Light spot detection device

Abstract

The invention relates to the technical field of additive manufacturing, in particular to a light spot detection device. The detection device comprises a mounting base, a diaphragm, a light spot detection unit and a reflection unit. Wherein the mounting seat is provided with a light beam channel, the diaphragm is used for dividing a laser beam projected on the diaphragm into a reflected light beam and a transmitted light beam, and the diaphragm is arranged in the light beam channel. During use, when a laser beam is projected to a preset position on the diaphragm, 99% of the laser beam is transmitted to form a transmitted beam, and less than 1% of the remaining laser beam is reflected to form a reflected beam. Wherein the transmission light beam is used for carrying out printing work in a printing area; and the reflected light beam is reflected to the detection end of the light spot detection unit through the reflection unit, and the light spot is identified through the detection end of the detection unit, so that the form information of the light spot is obtained. And when the light spot of the reflected light beam is detected, the transmitted light beam can still be printed, so that the detection work of the light spot can be carried out on line.

Description

Technical Field

[0001] The present invention relates to the technical field of additive manufacturing, and in particular to a light spot detection device. Background Art

[0002] Laser Powder Bed Fusion (LPBF) additive manufacturing is a technology that uses a focused laser beam to fuse loose powder along a designed path to form parts layer by layer. This technology is widely used in aerospace, automotive and medical fields. In the LPBF additive manufacturing process, the measurement of high-energy laser spot is an important means to ensure that the parameters of the high-energy laser spot are the preset parameters.

[0003] In the prior art, in order to determine whether the shape, size or energy intensity of the high-energy laser spot meets the requirements during operation, it is necessary to detect the high-energy laser spot. At present, when obtaining the parameters of the high-energy laser spot, it is necessary to place the spot detection device on the printing platform and let the laser directly hit the detection device for detection.

[0004] Although the existing high-energy laser spot detection method can obtain relatively accurate laser spot parameters, there are also some problems in the use process. First, since the spot detection device needs to be placed on the printing platform for spot detection, spot detection during the printing process will affect the printing work, making it difficult to detect the spot online; secondly, since the high-energy laser beam has high energy, the spot detection device is easily damaged and has a high safety risk. Summary of the invention

[0005] In view of the above-mentioned defects, the technical problem to be solved by the present invention is to provide a light spot detection device, which can detect light spots during the printing process.

[0006] The above technical objectives of the present invention are achieved through the following technical solutions:

[0007] A light spot detection device, comprising:

[0008] A mounting base having a beam channel thereon;

[0009] A window plate, used for dividing the laser beam projected thereon into a reflected beam and a transmitted beam, the window plate being arranged in the beam channel and located at an exit end of the beam channel;

[0010] A light spot detection unit, used for detecting the light spot projected on its detection end;

[0011] The reflection unit is used to reflect the reflected light beam of the laser light beam projected on the preset position on the window piece to the detection end.

[0012] By adopting the above scheme, when in use, the laser beam enters the beam channel, and when the laser beam is projected to the preset position on the window piece, the laser beam is divided into a reflected beam and a transmitted beam by the window piece. Among them, the transmitted beam is used to print in the printing area; the reflected beam is reflected by the reflection unit to the detection end of the light spot detection unit, and the light spot is identified by the detection end of the detection unit, so as to obtain information such as the shape and size of the light spot. Since the transmitted beam can still print when the light spot of the reflected beam is detected, the light spot detection work can be carried out during the printing process, that is, the light spot detection work can be carried out online. In addition, since the energy of the reflected beam of the laser beam is low, it is not easy to cause damage to the light spot detection unit when it is detected by the light spot detection unit, and the safety risk is low. In addition, the heat generated by the reflected beam is also low, so that the working temperature of the light spot detection unit is low, which is conducive to ensuring the working stability and service life of the light spot detection unit.

[0013] Preferably, the window sheet is configured to seal the exit end of the light beam channel. Since the window sheet seals the exit end of the light beam channel, the reflection unit is separated from the printing area to avoid mutual interference, and also serves as a sealing connection piece of the printing molding chamber.

[0014] Preferably, a mounting opening is provided on the side of the mounting seat, and the reflecting unit is arranged at the mounting opening. The reflecting unit is arranged at the mounting opening on the side of the mounting seat, which makes it easier for the reflecting unit to receive the reflected light beam.

[0015] Preferably, the reflection unit comprises a housing and a reflector group arranged inside the housing, the housing is fixedly connected at the mounting port, the light spot detection unit is fixedly connected to the housing, the housing is provided with a light inlet corresponding to the mounting port, and a light outlet corresponding to the detection end, and the reflector group is configured to reflect the reflected light beam of the laser beam projected at the preset position to the detection end. Since the reflector group is arranged inside the housing, the influence of the external environment on the reflector group is reduced.

[0016] Preferably, the reflector group includes a first reflector, a second reflector and a third reflector, the first reflector and the second reflector are arranged in parallel, the reflected light beam of the laser light beam projected on the preset position is reflected by the first reflector and the second reflector and then reflected to the third reflector, and the third reflector is configured to reflect the reflected light beam projected thereon to the detection end. Since the length of the reflected light beam needs to be the same as the length of the transmitted light beam in order to reflect the shape and size of the light spot of the transmitted light beam transmitted in the printing area and other information, the path of the reflected light beam is longer, resulting in a longer length of the reflection unit. Since the first reflector and the second reflector are parallel to each other, the reflected light beam can be reflected multiple times between being reflected by the first reflector and the second reflector, thereby meeting the length requirement of the path of the reflected light beam and reducing the overall length of the reflection unit.

[0017] Preferably, the first reflector is close to the entrance end of the beam channel, the second reflector is close to the exit end of the beam channel, and the length of the first reflector extending into the beam channel is greater than the length of the second reflector extending into the beam channel. Since the length of the first reflector extending into the beam channel is longer, the first reflector can receive a reflected light beam closer to a direction perpendicular to the window sheet, which can reduce the occupation range of the reflector group on the internal space of the beam channel.

[0018] Preferably, the reflective unit further comprises two pressing plates, which are respectively arranged corresponding to the first reflective lens and the second reflective lens, and the pressing plates are connected to the housing through a plurality of locking bolts, the first reflective lens is clamped between the corresponding pressing plates and the housing, and the second reflective lens is clamped between the corresponding pressing plates and the housing. The corresponding first reflective lens and the second reflective lens are fixed to the housing through the pressing plates, thereby enhancing the stability of the reflective lens assembly.

[0019] Preferably, a spring is sleeved on the locking bolt, one end of the spring abuts against the pressure plate, and the other end abuts against the head of the locking bolt. Since the locking bolt is provided with a spring, the spring can maintain the pressing force of the pressure plate on the corresponding first reflective lens and the second reflective lens. At the same time, due to the elastic characteristics of the spring, when installing the locking bolt, it can be avoided that the locking bolt is over-tightened to cause damage to the first lens and the second lens.

[0020] Preferably, the reflection unit further comprises an attenuation filter, which is arranged on the path from the reflected light beam to the detection end. The attenuation filter can reduce the energy of the reflected light beam, thereby reducing the risk of damage to the light spot detection unit.

[0021] Preferably, a cooling medium channel is provided inside the mounting seat, and a medium inlet and a medium outlet of the cooling medium channel are both opened outside the mounting seat. Since the laser beam generates high heat to the surrounding environment when working, the temperature of the mounting seat and the inside of the mounting seat can be reduced by passing the cooling medium into the cooling medium channel.

[0022] In summary, the light spot detection device provided by the present invention has at least the following beneficial effects:

[0023] 1. The shape, size and other information of the light spot can be detected online, which is more convenient to use.

[0024] 2. The safety risk of detecting light spots is lower. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] 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.

[0026] Figure 1 It is a schematic diagram of the three-dimensional structure of the present invention in a top view;

[0027] Figure 2 It is a schematic diagram of the three-dimensional structure of the present invention when looking up;

[0028] Figure 3 It is a front view of the present invention;

[0029] Figure 4 yes Figure 3 Sectional view at AA in the middle;

[0030] Figure 5 yes Figure 4 The enlarged view at a in the middle;

[0031] Figure 6 is a schematic diagram of the three-dimensional structure of the reflection unit in the present invention;

[0032] Figure 7 is an exploded schematic diagram of the reflection unit in the present invention;

[0033] Figure 8 It is a schematic diagram of the three-dimensional structure of the mounting seat in the present invention;

[0034] Fig. 9 It is a perspective view of the mounting seat in the present invention from a side perspective.

[0035] The reference numerals include: mounting base 1, beam channel 2, window piece 3, spot detection unit 4, reflection unit 5, shell 501, light outlet 502, reflector group 503, first reflector 5031, second reflector 5032, third reflector 5033, pressure plate 504, locking bolt 505, spring 506, attenuation filter 507, mounting groove 508, threaded hole 509, positioning bolt 510, card slot 511, avoidance hole 512, through hole 513, mirror base 514, mounting port 6, cooling medium channel 7, medium inlet 8, medium outlet 9, flange 10, end cover 11, laser beam 12, reflected beam 13, transmitted beam 14. DETAILED DESCRIPTION

[0036] In order to enable those skilled in the art to better understand the technical solution of the present invention, Figure 1-9 The present invention is further described in detail with specific implementation modes.

[0037] See also Figure 1-9 , a light spot detection device provided in this embodiment includes: a mounting seat 1, a window piece 3, a light spot detection unit 4 and a reflection unit 5. Among them, a beam channel 2 is provided on the mounting seat 1, and the beam channel 2 is arranged vertically, the upper end of the beam channel 2 is the entrance end, and the lower end of the beam channel 2 is the exit end. The window piece 3 is used to divide the laser beam 12 projected thereon into a reflected beam 13 and a transmitted beam 14. The window piece 3 is arranged in the beam channel 2 and is located at the exit end of the beam channel 2. In this embodiment, in order to ensure that the laser beam 12 has a high transmittance, it is preferred that the window piece 3 is made of high-transmittance fused quartz glass in the prior art. Even if it is high-transmittance fused quartz glass, less than 1% of the laser will be reflected, thereby forming a low-energy reflected beam 13 and a high-energy transmitted beam 14. The light spot detection unit 4 is used to detect the light spot projected on its detection end. Specifically, the detection unit 4 is used to detect the shape of the light spot projected on its detection end. The light spot detection unit 4 is a prior art, and specifically can be a planar array camera in the prior art. The reflection unit 5 is used for reflecting the reflected light beam 13 of the laser light beam 12 projected on a preset position on the window sheet 3 to the detection end.

[0038] By adopting the above scheme, when in use, the laser beam 12 enters the beam channel 2, and when the laser beam 12 is projected to the preset position on the window sheet 3, the laser beam 12 is divided into a reflected beam 13 and a transmitted beam 14 by the window sheet 3. Among them, the transmitted beam 14 is used to print in the printing area; the reflected beam 13 is reflected to the detection end of the light spot detection unit 4 by the reflection unit 5, and the light spot is identified by the detection end of the light spot detection unit 4, so as to obtain the shape, size and other information of the light spot. Since the transmitted beam 14 can still perform printing when the light spot of the reflected beam 13 is detected, the light spot detection work can be performed during the printing process, that is, the light spot detection work can be performed online. In addition, since the energy of the reflected beam 13 of the laser beam 12 is low, it is not easy to damage the light spot detection unit 4 when it is detected by the light spot detection unit 4, and the safety risk is low. In addition, the heat generated by the reflected beam 13 is also low, so that the working temperature of the light spot detection unit 4 is low, which is conducive to ensuring the working stability and service life of the light spot detection unit 4.

[0039] Please continue reading Figure 2 and Figure 4 Preferably, the window piece 3 is configured to close the exit end of the light beam channel 2. Specifically, the window piece 3 is a circular lens. The window piece 3 is fixed to the lower end of the mounting base 1 through a flange 10 and bolts, and the edge portion of the window piece 3 is clamped between the flange 10 and the lower end surface of the mounting base 1.

[0040] Please continue reading Figure 8 As a preference, a mounting opening 6 is provided on the right side of the mounting seat 1, and the reflective unit 5 is arranged at the mounting opening 6. Since the laser beam 12 is input from the upper end of the mounting seat 1, and during the printing process, the laser beam 12 adjusts the deflection angle through the galvanometer system, thereby scanning and printing in the printing area, the active range of the laser beam 12 is a conical spatial range. In order to adapt to the active range of the laser beam 12 and reduce the amount of material used to make the mounting seat 1, as a preference, the mounting seat 1 is a trumpet-shaped one with a small diameter at the upper end and a large diameter at the lower end.

[0041] See also Fig. 9 Preferably, a cooling medium channel 7 is provided inside the mounting base 1, and a medium inlet 8 and a medium outlet 9 of the cooling medium channel 7 are both opened on the outside of the mounting base 1. In order to improve the overall heat dissipation efficiency of the mounting base 1, the cooling medium channel 7 is arranged in a zigzag shape along the circumferential direction of the mounting base 1 to increase the heat exchange area of ​​the cooling medium.

[0042] Please continue reading Figure 4 and Figure 5Preferably, the reflection unit 5 includes a housing 501 and a reflector group 503 disposed inside the housing 501, and the housing 501 is fixedly connected to the mounting port 6. The light spot detection unit 4 is fixedly connected to the housing 501, and a light inlet corresponding to the mounting port 6 is provided on the left side of the housing 501, and a light outlet 502 corresponding to the detection end is provided on the right side of the housing 501, and the reflector group 503 is configured to be able to reflect the reflected light beam 13 of the laser light beam 12 projected at a preset position to the detection end. The light spot detection unit 4 is fixedly connected to the right side of the housing 501, and an end cover 11 is also fixedly connected to the right side of the housing 501, and the end cover 11 covers the light spot detection unit 4.

[0043] Please continue reading Figure 4 and Figure 5 Specifically, the reflector group 503 includes a first reflector 5031, a second reflector 5032 and a third reflector 5033. The first reflector 5031 and the second reflector 5032 are arranged in parallel. The reflected light beam 13 of the laser light beam 12 projected at the preset position is reflected by the first reflector 5031 and the second reflector 5032 and then reflected to the third reflector 5033. The third reflector 5033 is configured to reflect the reflected light beam 13 projected thereon to the detection end. More specifically, a mirror seat 514 is fixedly connected in the housing 501. The third reflector 5033 is fixedly connected to the mirror seat 514. The reflector is inclined at 45° toward the lower right. In the specific use process, the distance from the reflected light beam 13 of the laser light beam 12 projected at the preset position on the window sheet 3 to the detection end of the light spot detection unit 4 through the reflector group 503 is equal to the distance from the transmitted light beam 14 to the printing work plane. Since the length of the reflected light beam 13 is the same as the length of the transmitted light beam 14, the shape and size of the light spot of the transmitted light beam 14 in the printing area can be reflected, and the path of the reflected light beam 13 is longer, resulting in a longer length of the reflecting unit 5. Since the first reflecting mirror 5031 and the second reflecting mirror 5032 are parallel to each other, the reflected light beam 13 can be reflected multiple times between the first reflecting mirror 5031 and the second reflecting mirror 5032, thereby meeting the length requirement of the path of the reflected light beam 13 and reducing the overall length of the reflecting unit 5.

[0044] Please continue reading Figure 4 , 57. Since the laser beam 12 is projected onto the window 3 from above, in order to enable the reflected beam 13 to be reflected onto the first reflector 5031 when the angle with the vertical direction is small, preferably, the first reflector 5031 is arranged above the second reflector 5032, the first reflector 5031 is close to the entrance end of the beam channel 2, the second reflector 5032 is close to the exit end of the beam channel 2, and the length of the first reflector 5031 extending into the beam channel 2 is greater than the length of the second reflector 5032 extending into the beam channel 2. Since the length of the first reflector 5031 extending into the beam channel 2 is longer, the first reflector 5031 can receive the reflected beam 13 closer to the direction perpendicular to the window 3, and the occupation range of the internal space of the beam channel 2 by the reflector group 503 can be reduced.

[0045] Please continue reading Figure 7 In order to facilitate the fixing of the reflective mirror, preferably, the reflective unit 5 further includes two pressing plates 504, which are respectively arranged corresponding to the first reflector 5031 and the second reflector 5032, and the pressing plates 504 are connected to the housing 501 through a plurality of locking bolts 505. In this embodiment, preferably, the pressing plate 504 is connected to the housing 501 through four locking bolts 505. The housing 501 is provided with through holes 513 for the threaded sections of the corresponding locking bolts 505 to pass through. Specifically, the upper side of the housing 501 is provided with four through holes 513, and the lower side of the housing 501 is provided with four through holes 513. The first reflector 5031 is sandwiched between the corresponding pressing plate 504 and the housing 501, and the second reflector 5032 is sandwiched between the corresponding pressing plate 504 and the housing 501. Among them, the pressing plate 504 is provided with a plurality of avoidance holes 512 for the reflected light beam 13 to be projected onto the corresponding first reflector 5031 and the second reflector 5032.

[0046] Please continue reading Figure 7 Preferably, a spring 506 is sleeved on the locking bolt 505, one end of the spring 506 abuts against the pressure plate 504, and the other end abuts against the head of the locking bolt 505. Specifically, a slot 511 is provided on the side of the pressure plate 504 facing the corresponding reflective lens, and the first reflector 5031 and the second reflector 5032 are respectively installed in the corresponding slots 511. The end surfaces of the first reflector 5031 and the second reflector 5032 that are pressed against the housing 501 are located outside the corresponding slots 511, so that the housing 501 and the pressure plate 504 can clamp the corresponding reflective lens. Since the locking bolt 505 is provided with a spring 506, the spring 506 can maintain the pressing force of the pressure plate 504 on the corresponding first reflector 5031 and the second reflector 5032. At the same time, due to the elastic characteristics of the spring 506, when the locking bolt 505 is installed, it can be avoided that the locking bolt 505 is over-tightened to cause damage to the first lens and the second lens.

[0047] Please continue reading Figure 5 Preferably, the reflection unit 5 further includes an attenuation filter 507, which is arranged on the path from the reflected light beam 13 to the detection end. Specifically, a mounting slot 508 is provided on the right side of the housing 501, the mounting slot 508 is communicated with the light exit hole, and the attenuation filter 507 is installed in the mounting slot 508. In order to facilitate the fixing of the attenuation filter 507, a threaded hole 509 is provided on the lower side of the housing 501, and the threaded hole 509 is communicated with the mounting slot 508. A positioning bolt 510 is connected to the inner thread of the threaded hole 509, and the attenuation filter 507 is pressed against the upper end of the positioning bolt 510, so that the attenuation filter 507 is fixed in the mounting slot 508.

[0048] 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.

[0049] 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.

[0050] 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 light spot detection device, characterized in that: include: A mounting base (1) having a light beam channel (2) disposed thereon; A window plate (3) for dividing a laser beam (12) projected thereon into a reflected beam (13) and a transmitted beam (14), wherein the window plate (3) is arranged in the beam channel (2) and is located at an exit end of the beam channel (2); A light spot detection unit (4), used for detecting the light spot projected on its detection end; The reflection unit (5) is used to reflect the reflected light beam (13) of the laser light beam (12) projected on a preset position on the window sheet (3) to the detection end.

2. A light spot detection device according to claim 1, characterized in that: The window plate (3) is configured to close the exit end of the light beam channel (2).

3. A light spot detection device according to claim 1, characterized in that: A mounting opening (6) is provided on the side of the mounting seat (1), and the reflection unit (5) is arranged at the mounting opening (6).

4. A light spot detection device according to claim 3, characterized in that: The reflection unit (5) comprises a shell (501) and a reflection mirror group (503) arranged on the inner side thereof; the shell (501) is fixedly connected to the mounting port (6); the light spot detection unit (4) is fixedly connected to the shell (501); the shell (501) is provided with a light inlet corresponding to the mounting port (6) and a light outlet (502) corresponding to the detection end; the reflection mirror group (503) is configured to be able to reflect a reflected light beam (13) of the laser light beam (12) projected at the preset position to the detection end.

5. A light spot detection device according to claim 4, characterized in that: The reflector group (503) comprises a first reflector (5031), a second reflector (5032) and a third reflector (5033); the first reflector (5031) and the second reflector (5032) are arranged in parallel; a reflected light beam (13) of the laser light beam (12) projected on the preset position is reflected by the first reflector (5031) and the second reflector (5032) and then reflected onto the third reflector (5033); the third reflector (5033) is configured to reflect the reflected light beam (13) projected thereon to the detection end.

6. A light spot detection device according to claim 5, characterized in that: The first reflector (5031) is close to the entrance end of the light beam channel (2), the second reflector (5032) is close to the exit end of the light beam channel (2), and the length of the first reflector (5031) extending into the light beam channel (2) is greater than the length of the second reflector (5032) extending into the light beam channel (2).

7. A light spot detection device according to any one of claims 4 to 6, characterized in that: The reflection unit (5) further comprises two pressing plates (504), the two pressing plates (504) being respectively arranged corresponding to the first reflecting mirror (5031) sheet and the second reflecting mirror (5032) sheet, the pressing plates (504) being connected to the housing (501) via a plurality of locking bolts (505), the first reflecting mirror (5031) sheet being clamped between the corresponding pressing plates (504) and the housing (501), and the second reflecting mirror (5032) sheet being clamped between the corresponding pressing plates (504) and the housing (501).

8. A light spot detection device according to claim 7, characterized in that: A spring (506) is sleeved on the locking bolt (505), one end of the spring (506) abuts against the pressure plate (504), and the other end abuts against the head of the locking bolt (505).

9. A light spot detection device according to claim 4, characterized in that: The reflection unit (5) further comprises an attenuation filter (507), wherein the attenuation filter (507) is arranged on the path from the reflected light beam (13) to the detection end.

10. The light spot detection device according to claim 1, characterized in that: A cooling medium channel (7) is provided inside the mounting seat (1), and a medium inlet (8) and a medium outlet (9) of the cooling medium channel (7) are both opened on the outside of the mounting seat (1).

Images