Photocuring 3D printing device and printing method thereof

Abstract

The invention discloses a photocuring 3D printing device and a printing method thereof.The device comprises a resin tank used for containing liquid photosensitive resin; the resin tank moving mechanism is used for bearing and driving the resin tank to move in the vertical direction; the light source and projection assembly comprises a projection lens and a light outlet, and the light source and projection assembly is used for providing a light source for the photosensitive resin subjected to the light curing reaction and guiding the light source to be projected to the photosensitive resin from the light outlet; the film stretching assembly comprises a release film, the film stretching assembly is arranged at the position of the light outlet, and the release film is located on the focusing plane of the projection lens; the printing platform is used for supporting and fixing a model formed by curing the photosensitive resin in the printing process; the platform moving mechanism is used for bearing and driving the printing platform to move in the vertical direction so as to realize continuous printing; and the control mechanism is used for controlling the movement of the resin tank moving mechanism and the platform moving mechanism. In this way, the stability and consistency of printed products can be improved.

Description

Technical Field

[0001] The present application relates to the field of 3D printing technology, and in particular to a photocuring 3D printing device and a printing method thereof. Background Art

[0002] With its high precision, high efficiency and diversity, light-curing 3D printing technology has become an important tool in the field of product design and manufacturing. Its working principle is: the light-curing 3D printing device contains a resin tank inside, and a UV light source is installed above the resin tank. When printing, the photosensitive resin in the resin tank is irradiated by ultraviolet rays, and the photosensitive resin undergoes chemical cross-linking, thereby solidifying into a solid object. Then the platform descends, and the liquid resin is replenished and exposed again. By repeating this process continuously, the entire 3D printing process is finally completed.

[0003] In order to shorten the time for the liquid surface of the photosensitive resin to level and improve the molding efficiency, the light-curing 3D printing device is also provided with a film stretching assembly. At present, the film stretching assembly of the light-curing 3D printing device is arranged in the resin tank. The film stretching assembly must be taken out before each printed sample is taken out, and the film stretching assembly must be leveled and focused before the next printing, which will affect the stability and consistency of the printed sample. Summary of the invention

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

[0005] In a first aspect, the present application provides a light-curing 3D printing device, the device comprising:

[0006] A resin tank for containing liquid photosensitive resin;

[0007] A resin tank moving mechanism, used for carrying and driving the resin tank to move in a vertical direction;

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

[0009] A film stretching assembly, comprising a release film, wherein the film stretching assembly is arranged at the position of the light outlet, and the release film is located on the focal plane of the projection lens;

[0010] Printing platform, used to bond the cured photosensitive resin;

[0011] A platform moving mechanism, used for carrying and driving the printing platform to move in a vertical direction to achieve continuous printing;

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

[0013] In a second aspect, the present application provides a printing method of a light-curing 3D printing device, the method being applicable to the device as 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 the front-back direction Y;

[0015] After determining that the release film of the film stretching assembly is located on the focal plane of the projection lens, adjusting and recording the printing position Z0 of the printing platform in the vertical direction so that the distance between the molding surface of the printing platform and the lower surface of the release film of the film stretching assembly is within a preset distance range;

[0016] Pouring liquid photosensitive resin into the resin tank;

[0017] The position of the printing platform is adjusted to the recorded X0, Y0, and Z0 to perform printing.

[0018] Since the film assembly of the photocuring 3D printing device in the embodiment of the present application is arranged at the position of the light outlet, and the release film of the film assembly is located on the focal plane of the projection lens, compared with the related art, the embodiment of the present application can avoid taking out the film assembly before taking out the printed sample each time, and avoid leveling and focusing operations on the film assembly before the next printing, thereby improving the stability and consistency of the printed product. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of an embodiment of a light-curing 3D printing device of the present application;

[0020] Figure 2 It is a structural schematic diagram of another embodiment of the light-curing 3D printing device of the present application;

[0021] Figure 3 It is a structural schematic diagram of another embodiment of the light-curing 3D printing device of the present application;

[0022] Figure 4 It is a structural schematic diagram of another embodiment of the light-curing 3D printing device of the present application;

[0023] Figure 5 This is a flow chart of an embodiment of a printing method of a light-curing 3D printing device of the present application;

[0024] Figure 6 It is a partial structural schematic diagram of an embodiment of a light-curing 3D printing device of the present application.

[0025] Description 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 mark block; 91. First distance measuring module; 92. Second distance measuring module. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0028] The flowcharts shown in the accompanying drawings are only examples and do not necessarily include all the contents and operations / steps, nor must they be executed in the order described. For example, some operations / steps may also be decomposed, combined or partially merged, so the actual execution order may change according to actual conditions.

[0029] With its high precision, high efficiency and diversity, photocuring 3D printing technology has become an important tool in the field of product design and manufacturing. Its working principle is: the photocuring 3D printing device contains a resin tank inside, and a UV light source is installed above the resin tank. When printing, the photosensitive resin in the resin tank is irradiated by ultraviolet rays, and the photosensitive resin undergoes chemical cross-linking, thereby solidifying into a solid object. Then the platform descends, and the liquid resin is replenished and exposed again. By repeating this process continuously, the entire 3D printing process is finally completed. In order to shorten the leveling time of the liquid surface of the photosensitive resin and improve the molding efficiency, the photocuring 3D printing device is also provided with a film stretching assembly. At present, the film stretching assembly of the photocuring 3D printing device is set in the resin tank. Each time before taking out the printed sample, the film stretching assembly must be taken out, and the film stretching assembly must be leveled and focused before the next printing, which will affect the stability and consistency of the printed sample.

[0030] It should be noted that the photosensitive resin in the present application refers to all materials that can be used for photocuring 3D printing, for example, photosensitive resin, photosensitive resin doped with ceramic slurry, and photosensitive resin doped with metal slurry.

[0031] Since the film assembly of the photocuring 3D printing device in the embodiment of the present application is arranged at the position of the light outlet, and the release film of the film assembly is located on the focal plane of the projection lens, compared with the related art, the embodiment of the present application can avoid taking out the film assembly before taking out the printed sample each time, and avoid leveling and focusing operations on the film assembly before the next printing, thereby improving the stability and consistency of the printed product.

[0032] The embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0033] See also Figure 1 and Figure 2 , Figure 1 and Figure 2 It is a schematic diagram of the structure of two embodiments of the light-curing 3D printing device of the present application, wherein the device comprises: 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] The resin tank 1 is used to contain liquid photosensitive resin; the resin tank moving mechanism 2 is used to carry and drive the resin tank 1 to move in the vertical direction; the light source and projection assembly 3 includes a projection lens 31 and a light outlet 32, and the light source and projection assembly 3 is used to provide a light source for the photosensitive resin undergoing a photocuring reaction, and guide the light source to be projected from the light outlet 32 ​​to the photosensitive resin; the film stretching assembly 4 includes a release film, and the film stretching assembly 4 is arranged at the position of the light outlet 32, and the release film is located on the focusing plane of the projection lens 31; the printing platform 5 is used to support and fix the model formed by the curing of the photosensitive resin during the printing process; the platform moving mechanism 6 is used to carry and drive the printing platform 5 to move in the vertical direction to achieve continuous printing; the 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 assembly 3 may generally include an optical machine, an industrial camera, a beam splitter, a projection lens, and an optical path system connection structure; the light source driver and the spatial light modulator are built into the optical machine, and the optical machine projects ultraviolet light onto the beam splitter, which is reflected to the projection lens through the beam splitter. The light path of the light source projected by the optical machine is perpendicular to the projection light path of the industrial camera and the projection lens, and the beam splitter is installed at 45 degrees on the center line of the light path of the industrial camera and the projection lens.

[0036] The optical machine is the main component that affects the light source, and the most important component in the optical machine is the micro-display chip, which can be a reflective LCD screen or a digital optical demodulator. The reflective LCD screen is considered to have better image brightness and contrast than the traditional transmissive LCD screen. Each pixel of it adjusts the polarization state of the reflected light according to the applied voltage; and each pixel in the digital optical demodulator is a tiny reflector, which controls the direction of the reflected light by deflecting the micro-mirror surface. Each lens in the digital optical demodulator can deflect -10° to 10°. In this way, the brighter pixels are the reflected light entering the lens, and the opposite is the dark pixel, that is, the grayscale of the image is controlled by the frequency of the lens deflection, and the chip in the digital optical demodulator has better UV compatibility and higher contrast than the LCD chip.

[0037] In some embodiments, the light source may be a DLP (Digital Light Processing) light source. By adopting a DLP light source, the accuracy of the product may be further improved.

[0038] The film assembly 4 can use the release film to quickly flatten the liquid surface of the photosensitive resin to be printed and formed, which can greatly shorten the time for the liquid surface of the photosensitive resin to level and improve the efficiency of product molding. The related art sets the film assembly in the resin tank, and the film assembly must be taken out before each print sample is taken out, and the film assembly must be leveled and focused before the next print, which will affect the stability and consistency of the print sample. Compared with the related art, the film assembly 4 described in the embodiment of the present application is set at the position of the light outlet 32, and the release film of the film assembly 4 is located on the focal plane of the projection lens 31, so it is possible to avoid taking out the film assembly before each print sample, and avoid leveling and focusing the film assembly before the next print, thereby improving the stability and consistency of the printed product.

[0039] See also Figure 2 In some embodiments, the device further includes: a membrane regulating 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 focal plane of the projection lens 3 .

[0041] If the release film of the film-stretching assembly 4 is directly located on the focal plane of the projection lens, in actual production, on the one hand, the difficulty of producing the device will be increased, and on the other hand, the production efficiency of the device will also be reduced. Therefore, the embodiment of the present application adds a film adjustment mechanism 7, and the film adjustment mechanism 7 is arranged on the light outlet 32. The film-stretching assembly 4 is arranged on the film adjustment mechanism 7. The position of the film-stretching assembly 4 is adjusted by the film adjustment mechanism 7, so that the release film is located on the focal plane of the projection lens 31. This can reduce the production difficulty of the device on the one hand, and improve the production efficiency of the device on the other hand.

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

[0043] In the related art, the release film is printed by filling the resin tank with photosensitive resin, covering the release film on top of the photosensitive resin, and passing the light source through the release film to solidify the photosensitive resin on the lower surface of the release film. After that, the printing platform is lowered, and the solidified photosensitive resin is separated from the release film. After waiting for a new layer of photosensitive resin to be added to the lower surface of the release film, the printing platform is raised a certain distance, and then the release film is repeatedly rolled to make it flat through self-leveling or adding a roller device on the top of the release film. This release process may lead to the following three technical problems: (1) The strength of some models after curing with photosensitive resins is poor, and the smaller the size, the weaker 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, so the pulling of the release film can easily damage the model, making 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) For the roller-assisted leveling method, the movement trajectory of the roller needs to be kept in the same plane as the upper surface of the film, which is difficult to adjust, and repeated rolling can easily damage the release film.

[0044] In response to the above-mentioned technical problem (3), in the embodiment of the present application, the membrane adjustment mechanism 7 is used to adjust the position of the film stretching assembly 4. The membrane adjustment mechanism 7 is fixedly arranged on the light outlet 32, which can ensure the fixed and accurate position of the membrane adjustment mechanism 7 itself. The film stretching assembly 4 is detachably arranged on the membrane adjustment mechanism 7. On the one hand, it helps the independence of the film stretching assembly 4. On the other hand, when the release film is damaged, it helps the independent update of the film stretching assembly 4, which can reduce the update cost of the entire device.

[0045] In some embodiments, the film stretching assembly 4 is detachably arranged on the film adjustment mechanism 7 by using magnetic attraction and positioning pins. Both magnetic attraction and positioning pins are relatively common detachable arrangement methods, which are easy to implement. The embodiment of the present application combines the two detachable arrangement methods of magnetic attraction and positioning pins, which can ensure the reliability of the film stretching assembly 4 while ensuring the detachability.

[0046] See also 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 located 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 located in a position with the best imaging clarity in the vertical direction.

[0048] The function of the release film is, on the one hand, to quickly flatten the liquid surface of the photosensitive resin to be printed, which requires the release film to be in a horizontal position as much as possible; on the other hand, the light source passes through the release film to solidify the photosensitive resin on the lower surface of the release film, which requires the release film to be located on the focal plane of the projection lens, and the position of the release film in the vertical direction is as close as possible to the position with the best imaging clarity. Therefore, the film adjustment mechanism 7 is divided into a horizontal adjustment sub-mechanism 71 and a vertical adjustment sub-mechanism 72, which can more specifically adjust the position of the release film of the film stretching assembly 4.

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

[0050] According to the third technical problem in the above-mentioned related technology, the release film of the film stretching assembly is very easy to be damaged. Therefore, the release film of the film stretching assembly 4 is detachable, which is helpful for the replacement and update of the release film. Since only the release film of the film stretching assembly 4 can be replaced and other parts of the film stretching assembly 4 are retained, the cost of replacement and update of the device can be further reduced. Since the release film suitable for the photosensitive resin can be replaced according to the different photosensitive resins, the application range of the device can be expanded.

[0051] See also Figure 3 In some embodiments, the film stretching assembly 4 includes: a first film fixing part 41 , a circular release film (not shown), a second film fixing part 42 and a third film 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 matching 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 fixation can be achieved by locking.

[0053] According to the above-mentioned related technologies, the film stretching assembly is set in the resin tank, and the release film of the film stretching assembly is covered on the top of the photosensitive resin, which makes the area of ​​the release film relatively large, so there will be the second technical problem: the self-leveling method can only be applied to low-viscosity photosensitive resins, which is greatly affected by the area of ​​the release film. In the embodiment of the present application, 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, so this provides technical support for reducing the area of ​​the release film. On the one hand, the circular release film can also ensure the required area of ​​the release film, and on the other hand, it can more effectively reduce the area of ​​the release film than other shapes of release films. Therefore, it can reduce the leveling problem caused by viscosity, which makes the device of the embodiment of the present application applicable to both high and low viscosity photosensitive resins, expanding the scope of application of the device.

[0054] In addition, since the circular release film is fixed by the second film fixing part 42 and the first film fixing part 41, and the third film fixing part 43 is fixed to the first film fixing part 41 and the second film fixing part 42, it can ensure that the position of the circular release film remains unchanged. In this case, sedimentation exposure can be achieved, that is, the circular release film is immersed in the interior of the photosensitive resin, which makes the exposure and 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 photosensitive resin replenishment speed; the exposure and curing area is in the area where the circular release film is located, and the DLP (Digital Light Processing) exposure splicing solution can be implemented, so large-format printing can be performed.

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

[0056] The first distance measuring module 91 is arranged on the light source and projection assembly 3, and is used to monitor the parallelism error of the printing platform with respect to the plane where the XY axis is located. The second distance measuring module 92 is arranged below the resin tank 1, and is used to monitor the parallelism error of the release film with respect to the plane where the XY axis is located. The auxiliary mark block 8 is detachably arranged parallel to and flush with the printing platform 5, and is used to assist the first distance measuring module 91 in determining the parallelism error of the printing platform 5 with respect to the plane where the XY axis is located.

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

[0058] The first distance measuring module 91 and the second distance measuring module 92 detect the printing platform and the release film respectively, so as to control the variation of the parallelism error within a preset range and improve the printing accuracy.

[0059] The distance between the molding 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 even cause the photosensitive resin after printing to be unable to be firmly adhered to the printing platform 5, resulting in printing failure. Therefore, it is very important to accurately determine the position of the printing platform 5 in the horizontal and vertical directions. The position error of the printing platform 5 mainly comes from the variation of the parallelism error between the printing platform and the plane where the XY axis is located. Since the space size of the printing platform 5 is not enough for the first distance measuring module 91 to accurately monitor the position of the printing platform 5, the auxiliary block 8 is set parallel and flush with the printing platform 5. Through the auxiliary block 8, the first distance measuring module 91 can determine the variation of the parallelism error between the printing platform 5 and the plane where the XY axis is located. The auxiliary block 8 is detachable. When the position of the printing platform 5 is determined and printing is performed, the auxiliary block 8 can be disassembled 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 all possible within the preset error range.

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

[0061] According to the first problem in the above-mentioned related art, the photocuring reaction occurs on the lower surface of the release film, and the release process will be affected by the pulling effect of the release film. Since the strength of the cured model is poor, the smaller the size, the weaker the strength. Therefore, the pulling of the release film can easily damage the model, making it difficult to make a precise structure. The oxygen-permeable release film of the embodiment of the present application 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, and no cross-linking and curing will occur. There is no bonding 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 also Figure 5 , Figure 5 1 is a flow chart of an embodiment of a printing method of a light-curing 3D printing device of the present application, the method is applicable to any of the above-mentioned devices, and the method comprises:

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

[0064] In step S101, if the film assembly is detachable, the film assembly can be removed first. If the printing platform is detachable, the printing platform can be installed first, a full white image can be manually projected, and then the height of the printing platform in the vertical direction Z is fixed to a suitable height, and then the left and right directions X and the front and back directions Y are manually controlled to move so that the projection area presents a clearer image in the upper left corner of the printing platform. After the current Axis-X and Axis-Y positions are determined, the exposure is turned off, and then the current Axis-X and Axis-Y positions are recorded and saved, and later used as the initial printing positions X0 and Y0, and the printing platform is removed.

[0065] Step S102: After determining that the release film of the film stretching assembly is located on the focal 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 molding surface of the printing platform and the lower surface of the release film of the film stretching assembly is within a preset distance range.

[0066] In step S102, if the film stretching assembly is detachable, including a first film fixing part, a circular release film, a second film fixing part and a third film fixing part, the film stretching assembly needs to be assembled first, that is, the circular release film is placed in the circular groove of the first film fixing part, and then the first film fixing part and the second film fixing part are fixed by locking, and then the third film fixing part is fixed by locking with the first film fixing part and the second film fixing part, so that the circular release film is in a tensioned state. Then the film stretching assembly is fixed to the film adjustment mechanism by using magnets and positioning pins. In order to facilitate the fixing of the film stretching assembly to the film adjustment mechanism, an identification line can be set on the side of the third film fixing part, and the identification line faces outward during installation.

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

[0068] After the film assembly is installed, the release film of the film assembly needs to be adjusted to be on the focal plane of the projection lens. For example: (i) Project a grid image including multiple grids (for example, 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 (for example, 4 positions around the edge of the release film) to adjust the horizontal height difference of the multiple horizontal positions of the release film to be less than the preset height difference (for example, the preset height difference is within 50μm); (iii) Confirm again that the multiple projection areas are clear. If not, 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, the resin tank can be installed after adjusting the release film of the film stretching assembly to be on the focal plane of the projection lens. When installing the resin tank, for easy installation, the platform supporting the resin tank can be adjusted to the lowest point, and then the resin tank can be installed and fixed on the platform supporting the resin tank by locking.

[0070] If the printing platform is detachable, the printing platform can be installed after the resin tank is installed. To facilitate the installation of the printing platform, the platform moving mechanism can be raised to a certain height in the vertical direction, the X-axis and Y-axis movement can be controlled, and the film stretching assembly can be adjusted to the upper left corner of the resin tank; then the auxiliary block can be installed parallel and flush with the printing platform, and then the printing platform with the auxiliary block installed can be installed on the platform moving mechanism and fixed to the platform moving mechanism by locking.

[0071] Manually control the movement of the X-axis and Y-axis to enable the first distance measuring module 91 (such as a laser distance meter) to read the readings L1 of the four edges on the printing platform with the auxiliary block installed, adjust the horizontal position of the printing platform (i.e., the parallelism error between the printing platform 5 and the plane where the XY axis is located), and continuously adjust and control the fluctuation of the reading L1 (for example, the laser reading fluctuation is controlled within 30μm, 20μm, 10μm or 5μm) within the preset fluctuation range (i.e., the change in the preset parallelism error between the printing platform 5 and the plane where the XY axis is located). After the horizontal position of the printing platform is adjusted, move the X-axis and Y-axis to the initial printing position X0 and Y0. Move the printing platform to the vicinity of the appropriate focusing plane according to the value of the laser distance measurement, and record the vertical position Z0 of the printing platform at this time. Control the platform moving mechanism to move so that the printing platform slowly descends a certain distance (for example: about 2-5 mm), and remove the auxiliary block.

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

[0073] Move the Y axis to move the resin tank to a position that is as convenient as possible for pouring the photosensitive resin, and then pour in an appropriate amount of photosensitive resin.

[0074] Step S104: adjusting the position of the printing platform to the recorded X0, Y0, Z0, and performing printing.

[0075] X0 and Y0 are the initial printing positions of the printing platform on the X-axis and Y-axis. The initial printing position Z0 of the printing platform in the vertical direction can determine the distance between the molding 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 waiting to be printed.

[0076] In some embodiments, step S103, 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] Among them, move the X-axis and Y-axis to the initial printing position X0 and Y0, then control the resin tank to rise, observe and confirm that the photosensitive resin in the resin tank just immerses the release film, and if the photosensitive resin is insufficient, add photosensitive resin. After moving the printing platform to the recorded printing position Z0, you can enter the parameters for printing.

[0078] It should be understood that the terms used in the specification of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application.

[0079] It should also be understood that the term “and / or” used in the specification and appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0080] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed in the present application, and these modifications or replacements should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A light-curing 3D printing device, characterized in that: The device comprises: A resin tank for containing liquid photosensitive resin; A resin tank moving mechanism, used for carrying and driving the resin tank to move in a vertical direction; A light source and projection assembly, including a projection lens and a light outlet, the light source and projection assembly are used to provide a light source for the photosensitive resin undergoing a photocuring reaction, and guide the light source to be projected from the light outlet to the photosensitive resin; A film stretching assembly, comprising a release film, wherein the film stretching assembly is arranged at the position of the light outlet, and the release film is located on the focal plane of the projection lens; A printing platform, used to support and fix the model formed by curing the photosensitive resin during the printing process; A platform moving mechanism, used for carrying and driving the printing platform to move in a vertical direction to achieve continuous printing; The control mechanism is used to control the movement of the resin tank moving mechanism and the platform moving mechanism.

2. The device according to claim 1, characterized in that The device also includes: The film adjustment mechanism is arranged on the light outlet, the film stretching assembly is arranged on the film adjustment mechanism, and the film adjustment mechanism is used to adjust the position of the film stretching assembly so that the release film is located on the focal plane of the projection lens.

3. The device according to claim 2, characterized in that The film adjustment mechanism is fixedly arranged on the light outlet, and the film stretching assembly is detachably arranged on the film adjustment mechanism.

4. The device according to claim 3, characterized in that The film stretching assembly is detachably arranged on the film adjustment mechanism by using magnetic attraction and positioning pins.

5. The device according to claim 2, characterized in that The membrane regulating mechanism comprises: 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 located in a horizontal position; The vertical adjustment sub-mechanism is used to adjust the position of the film stretching assembly in the vertical direction so that the release film is located at a position with the best imaging clarity in the vertical direction.

6. The device according to claim 2, characterized in that The release film of the film stretching assembly is detachable.

7. The device according to claim 6, characterized in that The film stretching assembly comprises: The first film fixing part is provided with a circular groove; A circular release film, detachably placed in the circular groove of the first film fixing part; A second film fixing part, provided with a circular protrusion matching the circular groove of the first film fixing part, and used for detachably fixing the circular release film together with the first film fixing part; The third film fixing part is used to be detachably fixed to the first film fixing part and the second film fixing part.

8. The device according to any one of claims 1 to 7, characterized in that: The device also includes: A first distance measuring module, used to monitor the parallelism error between the printing platform and the plane where the XY axis is located; The second distance measuring module is used to monitor the parallelism error between the release film and the plane where the XY axis is located.

9. The device according to claim 8, characterized in that It also includes an auxiliary mark block which is detachably arranged parallel to and flush with the printing platform, and is used to assist the first distance measuring module in determining the parallelism error between the printing platform and the plane where the XY axis is located.

10. The device according to any one of claims 1 to 7, characterized in that: The release film includes an oxygen-permeable release film that can produce oxygen inhibition.

11. A printing method of a light-curing 3D printing device, characterized in that: The method is applicable to the device according to any one of claims 1 to 10, 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 the front-back direction Y; After determining that the release film of the film stretching assembly is located on the focal plane of the projection lens, adjusting and recording the printing position Z0 of the printing platform in the vertical direction so that the distance between the molding surface of the printing platform and the lower surface of the release film of the film stretching assembly is within a preset distance range; Pouring liquid photosensitive resin into the resin tank; The position of the printing platform is adjusted to the recorded X0, Y0, and Z0 to perform printing.

12. The method according to claim 10, characterized in that The step of pouring the liquid photosensitive resin into the resin tank comprises: Pour liquid photosensitive resin into the resin tank so that the release film is immersed in the photosensitive resin.

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