Light spot switching device for LPBF forming and light path system

Abstract

The invention relates to the technical field of laser additive manufacturing, in particular to a light spot switching device for LPBF forming and a light path system. The light spot switching device comprises a shell, a light beam shaping unit and a first driving unit. Wherein the shell is provided with a light inlet and a light outlet which are used for forming a laser path; the light beam shaping unit is movably arranged in the shell, and the light beam shaping unit is used for shaping a light spot of the light beam into a linear light spot; when the light beam shaping unit is located at the first working position, the input end of the light beam shaping unit corresponds to the light inlet, and the output end corresponds to the light outlet; and when the light beam shaping unit is located at the 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 and is switched between the first working position and the second working position, so that the circular light spot and the linear light spot are switched to carry out printing work of additive manufacturing, and the printing processing efficiency of additive manufacturing is effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of laser additive manufacturing, and in particular to a light spot switching device and an optical path system for LPBF forming. Background Art

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

[0003] However, the conventional circular laser spot additive manufacturing technology has a low processing width at a time, which can only reach the size of the spot diameter. Since the shapes of the layers of the printed parts are different during the printing process, some areas that need to be printed are narrow, so circular laser spots are more suitable for printing; some areas that need to be printed are wide, and the circular laser spot needs to be scanned repeatedly to complete the single-layer formation, which greatly limits the processing efficiency of laser additive manufacturing. Summary of the invention

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

[0005] The above technical objectives of the present invention are achieved through the following technical solutions:

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

[0009] The first driving unit is arranged in the housing, and is used for driving the beam shaping unit to switch between the first working position and the second working position.

[0010] By adopting the above scheme, when in use, the beam shaping unit is driven by the first driving unit to be located in the first working position. After the laser beam passes through the beam shaping unit, the spot of the beam is shaped into a linear spot. The linear spot is used for additive manufacturing, which increases the single processing width, thereby reducing the number of scans and improving the processing efficiency. For the contour part of the scanned print and the part that the linear spot cannot scan and print, the first driving unit drives the beam shaping unit to move to the second working position. At this time, the beam shaping unit leaves the laser path. The laser beam passes directly through the laser path, and the spot of the beam is circular. The beam shaping unit switches between the first working position and the second working position, thereby switching between the circular spot and the linear spot to perform additive manufacturing printing, effectively improving the printing processing efficiency of additive manufacturing. In addition, the shell can provide a space separated from the outside for the beam shaping unit to prevent the external environment from affecting the beam shaping unit.

[0011] Preferably, the beam shaping unit is disposed 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 scanning and printing in the printing area by the line light spot, the width of the light spot scanned by the printing area may be smaller than the length of the line light spot. For the printing area where the required scanning width is smaller than the length of the line light spot, or other areas with arc-shaped contours, the angle of the line light spot can be adjusted by rotating the beam shaping unit, thereby adjusting the width of the line light spot scanned on 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 slidably 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, and the beam shaping unit is rotatably installed in the fixed sleeve. Since the beam shaping unit is rotatably installed in the fixed sleeve, the stability of the rotation of the beam shaping unit is improved on the one hand, and the beam shaping unit is protected on the other hand.

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

[0014] Preferably, the stator of the linear motor is arranged in the first mounting groove, the movable block is provided with a second mounting groove on a side facing the first mounting groove, and the mover of the linear motor is arranged in the second mounting groove. Since the mover and the stator of the linear motor are respectively arranged in the corresponding first mounting groove and the second mounting groove, the overall structure is more compact and the overall size of the housing can be made smaller.

[0015] Preferably, the movable block and the fixed seat are connected via a guide rail pair, which can ensure the stability of relative sliding between the movable block and the fixed seat, thereby improving the stability of the beam shaping unit switching between the first working position and the second working position.

[0016] Preferably, the beam shaping unit comprises a lens sleeve and an optical lens group, wherein the lens sleeve is rotatably connected in a fixed sleeve, and the optical lens group is arranged in the lens sleeve, and the optical lens group is used to shape the spot of the light beam into a linear spot. The optical lens group is a precision component, and the lens sleeve can protect the optical lens group. In addition, since the linear spot is shaped by the optical lens group, the optical lens group has good light guiding properties, and the energy loss of the laser beam is small when passing through the optical lens group, thereby ensuring the energy efficiency of the laser beam.

[0017] Preferably, a second driving unit is further included, and the second driving unit is arranged in the fixing sleeve, and the second driving unit is used to drive the beam shaping unit to rotate. The second driving unit is convenient for driving the beam shaping unit to rotate, and because the second driving unit is located inside the fixing sleeve, the space utilization rate is high and the overall structure is more compact.

[0018] Preferably, the second driving unit includes a rotary voice coil motor and a positioning sleeve, wherein the positioning sleeve is arranged 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 fixing sleeve, which enables the second driving unit to be tightly combined with adjacent components, further making the structure more compact.

[0019] In a second aspect, the present invention further provides an optical 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 present invention has at least the following features:

[0021] Beneficial effects:

[0022] 1. The 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, which effectively improves the printing efficiency of additive manufacturing.

[0023] 2. Since the linear light spot is shaped by an optical lens group, which has good light guiding properties, the laser beam has less energy loss when passing through the optical lens group, thus ensuring the energy efficiency of the laser beam. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without expending any novel work.

[0025] Figure 1 is a schematic diagram of the three-dimensional structure of the light spot switching device of the present invention at the right viewing angle;

[0026] Figure 2 is a schematic diagram of the three-dimensional structure of the light spot switching device of the present invention at a left viewing angle;

[0027] Figure 3 It is a three-dimensional structural schematic diagram of the light spot switching device of the present invention from the right side viewing angle (the cover is hidden);

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

[0029] Figure 5 is a schematic diagram of the three-dimensional structure of the first driving unit and the beam shaping unit of the present invention from the right side viewing angle;

[0030] Figure 6 is a schematic diagram of the three-dimensional structure of the first driving unit and the beam shaping unit of the present invention from a left perspective;

[0031] Figure 7 is an exploded schematic diagram of the first driving unit of the present invention from a left side perspective;

[0032] Figure 8 is an exploded schematic diagram of the first driving unit of the present invention from the right side viewing angle;

[0033] Fig. 9 is an exploded schematic diagram of the beam shaping unit of the present invention at an upward viewing angle;

[0034] Fig.10 It is a three-dimensional structural schematic diagram of the optical path system of the present invention.

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

[0036] In order to enable those skilled in the art to better understand the technical solution of the present invention, Figure 1-10 The present invention is further described in detail with specific implementation modes.

[0037] See also Figure 1-9 , a spot switching device for LPBF forming provided in this embodiment includes: a housing 1, a beam shaping unit 2 and a first driving unit 3. Among them, the housing 1 is provided with a light inlet 103 and a light outlet 104 for forming a laser path. Specifically, the housing 1 includes a bottom shell 101 and a cover body 102, the bottom shell 101 is a groove shape with an opening on the right side, and the cover body 102 is detachably connected to the opening of the bottom shell 101 and closes the opening of the bottom shell 101; the light inlet 103 is opened on the cover body 102, and the light outlet 104 is opened on the left side of the bottom shell 101, the light inlet 103 corresponds to the light outlet 104, and the light inlet 103 and the light outlet 104 are both circular holes. The beam shaping unit 2 is movably arranged in the housing 1, and the beam shaping unit 2 is used to shape the light spot of the light beam into a linear light spot. Specifically, the beam shaping unit 12 is used to shape the circular light spot of the light beam into a linear light spot. When the beam shaping unit 2 is located at the first working position, the input end of the beam shaping unit 2 corresponds to the light inlet 103, and the output end of the beam shaping unit 2 corresponds to the light outlet 104; when the beam shaping unit 2 is located at the second working position, the beam shaping unit 2 is located outside the laser path. The first driving unit 3 is disposed in the housing 1, and the first driving unit 3 is used to drive the beam shaping unit 2 to switch between the first working position and the second working position.

[0038] By adopting the above scheme, when in use, the first driving unit 3 drives the beam shaping unit 2 to be located in the first working position. After the laser beam passes through the beam shaping unit 2, the circular spot of the beam is shaped into a linear spot. The linear spot is used for additive manufacturing, which increases the single processing width, thereby reducing the number of scans and improving the processing efficiency. For the contour part of the scanned print and the part that the linear spot cannot scan and print, the first driving unit 3 drives the beam shaping unit 2 to move to the second working position. At this time, the beam shaping unit 2 leaves the laser path. The laser beam passes directly through the laser path, and the spot of the beam is circular. The beam shaping unit 2 switches between the first working position and the second working position, thereby switching between the circular spot and the linear spot to perform additive manufacturing printing, which effectively improves the printing processing efficiency of additive manufacturing. In addition, the housing 1 can provide a space separated from the outside for the beam shaping unit 2 to prevent the external environment from affecting the beam shaping unit 2.

[0039] Please continue to see ,5 and Fig. 9 , because when the line spot is used to scan and print in the printing area, the width of the spot scanned by the printing area may be smaller than the length of the line spot. Preferably, the 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 beam shaping unit 2 to switch between the first working position and the second working position of the beam shaping unit 2 through its working end. Since the beam shaping unit 2 can rotate relative to the working end of the first driving unit 3, for the printing area where the required scanning width is smaller than the length of the line spot, or some other areas with arc-shaped contours, the angle of the linear spot can be adjusted by rotating the beam shaping unit 2, thereby adjusting the width of the line spot scanned along the scanning path on the printing area.

[0040] Please continue reading Figure 4-8 Preferably, the first driving unit 3 includes a linear motor, a fixed seat 301, a movable seat 303 and a fixed sleeve 304. The movable seat 303 is slidably 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 movable seat 303, the fixed sleeve 304 is fixedly connected to the movable seat 303, and the beam shaping unit 2 is rotatably installed in the fixed sleeve 304.

[0041] See also Figure 7 and Figure 8Preferably, the fixed seat 301 is provided with a first mounting groove 302, and the first mounting groove 302 is specifically located on the right side of the fixed seat 301. The movable seat 303 includes a movable block 3031 and a connecting member 3034 connected to each other, and the movable block 3031 is slidably connected in the first mounting groove 302. The fixed sleeve 304 is fixedly connected to the connecting member 3034, and specifically, the lower end of the connecting member 3034 is C-shaped matching the outer contour of the fixed sleeve 304, and the fixed sleeve 304 is connected to the connecting member 3034 by bolts.

[0042] Preferably, the stator of the linear motor is arranged in the first mounting groove 302, the movable block 3031 is provided with a second mounting groove 3032 on one 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] Preferably, the movable block 3031 and the fixed seat 301 are connected by a guide pair 305, and the guide pair 305 is a prior art. The guide pair 305 can specifically be a combination of a slider and a guide rail. In this embodiment, the guide pair 305 preferably adopts a rolling cross guide pair, that is, a cross roller guide. In this embodiment, the upper and lower sides of the movable block 3031 are respectively connected to the fixed seat 301 through a guide pair 305. Specifically, the upper and lower sides of the movable block 3031 are provided with a third mounting groove 3033, and the guide pair 305 includes 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 guide rail is fixedly arranged in the first mounting groove 302.

[0044] Please continue reading Fig. 9 Preferably, the beam shaping unit 2 includes a lens sleeve 201 and an optical lens group 202. The lens sleeve 201 is rotatably mounted in the fixed sleeve 304. The optical lens group 202 is arranged in the lens sleeve 201. The optical lens group 202 is used to shape the spot of the light beam into a linear spot. Among them, the optical lens group 202 is a combination of optical lenses. In this embodiment, a combination of two optical lenses is specifically adopted, which can shape the circular spot of the light beam into a linear spot. The technology of shaping the circular spot of the light beam into a linear spot by the optical lens group 202 is an existing technology. Since the linear spot is shaped by the optical lens group 202, the optical lens group 202 has good light guiding properties, and the energy loss of the laser beam is small when passing through the optical lens group 202, thereby ensuring the energy efficiency of the laser beam.

[0045] See also Fig. 9Preferably, the lens sleeve 201 includes 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 edge of the right end of the first connecting sleeve 2011 is provided with a first card slot 2013, and the inner hole edge of the left end of the second connecting sleeve 2012 is provided with a second card slot, and the two optical lenses of the optical lens group 202 are respectively installed in the first card slot 2013 and the second card slot. The first driving unit 3 also includes an end cover 306, and 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 to the left end of the fixed sleeve 304 by bolts. The first connecting sleeve 2011 and the second connecting sleeve 2012 are both connected to the fixed sleeve 304 through a bearing 203, and the bearing 203 is preferably a ceramic bearing in the prior art.

[0046] See also Fig. 9 In order to facilitate driving the beam shaping unit 2 to rotate, as a preferred embodiment, a second driving unit is further included, which is arranged in the fixing sleeve 304 and is used to drive the beam shaping unit 2 to rotate. Specifically, the second driving unit includes a rotary voice coil motor and a positioning sleeve 4, the positioning sleeve 4 is sleeved on the lens sleeve 201, the positioning sleeve 4 is fixedly connected to the lens sleeve 201, the mover of the voice coil motor is fixed on the outside of the positioning sleeve 4, and the stator of the voice coil motor is fixed on the inside of the fixing sleeve 304. Specifically, the positioning sleeve 4 is fixedly connected to the second connecting sleeve 2012. The rotary voice coil motor is an existing technology, and the rotary voice coil motor can drive the positioning sleeve 4 to rotate through the mover, thereby driving the lens sleeve 201 and the optical lens group 202 to rotate, thereby adjusting the tilt angle of the linear light spot.

[0047] Since the laser beam has high energy, high heat will be generated around the laser beam when in use. In order to improve the heat dissipation efficiency, the housing 1 is preferably made of aluminum alloy. Specifically, the cover 102 and the bottom shell 101 are both made of aluminum alloy. Since the housing 1 is made of aluminum alloy, the good thermal conductivity of aluminum alloy can improve the heat dissipation efficiency.

[0048] See also Fig.10Based on the same inventive concept, the present invention also provides an optical path system, which includes the above-mentioned spot switching device for LPBF. Specifically, the optical path system also includes 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. During use, the laser beam passes through the laser collimator 6 and then passes through the light inlet 103 and the light outlet 104 of the LPBF spot switching device to enter 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 both prior art, wherein the laser galvanometer device includes an XY optical scanning head, an electronic drive amplifier, an optical reflective lens and a computer controller. The signal provided by the computer controller drives the optical scanning head through the drive amplifier circuit, thereby controlling the deflection of the laser beam in the XY plane.

[0049] It should be noted that the words indicating direction in this article, such as up and down, are all based on Figure 1 The setting of the direction is only for the convenience of description and has no other specific meaning.

[0050] It should also be noted that, in this article, relational terms such as first and second, etc. 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 these entities or operations. Moreover, the terms "comprises", "comprising" or any other variants thereof are intended to cover non-exclusive inclusion, so that an article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such article or device. In the absence of further restrictions, the elements defined by the sentence "comprising a ..." do not exclude the existence of other identical elements in the article or device including the above elements.

[0051] The principles and implementation methods of the present invention are described in this article using specific examples. The description of the above embodiments is only used to help understand the core idea of ​​the present invention. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present invention, the present invention can also be improved and modified, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A spot switching device for LPBF forming, characterized in that: include: The housing (1) is provided with a light inlet (103) and a light outlet (104) for forming a laser path; A beam shaping unit (2) is movably arranged in the housing (1), and is used to shape the light spot of the light beam into a linear light spot; when the beam shaping unit (2) is located in a first working position, its input end corresponds to the light inlet (103), and its output end corresponds to the light outlet (104); when the beam shaping unit (2) is located in a second working position, the beam shaping unit (2) is located outside the laser path; A first driving unit (3) is arranged in the housing (1), and the first driving unit (3) is used to drive the beam shaping unit (2) to switch between the first working position and the second working position.

2. The spot switching device for LPBF forming according to claim 1, characterized in that: The beam shaping unit (2) is arranged on the working end of the first driving unit (3), and is configured to be rotatable relative to the working end of the first driving unit (3).

3. The spot switching device for LPBF forming according to claim 2, characterized in that: The first driving unit (3) comprises a linear motor, a fixed seat (301), a movable seat (303) and a fixed sleeve (304); the movable seat (303) is slidably 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 movable seat (303); the fixed sleeve (304) is fixedly connected to the movable seat (303); and the beam shaping unit (2) is rotatably mounted in the fixed sleeve (304).

4. The spot switching device for LPBF forming according to claim 3, characterized in that: The fixed seat (301) is provided with a first mounting groove (302), and the movable 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).

5. The spot switching device for LPBF forming according to claim 4, characterized in that: The stator of the linear motor is arranged in the first installation groove (302), the movable block (3031) is provided with a second installation groove (3032) on a side facing the first installation groove (302), and the mover of the linear motor is arranged in the second installation groove (3032).

6. The spot switching device for LPBF forming according to claim 4, characterized in that: The movable block (3031) and the fixed seat (301) are connected via a guide rail pair (305).

7. A spot switching device for LPBF forming according to any one of claims 3 to 6, characterized in that: The beam shaping unit (2) comprises a lens sleeve (201) and an optical lens group (202); the lens sleeve (201) is rotatably connected in a fixed sleeve (304); the optical lens group (202) is arranged in the lens sleeve (201); and the optical lens group (202) is used to shape the light spot of the light beam into a linear light spot.

8. The spot switching device for LPBF forming according to claim 7, characterized in that: It also comprises a second driving unit, which is arranged in the fixing sleeve (304) and is used to drive the beam shaping unit (2) to rotate.

9. The spot switching device for LPBF forming according to claim 8, characterized in that: The second driving unit comprises a rotary voice coil motor and a positioning sleeve (4), wherein the positioning sleeve (4) is sleeved on the mirror sleeve (201), the mover of the voice coil motor is fixed on the outside of the positioning sleeve (4), and the stator of the voice coil motor is fixed on the inside of the fixing sleeve (304).

10. An optical path system, characterized in that: The invention comprises a light spot switching device for LPBF as described in any one of claims 1 to 9.

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