to achieve the rapid switching between a high-power shaped light spot and a low-power Gaussian light spot, and the structure is simple and compact;

[0023] 3. The technical solution of the present invention can be used to print workpieces using high-power lasers (up to 30,000w), greatly improving printing efficiency while ensuring workpiece printing quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A working principle diagram of an embodiment of a laser scanning device based on spot switching provided by the present invention;

[0025] Figure 2A scanning schematic diagram of a preferred embodiment of the manufacturing method of the additive manufacturing device of the present invention;

[0026] Markings in the figure:

[0027] 1. Collimator, 2. Base, 3. Optical diffraction device, 4. Galvanometer system, 5. Shaped spot, 6. Gaussian spot, 7. Filling area, 8. Outer contour, 9. Virtual outer contour. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0029] like Figure 1 As shown, the laser scanning device based on spot switching of the present invention includes a laser (not shown in the figure), a collimator 1 and a galvanometer system 4, wherein:

[0030] The laser is one, the power is adjustable within the range of 5W-30000W, and the adjustment accuracy at each gear is ±5W;

[0031] An optical diffraction device 3 is provided between the collimator 1 and the galvanometer system 4, which is used to generate at least a first light spot and a second light spot and realize rapid switching between the first light spot and the second light spot to print the workpiece, wherein the first light spot is a Gaussian light spot 6, which is used to print the outer contour 8 of the workpiece, and the corresponding printing layer thickness is h1, and the second light spot is a shaping light spot 5, which is used to print the filling area 7 of the workpiece, and the corresponding printing layer thickness is h2; the switching speed between the first light spot and the second light spot does not exceed 200 milliseconds, the power of the first light spot is less than the power of the second light spot, the diameter of the first light spot is less than the diameter of the second light spot, and h1≦h2.

[0032] It can be understood that the optical path system of the present invention only includes a laser, a collimator 1, a galvanometer system 4 and an optical diffraction device 3. In order to enable those skilled in the art to better understand the working state of the optical diffraction device 3, Figure 1 The two working states of the optical path system generating the Gaussian spot 6 and the shaped spot 5 are respectively displayed. In a specific implementation, the optical diffraction device 3 is disposed between the collimator 1 and the galvanometer system 4 through the base 2 .

[0033] In the 3D printing process, too high power may affect the printing quality of the workpiece, and too low power may affect the printing efficiency; similarly, too thick a layer may affect the printing quality, and too thin a layer may affect the printing efficiency. As a preferred solution of the present application, in order to better balance the printing efficiency and printing quality of the workpiece, the power range of the first light spot is 5w~3000w, and the power range of the second light spot is 10w~30000w; the h1 is 10μm~500μm, the h2 is 10μm~8000μm, and the shaping light spot 5 is an annular light spot, an annular plus dotted light spot, a flat-top light spot, an optical spiral light spot, a honeycomb light spot or a star-shaped light spot. Further preferably, in order to make the printing method of the workpiece simpler, the h2 is an integer multiple of h1, and h2 is 2-9 times of h1.

[0034] In a specific implementation, the optical diffraction device 3 includes but is not limited to a vortex phase plate, a conical lens, a spiral phase plate, a rotator, a transmissive optical grating, a transmissive liquid crystal optical element, a transmissive spatial light modulator or a Fresnel lens. The specific selection of the device is not limited in the present application.

[0035] The present invention also provides an additive manufacturing device, including a powder spreading device, a control system, and a laser scanning device based on spot switching as described in any of the above embodiments. It should be noted that the main protection core of this application is the laser scanning device, and therefore, other existing components (such as a powder feeding cylinder, a forming cylinder, etc.) included in the additive manufacturing device are not specifically described.

[0036] The present invention further provides a method for manufacturing an additive manufacturing device, comprising:

[0037] The control system controls the powder spreading device to spread powder on the working area according to the layer thickness h1. After each layer of powder spreading is completed, the optical diffraction device 3 is controlled to move to form a first light spot to print the outer contour 8 of the workpiece; after each N layers of powder are spread, the optical diffraction device 3 is controlled to move to form a second light spot to print the filling area 7 of the workpiece; wherein N = h2 / h1. It should be noted that h2 is preferably an integer multiple of h1.

[0038] Preferably, after the outer contour 8 of the workpiece is printed using the first light spot, the first light spot is continued to be used to perform supplementary scanning around the outer contour 8 for at least one circle to form a virtual outer contour 9, such as Figure 2 As shown, this can make the shell of the workpiece denser, thereby making the surface of the workpiece finer. Of course, more nested scanning circles may lead to lower scanning efficiency. Therefore, in order to better balance scanning quality and scanning quality, the number of nested scanning circles is preferably 1-9 circles.

[0039] In order to enable those skilled in the art to better understand and implement the technical solution of the present invention, the technical solution of the present invention is described in detail below in the form of embodiments.

[0040] Example 1

[0041] This embodiment relates to a method for manufacturing an additive manufacturing device, wherein the additive manufacturing device includes a powder spreading device, a control system, and a laser scanning device based on spot switching; the printing material is 316 stainless steel powder.

[0042] The laser scanning device based on spot switching includes a laser, a collimator 1 and a galvanometer system 4, wherein:

[0043] The laser has one power adjustable within the range of 5W-3000W, and the adjustment accuracy at each gear is ±5W to meet different printing layer thickness requirements;

[0044] An optical diffraction device 3 is provided between the collimator 1 and the galvanometer system 4, which is used to generate at least a first light spot and a second light spot and realize rapid switching between the first light spot and the second light spot to print the workpiece, wherein the first light spot is a Gaussian light spot 6, which is used to print the outer contour 8 of the workpiece, and the corresponding printing layer thickness is h1, and the second light spot is a shaping light spot 5, which is used to print the filling area 7 of the workpiece, and the corresponding printing layer thickness is h2; the diameter d1 of the Gaussian light spot 6 is 50μm, the corresponding printing layer thickness h1 is 30μm, and the power is 190w.

[0045] After each layer of powder is applied, the optical diffraction device 3 is controlled to move to form a first light spot to print the outer contour 8 of the workpiece; after the outer contour 8 of the workpiece is printed using the first light spot, the first light spot is continued to be used to perform two additional scans around the outer contour 8.

[0046] After the 4-layer outer contour 8 is printed, the shaping spot 5 is switched to print the filling area 7 of the workpiece. The diameter d2 of the shaping spot 5 is 180 μm, the corresponding printing layer thickness h2 is 120 μm, and the power is 1500 W.

[0047] During the entire printing process, the spot switcher can quickly switch between the Gaussian spot 6 and the shaped spot 5, and the response time for each switch is 100 milliseconds, ensuring efficient and accurate completion of the printing task.

[0048] In the additive manufacturing method of this implementation, the printing accuracy is guaranteed, and the use of the shaped light spot 5 greatly improves the printing speed of the filling part; moreover, by switching between the Gaussian light spot 6 and the shaped light spot 5, the printing efficiency is effectively improved by 120%, while maintaining the high accuracy of the workpiece outer contour 8. In addition, the fast light spot switching technology allows the layer thickness to be flexibly adjusted during the printing process, improving the quality and efficiency of printing at different levels.

[0049] Example 2

[0050] This embodiment relates to a method for manufacturing an additive manufacturing device, wherein the additive manufacturing device includes a powder spreading device, a control system, and a laser scanning device based on light spot switching; the printing material is PA6 nylon powder.

[0051] The laser scanning device based on spot switching includes a laser, a collimator 1 and a galvanometer system 4, wherein:

[0052] The laser has one power adjustable between 50w and 500w, and the adjustment accuracy at each gear is ±5w to meet different printing layer thickness requirements;

[0053] An optical diffraction device 3 of a Fresnel grating device is provided between the collimator 1 and the galvanometer system 4, which is used to generate at least a first light spot and a second light spot and realize rapid switching between the first light spot and the second light spot to print the workpiece, wherein the first light spot is a Gaussian light spot 6, which is used to print the outer contour 8 of the workpiece, and the corresponding printing layer thickness is h1, and the second light spot is a shaping light spot 5 (the shaping light spot 5 is a flat-top light spot), which is used to print the filling area 7 of the workpiece, and the corresponding printing layer thickness is h2; the diameter d1 of the Gaussian light spot 6 is 150 μm, the corresponding printing layer thickness h1 is 60 μm, and the power is 50 W.

[0054] After each layer of powder is applied, the optical diffraction device 3 is controlled to move to form a first light spot to print the outer contour 8 of the workpiece; after the outer contour 8 of the workpiece is printed using the first light spot, the first light spot is continued to be used to perform five additional scans around the outer contour 8.

[0055] After completing the printing of the two-layer outer contour 8, switch to the shaping spot 5 to print the filling area 7 of the workpiece. The diameter d2 of the shaping spot 5 is 800 μm, the corresponding printing layer thickness h2 is 120 μm, and the power is 500 W.

[0056] During the entire printing process, the spot switcher can quickly switch between the Gaussian spot 6 and the shaped spot 5, and the response time of each switch does not exceed 200 milliseconds, ensuring efficient and accurate completion of the printing task.

[0057] In the additive manufacturing method of this implementation, printing accuracy is guaranteed, and the use of the shaped spot 5 greatly improves the printing speed of the filling part; moreover, by switching between the Gaussian spot 6 and the shaped spot 5, the printing efficiency is effectively improved by 80%, while maintaining the high accuracy of the workpiece outer contour 8.

[0058] Example 3

[0059] This embodiment relates to a method for manufacturing an additive manufacturing device, wherein the additive manufacturing device includes a powder spreading device, a control system, and a laser scanning device based on spot switching; the printing material is 316L powder.

[0060] The laser scanning device based on spot switching includes a laser, a collimator 1 and a galvanometer system 4, wherein:

[0061] The laser is one, and the power is adjustable in the range of 50w-500w, and the adjustment accuracy in each gear is ±5w to meet different printing layer thickness requirements;

[0062] A spiral phase plate is provided between the collimator 1 and the galvanometer system 4, which is used to generate at least a first light spot and a second light spot and realize rapid switching between the first light spot and the second light spot to print the workpiece, wherein the first light spot is a Gaussian light spot 6, which is used to print the outer contour 8 of the workpiece, and the corresponding printing layer thickness is h1, and the second light spot is a shaped light spot 5 (the shaped light spot 5 is a ring-shaped light spot), which is used to print the filling area 7 of the workpiece, and the corresponding printing layer thickness is h2; the diameter d1 of the Gaussian light spot 6 is 55 μm, the corresponding printing layer thickness h1 is 30 μm, and the power is 190 W.

[0063] After each layer of powder is laid, the optical diffraction device 3 is controlled to move to form a first light spot to print the outer contour 8 of the workpiece; after the outer contour 8 is printed, it is switched to the shaping light spot 5 to print the filling area 7 of the workpiece. The diameter d2 of the shaping light spot 5 is 110μm, the corresponding printing layer thickness h2 is 30μm, and the power is 300w.

[0064] During the entire printing process, the spot switcher can quickly switch between the Gaussian spot 6 and the shaped spot 5, and the response time of each switch does not exceed 50 milliseconds, ensuring efficient and accurate completion of the printing task.

[0065] In the additive manufacturing method of this implementation, printing accuracy is guaranteed, and the use of the shaped spot 5 greatly improves the printing speed of the filling area; moreover, by switching between the Gaussian spot 6 and the shaped spot 5, the printing efficiency is effectively improved by 50%, while maintaining the high accuracy of the workpiece outer contour 8.

[0066] Example 4

[0067] This embodiment relates to a method for manufacturing an additive manufacturing device, wherein the additive manufacturing device includes a powder spreading device, a control system, and a laser scanning device based on light spot switching; the printing material is aluminum alloy powder.

[0068] The laser scanning device based on spot switching includes a laser, a collimator 1 and a galvanometer system 4, wherein:

[0069] The laser has one power adjustable within the range of 5W-3000W, and the adjustment accuracy at each gear is ±5W to meet different printing layer thickness requirements;

[0070] A spiral phase plate is provided between the collimator 1 and the galvanometer system 4, which is used to generate at least a first light spot and a second light spot and realize rapid switching between the first light spot and the second light spot to print the workpiece, wherein the first light spot is a Gaussian light spot 6, which is used to print the outer contour 8 of the workpiece, and the corresponding printing layer thickness is h1, and the second light spot is a shaped light spot 5 (the shaped light spot 5 is a ring-shaped light spot), which is used to print the filling area 7 of the workpiece, and the corresponding printing layer thickness is h2; the diameter d1 of the Gaussian light spot 6 is 70 μm, the corresponding printing layer thickness h1 is 60 μm, and the power is 500 w.

[0071] After each layer of powder is applied, the optical diffraction device 3 is controlled to move to form a first light spot to print the outer contour 8 of the workpiece; after the outer contour 8 of the workpiece is printed using the first light spot, the first light spot is continued to be used to perform two additional scans around the outer contour 8.

[0072] After completing the printing of the two-layer outer contour 8, switch to the shaping spot 5 to print the filling area 7 of the workpiece. The diameter d2 of the shaping spot 5 is 210 μm, the corresponding printing layer thickness h2 is 120 μm, and the power is 3000 W.

[0073] During the entire printing process, the spot switcher can quickly switch between the Gaussian spot 6 and the shaped spot 5, and the response time of each switch does not exceed 50 milliseconds, ensuring efficient and accurate completion of the printing task.

[0074] In the additive manufacturing method of this implementation, printing accuracy is guaranteed, and the use of the shaped spot 5 greatly improves the printing speed of the filling part; moreover, by switching between the Gaussian spot 6 and the shaped spot 5, the printing efficiency is effectively improved by 120%, while maintaining the high accuracy of the workpiece outer contour 8.

[0075] Example 5

[0076] This embodiment relates to a manufacturing method of an additive manufacturing device, wherein the additive manufacturing device includes a powder spreading device, a control system, and a laser scanning device based on spot switching; the printing material is aluminum alloy powder, the printed workpiece can be applied in the shipbuilding industry, and the size of the printed workpiece exceeds 10*10m*5m.

[0077] The laser scanning device based on spot switching includes a laser, a collimator 1 and a galvanometer system 4, wherein:

[0078] The laser has one power adjustable between 5000w and 30000w, and the adjustment accuracy at each gear is ±5w to meet different printing layer thickness requirements;

[0079] An optical diffraction device 3 is provided between the collimator 1 and the galvanometer system 4, which is used to generate at least a first light spot and a second light spot and realize rapid switching between the first light spot and the second light spot to print the workpiece, wherein the first light spot is a Gaussian light spot 6, which is used to print the outer contour 8 of the workpiece, and the corresponding printing layer thickness is h1, and the second light spot is a shaped light spot 5 (the shaped light spot 5 is a ring-shaped light spot with dots), which is used to print the filling area 7 of the workpiece, and the corresponding printing layer thickness is h2; the diameter d1 of the Gaussian light spot 6 is 100 μm, the corresponding printing layer thickness h1 is 100 μm, and the power is 5000 w.

[0080] After each layer of powder is applied, the optical diffraction device 3 is controlled to move to form a first light spot to print the outer contour 8 of the workpiece; after the outer contour 8 of the workpiece is printed using the first light spot, the first light spot is continued to be used to perform additional scanning around the outer contour 8 for ten circles.

[0081] After the 8-layer outer contour 8 is printed, the shaping spot 5 is switched to print the filling area 7 of the workpiece. The diameter d2 of the shaping spot 5 is 8000 μm, the corresponding printing layer thickness h2 is 800 μm, and the power is 30000 W.

[0082] During the entire printing process, the spot switcher can quickly switch between the Gaussian spot 6 and the shaped spot 5, and the response time of each switch does not exceed 200 milliseconds, ensuring efficient and accurate completion of the printing task.

[0083] In the additive manufacturing method implemented in this embodiment, printing accuracy is guaranteed, and the use of the dot ring light spot greatly improves the printing speed of the filling part; moreover, by switching between the Gaussian light spot 6 and the shaping light spot 5, the printing efficiency is effectively improved by 500%, while maintaining the high accuracy of the workpiece outer contour 8.

[0084] Example 6

[0085] This embodiment relates to a method for manufacturing an additive manufacturing device, wherein the additive manufacturing device includes a powder spreading device, a control system, and a laser scanning device based on light spot switching; the printing material is PA11 nylon powder.

[0086] The laser scanning device based on spot switching includes a laser, a collimator 1 and a galvanometer system 4, wherein:

[0087] The laser has one power adjustable between 5w-300w, and the adjustment accuracy at each gear is ±5w to meet different printing layer thickness requirements;

[0088] A vortex phase plate is provided between the collimator 1 and the galvanometer system 4, which is used to generate at least a first light spot and a second light spot and realize rapid switching between the first light spot and the second light spot to print the workpiece, wherein the first light spot is a Gaussian light spot 6, which is used to print the outer contour 8 of the workpiece, and the corresponding printing layer thickness is h1, and the second light spot is a shaping light spot 5 (the shaping light spot 5 is a ring-shaped light spot), which is used to print the filling area 7 of the workpiece, and the corresponding printing layer thickness is h2; the diameter d1 of the Gaussian light spot 6 is 60 μm, the corresponding printing layer thickness h1 is 30 μm, and the power is 5 W.

[0089] After each layer of powder is applied, the optical diffraction device 3 is controlled to move to form a first light spot to print the outer contour 8 of the workpiece; after the outer contour 8 of the workpiece is printed using the first light spot, the first light spot is continued to be used to perform a supplementary scan around the outer contour 8.

[0090] After completing the printing of the three-layer outer contour 8, the shaping spot 5 is switched to print the filling area 7 of the workpiece. The diameter d2 of the shaping spot 5 is 180 μm, the corresponding printing layer thickness h2 is 90 μm, and the power is 300 W.

[0091] During the entire printing process, the spot switcher can quickly switch between the Gaussian spot 6 and the shaped spot 5, and the response time of each switch does not exceed 200 milliseconds, ensuring efficient and accurate completion of the printing task.

[0092] In the additive manufacturing method of this implementation, printing accuracy is guaranteed, and the use of the shaped spot 5 greatly improves the printing speed of the filling part; moreover, by switching between the Gaussian spot 6 and the shaped spot 5, the printing efficiency is effectively improved by 50%, while maintaining the high accuracy of the workpiece outer contour 8.

[0093] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0094] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims.

Claims

1. A laser scanning device based on spot switching, characterized in that: It includes a laser, a collimator and a galvanometer system, wherein: The laser is one, the power is adjustable within the range of 5W-30000W, and the adjustment accuracy at each gear is ±5W; An optical diffraction device is provided between the collimator and the galvanometer system, which is used to generate at least a first light spot and a second light spot, and to realize rapid switching between the first light spot and the second light spot to print the workpiece, wherein the first light spot is a Gaussian light spot, which is used to print the outer contour of the workpiece, and the corresponding printing layer thickness is h1, and the second light spot is a shaping light spot, which is used to print the filling area of ​​the workpiece, and the corresponding printing layer thickness is h2; the switching speed between the first light spot and the second light spot does not exceed 200 milliseconds, the power of the first light spot is less than the power of the second light spot, the diameter of the first light spot is less than the diameter of the second light spot, and h1≦h2.

2. The laser scanning device based on spot switching according to claim 1, characterized in that: The power range of the first light spot is 5w-3000w, and the power range of the second light spot is 10w-30000w.

3. The laser scanning device based on spot switching according to claim 2, characterized in that: The optical diffraction device includes a vortex phase plate, a conical lens, a spiral phase plate, an optical rotator, a transmission optical grid, a transmission spatial light modulator, a Fresnel lens or a Fresnel grating device.

4. The laser scanning device based on spot switching according to any one of claims 1 to 3, characterized in that: The shaped light spot is an annular light spot, an annular plus dotted light spot, a flat-top light spot, an optical spiral light spot, a honeycomb light spot or a star-shaped light spot.

5. The laser scanning device based on spot switching according to claim 4, characterized in that: The h1 is 10 μm to 500 μm, and the h2 is 10 μm to 8000 μm.

6. The laser scanning device based on spot switching according to claim 5, characterized in that: The h2 is an integer multiple of h1, and h2 is 2-9 times of h1.

7. An additive manufacturing device, characterized in that: It comprises a powder spreading device, a control system and a laser scanning device based on light spot switching as described in any one of claims 1 to 6.

8. A method for manufacturing the additive manufacturing device according to claim 7, characterized in that: include: The control system controls the powder spreading device to spread powder on the working area according to the layer thickness h1. After each layer of powder is spread, the optical diffraction device is controlled to move to form a first light spot to print the outer contour of the workpiece; after each N layers of powder are spread, the optical diffraction device is controlled to move to form a second light spot to print the filling area of ​​the workpiece; wherein N=h2 / h1.

9. The manufacturing method of the additive manufacturing equipment according to claim 8, characterized in that: After the outer contour of the workpiece is printed using the first light spot, the first light spot is continued to be used to perform supplementary scanning around the outer contour for at least one circle.

10. The manufacturing method of the additive manufacturing equipment according to claim 9, characterized in that: The number of nested scans is 1-9.

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