A light spot switching device and a light path system for LPBF forming

Abstract

The present application relates to the technical fields of laser additive manufacturing, and particularly relates to a light spot switching device and an optical path system for LPBF forming. The light spot switching device comprises a shell, a light beam shaping unit and a first driving unit. The shell is provided with a light inlet and a light outlet for forming a laser path. The light beam shaping unit is movably arranged in the shell, and is used for shaping a light spot of a light beam into a linear light spot. When the light beam shaping unit is located at a first working position, an input end of the light beam shaping unit corresponds to the light inlet, and an output end of the light beam shaping unit corresponds to the light outlet. When the light beam shaping unit is located at a second working position, the light beam shaping unit is located outside the laser path. The light beam shaping unit is driven by the first driving unit to switch between the first working position and the second working position, so as to switch between a circular light spot and a linear light spot to perform printing work of additive manufacturing, thereby effectively improving the printing processing efficiency of additive manufacturing.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of laser additive manufacturing technology, and particularly relates to a light spot switching device and an optical path system for LPBF forming. BACKGROUND

[0002] The laser powder bed fusion (LPBF) technology is an important branch of the laser additive manufacturing (AM) technology. Based on the layer-by-layer manufacturing and accumulation forming principle, the LPBF technology can utilize software to slice a three-dimensional model of a part, and utilize a focused laser beam to selectively fuse powder particles layer by layer, so as to directly obtain a metal part with high performance and high density. When the laser powder bed fusion technology is used for additive manufacturing, a traditional technology is to use a circular laser spot for printing work.

[0003] However, the traditional circular laser spot additive manufacturing technology has a low single processing width, which is only comparable to the diameter of the spot. Since the shapes of the layers are different during the printing process, it is more suitable to use the circular laser spot for printing in some narrow areas, and it is necessary to repeat the scanning and processing multiple times to complete the single layer forming in some wide areas, so that the processing efficiency of the laser additive manufacturing is greatly limited. SUMMARY

[0004] In view of the above defects, the technical problem to be solved by the present application is to provide a light spot switching device and an optical path system for LPBF forming, which can switch the laser to a linear spot when needed, thereby improving the single processing width and the processing efficiency of the additive manufacturing.

[0005] The above technical purpose of the present application is achieved by the following technical scheme:

[0006] In a first aspect, a light spot switching device for LPBF forming is provided, comprising:

[0007] a housing, provided with a light inlet and a light outlet for forming a laser path;

[0008] a beam shaping unit movably arranged in the housing, the beam shaping unit being configured to shape a light spot of a light beam into a linear light spot; when the beam shaping unit is in a first working position, an input end of the beam shaping unit corresponds to the light inlet, and an output end of the beam shaping unit corresponds to the light outlet; when the beam shaping unit is in a second working position, the beam shaping unit is located outside the laser path;

[0009] A first driving unit is arranged in the housing, and is configured to drive the light beam shaping unit to switch between the first working position and the second working position.

[0010] By using the above scheme, when in use, the first driving unit drives the light beam shaping unit to be located at the first working position. After the laser beam passes through the light beam shaping unit, the light spot of the light beam is shaped into a linear light spot. The linear light spot is used for additive manufacturing processing, which increases the single processing width, reduces the number of scans, and improves the processing efficiency. For the profile part that can be scanned and printed by the linear light spot and the part that cannot be scanned and printed by the linear light spot, the first driving unit drives the light beam shaping unit to move to the second working position. At this time, the light beam shaping unit is away from the laser path. The laser beam directly passes through the laser path, and the light spot of the light beam is circular. The light beam shaping unit switches between the first working position and the second working position, thereby switching between the circular light spot and the linear light spot to perform the printing work of additive manufacturing, which effectively improves the printing and processing efficiency of additive manufacturing. Moreover, the housing can provide a space separated from the outside for the light beam shaping unit, thereby preventing the influence of the external environment on the light beam shaping unit.

[0011] Preferably, the light beam shaping unit is arranged on the working end of the first driving unit and is configured to be rotatable relative to the working end of the first driving unit. When the linear light spot is used for scanning and printing in the printing area, the width of the light spot required for scanning in the printing area may be smaller than the length of the linear light spot. For the printing area with a required scanning width smaller than the length of the linear light spot or other areas with an arc-shaped profile, the angle of the linear light spot can be adjusted by rotating the light beam shaping unit, thereby adjusting the width of the linear light spot for scanning in the printing area.

[0012] Preferably, the first driving unit comprises a linear motor, a fixed seat, a moving seat, and a fixed sleeve. The moving seat is slidingly connected to the fixed seat. The linear motor is arranged on the fixed seat. The working end of the linear motor is connected to the moving seat. The fixed sleeve is fixedly connected to the moving seat. The light beam shaping unit is rotatably arranged in the fixed sleeve. Since the light beam shaping unit is rotatably arranged in the fixed sleeve, the stability of the rotation of the light beam shaping unit is improved, and the light beam shaping unit is also protected.

[0013] Preferably, the fixed seat is provided with a first mounting groove. The moving seat comprises a movable block and a connecting piece connected to each other. The movable block is slidingly connected to the first mounting groove. The fixed sleeve is fixedly connected to the connecting piece. Since the movable block is slidingly connected to the first mounting groove, the overall structure is more compact, and the installation space is saved.

[0014] As preferred, the stator of the linear motor is arranged in the first mounting slot, the second mounting slot is arranged on the side of the movable block facing the first mounting slot, and the mover of the linear motor is arranged in the second mounting slot. Since the mover and the stator of the linear motor are arranged in the corresponding first mounting slot and the second mounting slot respectively, the overall structure is more compact, and the overall size of the shell can be smaller.

[0015] As preferred, the movable block and the fixed seat are connected through a guide rail pair. The guide rail pair can ensure the stability of the relative sliding between the movable block and the fixed seat, thereby improving the stability of the light beam shaping unit in switching between the first working position and the second working position.

[0016] As preferred, the light beam shaping unit comprises a mirror sleeve and an optical mirror group, the mirror sleeve is rotationally connected in the fixed sleeve, and the optical mirror group is arranged in the mirror sleeve and is used for shaping the light spot of the light beam into a linear light spot. The optical mirror group is a precision component, and the mirror sleeve can protect the optical mirror group. In addition, since the linear light spot is shaped by the optical mirror group, the optical mirror group has good light guiding property, and the energy loss of the laser beam when passing through the optical mirror group is small, thereby ensuring the energy efficiency of the laser beam.

[0017] As preferred, a second driving unit is further included, the second driving unit is arranged in the fixed sleeve, and the second driving unit is used for driving the light beam shaping unit to rotate. The second driving unit facilitates the rotation of the light beam shaping unit, and since the second driving unit is located inside the fixed sleeve, the space utilization is high, and the overall structure is more compact.

[0018] As preferred, the second driving unit comprises a rotary voice coil motor and a positioning sleeve, the positioning sleeve is sleeved on the mirror sleeve, the mover of the voice coil motor is fixed on the outside of the positioning sleeve, and the stator of the voice coil motor is fixed on the inside of the fixed sleeve, which makes the second driving unit closely combined with adjacent parts, and further makes the structure more compact.

[0019] In a second aspect, the application further provides a light path system comprising the above-mentioned light spot switching device for LPBF.

[0020] In summary, the light spot switching device for LPBF forming provided by the application at least has the following advantages

[0021] Advantages:

[0022] 1. The light beam shaping unit switches between the first working position and the second working position, thereby switching between the circular light spot and the linear light spot, effectively improving the printing processing efficiency of additive manufacturing.

[0023] 2. Since the linear light spot is shaped by optical lens group, the optical lens group has good light guiding property, and the energy loss of laser beam is small when passing through the optical lens group, thereby ensuring the energy efficiency of the laser beam. BRIEF DESCRIPTION OF DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without paying novel labor on the basis of these drawings.

[0025] Figure 1 is a perspective structural schematic view of the light spot switching device of the present application at a right side view angle;

[0026] Figure 2 is a perspective structural schematic view of the light spot switching device of the present application at a left side view angle;

[0027] Figure 3 is a perspective structural schematic view of the light spot switching device of the present application at a right side view angle (with the cover hidden);

[0028] Figure 4 is a right view of the light spot switching device of the present application (with the cover hidden);

[0029] Figure 5 is a perspective structural schematic view of the first driving unit and the light beam shaping unit of the present application at a right side view angle;

[0030] Figure 6 is a perspective structural schematic view of the first driving unit and the light beam shaping unit of the present application at a left side view angle;

[0031] Figure 7 is an exploded schematic view of the first driving unit of the present application at a left side view angle;

[0032] Figure 8 is an exploded schematic view of the first driving unit of the present application at a right side view angle;

[0033] Figure 9 is an exploded schematic view of the light beam shaping unit of the present application at a bottom view angle;

[0034] Figure 10 is a perspective structural schematic view of the light path system of the present application.

[0035] The reference signs include: a shell 1, a bottom shell 101, a cover 102, a light inlet 103, a light outlet 104, a light beam shaping unit 2, a mirror sleeve 201, a first connecting sleeve 2011, a second connecting sleeve 2012, a first clamping groove 2013, an optical lens group 202, a bearing 203, a first driving unit 3, a fixing seat 301, a first mounting groove 302, a moving seat 303, a movable block 3031, a second mounting groove 3032, a third mounting groove 3033, a connecting piece 3034, a fixing sleeve 304, a guide rail pair 305, an end cover 306, a through hole 307, a positioning sleeve 4, a laser galvanometer device 5, and a laser collimator 6. DETAILED DESCRIPTION

[0036] In order for those skilled in the art to better understand the technical solutions of the present application, the present application will be further described in detail below with reference to the accompanying drawings. Figures 1-10 and the specific embodiments.

[0037] Please refer to Figures 1-9 The present embodiment provides a light spot switching device for LPBF forming, which comprises a shell 1, a light beam shaping unit 2, and a first driving unit 3. The shell 1 is provided with a light inlet 103 and a light outlet 104 for forming a laser passage. Specifically, the shell 1 comprises a bottom shell 101 and a cover 102. The bottom shell 101 is a groove-shaped opening on the right side. The cover 102 is detachably connected to the opening of the bottom shell 101 and seals the opening of the bottom shell 101. The light inlet 103 is formed on the cover 102, and the light outlet 104 is formed on the left side of the bottom shell 101. The light inlet 103 corresponds to the light outlet 104, and both the light inlet 103 and the light outlet 104 are circular holes. The light beam shaping unit 2 is movably arranged in the shell 1. The light beam shaping unit 2 is used to shape the light spot of the light beam into a linear light spot. Specifically, the light beam shaping unit 12 is used to shape the circular light spot of the light beam into a linear light spot. When the light beam shaping unit 2 is located at a first working position, the input end of the light beam shaping unit 2 corresponds to the light inlet 103, and the output end of the light beam shaping unit 2 corresponds to the light outlet 104. When the light beam shaping unit 2 is located at a second working position, the light beam shaping unit 2 is located outside the laser passage. The first driving unit 3 is arranged in the shell 1. The first driving unit 3 is used to drive the light beam shaping unit 2 to switch between the first working position and the second working position.

[0038] By adopting the above scheme, in use, the first driving unit 3 drives the light beam shaping unit 2 to be located at the first working position, and after the laser beam passes through the light beam shaping unit 2, the circular spot of the light beam is shaped into a linear spot. The linear spot is used for additive manufacturing processing, which increases the single processing width, thereby reducing the number of scans and improving the processing efficiency. For the profile part that can be scanned and printed by the linear spot and the part that cannot be scanned and printed by the linear spot, the first driving unit 3 drives the light beam shaping unit 2 to move to the second working position, at this time, the light beam shaping unit 2 is away from the laser path. The laser beam directly passes through the laser path, and the spot of the light beam is circular. The light beam shaping unit 2 switches between the first working position and the second working position, thereby switching the circular spot and the linear spot to perform the printing work of additive manufacturing, which effectively improves the printing and processing efficiency of additive manufacturing. Moreover, the shell 1 can provide a space separated from the outside for the light beam shaping unit 2, so as to prevent the influence of the external environment on the light beam shaping unit 2.

[0039] Please continue to refer to 5 and Figure 9 When the linear spot is used for scanning and printing in the printing area, the width of the spot required for scanning in the printing area may be less than the length of the linear spot. As preferred, the light beam shaping unit 2 is arranged on the working end of the first driving unit 3 and is configured to be able to rotate relative to the working end of the first driving unit 3. The first driving unit 3 can drive the light beam shaping unit 2 to switch between the first working position and the second working position of the light beam shaping unit 2 through the working end. Since the light beam shaping unit 2 can rotate relative to the working end of the first driving unit 3, for the printing area whose required scanning width is less than the length of the linear spot or other areas whose profile is arc-shaped, the angle of the linear spot can be adjusted by rotating the light beam shaping unit 2, so as to adjust the width of the linear spot for scanning along the scanning path on the printing area.

[0040] Please continue to refer to Figures 4-8 As preferred, the first driving unit 3 includes a linear motor, a fixed seat 301, a moving seat 303, and a fixed sleeve 304. The moving seat 303 is slidingly connected to the fixed seat 301, the linear motor is arranged on the fixed seat 301, the working end of the linear motor is connected to the moving seat 303, the fixed sleeve 304 is fixedly connected to the moving seat 303, and the light beam shaping unit 2 is rotatably installed in the fixed sleeve 304.

[0041] Please refer to Figure 7 and Figure 8As preferred, the fixed seat 301 is provided with a first mounting groove 302, which is specifically located at the right side of the fixed seat 301. The moving seat 303 comprises a movable block 3031 and a connecting piece 3034 connected with each other, and the movable block 3031 is slidingly connected in the first mounting groove 302. The fixed sleeve 304 is fixedly connected on the connecting piece 3034. Specifically, the lower end of the connecting piece 3034 is in a C shape matching the outer contour of the fixed sleeve 304, and the fixed sleeve 304 is connected with the connecting piece 3034 through bolts.

[0042] As preferred, the stator of the linear motor is arranged in the first mounting groove 302, and the movable block 3031 is provided with a second mounting groove 3032 on the side facing the first mounting groove 302, and the mover of the linear motor is arranged in the second mounting groove 3032. The linear motor is a prior art, and the mover of the linear motor can drive the movable block 3031 to move linearly.

[0043] As preferred, the movable block 3031 and the fixed seat 301 are connected through a guide rail pair 305, which is a prior art. The guide rail pair 305 can specifically be a combination of a sliding block and a guide rail, and in the embodiment, the guide rail pair 305 preferably adopts a rolling cross guide rail pair, that is, a cross roller guide rail. In the embodiment, the upper and lower sides of the movable block 3031 are respectively connected with the fixed seat 301 through a guide rail pair 305. Specifically, the upper and lower sides of the movable block 3031 are provided with third mounting grooves 3033, and the guide rail pair 305 comprises two guide rails that can slide relative to each other, one of which is fixedly arranged in the corresponding third mounting groove 3033, and the other is fixedly arranged in the first mounting groove 302.

[0044] Please continue to refer to Figure 9 As preferred, the light beam shaping unit 2 comprises a mirror sleeve 201 and an optical lens group 202, the mirror sleeve 201 is rotatably installed in the fixed sleeve 304, and the optical lens group 202 is arranged in the mirror sleeve 201 and is used for shaping the light spot of the light beam into a linear light spot. The optical lens group 202 is a combination of optical lenses. In the embodiment, a combination of two optical lenses is specifically adopted, which can shape the circular light spot of the light beam into a linear light spot. The technology of shaping the circular light spot of the light beam into a linear light spot through the optical lens group 202 is a prior art. Since the linear light spot is shaped by the optical lens group 202, the optical lens group 202 has good light guiding property, and the energy loss of the laser beam when passing through the optical lens group 202 is small, thereby ensuring the energy efficiency of the laser beam.

[0045] Please refer to Figure 9As preferred, the mirror sleeve 201 comprises a first connecting sleeve 2011 and a second connecting sleeve 2012, and the first connecting sleeve 2011 and the second connecting sleeve 2012 are connected by bolts. The inner side edge of the right end of the first connecting sleeve 2011 is provided with a first clamping groove 2013, and the inner hole edge of the left end of the second connecting sleeve 2012 is provided with a second clamping groove, and the two optical lenses of the optical lens group 202 are respectively installed in the first clamping groove 2013 and the second clamping groove. The first driving unit 3 further comprises an end cover 306, the end cover 306 is provided with a through hole 307 for the laser beam to pass through, and the end cover 306 is connected with the left end of the fixing sleeve 304 by bolts. The first connecting sleeve 2011 and the second connecting sleeve 2012 are connected with the fixing sleeve 304 through bearings 203, and the bearings 203 are preferably ceramic bearings in the prior art.

[0046] Please refer to Figure 9 In order to facilitate the rotation of the light beam shaping unit 2, as preferred, a second driving unit is further provided, the second driving unit is arranged in the fixing sleeve 304, and the second driving unit is used to drive the rotation of the light beam shaping unit 2. Specifically, the second driving unit comprises a rotary voice coil motor and a positioning sleeve 4, the positioning sleeve 4 is sleeved on the mirror sleeve 201, and the positioning sleeve 4 is fixedly connected with the mirror sleeve 201, the rotor of the voice coil motor is fixed on the outer side of the positioning sleeve 4, and the stator of the voice coil motor is fixed on the inner side of the fixing sleeve 304. Specifically, the positioning sleeve 4 is fixedly connected with the second connecting sleeve 2012. The rotary voice coil motor is a prior art, and the rotary voice coil motor can drive the positioning sleeve 4 to rotate, thereby driving the mirror sleeve 201 and the optical lens group 202 to rotate, so as to adjust the inclination angle of the linear light spot.

[0047] Because the laser beam has high energy, high heat will be generated around the laser beam during use. In order to improve the heat dissipation efficiency, as preferred, the shell 1 is made of aluminum alloy material. Specifically, the cover 102 and the bottom shell 101 are made of aluminum alloy material. Because the shell 1 is made of aluminum alloy material, the heat dissipation efficiency can be improved by the good heat conductivity of the aluminum alloy.

[0048] Please refer to Figure 10Based on the same inventive concept, the application also provides an optical path system comprising the above-mentioned spot switching device for LPBF. Specifically, the optical path system further comprises a laser galvanometer device 5 and a laser collimator 6, the LPBF spot switching device is fixedly installed on the right side of the laser galvanometer device 5, and the laser collimator 6 is fixedly installed on the right side of the LPBF spot switching device. In use, the laser beam passes through the laser collimator 6, then passes through the light inlet 103 and the light outlet 104 of the LPBF spot switching device, and finally enters the laser galvanometer device 5, and the laser beam finally scans and prints the printing area through the laser beam output end of the laser galvanometer device 5. The laser galvanometer device and the laser collimator are prior art, wherein the laser galvanometer device comprises an X-Y optical scanning head, an electronic driving amplifier, an optical mirror and a computer controller. The signal provided by the computer controller drives the optical scanning head through the driving amplifier circuit, so as to control the deflection of the laser beam in the X-Y plane.

[0049] It should be noted that the words indicating the orientation, such as up and down, are set in the direction of the paper, only for the convenience of description, and do not have other specific meanings. Figure 1

[0050] It should also be noted that in this paper, relationship terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between the entities or operations. Moreover, the terms "include", "contain" or any other variants thereof are intended to cover non-exclusive inclusion, so that the article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such article or device. Without more limitation, the element defined by the statement "including a" does not exclude the presence of another identical element in the article or device including the above-mentioned element.

[0051] The principles and embodiments of the application are described by applying specific examples in this paper, and the above description of the examples is only used to help understand the core idea of the application. It should be noted that for ordinary skilled persons in the art, without departing from the principles of the application, the application can be improved and modified in several ways, and these improvements and modifications also fall within the protection scope of the claims of the application.​

Claims

1. A spot switching device for LPBF shaping, characterized in that, The application relates to a laser beam spot switching device for laser powder bed fusion (LPBF). The device comprises a housing (1) provided with an entrance (103) and an exit (104) for forming a laser beam path; a beam shaping unit (2) movably arranged in the housing (1), the beam shaping unit (2) being used for shaping a light spot of a laser beam into a linear light spot; when the beam shaping unit (2) is in a first working position, an input end of the beam shaping unit (2) corresponds to the entrance (103) and an output end of the beam shaping unit (2) corresponds to the exit (104); when the beam shaping unit (2) is in a second working position, the beam shaping unit (2) is located outside the laser beam path; a first driving unit (3) arranged in the housing (1), the first driving unit (3) being used for driving the beam shaping unit (2) to switch between the first working position and the second working position; the beam shaping unit (2) is arranged on a working end of the first driving unit (3) and is configured to be able to rotate relative to the working end of the first driving unit (3). The first driving unit (3) comprises a linear motor, a fixed seat (301), a moving seat (303) and a fixed sleeve (304), the moving seat (303) is slidably connected to the fixed seat (301), the linear motor is arranged on the fixed seat (301), a working end of the linear motor is connected to the moving seat (303), the fixed sleeve (304) is fixedly connected to the moving seat (303), and the beam shaping unit (2) is rotatably arranged in the fixed sleeve (304). A first mounting groove (302) is arranged on the fixed seat (301), the moving seat (303) comprises a movable block (3031) and a connecting piece (3034) connected to each other, the movable block (3031) is slidably connected in the first mounting groove (302), and the fixed sleeve (304) is fixedly connected to the connecting piece (3034).

2. The spot switching device for LPBF forming according to claim 1, wherein, A stator of the linear motor is arranged in the first mounting groove (302), a second mounting groove (3032) is arranged on one side of the movable block (3031) facing the first mounting groove (302), and a rotor of the linear motor is arranged in the second mounting groove (3032).

3. The spot switching device for LPBF forming according to claim 2, characterized in that, The movable block (3031) and the fixed seat (301) are connected through a guide rail pair (305).

4. The spot switching device for LPBF forming according to claim 3, characterized in that, The beam shaping unit (2) comprises a mirror sleeve (201) and an optical mirror group (202), the mirror sleeve (201) is rotatably connected in the fixed sleeve (304), the optical mirror group (202) is arranged in the mirror sleeve (201), and the optical mirror group (202) is used for shaping a light spot of a laser beam into a linear light spot.

5. The spot switching device for LPBF forming according to claim 3, wherein, The device further comprises a second driving unit, the second driving unit is arranged in the fixed sleeve (304), and the second driving unit is used for driving the beam shaping unit (2) to rotate.

6. A spot switching device for LPBF forming according to any of claims 2-5, characterized in that, The second driving unit comprises a rotary voice coil motor and a positioning sleeve (4), the positioning sleeve (4) is sleeved on the mirror sleeve (201), a rotor of the voice coil motor is fixed on an outer side of the positioning sleeve (4), and a stator of the voice coil motor is fixed on an inner side of the fixed sleeve (304).

7. The spot switching device for LPBF forming according to claim 6, characterized in that, The device comprises the beam spot switching device for LPBF according to any one of claims 1-8.

8. The spot switching device for LPBF forming according to claim 7, characterized in that, ​ 9. An optical path system, characterized by comprising: ​

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