Sinking 3D Printers and 3D Printing Methods

Abstract

This invention discloses a recessed 3D printer and a 3D printing method. In this recessed 3D printer, the output end of a first drive mechanism is connected to the printing platform, which can drive the printing platform to move up and down along the height direction of the worktable. The output shaft of a second drive mechanism is connected to a scraper, which can drive the scraper to move up and down along the height direction of the worktable and rotate around its output shaft. The output shaft of the second drive mechanism is parallel to the height direction of the worktable. A laser displacement sensor is used to monitor the liquid level in the resin tank. A liquid level adjustment mechanism can deliver resin into the resin tank or extract resin from the resin tank. The optical engine, second drive mechanism, scraper, printing platform, resin tank, and liquid level adjustment mechanism are arranged at intervals from top to bottom along the height direction of the worktable. This improves the surface quality of the printed model, avoids horizontal lines on the model surface, and increases the printing speed.

Description

Technical Field

[0001] This invention relates to the field of 3D printing technology, and more particularly to a sunken 3D printer and a 3D printing method. Background Technology

[0002] 3D printers combine computer-aided design with material processing and molding technology. Through a control system and programming software, various materials are deposited layer by layer to form a solid product. The product is deposited from bottom to top on the printing platform according to the projection of the photoengine, forming an actual image. Existing 3D photopolymerization printers are mainly divided into two categories based on the placement of the photoengine: pull-up 3D printers and sink-down 3D printers.

[0003] In existing sunken 3D printers, the printing platform moves downwards during 3D printing, allowing resin from the resin tank to adhere to the platform surface. The platform then moves upwards to a designated position, where a laser rangefinder on the squeegee detects the resin level and adjusts the squeegee and optical engine accordingly. When the resin level changes, the squeegee and optical engine are adjusted based on the laser rangefinder's data. Essentially, the squeegee scraping and exposure operations are always based on the resin level. However, this type of sunken 3D printer has the following drawbacks:

[0004] 1) The laser rangefinder is located on a movable / rotating scraper. The installation accuracy of the scraper and the vibration generated by its movement will affect the detection accuracy of the laser rangefinder. In addition, the laser rangefinder will limit the rotation speed of the scraper.

[0005] 2) Due to the large size and weight of the optical engine, the lifting and lowering process of the optical engine will limit the printing speed of the sinking 3D printer.

[0006] 3) Both the laser rangefinder and the optical engine are electrical components that require wiring. Therefore, placing the laser rangefinder on a movable / rotating scraper will increase the difficulty of wiring, and the lifting and lowering of the optical engine will also increase the difficulty of wiring.

[0007] 4) Adjusting the scraper movement and the optical engine movement need to be done sequentially, which limits the printing speed of the sinking 3D printer; and the repeated movement of the scraper and optical engine requires the scraper and optical engine to be repositioned multiple times, and the positioning error will affect the printing accuracy. Summary of the Invention

[0008] The purpose of this invention is to provide a sunken 3D printer and a 3D printing method to solve the problems of low printing speed and poor printing accuracy of existing sunken 3D printers.

[0009] To achieve this objective, the present invention adopts the following technical solution:

[0010] A submerged 3D printer includes a worktable, and an optical engine, a first drive mechanism, a second drive mechanism, a scraper, a printing platform, a resin tank, a laser displacement sensor, and a liquid level adjustment mechanism disposed on the worktable. The output end of the first drive mechanism is connected to the printing platform, and the first drive mechanism can drive the printing platform to move up and down along the height direction of the worktable. The output shaft of the second drive mechanism is connected to the scraper, and the second drive mechanism can drive the scraper to move up and down along the height direction of the worktable and can also drive the scraper to rotate around the output shaft of the second drive mechanism. The output shaft of the second drive mechanism is parallel to the height direction of the worktable. The laser displacement sensor is used to monitor the liquid level in the resin tank. The liquid level adjustment mechanism can deliver resin into the resin tank or extract resin from the resin tank.

[0011] The optical engine, the second drive mechanism, the scraper, the printing platform, the resin tank, and the liquid level adjustment mechanism are arranged at intervals from top to bottom along the height direction of the worktable.

[0012] Preferably, the first drive mechanism includes a first motor, a first ball screw assembly, and an L-shaped connector. The first motor is fixedly mounted on the worktable. The first ball screw assembly includes a threaded first screw and a first screw nut. The output shaft of the first motor is fixedly connected to the first screw. The first screw nut is slidably mounted on the worktable along the height direction of the worktable and connected to one end of the connector. The printing platform is fixedly mounted on the other end of the connector.

[0013] Along the height direction of the worktable, the first drive mechanism is located between the liquid level adjustment mechanism and the optomechanism.

[0014] Preferably, the sunken 3D printer includes a worktable and a controller, which is electrically connected to the optical engine, the first drive mechanism, the second drive mechanism, the laser displacement sensor, and the liquid level adjustment mechanism.

[0015] A 3D printing method for controlling the aforementioned sinking 3D printer, the 3D printing method comprising:

[0016] Control the printing platform to obtain resin from the resin tank;

[0017] The scraper is controlled to rotate from a first initial position to a first clockwise direction by a set angle to flatten the resin on the printing platform, so that the thickness of the resin on the printing platform is a set layer thickness;

[0018] Control the scraper to rise upwards by a first predetermined distance;

[0019] Set the settling time for the sunken 3D printer;

[0020] Control the optical engine to expose and print images;

[0021] Obtain the liquid level height of the resin in the resin tank;

[0022] Determine whether the resin level in the resin tank is within the set liquid level range;

[0023] If the resin level in the resin tank is within the set liquid level range, the scraper is controlled to return to the first initial position, and the printing platform is controlled to pick up resin from the resin tank again simultaneously.

[0024] If the resin level in the resin tank is not within the set liquid level range, the scraper is controlled to return to the first initial position, the liquid level adjustment mechanism is controlled to adjust the liquid level in the resin tank to be within the set liquid level range, and the printing platform is controlled to pick up resin from the resin tank again simultaneously.

[0025] Preferably, the specific steps for controlling the printing platform to obtain resin from the resin tank include:

[0026] The printing platform is controlled to descend from a second initial position a second predetermined distance and immerse itself in the resin tank;

[0027] After the first set time period, the printing platform is controlled to rise by the second set distance to reach the second initial position.

[0028] Preferably, the specific steps for controlling the scraper to return to the first initial position include:

[0029] The scraper is controlled to rotate by a set angle in a second clockwise direction, where the second clockwise direction and the first clockwise direction are opposite clockwise directions.

[0030] Control the scraper to descend downwards by the first predetermined distance.

[0031] Preferably, the output shaft of the second drive mechanism is located at the middle position of the printing platform along the length direction and on one side of the printing platform along the width direction;

[0032] The set angle is greater than or equal to 135 degrees.

[0033] Preferably, the specific steps for controlling the printing platform to obtain resin from the resin tank again include:

[0034] The printing platform is controlled to descend from a second initial position and then immerse itself in the resin tank a third predetermined distance.

[0035] After the first set duration, control the printing platform to rise upwards by the fourth set distance;

[0036] Wherein, the fourth set distance = the third set distance - the set layer thickness.

[0037] Preferably, if the resin level in the resin tank is greater than the maximum value of the set liquid level range, the liquid level regulating mechanism is controlled to extract resin from the resin tank until the resin level in the resin tank is within the set liquid level range.

[0038] If the resin level in the resin tank is less than the minimum value of the set liquid level range, the liquid level regulating mechanism is controlled to deliver resin into the resin tank until the resin level in the resin tank is within the set liquid level range.

[0039] Preferably, the adjustment time for the liquid level regulating mechanism to adjust the liquid level height of the resin tank within the set liquid level height range is less than the total time for the printing platform to re-obtain resin from the resin tank.

[0040] The beneficial effects of this invention are:

[0041] The present invention aims to provide a submerged 3D printer and a 3D printing method. The submerged 3D printer includes a worktable, and an optical engine, a first drive mechanism, a second drive mechanism, a scraper, a printing platform, a resin tank, a laser displacement sensor, and a liquid level adjustment mechanism disposed on the worktable. When 3D printing is performed, the first drive mechanism drives the printing platform to move downward along the height direction of the worktable and immerse it in the resin tank. Then, it drives the printing platform to move upward along the height direction of the worktable. At this time, the printing platform is still in the resin tank. It can be understood that the printing platform is always in the resin tank throughout the printing process. The second drive mechanism drives the scraper to rotate and smooth the resin on the printing platform, so that the thickness of the newly added resin on the upper molding surface of the model on the printing platform is the set layer thickness. Then, the second drive mechanism drives the scraper to rise upward and move away from the printing platform. After the printing platform is left to stand for a set time, the optical engine exposes and prints the image. The scraper returns to the initial position to complete one 3D printing process. The above process is repeated until the 3D printing is completed. In this method, the optical engine is fixed at the top of the worktable, and the laser displacement sensor is fixed on the worktable above the resin tank. This means that during 3D printing, the positions of the optical engine and laser displacement sensor remain constant. Only the working position of the printing platform needs adjustment. Furthermore, during each print, the scraper remains at the same height, rotating and leveling the resin on the printing platform. This effectively avoids the problems of printing speed and accuracy caused by the movement of the optical engine and laser displacement sensor in existing technologies. It also means that when the optical engine exposes and prints the resin on the printing platform, the resin maintains a static, constant level, effectively improving the surface quality of the printed model and preventing horizontal lines from forming on the surface. This design eliminates the printing accuracy issues caused by the movement of the optomechanical system and laser displacement sensor, as well as the printing speed issues caused by the large size and weight of the optomechanical system. It also reduces the wiring complexity of the optomechanical system and laser displacement sensor. Secondly, the first drive mechanism can move the printing platform up and down along the height of the worktable, and the second drive mechanism can move the squeegee up and down along the height of the worktable. It can also rotate the squeegee around the output shaft of the second drive mechanism. It can be understood that the process of the first drive mechanism moving the printing platform up and down along the height of the worktable to obtain resin from the resin tank can be carried out simultaneously with the process of the second drive mechanism moving the squeegee around the output shaft of the second drive mechanism and moving it up and down along the height of the worktable to adjust it to the working position, thereby further improving the printing speed. Attached Figure Description

[0042] Figure 1 This is a schematic diagram of the structure of a sunken 3D printer provided in a specific embodiment of the present invention from a first perspective;

[0043] Figure 2 This is a schematic diagram of the sinking 3D printer provided in a specific embodiment of the present invention from a second perspective;

[0044] Figure 3 This is a partial structural schematic diagram of a sunken 3D printer provided in a specific embodiment of the present invention;

[0045] Figure 4 This is a flowchart of a 3D printing method provided in a specific embodiment of the present invention;

[0046] Figure 5 This is a schematic diagram of the 3D printing method provided in a specific embodiment of the present invention.

[0047] In the picture:

[0048] 1. Workbench; 11. First workbench; 12. Second workbench; 13. Third workbench;

[0049] 2. Optical mechanism;

[0050] 3. First drive mechanism; 31. First motor; 32. First roller screw assembly; 33. Connecting part; 321. First screw; 322. First screw nut;

[0051] 4. Second drive mechanism; 41. Second motor; 42. Third motor; 43. Belt drive mechanism;

[0052] 5. Scraper;

[0053] 6. Printing platform;

[0054] 7. Resin tank;

[0055] 8. Laser displacement sensor;

[0056] 9. Liquid level regulating mechanism; 91. Hydraulic pump; 92. Liquid storage tank. Detailed Implementation

[0057] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0058] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0059] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0060] In the description of this embodiment, the terms "upper," "lower," "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In addition, the terms "first" and "second" are used only for distinction in description and have no special meaning.

[0061] This invention provides a sunken 3D printer, such as... Figure 1-3 As shown, the sunken 3D printer includes a worktable 1, and an optical engine 2, a first drive mechanism 3, a second drive mechanism 4, a scraper 5, a printing platform 6, a resin tank 7, a laser displacement sensor 8, and a liquid level adjustment mechanism 9, all mounted on the worktable 1. The output end of the first drive mechanism 3 is connected to the printing platform 6, and the first drive mechanism 3 can drive the printing platform 6 to move up and down along the height direction of the worktable 1. The output shaft of the second drive mechanism 4 is connected to the scraper 5, and the second drive mechanism 4 can drive the scraper 5 to move up and down along the height direction of the worktable 1, and can also drive the scraper 5 to rotate around the output shaft of the second drive mechanism 4. The output shaft of the second drive mechanism 4 is parallel to the height direction of the worktable 1. The laser displacement sensor 8 is used to monitor the liquid level in the resin tank 7. The liquid level adjustment mechanism 9 can deliver resin into the resin tank 7 or extract resin from the resin tank 7. The optical engine 2, the second drive mechanism 4, the scraper 5, the printing platform 6, the resin tank 7, and the liquid level adjustment mechanism 9 are arranged at intervals from top to bottom along the height direction of the worktable 1.

[0062] like Figure 1-3 As shown, in this submerged 3D printer, during 3D printing, the first drive mechanism 3 moves the printing platform 6 downward along the height direction of the worktable 1 to immerse it in the resin tank 7, and then moves the printing platform 6 upward along the height direction of the worktable 1. At this time, the printing platform 6 is still in the resin of the resin tank 7. It can be understood that throughout the printing process, the printing platform 6 is always in the resin of the resin tank 7. The second drive mechanism 4 drives the scraper 5 to rotate and smooth the resin on the printing platform 6, so that the thickness of the resin on the printing platform 6 is the set layer thickness. Then, the second drive mechanism 4 drives the scraper 5 to rise upward and move away from the printing platform 6. After the 3D printer is left to stand for the set time, the image is exposed and printed by the optical engine 2. The scraper 5 returns to the initial position to complete one 3D printing process. The above process is repeated until the 3D printing is finished. In this design, by fixing the optical engine 2 at the top of the worktable 1 and fixing the laser displacement sensor 8 on the worktable 1 above the resin tank 7, it can be understood that during the 3D printing process, the positions of the optical engine 2 and the laser displacement sensor 8 remain unchanged. Only the working position of the printing platform 6 needs to be adjusted. Furthermore, during each print, the scraper 5 remains at the same height, rotating to smooth the newly added resin on the upper molding surface of the model on the printing platform 6. This effectively avoids the problems of printing speed and accuracy caused by the movement of the optical engine 2 and the laser displacement sensor 8 in existing technologies. It can also be understood that when the optical engine 2 exposes and prints the resin on the upper molding surface of the model on the printing platform 6, the resin is at a static, constant liquid level, which effectively improves the surface quality of the printed model and prevents horizontal lines from forming on the model surface. This effectively avoids the printing accuracy issues caused by the movement of the optomechanism and laser displacement sensor in existing technologies, as well as the printing speed issues caused by the large size and weight of the optomechanism. It also reduces the wiring difficulty of the optomechanism 2 and laser displacement sensor 8. Secondly, the first drive mechanism 3 can drive the printing platform 6 to move up and down along the height direction of the worktable 1, and the second drive mechanism 4 can drive the scraper 5 to move up and down along the height direction of the worktable 1, and can also drive the scraper 5 to rotate around the output shaft of the second drive mechanism 4. It can be understood that the process of the first drive mechanism 3 driving the printing platform 6 to obtain resin from the resin tank 7 along the height direction of the worktable 1 and the process of the second drive mechanism 4 driving the scraper 5 to rotate around the output shaft of the second drive mechanism 4 and move up and down along the height direction of the worktable 1 to adjust to the working position can be carried out synchronously, thereby further improving the printing speed.

[0063] in, Figure 1-3 In this context, the direction ab is the height direction of workbench 1; Figure 1-3 The cd direction in the figure is the length direction of the worktable 1, which is parallel to the length direction of the printing platform 6. Figure 1 and Figure 3The ef direction in the figure is the width direction of worktable 1, which is parallel to the width direction of printing platform 6.

[0064] Specifically, such as Figure 1-3 As shown, the worktable 1 includes a first worktable 11, a second worktable 12 and a third worktable 13. The two ends of the second worktable 12 are connected to the first worktable 11 and the third worktable 13 respectively. The optomechanism 2 is set on the first worktable 11. The first drive mechanism 3 and the second drive mechanism 4 are both set on the second worktable 12. The resin tank 7, the laser displacement sensor 8 and the liquid level adjustment mechanism 9 are all set on the third worktable 13.

[0065] More specifically, such as Figure 1 and Figure 2 As shown, the first worktable 11 and the third worktable 13 are distributed opposite to each other, and both the first worktable 11 and the third worktable 13 are set perpendicular to the second worktable 12. This arrangement ensures that the optical engine 2 faces the printing platform 6 along the height direction of the worktable 1, so as to ensure that the optical engine 2 can accurately expose and print the image and generate the formed model on the printing platform 6.

[0066] Among them, such as Figure 1-3 As shown, the first drive mechanism 3 includes a first motor 31, a first ball screw assembly 32, and an L-shaped connector 33. The first motor 31 is fixedly mounted on the worktable 1. The first ball screw assembly 32 includes a threaded first lead screw 321 and a first lead screw nut 322. The output shaft of the first motor 31 is fixedly connected to the first lead screw 321. The first lead screw nut 322 is slidably mounted on the worktable 1 along its height direction and connected to one end of the connector 33. The printing platform 6 is fixedly mounted on the other end of the connector 33. Along the height direction of the worktable 1, the first drive mechanism 3 is located between the liquid level adjustment mechanism 9 and the optical engine 2. Specifically, the first motor 31 is fixedly mounted on the second worktable 12 and located below the third worktable 13. The first lead screw 321 is rotatably mounted on the second worktable 12 via a bearing. The first lead screw nut 322 is slidably mounted on the worktable 1 along its height direction and connected to one end of the connector 33. The first motor 31 drives the first lead screw 321 to rotate around its central axis, thereby causing the first lead screw nut 322, which is threaded to the first lead screw 321, to move along the axial direction of the first lead screw 321. This, in turn, causes the connecting piece 33 to move along the axial direction of the first lead screw 321. It can be understood that the axial direction of the first lead screw 321 is parallel to the height direction of the worktable 1. The printing platform 6 is fixedly set on the connecting piece 33, thereby causing the printing platform 6 to rise and fall along the height direction of the worktable 1. This allows the printing platform 6 to be immersed in the resin tank 7 or moved away from the resin tank 7. During the 3D printing process, the printing platform 6 is always immersed in the resin in the resin tank 7. After the 3D printing is completed, the first motor 31 drives the printing platform 6 away from the resin tank 7.

[0067] Among them, such as Figure 1 and Figure 2 As shown, the second drive mechanism 4 includes a lifting mechanism and a rotating mechanism. The lifting mechanism includes a second motor 41 and a second roller screw assembly. The rotating mechanism includes a third motor 42 and a pulley transmission mechanism 43. The second roller screw assembly includes a threaded second screw and a second screw nut. The output shaft of the second motor 41 is fixedly connected to the second screw. The second screw nut is slidably disposed on the worktable 1 along the height direction and connected to the housing of the third motor 42. The output shaft of the third motor 42 is fixedly connected to the input shaft of the pulley transmission mechanism 43. The output shaft of the pulley transmission mechanism 43 is connected to the scraper 5. Specifically, the second motor 41 is fixedly disposed on the second worktable 12. The output shaft of the second motor 41 is fixedly connected to the second screw, and the second screw is rotatably disposed on the second worktable 12 through a bearing. The second screw nut is slidably disposed on the second worktable 12 along the height direction and connected to the housing of the third motor 42. With this configuration, the second motor 41 drives the third motor 42 of the rotating mechanism and the pulley transmission mechanism 43 to move up and down synchronously, thereby driving the scraper 5 to move up and down. The third motor 42 drives the scraper 5 to rotate, thus realizing the second drive mechanism 4 driving the scraper 5 to move up and down and rotate. It can be understood that the lifting and rotation of the scraper 5 can be carried out simultaneously, thereby further improving the printing speed of this sinking 3D printer.

[0068] Among them, such as Figure 1 and Figure 2 As shown, the liquid level regulating mechanism 9 includes a hydraulic pump 91 and a liquid storage tank 92. The two ends of the hydraulic pump 91 are connected to the liquid storage tank 92 and the resin tank 7, respectively. Specifically, both the hydraulic pump 91 and the liquid storage tank 92 are located on the third worktable 13. It is understood that the liquid storage tank 92 stores resin, thereby enabling the liquid level regulating mechanism 9 to deliver resin to or extract resin from the resin tank 7. The hydraulic pump 91 can be one of a gear pump, diaphragm pump, plunger pump, or peristaltic pump. Specifically, in this embodiment, the hydraulic pump 91 is preferably a peristaltic pump.

[0069] The sunken 3D printer includes a worktable 1 and a controller, which is electrically connected to the optical engine 2, the first drive mechanism 3, the second drive mechanism 4, the laser displacement sensor 8, and the liquid level adjustment mechanism 9. Specifically, the controller can control the operation of the first motor 31 of the optical engine 2 and the first drive mechanism 3, as well as the second motor 41 and the third motor 42 of the second drive mechanism 4, and can control the operation of the hydraulic pump 91 of the liquid level adjustment mechanism 9 based on the electrical signal from the laser displacement sensor 8.

[0070] This invention also provides a 3D printing method for controlling the aforementioned sinking 3D printer. For example... Figure 4 and Figure 5As shown, the 3D printing method includes:

[0071] S100, control the printing platform 6 to obtain resin from the resin tank 7.

[0072] The specific steps for controlling the printing platform 6 to obtain resin from the resin tank 7 include:

[0073] S110, control the printing platform 6 to descend from the second initial position and immerse it into the resin tank 7 by a second set distance.

[0074] The second set distance is an empirical value obtained from a large number of previous experiments.

[0075] S120. After the first set time, the printing platform 6 is controlled to rise a second set distance to reach the second initial position, while the printing platform 6 is still immersed in the resin in the resin tank 7.

[0076] in, Figure 5 In this equation, A represents the second set distance, B represents the third set distance, and C represents the fourth set distance. A and B can be the same or different. C = B - set layer thickness.

[0077] S200, control the scraper 5 to rotate from the first initial position to the first clockwise direction by a set angle to scrape the resin on the printing platform 6 so that the thickness of the resin on the printing platform 6 is the set layer thickness.

[0078] It is understandable that, along the height direction of worktable 1, the first initial position is higher than the second initial position, and along the height direction of worktable 1, the distance between the first initial position and the second initial position is equal to the set layer thickness.

[0079] Specifically, the output shaft of the second drive mechanism 4 is located at the middle position along the length direction of the printing platform 6 and on one side along the width direction of the printing platform 6; the set angle is greater than or equal to 135 degrees. It can be understood that the output shaft of the pulley drive mechanism 43 is located at the middle position along the length direction of the printing platform 6 and on one side along the width direction of the printing platform 6. When the scraper 5 rotates around the output shaft of the pulley drive mechanism 43 from the first initial position by a set angle, the resin on the printing platform 6 is scraped flat and the thickness of the resin on the printing platform 6 is the set layer thickness. Preferably, in this embodiment, exemplarily, when the scraper 5 is in the first initial position and the scraper 5 is parallel to the length direction of the printing platform 6, the set angle is equal to 180 degrees.

[0080] S300, control the scraper 5 to rise upwards by the first set distance.

[0081] This configuration allows the scraper 5 to rotate rapidly in the second clockwise direction without contacting the resin, reducing the risk of resin level fluctuations.

[0082] At this point, the printing platform 6 remains inside the resin in the resin tank 7. It is understandable that throughout the entire printing process, the printing platform 6 remains within the resin in the resin tank 7.

[0083] The S400 static 3D printer's set resting time is determined. This set resting time is an empirical value obtained from extensive prior experiments. It's used to ensure stable resin levels, thereby improving 3D printing quality.

[0084] S500, control optical engine 2 to expose and print images.

[0085] S600, Obtain the liquid level of the resin in the resin tank 7.

[0086] S700: Determine whether the liquid level of the resin in the resin tank 7 is within the set liquid level range.

[0087] If the resin level in resin tank 7 is within the set liquid level range, then steps S800 and S900 are performed simultaneously.

[0088] S800, control scraper 5 to return to the first initial position.

[0089] The specific steps for controlling the scraper 5 to return to the first initial position include:

[0090] S810, Control the scraper 5 to rotate at a set angle in the second clockwise direction, the second clockwise direction and the first clockwise direction are opposite clockwise directions.

[0091] S820, control the scraper 5 to descend the first set distance.

[0092] S900: Control the printing platform 6 to draw resin from the resin tank 7 again. This ensures that the upper surface of the molded model on the printing platform 6 is covered with resin.

[0093] Specifically, the steps for controlling the printing platform 6 to retrieve resin from the resin tank 7 again include:

[0094] S910, control the printing platform 6 to descend from the second initial position and immerse it into the resin tank 7 from the third set distance.

[0095] S920, after the first set duration, control the printing platform 6 to rise upwards by a fourth set distance; where the fourth set distance = the third set distance - the set layer thickness.

[0096] Understandably, during 3D printing, for the first layer, the printing platform 6 descends a second predetermined distance and rises a second predetermined distance. For each subsequent layer, the printing platform 6 descends a third predetermined distance and rises (the third predetermined distance minus the predetermined layer thickness) to ensure that the printed thickness is the predetermined layer thickness for each layer. Understandably, if the resin level in the resin tank 7 is within the predetermined range, steps S800 and S900 are performed simultaneously, which can increase the printing speed of this sink-type 3D printer.

[0097] If the resin level in resin tank 7 is not within the set liquid level range, then steps S1000, S1100 and S1200 are performed simultaneously.

[0098] S1000, control the scraper 5 to return to the first initial position.

[0099] Specifically, the steps for controlling the scraper 5 to return to the first initial position include:

[0100] S1010: Control the scraper 5 to rotate at a set angle in the second clockwise direction, where the second clockwise direction and the first clockwise direction are opposite clockwise directions.

[0101] S1020, Control the scraper 5 to descend the first set distance.

[0102] S1100, the liquid level adjustment mechanism 9 adjusts the liquid level height of the resin tank 7 to be within the set liquid level height range.

[0103] If the resin level in the resin tank 7 exceeds the maximum value of the set liquid level range, the liquid level regulating mechanism 9 is controlled to extract resin from the resin tank 7 until the resin level in the resin tank 7 is within the set liquid level range. Specifically, the controller controls the hydraulic pump 91 to operate and extract resin from the resin tank 7.

[0104] If the resin level in the resin tank 7 is less than the minimum value of the set liquid level range, the liquid level regulating mechanism 9 is controlled to supply resin into the resin tank 7 until the resin level in the resin tank 7 is within the set liquid level range. Specifically, the controller controls the hydraulic pump 91 to operate and supply resin into the resin tank 7.

[0105] S1200, control the printing platform 6 to draw resin from the resin tank 7 again.

[0106] Specifically, the steps for controlling the printing platform 6 to retrieve resin from the resin tank 7 again include:

[0107] S1210, control the printing platform 6 to descend a third set distance and immerse it in the resin tank 7.

[0108] S1220 After the first set duration, control the printing platform 6 to rise up a fourth set distance; where the fourth set distance = the third set distance - the set layer thickness.

[0109] Understandably, during 3D printing, for the first layer, the printing platform 6 descends a second predetermined distance and rises a second predetermined distance. For each subsequent layer, the printing platform 6 descends a third predetermined distance and rises (the third predetermined distance minus the predetermined layer thickness) to ensure that the printed thickness is the predetermined layer thickness for each layer. Understandably, if the resin level in the resin tank 7 is not within the predetermined level range, steps S1000, S1100, and S1200 are performed simultaneously to increase the printing speed of the submersible 3D printer.

[0110] It is understandable that steps S200 to S700 are repeated after S920 or S1220 is completed. If the resin level in the resin tank 7 is within the set liquid level range, steps S800 and S900 are performed simultaneously; if the resin level in the resin tank 7 is not within the set liquid level range, steps S1000, S1100, and S1200 are performed simultaneously.

[0111] Therefore, by controlling the sinking 3D printer to perform 3D printing through this 3D printing method, the problem of affecting printing speed and accuracy caused by the movement of the optomechanical 2 and the laser displacement sensor 8 in the prior art is effectively avoided, thus improving the printing speed and accuracy of the sinking 3D printer.

[0112] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art will be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A 3D printing method for controlling a sinking 3D printer, the sinking 3D printer comprising a worktable (1), and an optical engine (2), a first drive mechanism (3), a second drive mechanism (4), a scraper (5), a printing platform (6), a resin tank (7), a laser displacement sensor (8), and a liquid level adjustment mechanism (9) disposed on the worktable (1). The output end of the first drive mechanism (3) is connected to the printing platform (6), and the first drive mechanism (3) can drive the printing platform (6) to rise and fall along the height direction of the worktable (1). The output shaft of the drive mechanism (4) is connected to the scraper (5). The second drive mechanism (4) can drive the scraper (5) to rise and fall along the height direction of the worktable (1) and can drive the scraper (5) to rotate around the output shaft of the second drive mechanism (4). The output shaft of the second drive mechanism (4) is parallel to the height direction of the worktable (1). The laser displacement sensor (8) is used to monitor the liquid level in the resin tank (7). The liquid level adjustment mechanism (9) can deliver resin into the resin tank (7) or extract resin from the resin tank (7). The optical engine (2), the second drive mechanism (4), the scraper (5), the printing platform (6), the resin tank (7), and the liquid level adjustment mechanism (9) are arranged at intervals from top to bottom along the height direction of the worktable (1); characterized in that The 3D printing method includes: The printing platform (6) is controlled to obtain resin from the resin tank (7); Control the scraper (5) to rotate from the first initial position along the first clockwise direction by a set angle to scrape the resin on the printing platform (6) so that the thickness of the resin on the printing platform (6) is a set layer thickness; Control the scraper (5) to rise upwards by a first set distance; Set the settling time for the sunken 3D printer; Control the optical engine (2) to expose and print images; Obtain the liquid level height of the resin in the resin tank (7); Determine whether the liquid level of the resin in the resin tank (7) is within the set liquid level range; If the resin level in the resin tank (7) is within the set liquid level range, the scraper (5) is controlled to return to the first initial position, and the printing platform (6) is controlled to pick up resin from the resin tank (7) again simultaneously. If the resin level in the resin tank (7) is not within the set liquid level range, the scraper (5) is controlled to return to the first initial position, the liquid level adjustment mechanism (9) is controlled to adjust the liquid level in the resin tank (7) to be within the set liquid level range, and the printing platform (6) is controlled to retrieve resin from the resin tank (7) again.

2. The 3D printing method according to claim 1, characterized in that, The first drive mechanism (3) includes a first motor (31), a first ball screw assembly (32), and an L-shaped connector (33). The first motor (31) is fixedly mounted on the worktable (1). The first ball screw assembly (32) includes a threaded first screw (321) and a first screw nut (322). The output shaft of the first motor (31) is fixedly connected to the first screw (321). The first screw nut (322) is slidably mounted on the worktable (1) along the height direction of the worktable (1) and connected to one end of the connector (33). The printing platform (6) is fixedly mounted on the other end of the connector (33). Along the height direction of the worktable (1), the first drive mechanism (3) is located between the liquid level adjustment mechanism (9) and the optomechanism (2).

3. The 3D printing method according to claim 2, characterized in that, The sinking 3D printer also includes a controller, which is electrically connected to the optical engine (2), the first drive mechanism (3), the second drive mechanism (4), the laser displacement sensor (8), and the liquid level adjustment mechanism (9).

4. The 3D printing method according to claim 1, characterized in that, The specific steps for controlling the printing platform (6) to obtain resin from the resin tank (7) include: The printing platform (6) is controlled to descend from the second initial position by a second set distance and immerse itself in the resin tank (7); After the first set time period, the printing platform (6) is controlled to rise up the second set distance to reach the second initial position.

5. The 3D printing method according to claim 1, characterized in that, The specific steps for controlling the scraper (5) to return to the first initial position include: Control the scraper (5) to rotate by the set angle in the second clockwise direction, where the second clockwise direction and the first clockwise direction are opposite clockwise directions; Control the scraper (5) to descend the first set distance.

6. The 3D printing method according to claim 5, characterized in that, The output shaft of the second drive mechanism (4) is located at the middle position of the printing platform (6) along the length direction and on one side of the printing platform (6) along the width direction; The set angle is greater than or equal to 135 degrees.

7. The 3D printing method according to claim 1, characterized in that, The specific steps for controlling the printing platform (6) to retrieve resin from the resin tank (7) again include: The printing platform (6) is controlled to descend from the second initial position by a third set distance and immerse itself in the resin tank (7); After the first set duration, control the printing platform (6) to rise upwards by a fourth set distance; Wherein, the fourth set distance = the third set distance - the set layer thickness.

8. The 3D printing method according to claim 1, characterized in that, If the resin level in the resin tank (7) is greater than the maximum value of the set liquid level range, the liquid level adjustment mechanism (9) is controlled to extract the resin in the resin tank (7) until the resin level in the resin tank (7) is within the set liquid level range. If the resin level in the resin tank (7) is less than the minimum value of the set liquid level range, the liquid level regulating mechanism (9) is controlled to deliver resin into the resin tank (7) until the resin level in the resin tank (7) is within the set liquid level range.

9. The 3D printing method according to claim 1, characterized in that, The time for the liquid level adjustment mechanism (9) to adjust the liquid level height of the resin tank (7) within the set liquid level height range is less than the total time for the printing platform (6) to re-obtain resin from the resin tank (7).

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