3D printing device galvanometer point calibration device and 3D printing device galvanometer point calibration method

Abstract

The application relates to the field of 3D printing, aims to solve the problems of low efficiency or high labor cost of known 3D printing equipment calibration schemes, and provides a 3D printing equipment galvanometer point calibration device and method. The 3D printing equipment galvanometer point calibration device comprises a calibration plate and a photoelectric sensor; the calibration plate has opposite first and second surfaces; the calibration plate is provided with a plurality of calibration holes distributed on the surface; the aperture of the calibration hole is greater than the laser spot diameter and less than 1.5 times the laser spot diameter; the calibration hole corresponds to the photoelectric sensor; the hole surface of the calibration hole is a reflecting surface, which is used for conducting the laser reflected once or more times to the photoelectric sensor after the laser is emitted by the galvanometer control and incident from the calibration hole; the photoelectric sensor can detect the light intensity incident thereon, the light intensity is used for judging the amount of laser entering the calibration hole, and then judging the positional relationship between the laser spot irradiated on the calibration plate and the corresponding calibration hole. The application has the beneficial effects of high efficiency and low labor cost.

Description

Technical Field

[0001] This application relates to the field of 3D printing, and more specifically, to a galvanometer point calibration device and a galvanometer point calibration method for 3D printing equipment. Background Technology

[0002] When calibrating the galvanometer of a known 3D printing device, optical measuring instruments such as two-dimensional measuring instruments are required. During the calibration process, the marking paper needs to be transferred from the printing chamber of the device to the optical measuring instrument multiple times. Furthermore, the readings of the optical measuring instrument are subject to human subjective interference. Operators need to have professional data statistical measurement knowledge. After each measurement, the corrected data needs to be obtained, and the printing needs to be repeated to verify the optical measurement. This process is labor-intensive and inefficient.

[0003] Using a high-precision camera for online reading essentially replaces optical measuring instruments with a camera. However, high-precision cameras require lens distortion calibration and dimensional calibration before they can be used. Furthermore, the inherent characteristics of cameras inevitably include pixel drift and theoretical resolution being lower than actual resolution, resulting in measurement data that is slightly inferior to that of two-dimensional measuring instruments. They also require professional operation to achieve good results, leading to issues of low efficiency or high labor costs. Summary of the Invention

[0004] This application provides a galvanometer point calibration device and a galvanometer point calibration method for 3D printing equipment, in order to solve the problems of low efficiency or high labor costs of known 3D printing equipment calibration schemes.

[0005] In a first aspect, this application provides a galvanometer point calibration device for a 3D printing equipment. The galvanometer can be controlled to move to control the irradiation position of the laser emitted by the 3D printing equipment. The galvanometer point calibration device for a 3D printing equipment includes a calibration plate and a photoelectric sensor.

[0006] The calibration plate has a first surface and a second surface with opposite sides, with the galvanometer located on one side of the first surface and the photoelectric sensor located on one side of the second surface;

[0007] The calibration plate has multiple calibration holes distributed across its surface, which penetrate the first and second surfaces of the calibration plate; the diameter of the calibration holes is larger than the diameter of the laser spot but smaller than 1.5 times the diameter of the laser spot.

[0008] The calibration hole corresponds to the photoelectric sensor;

[0009] The aperture surface of the calibration hole is a reflective surface, which is used to reflect the laser light emitted by the galvanometer and entering through the calibration hole once or multiple times before transmitting it to the photoelectric sensor.

[0010] The photoelectric sensor can detect the intensity of light incident on it. The light intensity is used to determine the amount of laser light entering the calibration hole, and then to determine the positional relationship between the laser spot illuminating the calibration plate and the corresponding calibration hole. The positional relationship is used to calibrate the galvanometer.

[0011] In the galvanometer point calibration device for 3D printing equipment in this application, each calibration hole can serve as a calibration point. By calibrating multiple calibration holes distributed across the surface, the complete calibration of the galvanometer can be achieved.

[0012] When calibrating for a specific calibration hole, the galvanometer of the 3D printing equipment is deflected to the corresponding angle. The laser emitted by the 3D printing equipment is reflected by the galvanometer located at that deflection angle and illuminates the vicinity of the calibration hole on the calibration plate. Due to the uncertainty of the galvanometer error, the actual irradiation position of the laser may correspond exactly to the calibration hole, or it may be around the calibration hole.

[0013] If the entire light spot illuminating the calibration plate falls within the range of the calibration hole, all the light will enter the calibration hole and be reflected by the hole surface to the photoelectric sensor, resulting in the highest light intensity detected by the photoelectric sensor. If only a portion of the light spot illuminating the calibration plate falls within the range of the calibration hole, only a portion of the light will enter the calibration hole and be reflected by the hole surface to the photoelectric sensor, while the remaining light will be absorbed by the first surface or reflected elsewhere; in this case, the light intensity detected by the photoelectric sensor will be relatively low. That is, the farther the laser spot's illumination position deviates from the center of the calibration hole, the less light enters the calibration hole, and the lower the corresponding detected light intensity.

[0014] In this way, the amount of laser light entering the calibration aperture can be determined by the intensity of the light detected by the photoelectric sensor, and then the positional relationship between the laser spot and the corresponding calibration aperture can be determined. This positional relationship can then be used to calibrate the galvanometer.

[0015] In one possible implementation:

[0016] The laser spot is a circular spot with a diameter of 4μm, and the calibration hole is a circular hole with a diameter of 5μm;

[0017] The calibration hole is a long, narrow hole with a depth-to-diameter ratio greater than 100.

[0018] In one possible implementation:

[0019] The calibration plate is made of stainless steel, and the reflectivity of the aperture surface is greater than 85% and less than 90%.

[0020] In one possible implementation:

[0021] The galvanometer point calibration device for 3D printing equipment also includes multiple optical fibers;

[0022] Multiple optical fibers are connected to multiple calibration holes respectively; one end of the optical fiber is connected to the calibration hole near the second surface, and the other end is connected to the photoelectric sensor.

[0023] In one possible implementation:

[0024] The galvanometer point calibration device for 3D printing equipment also includes a sealed chamber, which is connected to one side of the second surface of the calibration plate and forms a light-shielding space with the sealed chamber.

[0025] The photoelectric sensor and optical fiber are located in a shaded space.

[0026] In one possible implementation:

[0027] The galvanometer is rotated by a galvanometer driver. The calibration device also includes a control device, which is electrically connected to the photoelectric sensor and the galvanometer driver. The control device is used to receive the light intensity detected by the photoelectric sensor.

[0028] The galvanometer driver is used to control the rotation of the galvanometer within a certain range so that the laser spot scans within a certain range around the selected calibration hole until the light intensity detected by the photoelectric sensor reaches the maximum value.

[0029] When the light intensity detected by the photoelectric sensor reaches its maximum value, the angle value of the galvanometer is used as the calibrated angle value of the position of the calibration hole corresponding to the galvanometer.

[0030] In one possible implementation:

[0031] The calibration board is divided into multiple partitions;

[0032] There are multiple galvanometers, and each galvanometer corresponds to a different partition.

[0033] Adjacent partitions have overlapping areas, and each overlapping area contains at least one calibration hole.

[0034] In one possible implementation:

[0035] The overlapping areas form a cross shape, and there are multiple calibration holes distributed in a cross shape within the overlapping areas.

[0036] Secondly, this application provides a 3D printing equipment galvanometer point calibration method, which is based on the aforementioned 3D printing equipment galvanometer point calibration device. The 3D printing equipment galvanometer point calibration method includes:

[0037] Select a calibration hole. The location of the calibration hole is the theoretical point of the galvanometer. The theoretical point of the galvanometer refers to the theoretical point of illumination of the laser spot when the galvanometer is rotated at a set angle.

[0038] The galvanometer is controlled to rotate to a set rotation angle and rotates within a certain range around the set rotation angle; during rotation, the intensity of the incident light is detected by a photoelectric sensor; when the light intensity reaches the set maximum value, the rotation angle value of the galvanometer's position is corrected to the set rotation angle corresponding to the theoretical position of the galvanometer.

[0039] Repeat the above calibration process for each of the other calibration holes in turn, until all calibration holes or the required number of calibration holes are calibrated.

[0040] In one possible implementation:

[0041] The calibration plate is divided into multiple partitions, with overlapping areas between adjacent partitions. The overlapping areas include multiple calibration holes arranged in a cross shape.

[0042] There are multiple galvanometers, each corresponding to a different partition. Adjacent galvanometers are calibrated through calibration holes in overlapping areas to achieve point splicing of multiple galvanometers. Attached Figure Description

[0043] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0044] Figure 1 The diagram shows a schematic representation of a galvanometer point calibration device for a 3D printing equipment according to an embodiment of this application.

[0045] Figure 2 for Figure 1 A partial sectional view from another perspective;

[0046] Figure 3 The diagram shows a structural schematic of a galvanometer point calibration device for a 3D printing equipment according to another embodiment of this application.

[0047] Explanation of key component symbols:

[0048] 3D printing equipment 100

[0049] Galvanometer 101

[0050] Mirror driver 102

[0051] Laser L1

[0052] Separator line L3

[0053] 3D Printing Equipment Galvanometer Point Calibration Device 10

[0054] Calibration plate 11

[0055] Photoelectric sensor 12

[0056] Fiber 13

[0057] Enclosed Room 14

[0058] Control device 30

[0059] Calibration Hole K1

[0060] First surface P1

[0061] Second surface P2

[0062] Hole surface P3

[0063] Shading space Q1

[0064] Partitions S1 and S2

[0065] Overlapping region S3 Detailed Implementation

[0066] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0067] It should be noted that when a component is said to be "fixed to" another component, it can be directly on the other component or there may be an intervening component. When a component is said to be "connected to" another component, it can be directly connected to the other component or there may be an intervening component. When a component is said to be "set on" another component, it can be directly set on the other component or there may be an intervening component. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0068] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "or / and" as used herein includes any and all combinations of one or more of the associated listed items.

[0069] Some embodiments of this application are described in detail. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0070] 3D printing equipment (such as SLM metal 3D printing equipment) mainly uses optical devices such as galvanometers to control the laser emitted by the laser to irradiate the powder material (such as metal powder) in the printing area along a set scanning path. The powder material in the laser-irradiated area receives the laser energy and fuses to form a solid.

[0071] To ensure that the laser accurately illuminates the scanning path, the galvanometer needs to have high control precision, that is, there needs to be a precise correspondence between the rotation angle of the galvanometer and the corresponding irradiation position.

[0072] Taking a two-dimensional galvanometer as an example, under ideal conditions, the functional relationship between the coordinates (x,y) of a point P on the scanning path on the printing surface and the two-dimensional rotation angle (α,β) of the galvanometer is (x,y)=F(α,β). That is, when the two-dimensional rotation angle of the galvanometer is α and β respectively, the coordinates of the position of the light spot formed by the laser being reflected by the galvanometer onto the printing surface are (x,y).

[0073] Thus, when the laser needs to illuminate a point D1(x1,y1) on the set scanning path, the corresponding turning angle value can be obtained by inversely operating the above function, resulting in (α1,β1)=F -1 (x1, y1). Thus, by controlling the galvanometer to rotate at an angle (α1, β1) through the galvanometer control device 30, the light spot can be made to illuminate the desired coordinate position (x1, y1).

[0074] However, due to the offset of the relative positions of the components or structural deformation during use, the galvanometer may rotate to a certain angle, such as (α1,β1), and the actual irradiation position of the laser spot may deviate from the theoretical coordinate position (x1,y1), thus affecting the printing accuracy.

[0075] The 3D printing equipment galvanometer point calibration device and 3D printing equipment galvanometer point calibration method provided in this embodiment can perform precise point calibration of the galvanometer so that the rotation angle of the galvanometer after calibration has a more accurate correspondence with the laser irradiation position, thereby ensuring the accuracy of the printed parts. The following will be described by example.

[0076] Example

[0077] See Figure 1 and Figure 2 This embodiment provides a galvanometer point calibration device 10 for a 3D printing equipment. The galvanometer 101 can be rotated under the control of the galvanometer driver 102 to control the irradiation position of the laser L1 emitted by the 3D printing equipment 100.

[0078] The galvanometer point calibration device 10 for 3D printing equipment includes a calibration plate 11, a photoelectric sensor 12, and multiple optical fibers 13. The photoelectric sensor 12 can be a light intensity sensor or other sensors based on the photoelectric effect.

[0079] The calibration plate 11 has a first surface P1 and a second surface P2 opposite to each other, with the galvanometer 101 located on the first surface P1 side and the photoelectric sensor 12 located on the second surface P2 side.

[0080] The calibration plate 11 has multiple calibration holes K1 distributed on a surface. The multiple calibration holes K1 can be distributed in a matrix or in a circular distribution with inner and outer rings. No limitation is made here.

[0081] The calibration hole K1 is a through hole that penetrates the first surface P1 and the second surface P2 of the calibration plate 11. The diameter of the calibration hole K1 is larger than the diameter of the laser L1 spot but less than 1.5 times the diameter of the laser L1 spot. For example, in one embodiment, the laser L1 spot is a circular spot with a diameter of 4 μm, and the calibration hole K1 is a circular hole with a diameter of 5 μm, meaning the diameter of the calibration hole K1 is slightly larger than the laser L1 spot.

[0082] It should be noted that, in order to ensure that the laser spot shape of L1, which is irradiated onto the first surface P1 of the printing surface or calibration plate 11 from different angles, remains circular, common optical modulation schemes (such as modulation by optical elements such as field lenses and collimating lenses) can be used, which will not be elaborated here.

[0083] Multiple optical fibers 13 are respectively connected to multiple calibration holes K1. Specifically, one end of the optical fiber 13 is connected to the calibration hole K1 near the second surface P2, and the other end corresponds to the photoelectric sensor 12. Optionally, one end of the optical fiber 13 is inserted into the calibration hole K1 near the second surface P2 and is glued to the second surface P2. In this way, the laser L1 entering the calibration hole K1 can be conducted into the optical fiber 13. It should be noted that, for Figure 2 Only one calibration hole K1 and one optical fiber 13 are shown for illustration purposes; the other calibration holes K1 and optical fibers 13 are not shown.

[0084] The aperture surface P3 of the calibration hole K1 is a reflective surface, which is used to reflect the laser L1, which is controlled by the galvanometer 101 and enters the calibration hole K1, once or multiple times and then enters the optical fiber 13, and is conducted by the optical fiber 13 to the photoelectric sensor 12.

[0085] The reflective surface mentioned here refers to a surface with high light reflectivity, such as a surface with a reflectivity of 85% or higher. By setting the aperture surface P3 as a reflective surface, the laser L1 injected into the calibration aperture K1 can be reflected and transmitted to the optical fiber 13 through the aperture surface P3, and then detected by the photoelectric sensor 12.

[0086] Optionally, the calibration hole K1 can be formed by high-speed rotary head forming and subsequent fluid grinding, so that the hole surface P3 forms a smooth reflective surface.

[0087] The photoelectric sensor 12 can detect the light intensity incident on it. The light intensity is used to determine the amount of laser L1 entering the calibration hole K1, and then to determine the positional relationship between the laser L1 spot illuminating the calibration plate 11 and the corresponding calibration hole K1. The positional relationship is used to calibrate the galvanometer 101.

[0088] In the galvanometer point calibration device 10 of the 3D printing equipment in this embodiment, each calibration hole K1 can be used as a calibration point. By calibrating multiple calibration holes K1 distributed on the surface, the complete calibration of the galvanometer 101 can be completed.

[0089] When calibrating for a specific calibration hole K1, the galvanometer 101 of the 3D printing equipment 100 is deflected to the corresponding angle. The laser L1 emitted by the 3D printing equipment 100 is reflected by the galvanometer 101 located at that deflection angle and illuminates the vicinity of the calibration hole K1 on the calibration plate 11. Due to the uncertain error of the galvanometer 101, the actual irradiation position of the laser L1 may correspond exactly to the calibration hole K1, or it may be around the calibration hole K1.

[0090] If the entire light spot illuminating the calibration plate 11 falls within the range of the calibration hole K1, all the light will enter the calibration hole K1 and be reflected by the aperture surface P3 of the calibration hole K1 into the optical fiber 13, and then transmitted by the optical fiber 13 to the photoelectric sensor 12. The light intensity detected by the photoelectric sensor 12 will be the maximum. If only a portion of the light spot illuminating the calibration plate 11 falls within the range of the calibration hole K1, only a portion of the light will enter the calibration hole K1 and be reflected by the aperture surface P3 of the calibration hole K1 into the optical fiber 13, and then transmitted by the optical fiber 13 to the photoelectric sensor 12. The remaining portion of the light will be absorbed by the first surface P1 or reflected elsewhere. In this case, the light intensity detected by the photoelectric sensor 12 will be relatively small. That is, the farther the illumination position of the laser L1 spot is from the center of the calibration hole K1, the less light enters the calibration hole K1, and the smaller the corresponding detected light intensity.

[0091] In this way, the amount of laser L1 entering the calibration hole K1 can be determined by the light intensity detected by the photoelectric sensor 12, and then the positional relationship between the laser L1 spot and the corresponding calibration hole K1 can be determined. This positional relationship can then be used to calibrate the galvanometer 101.

[0092] During testing, it was found that when the space between the first surface P1 of the calibration hole K1 and the galvanometer 101 was treated in a darkroom, the point calibration accuracy of the galvanometer point calibration device 10 of the 3D printing equipment in this embodiment was improved to a certain extent. This may be because when the reflectivity of the hole surface P3 is extremely high, if the darkroom treatment is not performed, stray light (light generated by ambient light or other light sources) on the side of the first surface P1 will also be reflected by the hole surface P3 and enter the optical fiber 13, and then be sensed by the photoelectric sensor 12, thus affecting the measurement results. In a real testing environment, performing darkroom treatment between the first surface P1 and the galvanometer 101 is time-consuming, labor-intensive, and costly.

[0093] This embodiment increases the number of reflections of laser L1 on the aperture surface P3 by setting a larger aperture depth-to-diameter ratio for the calibration aperture K1, and reduces the impact on the detection results by appropriately limiting the reflectivity of the aperture surface P3 to cause greater loss of stray light entering the calibration aperture K1.

[0094] For example, in one embodiment, the reflectivity of the aperture surface P3 is limited to below 90% (specifically between 85% and 90%), and the calibration aperture K1 is set as an elongated aperture with a depth-to-diameter ratio greater than 100, which can greatly reduce the influence of stray light on the detection results and obtain higher detection accuracy.

[0095] In this embodiment, the calibration plate 11 can be made of stainless steel, and the aperture surface P3 can achieve a reflectivity of 85%-90% through polishing or other methods.

[0096] In this embodiment, optionally, the galvanometer point calibration device 10 of the 3D printing equipment further includes a closed chamber 14, which is connected to one side of the second surface P2 of the calibration plate 11 and forms a light-shielding space Q1 with the closed chamber 14. The photoelectric sensor 12 and the optical fiber 13 are located within the light-shielding space Q1 to avoid detection errors caused by external light directly shining on the photoelectric sensor 12.

[0097] In another embodiment, the optical fiber 13 may be omitted, and the calibration hole K1 may be directly aligned with the photoelectric sensor 12, so that the light reflected from the hole surface P3 of the calibration hole K1 directly illuminates the photoelectric sensor 12.

[0098] The 3D printing equipment galvanometer point calibration device 10 also includes a control device 30, which is electrically connected to the photoelectric sensor 12 and the galvanometer driver 102. The control device 30 is used to receive the light intensity detected by the photoelectric sensor 12. The galvanometer driver 102 is used to control the galvanometer 101 to rotate within a certain range so that the spot of the laser L1 scans within a certain range around the selected calibration hole K1 until the light intensity detected by the photoelectric sensor 12 reaches a maximum value. When the light intensity detected by the photoelectric sensor 12 reaches a maximum value, the angle value of the galvanometer 101 is used as the calibrated angle value of the position of the calibration hole K1 corresponding to the galvanometer 101.

[0099] See Figure 3 In one embodiment, the calibration plate 11 is divided into multiple partitions, and there are multiple galvanometers 101, each corresponding to a different partition. For example, as shown in the figure, there are two partitions, labeled partition S1 and partition S2 respectively. Figure 3 The dividing line L3 shown serves as the boundary. There are two corresponding galvanometers 101.

[0100] Partitions S1 and S2 have an overlapping region S3, and the overlapping region S3 has at least one calibration hole K1. The two galvanometers 101 are point-calibrated through the calibration hole K1 in the overlapping region S3, so that the printing paths of the two galvanometers 101 can be spliced, that is, the point splicing of the two galvanometers 101 is completed.

[0101] Optionally, the overlapping region S3 is cross-shaped, and the overlapping region S3 has multiple calibration holes K1 distributed in a cross shape. The multiple calibration holes K1 distributed in a cross shape calibrate the two galvanometers 101 respectively, which helps to improve the point splicing accuracy of the galvanometers 101 in two directions.

[0102] This application embodiment also provides a 3D printing equipment galvanometer point calibration method, which is based on the aforementioned 3D printing equipment galvanometer point calibration device 10. The 3D printing equipment galvanometer point calibration method includes:

[0103] Select a calibration hole K1. The position of calibration hole K1 is the theoretical point of the galvanometer. The theoretical point of the galvanometer refers to the theoretical irradiation point of the laser L1 spot when the galvanometer 101 is rotated at a set angle.

[0104] The galvanometer 101 is controlled to rotate to a set rotation angle and rotates within a certain range near the set rotation angle. During rotation, the incident light intensity is detected by the photoelectric sensor 12. When the light intensity reaches the set maximum value, the rotation angle value of the position of the galvanometer 101 is corrected to the set rotation angle corresponding to the theoretical position of the galvanometer 101.

[0105] Repeat the above calibration process for each of the other calibration holes K1 in turn, until all calibration holes K1 or the required portion of calibration holes K1 are calibrated.

[0106] Optionally, such as Figure 3 As shown, the calibration plate 11 is divided into multiple partitions (such as partition S1 and partition S2), and adjacent partitions have overlapping areas S3. The overlapping areas S3 include multiple calibration holes K1 arranged in a cross shape.

[0107] There are multiple galvanometers 101, and each galvanometer 101 corresponds to a different partition. The adjacent galvanometers 101 are calibrated through the calibration holes K1 in the overlapping area S3, so as to achieve point splicing of multiple galvanometers 101.

[0108] When multiple galvanometers 101 are spliced ​​together, their printing paths can be spliced ​​together with high precision during printing, which helps to improve the splicing accuracy of multiple galvanometers 101 during splicing printing.

[0109] Therefore, by using the 3D printing equipment galvanometer point calibration device 10 in this embodiment, precise point calibration or point splicing of the galvanometer 101 can be performed, with a calibration accuracy of 0.02mm. Furthermore, this calibration device and method can be operated entirely online, without leaving the printing chamber or using measuring instruments such as two-dimensional measuring instruments. It is simple to operate, saves labor costs, and provides reliable detection accuracy, avoiding the influence of human factors.

[0110] Taking a printing area of ​​650mm*650mm with four galvanometers as an example, using the conventional two-dimensional measurement method, it is necessary to repeat the measurement 3 times, each time taking 2 hours, with a calibration accuracy of 0.03mm, and technical personnel need to be involved throughout the process.

[0111] The galvanometer point calibration device 10 for 3D printing equipment using this application takes 1 hour to complete a single scan, with a calibration accuracy of 0.02mm. It does not require full-time personnel involvement; simply connecting the device and starting the program will complete the process automatically.

[0112] Furthermore, the calibration plate 11 is manufactured using high-precision machining in this embodiment. Existing machining capabilities meet the processing requirements, and the cost is far lower than that of optical measuring instruments such as two-dimensional measuring instruments.

[0113] The galvanometer point calibration device 10 for 3D printing equipment in this embodiment is small in size, easy to carry, and plug-and-play. Other similar measurement devices are large instruments that need to be placed in specific locations for use.

[0114] The above embodiments are only used to illustrate the technical solutions of this application and are not intended to limit it. Although this application has been described in detail with reference to the above preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions to the technical solutions of this application should not depart from the spirit and scope of the technical solutions of this application.

Claims

1. A galvanometer point calibration device for a 3D printing equipment, wherein the galvanometer is controllably movable to control the irradiation position of a laser emitted by the 3D printing equipment, characterized in that: The galvanometer point calibration device for the 3D printing equipment includes a calibration plate and a photoelectric sensor; The calibration plate has a first surface and a second surface opposite to each other, with the galvanometer located on one side of the first surface and the photoelectric sensor located on one side of the second surface; The calibration plate has a plurality of calibration holes distributed on a surface, the calibration holes penetrating the first surface and the second surface of the calibration plate; the diameter of the calibration hole is larger than the diameter of the laser spot but smaller than 1.5 times the diameter of the laser spot; The calibration hole corresponds to the photoelectric sensor; The aperture surface of the calibration hole is a reflective surface, used to reflect the laser light emitted by the galvanometer and entering through the calibration hole once or multiple times before transmitting it to the photoelectric sensor; The photoelectric sensor can detect the light intensity incident on it. The light intensity is used to determine the amount of laser light entering the calibration hole, and then to determine the positional relationship between the laser spot irradiating the calibration plate and the corresponding calibration hole. The positional relationship is used to calibrate the galvanometer.

2. The galvanometer point calibration device for 3D printing equipment according to claim 1, characterized in that: The laser spot is a circular spot with a diameter of 4 μm, and the calibration hole is a circular hole with a diameter of 5 μm; The calibration hole is a long, narrow hole with a depth-to-diameter ratio greater than 100.

3. The galvanometer point calibration device for 3D printing equipment according to claim 1, characterized in that: The calibration plate is made of stainless steel, and the reflectivity of the aperture surface is greater than 85% and less than 90%.

4. The galvanometer point calibration device for 3D printing equipment according to claim 1, characterized in that: The 3D printing equipment galvanometer point calibration device also includes multiple optical fibers; The optical fibers are respectively connected to the calibration holes; one end of the optical fiber is connected to the calibration hole near the second surface, and the other end is connected to the photoelectric sensor.

5. The galvanometer point calibration device for 3D printing equipment according to claim 4, characterized in that: The 3D printing equipment galvanometer point calibration device also includes a closed chamber, which is connected to one side of the second surface of the calibration plate and forms a light-shielding space with the closed chamber; The photoelectric sensor and the optical fiber are located within the light-shielding space.

6. The galvanometer point calibration device for 3D printing equipment according to claim 1, characterized in that: The galvanometer is controlled to rotate by a galvanometer driver. The calibration device also includes a control device, which is electrically connected to the photoelectric sensor and the galvanometer driver. The control device is used to receive the light intensity detected by the photoelectric sensor. The galvanometer driver is used to control the galvanometer to rotate within a certain range so that the laser spot scans within a certain range around the selected calibration hole until the light intensity detected by the photoelectric sensor reaches a maximum value. When the light intensity detected by the photoelectric sensor reaches its maximum value, the angle value of the galvanometer is used as the calibrated angle value of the position of the calibration hole corresponding to the galvanometer.

7. The galvanometer point calibration device for 3D printing equipment according to any one of claims 1-6, characterized in that: The calibration board is divided into multiple partitions; There are multiple galvanometers, and each of the multiple galvanometers corresponds to a multiple of the partitions; Adjacent partitions have overlapping areas, and at least one of the calibration holes is located within the overlapping areas.

8. The galvanometer point calibration device for 3D printing equipment according to claim 7, characterized in that: The overlapping area is cross-shaped, and the overlapping area has multiple calibration holes distributed in a cross shape.

9. A method for calibrating the galvanometer points of a 3D printing device, characterized in that, Based on the 3D printing equipment galvanometer point calibration device according to any one of claims 1-8, the 3D printing equipment galvanometer point calibration method includes: Select a calibration hole, the position of which is the theoretical point of the galvanometer, which refers to the theoretical point of illumination of the laser spot when the galvanometer is rotated at a set angle; The galvanometer is controlled to rotate to the set rotation angle, and the galvanometer rotates within a certain range near the set rotation angle; during rotation, the incident light intensity is detected by the photoelectric sensor; when the light intensity reaches the set maximum value, the rotation angle value of the position of the galvanometer is corrected to the set rotation angle corresponding to the theoretical position of the galvanometer. Repeat the above calibration process for each of the other calibration holes in turn, until all calibration holes or the required number of calibration holes are calibrated.

10. The galvanometer point calibration method for 3D printing equipment according to claim 9, characterized in that: The calibration plate is divided into multiple partitions, with adjacent partitions having overlapping areas, and the overlapping areas include multiple calibration holes arranged in a cross shape. There are multiple galvanometers, each corresponding to a different partition. Adjacent galvanometers are calibrated through calibration holes in the overlapping areas to achieve point splicing of multiple galvanometers.

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