Light-cured 3D printing device and printing method thereof

Abstract

The application discloses a kind of photocuring 3D printing device and its printing method, the device includes: resin tank, for accommodating liquid photosensitive resin;Resin tank moving mechanism, for carrying and driving resin tank moves in vertical direction;Light source and projection component, including projection lens and light outlet, light source and projection component are used to provide light source for photosensitive resin for carrying out photocuring reaction, guide light source to project from light outlet to photosensitive resin;Membrane stretching assembly, including release film, membrane stretching assembly is set at the position of light outlet, and release film is located on the focusing plane of projection lens;Printing platform, for supporting and fixing the model formed by photosensitive resin solidification in printing process;Platform moving mechanism, for carrying and driving printing platform moves in vertical direction to realize continuous printing;Control mechanism, for controlling the movement of resin tank moving mechanism, platform moving mechanism. By this way, the stability and consistency of printing product can be improved.

Description

Technical Field

[0001] This application relates to the field of 3D printing technology, and in particular to a photopolymerization 3D printing apparatus and its printing method. Background Technology

[0002] Photopolymer 3D printing technology, with its high precision, high efficiency, and versatility, has become an important tool in product design and manufacturing. Its working principle is as follows: The photopolymer 3D printing device contains a resin tank, above which is equipped a UV lamp. During printing, the photosensitive resin in the tank is irradiated by the UV light, causing chemical cross-linking and solidification into a solid object. The platform then descends, replenishes liquid resin, and is exposed again. By continuously repeating this process, the entire 3D printing process is completed.

[0003] In order to shorten the leveling time of the photosensitive resin and improve the molding efficiency, the photopolymer 3D printing device is also equipped with a film stretching component. Currently, the film stretching component of the photopolymer 3D printing device is set in the resin tank. The film stretching component must be removed before each printing sample is taken out, and leveling and focusing operations must be performed on the film stretching component before the next printing. This will affect the stability and consistency of the printed sample. Summary of the Invention

[0004] Based on this, this application provides a photopolymerization 3D printing device and its printing method, which can improve the stability and consistency of printed products.

[0005] In a first aspect, this application provides a photopolymerization 3D printing apparatus, the apparatus comprising:

[0006] Resin tank, used to hold liquid photosensitive resin;

[0007] A resin tank moving mechanism is used to carry and drive the resin tank to move in the vertical direction;

[0008] A light source and projection assembly, including a light outlet, wherein the light source and projection assembly are used to provide a light source for a photosensitive resin undergoing a photocuring reaction, and to guide the light source from the light outlet onto the photosensitive resin;

[0009] A film-stretching assembly, including a release film, is disposed at the light outlet, and the release film is located on the focusing plane of the projection lens;

[0010] A printing platform used to bond the cured photosensitive resin.

[0011] A platform moving mechanism is used to carry and drive the printing platform to move vertically to achieve continuous printing;

[0012] A control mechanism is used to control the movement of the resin tank moving mechanism and the platform moving mechanism.

[0013] Secondly, this application provides a printing method for a photopolymerization 3D printing apparatus, the method being applicable to the apparatus described above, the method comprising:

[0014] Adjust and record the initial printing positions X0 and Y0 of the printing platform in the left-right direction (X) and front-back direction (Y);

[0015] After determining that the release film of the stretching assembly is located on the focusing plane of the projection lens, adjust and record the printing position Z0 of the printing platform in the vertical direction so that the distance between the forming surface of the printing platform and the lower surface of the release film of the stretching assembly is within a preset distance range.

[0016] The liquid photosensitive resin is poured into the resin tank;

[0017] Adjust the position of the printing platform to the recorded X0, Y0, Z0, and then print.

[0018] In this embodiment of the photopolymerization 3D printing apparatus, the stretching assembly is located at the light outlet, and the release film of the stretching assembly is located on the focusing plane of the projection lens. Therefore, compared with related technologies, this embodiment can avoid removing the stretching assembly before each printing sample is taken out, and avoid leveling and focusing operations on the stretching assembly before the next printing, thereby improving the stability and consistency of the printed products. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of an embodiment of the photopolymerization 3D printing apparatus of this application;

[0020] Figure 2 This is a schematic diagram of another embodiment of the photopolymerization 3D printing apparatus of this application;

[0021] Figure 3 This is a schematic diagram of another embodiment of the photopolymerization 3D printing apparatus of this application;

[0022] Figure 4 This is a schematic diagram of another embodiment of the photopolymerization 3D printing apparatus of this application;

[0023] Figure 5 This is a schematic flowchart of an embodiment of the printing method of the photopolymer 3D printing apparatus of this application;

[0024] Figure 6 This is a partial structural schematic diagram of an embodiment of the photopolymerization 3D printing apparatus of this application.

[0025] Explanation of main components and symbols:

[0026] 1. Resin tank; 2. Resin tank moving mechanism; 3. Light source and projection assembly; 31. Projection lens; 32. Light outlet; 4. Film stretching assembly; 41. First film fixing part; 411. Circular groove; 42. Second film fixing part; 421. Circular protrusion; 43. Third film fixing part; 5. Printing platform; 6. Platform moving mechanism; 7. Film adjustment mechanism; 71. Horizontal adjustment sub-mechanism; 72. Vertical adjustment sub-mechanism; 8. Auxiliary marker block; 91. First ranging module; 92. Second ranging module. Detailed Implementation

[0027] The technical solutions of 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, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0028] The flowchart shown in the attached diagram is for illustrative purposes only and does not necessarily include all content and operations / steps, nor does it necessarily have to be performed in the order described. For example, some operations / steps can be broken down, combined, or partially merged, so the actual execution order may change depending on the actual situation.

[0029] Photopolymer 3D printing technology, with its high precision, high efficiency, and versatility, has become an important tool in product design and manufacturing. Its working principle is as follows: The photopolymer 3D printing device contains a resin tank equipped with an ultraviolet lamp above it. During printing, the photosensitive resin in the tank is irradiated by the ultraviolet light, causing chemical cross-linking and solidification into a solid object. The platform then descends, replenishes liquid resin, and is exposed again. This process is repeated continuously to complete the entire 3D printing process. To shorten the leveling time of the photosensitive resin and improve molding efficiency, the photopolymer 3D printing device also includes a stretching assembly. Currently, the stretching assembly is located in the resin tank. Before each printed sample, the stretching assembly must be removed, and before the next print, leveling and focusing operations must be performed on the stretching assembly, which affects the stability and consistency of the printed sample.

[0030] It should be noted that the photosensitive resin in this application refers to all materials that can be photocured for 3D printing, such as photosensitive resin, photosensitive resin doped with ceramic paste, and photosensitive resin doped with metal paste.

[0031] In this embodiment of the photopolymer 3D printing apparatus, the stretching assembly is located at the light outlet, and the release film of the stretching assembly is located on the focusing plane of the projection lens. Therefore, compared with related technologies, this embodiment can avoid removing the stretching assembly before each printing sample is taken out, and avoid leveling and focusing operations on the stretching assembly before the next printing, thereby improving the stability and consistency of the printed products.

[0032] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0033] See Figure 1 and Figure 2 , Figure 1 and Figure 2 These are schematic diagrams of two embodiments of the photopolymer 3D printing apparatus of this application. The apparatus includes: a resin tank 1, a resin tank moving mechanism 2, a light source and projection assembly 3, a film stretching assembly 4, a printing platform 5, a platform moving mechanism 6, and a control mechanism (not shown in the figure).

[0034] A resin tank 1 is used to contain liquid photosensitive resin; a resin tank moving mechanism 2 is used to carry and drive the resin tank 1 to move vertically; a light source and projection assembly 3 includes a projection lens 31 and a light outlet 32, the light source and projection assembly 3 is used to provide a light source for the photosensitive resin undergoing photocuring reaction, and guide the light source to be projected onto the photosensitive resin from the light outlet 32; a film stretching assembly 4 includes a release film, the film stretching assembly 4 is disposed at the position of the light outlet 32, and the release film is located on the focusing plane of the projection lens 31; a printing platform 5 is used to support and fix the model formed by the curing of photosensitive resin during the printing process; a platform moving mechanism 6 is used to carry and drive the printing platform 5 to move vertically to achieve continuous printing; a control mechanism is used to control the movement of the resin tank moving mechanism 2 and the platform moving mechanism 6.

[0035] The light source and projection component 3 typically includes an optical engine, an industrial camera, a beam splitter, a projection lens, and an optical path system connection structure. The light source driver and spatial light modulator are built into the optical engine. The optical engine projects ultraviolet light onto the beam splitter, which then reflects it to the projection lens. The light path of the light source projected by the optical engine is perpendicular to the projection light path of the industrial camera and the projection lens. The beam splitter is mounted at 45° on the center line of the optical path of the industrial camera and the projection lens.

[0036] The optical engine is the main component affecting the light source, and the most important component within it is the microdisplay chip. This can be a reflective liquid crystal display (LCD) or a digital light demodulator (DLM). Reflective LCDs are considered to have better image brightness and contrast than traditional transmissive LCDs, as each pixel adjusts the polarization state of the reflected light according to the applied voltage. In a DLM, each pixel is a tiny mirror that controls the direction of reflected light by deflecting the micromirror. Each mirror in the DLM can deflect from -10° to 10°. Thus, brighter pixels are those where reflected light enters the lens, while darker pixels are those where the image grayscale is controlled by the frequency of mirror deflection. Furthermore, the chip in the DLM has better ultraviolet compatibility and higher contrast than an LCD chip.

[0037] In some embodiments, the light source described above may be a DLP (Digital Light Processing) light source, which can further improve the accuracy of the product.

[0038] The film-stretching assembly 4 can quickly flatten the liquid surface of the photosensitive resin to be printed using the release film, which can significantly shorten the leveling time of the photosensitive resin liquid surface and improve the efficiency of product molding. Related technologies place the film-stretching assembly in the resin tank. Before each printed sample is removed, the film-stretching assembly must be removed, and before the next print, leveling and focusing operations must be performed on the film-stretching assembly. This affects the stability and consistency of the printed samples. Compared to related technologies, in this embodiment, the film-stretching assembly 4 is located at the light outlet 32, and the release film of the film-stretching assembly 4 is located on the focusing plane of the projection lens 31. Therefore, it avoids removing the film-stretching assembly before each printed sample and avoids the leveling and focusing operations before the next print, thus improving the stability and consistency of the printed products.

[0039] See Figure 2 In some embodiments, the device further includes a membrane conditioning mechanism 7.

[0040] The film adjustment mechanism 7 is disposed on the light outlet 32, and the film stretching assembly 4 is disposed on the film adjustment mechanism 7. The film adjustment mechanism 7 is used to adjust the position of the film stretching assembly 4 so that the release film is located on the focusing plane of the projection lens 3.

[0041] If the release film of the stretching assembly 4 is directly located on the focusing plane of the projection lens, it will increase the difficulty of manufacturing the device and reduce its production efficiency in actual production. Therefore, this embodiment adds a film adjustment mechanism 7, which is set on the light outlet 32 ​​and the stretching assembly 4 is set on the film adjustment mechanism 7. The position of the stretching assembly 4 is adjusted by the film adjustment mechanism 7 so that the release film is located on the focusing plane of the projection lens 31. This can reduce the difficulty of manufacturing the device and improve its production efficiency.

[0042] In some embodiments, the membrane adjustment mechanism 7 is fixedly mounted on the light outlet 32, and the membrane stretching assembly 7 is detachably mounted on the membrane adjustment mechanism 7.

[0043] In related technologies, the printing method for release films involves filling a resin tank with photosensitive resin, placing the release film on top of the resin, and then using a light source to cure the photosensitive resin on the underside of the release film. The printing platform then descends, separating the cured photosensitive resin from the release film. After a new layer of photosensitive resin is added to the underside of the release film, the printing platform rises a certain distance, and then, using a self-leveling compound or a roller cutter device added above the release film, it is repeatedly rolled to achieve a smooth surface. The following three technical problems may occur in this release process: (1) Some photosensitive resins have poor strength after curing, and the smaller the size, the worse the strength. The photocuring reaction occurs on the lower surface of the release film. During the release process, the model will be pulled by the release film. Therefore, the pulling of the release film can easily damage the model and make it difficult to make a precise structure; (2) In addition, the self-leveling method can only be applied to low viscosity photosensitive resins and is greatly affected by the area of ​​the release film; (3) In the roller-assisted leveling method, the movement trajectory of the roller needs to be kept on the same plane as the upper surface of the film, which is very difficult to adjust, and repeated rolling can easily damage the release film.

[0044] Regarding the third technical problem mentioned above, in this embodiment of the application, the film adjustment mechanism 7 is used to adjust the position of the film stretching assembly 4. The film adjustment mechanism 7 is fixedly installed on the light outlet 32, which can ensure the fixed and accurate position of the film adjustment mechanism 7 itself. The film stretching assembly 4 is detachably installed on the film adjustment mechanism 7. On the one hand, this helps the independence of the film stretching assembly 4. On the other hand, it helps the independent replacement of the film stretching assembly 4 when the release film is damaged, which can reduce the replacement cost of the entire device.

[0045] In some embodiments, the membrane assembly 4 is detachably mounted on the membrane adjustment mechanism 7 using magnetic attraction and positioning pins. Magnetic attraction and positioning pins are both common and easy-to-implement detachable mounting methods. This embodiment combines both magnetic attraction and positioning pins to ensure the reliability of the membrane assembly 4 while maintaining detachability.

[0046] See Figure 2 In some embodiments, the membrane adjustment mechanism 7 includes a horizontal adjustment sub-mechanism 71 and a vertical adjustment sub-mechanism 72.

[0047] The horizontal adjustment sub-mechanism 71 is used to adjust the position of the film stretching assembly 4 in the horizontal direction so that the release film is in a horizontal position; the vertical adjustment sub-mechanism 72 is used to adjust the position of the film stretching assembly 4 in the vertical direction so that the release film is in the position with the best imaging clarity in the vertical direction.

[0048] The release film serves two purposes: firstly, it quickly flattens the liquid surface of the photosensitive resin to be printed, requiring the release film to be positioned as horizontally as possible; secondly, it allows the light source to pass through the release film and cure the photosensitive resin on the lower surface of the release film, requiring the release film to be positioned on the focusing plane of the projection lens. The vertical position of the release film should ideally be the position with the best image clarity. Therefore, the film adjustment mechanism 7 is divided into a horizontal adjustment sub-mechanism 71 and a vertical adjustment sub-mechanism 72, which allows for more targeted adjustment of the position of the release film in the film stretching assembly 4.

[0049] In some embodiments, the release film of the film assembly 4 is removable.

[0050] According to the third technical problem in the above-mentioned related technologies, the release film of the stretching assembly is easily damaged. Therefore, the release film of the stretching assembly 4 is detachable, which helps to replace and update the release film. Since only the release film of the stretching assembly 4 can be replaced and the other parts of the stretching assembly 4 can be retained, the cost of replacing and updating the device can be further reduced. Since the release film can be replaced with one that is compatible with the photosensitive resin according to the different photosensitive resins, the applicability of the device can also be expanded.

[0051] See also Figure 3 In some embodiments, the membrane assembly 4 includes: a first membrane fixing part 41, a circular release membrane (not shown), a second membrane fixing part 42, and a third membrane fixing part 43.

[0052] The first film fixing part 41 is provided with a circular groove 411; the circular release film is detachably placed in the circular groove 411 of the first film fixing part 41; the second film fixing part 42 is provided with a circular protrusion 421 that matches the circular groove 411 of the first film fixing part 41, and the second film fixing part 42 and the first film fixing part 41 together detachably fix the circular release film; the third film fixing part 43 is detachably fixed to the first film fixing part 41 and the second film fixing part 42. The detachable and washable fixing can be achieved by locking.

[0053] As can be seen from the above-mentioned related technologies, the film-stretching assembly is set in the resin tank, and the release film of the film-stretching assembly covers the photosensitive resin. This makes the area of ​​the release film relatively large, thus presenting the second technical problem: the self-leveling method can only be applied to low viscosity photosensitive resins, and is greatly affected by the area of ​​the release film. In this embodiment, the film-stretching assembly 4 is set at the position of the light outlet 32, and the position of the release film is located on the focusing plane of the projection lens 31. Therefore, this provides technical support for reducing the area of ​​the release film. The circular release film can ensure the area required for the release film on the one hand, and on the other hand, it can more effectively reduce the area of ​​the release film compared with other shapes of release films. Therefore, it can reduce the leveling problem caused by viscosity. This makes the device of this embodiment applicable to both high and low viscosity photosensitive resins, expanding the applicability of the device.

[0054] Furthermore, since the circular release film is fixed together by the second film fixing part 42 and the first film fixing part 41, and the third film fixing part 43 is fixed together with the first film fixing part 41 and the second film fixing part 42, the position of the circular release film can be kept fixed. In this case, sinking exposure can be achieved, that is, the circular release film is immersed in the interior of the photosensitive resin. This makes the exposure curing area located inside the photosensitive resin, away from the surface of the photosensitive resin, less affected by the environment, and can speed up the replenishment speed of the photosensitive resin. The exposure curing area is in the area where the circular release film is located, which can realize the DLP (Digital Light Processing) exposure splicing scheme, so large-format printing can be performed.

[0055] See also Figure 4 and Figure 6 In some embodiments, the device further includes: a first ranging module 91, a second ranging module 92, and an auxiliary target block 8.

[0056] The first ranging module 91, mounted on the light source and projection assembly 3, is used to monitor the parallelism error of the printing platform with respect to the plane containing the XY axes. The second ranging module 92, mounted below the resin tank 1, is used to monitor the parallelism error of the release film with respect to the plane containing the XY axes. An auxiliary marker block 8 is detachably mounted parallel and flush with the printing platform 5, assisting the first ranging module 91 in determining the parallelism error between the printing platform 5 and the plane containing the XY axes.

[0057] It should be noted that the plane containing the XY axis in this application refers to the plane determined by the XY axis of the reference coordinates in this device; the parallelism error of the printing platform with respect to the plane containing the XY axis refers to the parallelism error between the model forming surface of the printing platform and the plane containing the XY axis.

[0058] By using the first ranging module 91 and the second ranging module 92 to detect the printing platform and the release film respectively, the variation in parallelism error is controlled within a preset range, thereby improving printing accuracy.

[0059] The distance between the forming surface of the printing platform 5 and the lower surface of the release film of the film stretching assembly 4 is the thickness of the first layer of printing. If this thickness is too thick or too thin, it will affect the printing effect and may even cause the photosensitive resin to fail to adhere firmly to the printing platform 5, resulting in printing failure. Therefore, accurately determining the position of the printing platform 5 in the horizontal and vertical directions is crucial. The positional error of the printing platform 5 mainly originates from the variation in the parallelism error between the printing platform and the plane containing the XY axes. Since the space of the printing platform 5 is insufficient for the first ranging module 91 to accurately monitor its position, an auxiliary marker block 8 is set parallel and flush with the printing platform 5. Through the auxiliary marker block 8, the first ranging module 91 can determine the variation in the parallelism error between the printing platform 5 and the plane containing the XY axes. The auxiliary marker block 8 is detachable; it can be removed when the position of the printing platform 5 is determined and printing is to begin, without affecting subsequent printing. It should be noted that the parallelism and flushness referred to in this application refer to basic parallelism and flushness, which are acceptable within a preset error range.

[0060] In some embodiments, the release film includes an oxygen-permeable release film that produces oxygen inhibition.

[0061] According to the first problem in the above-mentioned related technologies: the photocuring reaction occurs on the lower surface of the release film, and the release process is subject to the pulling action of the release film. Because the cured model has poor strength, the smaller the size, the weaker the strength. Therefore, the pulling action of the release film can easily damage the model, making it difficult to make a precise structure. The oxygen-permeable release film of this application embodiment has high air permeability. Due to the oxygen inhibition phenomenon, the photocuring reaction will be inhibited in the presence of oxygen. There is a thin layer of photosensitive resin between the model and the lower surface of the release film that will not undergo cross-linking and curing. There is no adhesion between the model and the lower surface of the release film. The release force generated during release is very small. Therefore, the liquid layer is stable, the printing precision is high, and the printing speed and success rate are greatly improved.

[0062] See Figure 5 , Figure 5 This is a schematic flowchart of an embodiment of the printing method of the photopolymer 3D printing apparatus of this application. The method is applicable to any of the apparatuses described above, and the method includes:

[0063] Step S101: Adjust and record the initial printing positions X0 and Y0 of the printing platform in the left-right direction (X) and front-back direction (Y). The left-right direction (X) and the front-back direction (Y) are the horizontal directions.

[0064] In step S101, if the stretching assembly is detachable, it can be removed first. If the printing platform is detachable, it can be installed first. A completely white image is manually projected, and the vertical Z-position of the printing platform is fixed at a suitable height. Then, the X-direction (left-right) and Y-direction (back-forward) are manually controlled to move the platform so that the projected area presents a relatively clear image in the upper left corner of the printing platform. After determining the current Axis-X and Axis-Y positions, exposure is turned off, and the current Axis-X and Axis-Y positions are recorded and saved as the initial printing positions X0 and Y0. The printing platform is then removed.

[0065] Step S102: After determining that the release film of the stretching assembly is located on the focusing plane of the projection lens, adjust and record the printing position Z0 of the printing platform in the vertical direction so that the distance between the forming surface of the printing platform and the lower surface of the release film of the stretching assembly is within a preset distance range.

[0066] In step S102, if the film tensioning assembly is detachable and includes a first film fixing part, a circular release film, a second film fixing part, and a third film fixing part, the film tensioning assembly must first be assembled. This involves placing the circular release film into the circular groove of the first film fixing part, then fixing the first and second film fixing parts together by locking them in place. Next, the third film fixing part is then fixed together with the first and second film fixing parts by locking them in place, thus putting the circular release film in a tensioned state. Then, the film tensioning assembly is fixed to the film adjustment mechanism using magnets and positioning pins. To facilitate fixing the film tensioning assembly to the film adjustment mechanism, a marking line can be provided on the side of the third film fixing part, with the marking line facing outwards during installation.

[0067] Before installing the circular release membrane, you can first use a lint-free cloth dipped in alcohol to gently wipe the upper and lower surfaces of the membrane to ensure that there is no dust or other foreign matter on the upper and lower surfaces of the membrane.

[0068] After the tensioning assembly is installed, the release film of the tensioning assembly needs to be adjusted to be on the focusing plane of the projection lens. For example: (i) Project a grid image including multiple grids (e.g., 5 grids), and adjust the height of the release film until the projection areas corresponding to the multiple grids are in focus; (ii) Measure multiple horizontal positions of the release film (e.g., 4 positions around the perimeter of the release film) to adjust the horizontal height difference of the multiple horizontal positions of the release film to be less than a preset height difference (e.g., the preset height difference is within 50μm); (iii) Confirm again that the multiple projection areas are clear. If they are not clear, repeat steps ii and iii until the horizontal height difference of the release film is less than the preset height difference and the multiple projection areas are clear.

[0069] If the resin tank is detachable, it can be installed after the release film of the tensioning assembly is positioned on the focusing plane of the projection lens. For ease of installation, the platform supporting the resin tank can be adjusted to its lowest point, and then the resin tank can be installed and secured to the platform by locking.

[0070] If the printing platform is detachable, it can be installed after the resin tank is installed. To facilitate the installation of the printing platform, the platform moving mechanism can be raised vertically to a certain height, and the X and Y axes can be moved to adjust the film stretching assembly to the upper left corner of the resin tank. Then, the auxiliary marker block is installed parallel and flush with the printing platform. Finally, the printing platform with the auxiliary marker block is installed onto the platform moving mechanism and fixed to the platform moving mechanism by locking.

[0071] Manually control the X and Y axes to move the first ranging module 91 (e.g., a laser rangefinder) to read the readings L1 of the four sides of the printing platform on which the auxiliary marker is installed. Adjust the horizontal position of the printing platform (i.e., the parallelism error between the printing platform 5 and the plane containing the X and Y axes), continuously adjusting the fluctuation of the reading L1 (e.g., controlling the laser reading fluctuation within 30μm, 20μm, 10μm, or 5μm) within a preset fluctuation range (i.e., the change in the preset parallelism error between the printing platform 5 and the plane containing the X and Y axes). After the horizontal position of the printing platform is adjusted, move the X and Y axes to the initial printing positions X0 and Y0. Based on the laser ranging value, move the printing platform to the vicinity of a suitable focusing plane and record the vertical position Z0 of the printing platform at this time. Control the platform moving mechanism to slowly lower the printing platform a certain distance (e.g., about 2-5 mm), and remove the auxiliary marker.

[0072] Step S103: Pour the liquid photosensitive resin into the resin tank.

[0073] Move the Y-axis to a position that makes it easy to pour the photosensitive resin, and then pour in an appropriate amount of photosensitive resin.

[0074] Step S104: Adjust the position of the printing platform to the recorded X0, Y0, Z0, and then print.

[0075] X0 and Y0 are the initial printing positions of the printing platform on the X and Y axes, respectively. The initial printing position Z0 of the printing platform in the vertical direction can determine the distance between the forming surface of the printing platform and the lower surface of the release film of the film stretching assembly, that is, the thickness of the photosensitive resin to be printed.

[0076] In some embodiments, step S103, which involves pouring the liquid photosensitive resin into the resin tank, may include: pouring the liquid photosensitive resin into the resin tank so that the release film is immersed in the photosensitive resin.

[0077] The process involves moving the X and Y axes to the initial printing positions X0 and Y0, respectively, then raising the resin tank. It's observed that the photosensitive resin in the tank just completely submerges the release film; if insufficient, more photosensitive resin is added. After moving the printing platform to the recorded printing position Z0, parameters can be input to begin printing.

[0078] It should be understood that the terminology used in this application specification is for the purpose of describing particular embodiments only and is not intended to limit the application.

[0079] It should also be understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0080] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and such modifications or substitutions should all be covered within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A photopolymerization 3D printing device, characterized in that, The device includes: Resin tank, used to hold liquid photosensitive resin; A resin tank moving mechanism is used to carry and drive the resin tank to move in the vertical direction; A light source and projection assembly, including a projection lens and a light outlet, is used to provide a light source for a photosensitive resin undergoing a photocuring reaction and to guide the light source from the light outlet onto the photosensitive resin. A film-stretching assembly, including a release film, is disposed at the light outlet, and the release film is located on the focusing plane of the projection lens; A printing platform is used to support and fix the model formed by the curing of photosensitive resin during the printing process. A platform moving mechanism is used to carry and drive the printing platform to move vertically to achieve continuous printing; A control mechanism is provided for controlling the movement of the resin tank moving mechanism and the platform moving mechanism. The device further includes: A film adjustment mechanism is disposed on the light outlet, and the film stretching assembly is disposed on the film adjustment mechanism. The film adjustment mechanism is used to adjust the position of the film stretching assembly so that the release film is located on the focusing plane of the projection lens. The membrane adjustment mechanism is fixedly mounted on the light outlet, and the membrane stretching assembly is detachably mounted on the membrane adjustment mechanism; The membrane conditioning mechanism includes: A horizontal adjustment sub-mechanism is used to adjust the position of the film-stretching assembly in the horizontal direction so that the release film is in a horizontal position; The vertical adjustment sub-mechanism is used to adjust the position of the film assembly in the vertical direction so that the release film is in the position with the best imaging clarity in the vertical direction.

2. The apparatus according to claim 1, characterized in that, The membrane assembly is detachably mounted on the membrane adjustment mechanism using magnetic attraction and positioning pins.

3. The apparatus according to claim 1, characterized in that, The release film of the stretching assembly is removable.

4. The apparatus according to claim 3, characterized in that, The membrane assembly includes: The first membrane fixing part is provided with a circular groove; A circular release film is detachably placed in the circular groove of the first film fixing part; The second film fixing component is provided with a circular protrusion that matches the circular groove of the first film fixing component, for detachably fixing the circular release film together with the first film fixing component; The third membrane fixing component is used to detachably fix it to the first membrane fixing component and the second membrane fixing component.

5. The apparatus according to any one of claims 1-4, characterized in that, The device further includes: The first ranging module is used to monitor the parallelism error between the printing platform and the plane containing the XY axes; The second ranging module is used to monitor the parallelism error between the release film and the plane containing the XY axis.

6. The apparatus according to claim 5, characterized in that, It also includes an auxiliary marker block that is detachably set parallel and flush with the printing platform, used to assist the first ranging module in determining the parallelism error between the printing platform and the plane containing the XY axis.

7. The apparatus according to any one of claims 1-4, characterized in that, The release film includes an oxygen-permeable release film that can cause oxygen inhibition.

8. A printing method for a photopolymerization 3D printing device, characterized in that, The method is applicable to the apparatus as described in any one of claims 1-7, and the method comprises: Adjust and record the initial printing positions X0 and Y0 of the printing platform in the left-right direction (X) and front-back direction (Y); After determining that the release film of the stretching assembly is located on the focusing plane of the projection lens, adjust and record the printing position Z0 of the printing platform in the vertical direction so that the distance between the forming surface of the printing platform and the lower surface of the release film of the stretching assembly is within a preset distance range. The liquid photosensitive resin is poured into the resin tank; Adjust the position of the printing platform to the recorded X0, Y0, Z0, and then print.

9. The method according to claim 8, characterized in that, The step of pouring liquid photosensitive resin into the resin tank includes: Liquid photosensitive resin is poured into the resin tank, so that the release film is immersed in the photosensitive resin.

Images