Filter System, Method of a 3D Printing Device, and Applicable 3D Printing Device

Abstract

The present application discloses a filtering system, method and applicable 3D printing device for a 3D printing device. The filtering system includes: a suction device disposed on one side of a resin tank for sucking the photocuring material in the resin tank; a liquid storage device communicating with the suction device for storing the photocuring material sucked from the resin tank; a filtering device disposed between the suction device and the liquid storage device and / or in the liquid storage device for filtering residues in the photocuring material output from the resin tank; and a scraping device adjacent to the resin tank for scraping the photocuring material at the bottom of the resin tank in a moving state to facilitate the suction device to suck the photocuring material in the resin tank. The filtering system involved in the present application effectively filters residues in the photocuring material to protect the release film, and can not affect its operation during the manufacturing process of the 3D printing device, is conducive to the replacement of the resin tank, and provides an automated operation solution for photocuring material filtration.

Description

Technical Field

[0001] This application relates to the field of 3D printing technology, and particularly to a filtering system and method for a 3D printing device and a 3D printing device to which the filtering system and method are applicable. Background Art

[0002] In a 3D printing device based on stereolithography, a photocurable material is usually placed in a resin tank, and a release film is provided in the resin tank to facilitate the separation of the cured layer from the resin tank during the printing operation. However, due to various reasons during the printing process, resin residues will appear in the liquid resin in the resin tank. If these residues are not cleaned in time, it will affect the release film and cause the release film to break, increasing the production cost. In some embodiments, a method of manually timing to drain the resin in the resin tank for filtration and then pouring the filtered resin back into the resin tank for continued use is adopted, but this method is time-consuming and laborious, which poses an obstacle to the automation of 3D printing. Summary of the Invention

[0003] In view of the above-mentioned disadvantages of the related art, the purpose of this application is to provide a filtering system and method for a 3D printing device and a 3D printing device to which the filtering system and method are applicable, so as to maintain the cleanliness of the photocurable material in the resin tank while protecting the release film and improving the forming accuracy.

[0004] To achieve the above object and other related objects, this application discloses a filtering system for a 3D printing device. The 3D printing device includes a resin tank. The filtering system includes: a suction device, disposed on one side of the resin tank, for sucking the photocurable material in the resin tank; a liquid storage device, communicating with the suction device, for storing the photocurable material sucked from the resin tank; a filtering device, disposed between the suction device and the liquid storage device and / or in the liquid storage device, for filtering the residues in the photocurable material output from the resin tank; a scraping device, adjacent to the resin tank, for scraping the photocurable material at the bottom of the resin tank in a moving state to facilitate the suction device to suck the photocurable material in the resin tank.

[0005] In certain embodiments of the first aspect of this application, the scraping device includes a scraper and a scraper control mechanism adjacent to one side of the resin tank, for driving the scraper to be placed into or away from the resin tank in a flipped state, and for driving the scraper to move from one side of the resin tank to the opposite side in a scraping state to scrape the photocurable material at the bottom of the resin tank.

[0006] In certain embodiments of the first aspect of this application, the scraper includes a scraper body and a connecting arm for connecting the scraper body to the scraper control mechanism, and the width of the scraper body is equal to the width of the resin tank.

[0007] In some embodiments of the first aspect of the present application, the squeegee control mechanism includes: a squeegee control motor for outputting a driving force in the working state; a lead screw adjacent to one side of the resin tank, with its proximal end connected to the power output shaft of the squeegee control motor and its distal end pivotally connected to a support; a displacement block helically arranged on the lead screw and connected to the connecting arm of the squeegee for displacing between the proximal end and the distal end of the lead screw when the lead screw rotates; a guide rail arranged on the lead screw, including a turning section and a linear displacement section communicating with the turning section, and the turning section includes a limiting portion for restricting the excessive rotation of the connecting arm along with the displacement block.

[0008] In some embodiments of the first aspect of the present application, the suction device includes: a suction mechanism for sucking the photocuring material in the resin tank; a first transfer pump for providing suction power; a first pipeline connecting the suction mechanism, the first transfer pump, and the liquid storage device; and a filtering device is arranged in the first pipeline.

[0009] In some embodiments of the first aspect of the present application, the suction mechanism includes: a suction cup communicating with the first pipeline for sucking the photocuring material swept by the squeegee device by the suction power provided by the first transfer pump when placed in the resin tank; a suction cup swing arm arranged on one side of the resin tank to fix the suction cup for driving the suction cup to be placed into or away from the resin tank; and a suction cup control motor for providing a driving force for the suction cup swing arm in the working state.

[0010] In some embodiments of the first aspect of the present application, the suction width of the suction cup is equal to the width of the resin tank.

[0011] In some embodiments of the first aspect of the present application, it further includes a transfer device communicating with the liquid storage device for transferring the photocuring material in the liquid storage device to the resin tank, and a filtering device is arranged between the liquid storage device and the transfer device.

[0012] In some embodiments of the first aspect of the present application, the transfer device includes: a transfer mechanism for transferring the photocuring material stored in the liquid storage device to the resin tank; a second transfer pump for providing suction power; a second pipeline connecting the second transfer pump and the liquid storage device; and a filtering device is arranged in the second pipeline.

[0013] In some embodiments of the first aspect of the present application, the transfer mechanism includes: a transfer port communicating with the second pipeline for transferring the photocuring material stored in the liquid storage device to the resin tank; a transfer swing arm arranged on one side of the resin tank to fix the transfer port for driving the transfer port to be placed into or away from the resin tank; and a transfer control motor for providing a driving force for the transfer swing arm in the working state.

[0014] In certain embodiments of the first aspect of the present application, the filtration system further includes a liquid level sensor disposed in or adjacent to the resin tank for detecting the remaining amount of the photocurable material in the resin tank.

[0015] In certain embodiments of the first aspect of the present application, the 3D printing device is a 3D printing device including a DLP system or a 3D printing device including an SLA system.

[0016] The second aspect of the present application further provides a filtration method applied to a 3D printing device having a resin tank. The filtration method includes the following steps: causing a suction device to suck the photocurable material in the resin tank into a liquid storage device, and a filtration device is provided between the suction device and the liquid storage device and / or in the liquid storage device to filter residues in the sucked photocurable material; when it is detected that the liquid level of the photocurable material in the resin tank is lower than a threshold, causing a scraper device to scrape the photocurable material at the bottom of the resin tank to facilitate the suction device to continue sucking the photocurable material in the resin tank; causing the suction device to suck the photocurable material scraped by the scraper device.

[0017] In certain embodiments of the second aspect of the present application, the step of causing a scraper device to scrape the photocurable material at the bottom of the resin tank when it is detected that the liquid level of the photocurable material in the resin tank is lower than a threshold includes: when it is detected that the liquid level of the photocurable material in the resin tank is lower than a first threshold, causing a scraper control mechanism to flip the scraper device so that its scraper is placed in the resin tank, and causing the lower edge of the scraper to contact the bottom of the resin tank; causing the scraper control mechanism to drive the scraper to move from one side of the resin tank towards the side of the suction device to scrape the photocurable material at the bottom of the resin tank

[0018] In certain embodiments of the second aspect of the present application, it further includes the step of adding photocurable material into the resin tank: when receiving an instruction to add photocurable material, causing a conveying device to convey the photocurable material in the liquid storage device into the resin tank, and a filtration device is provided between the liquid storage device and the conveying device; when it is detected that the liquid level of the photocurable material in the resin tank is higher than a second threshold, causing the conveying device to stop working.

[0019] The third aspect of the present application further provides a 3D printing device, including: a frame; a resin tank for containing a photocurable material to be cured; an energy radiation device disposed at a preset position on one side of the bottom of the resin tank, configured to radiate energy to the bottom surface of the resin tank in a projection manner or a dot matrix scanning manner when receiving a printing instruction, so as to cure the liquid photocurable material on a preset curing surface in the resin tank; a component platform located in the resin tank in a printing state, for attaching a pattern curing layer obtained after energy radiation, so as to form a 3D component through the accumulation of the pattern curing layer; a Z-axis driving mechanism connected to the component platform, configured to adjust the distance between the component platform and the bottom surface of the resin tank according to a printing instruction to fill the photocurable material to be cured; a filtering system as described in the embodiments of the first aspect of the present application, adjacent to the resin tank, for filtering residues in the photocurable material in the resin tank; a control device electrically connected to the energy radiation device, the Z-axis driving mechanism, and the filtering system, for controlling the working states of the energy radiation device, the Z-axis driving mechanism, and the filtering system.

[0020] In some embodiments of the third aspect of the present application, the 3D printing device is a 3D printing device including a DLP system or a 3D printing device including an SLA system.

[0021] One of the above technical solutions has the following advantages:

[0022] The filtering system of the present application can timely filter the photocurable material in the resin tank in the first aspect, thereby avoiding damage to the release film caused by residues in the photocurable material. And during the suction process, the lower surface of the suction cup adheres to the release film at the bottom of the resin tank, and the scraping device cooperates to scrape the photocurable material remaining in the resin tank to the edge of the suction cup, so as to ensure that the photocurable material in the resin tank can be completely sucked out. On the other hand, each device of the filtering system does not affect the normal operation of the 3D printing device in a non-working state, does not interfere with the workpiece manufacturing process and does not affect the replacement of the resin tank. Therefore, the filtering system involved in the present application effectively filters residues in the photocurable material to protect the release film and improve the printing accuracy, and can not affect its operation during the workpiece manufacturing process of the 3D printing device, is conducive to the replacement of the resin tank, provides an automated operation solution for filtering the photocurable material, and lays a foundation for the overall automated operation of 3D printing. Description of the Drawings

[0023] The specific features of the invention involved in the present application are shown in the appended claims. The features and advantages of the invention involved in the present application can be better understood by referring to the exemplary embodiments and drawings described in detail below. A brief description of the drawings is as follows:

[0024] Figure 1Shown is a schematic structural view of the filtration system in an embodiment of the present application.

[0025] Figure 2 Shown is a schematic structural view of the scraper device in an embodiment of the present application.

[0026] Figure 3 Shown is a schematic structural view of the scraper in the scraper device of the present application in an embodiment.

[0027] Figure 4 Shown is a schematic structural view of the guide rail of the scraper control mechanism in the present application in an embodiment.

[0028] Figure 5 Shown is a schematic structural view of the suction mechanism in an embodiment of the present application.

[0029] Figure 6 Shown is a schematic structural view of the suction cup in an embodiment of the present application.

[0030] Figure 7 Shown is a schematic structural view of the filtration system in another embodiment of the present application.

[0031] Figure 8 Shown is a schematic structural view of the conveying mechanism in an embodiment of the present application.

[0032] Figure 9 Shown is a schematic structural view of the filtration system in yet another embodiment of the present application.

[0033] Figure 10 Shown is a schematic structural view of the filtration system and the applicable 3D printing device in an embodiment of the present application.

[0034] Figure 11 Shown is a schematic view of the filtration method in an embodiment of the present application.

[0035] Figures 12a to 12c Shown is a schematic structural view of the working process of the filtration system in an embodiment of the present application.

[0036] Figure 13 Shown is a schematic structural view of the 3D printing device in an embodiment of the present application. Detailed Embodiments

[0037] The following specific embodiments illustrate the embodiments of the present application, and those skilled in the art can easily understand the other advantages and effects of the present application from the content disclosed in this specification.

[0038] In the following description, reference is made to the accompanying drawings, which describe several embodiments of the present application. It should be understood that other embodiments may also be used, and mechanical compositions, structures, electrical, and operational changes may be made without departing from the spirit and scope of the present disclosure. The following detailed description should not be considered restrictive, and the scope of the embodiments of the present application is only defined by the claims of the published patent. The terms used herein are only for describing specific embodiments and are not intended to limit the present application. Spatially relative terms, such as "upper", "lower", "left", "right", "below", "beneath", "lower", "above", "upper", etc., may be used herein to facilitate the description of the relationship of one element or feature shown in the drawings to another element or feature.

[0039] Although in some instances the terms first, second, etc. are used herein to describe various elements or parameters, these elements or parameters should not be limited by these terms. These terms are only used to distinguish one element or parameter from another. For example, a first threshold may be referred to as a second threshold, and similarly, a second threshold may be referred to as a first threshold, without departing from the scope of the various described embodiments. The first threshold and the second threshold are both describing a threshold, but they are not the same threshold unless the context clearly indicates otherwise in some other way. Similar situations also include a first pipeline and a second pipeline, or a first transfer pump and a second transfer pump.

[0040] Furthermore, as used herein, the singular forms "a", "an", and "the" are intended to also include the plural forms, unless the context indicates otherwise. It should be further understood that the terms "comprising", "including" indicate the presence of the described features, steps, operations, elements, components, items, types, and / or groups, but do not exclude the presence, occurrence, or addition of one or more other features, steps, operations, elements, components, items, types, and / or groups. The terms "or" and "and / or" used herein are interpreted as inclusive, or meaning any one or any combination. Thus, "A, B, or C" or "A, B, and / or C" means "any of the following: A; B; C; A and B; A and C; B and C; A, B, and C". An exception to this definition only occurs when the combination of elements, functions, steps, or operations is inherently mutually exclusive in some way.

[0041] As described in the background art, in a 3D printing device based on stereolithography, a photocurable material is usually placed in a resin tank. Taking a DLP (Digital Light Procession) 3D printing device as an example, after irradiating the photocurable material at the bottom of the container through an exposure device, a first cured layer is formed, and this first cured layer adheres to the building plate. The building plate moves upward under the drive of a Z-axis drive mechanism, causing the cured layer to separate from the bottom of the container. In the separation operation of the cured layer printed layer by layer from the bottom of the container, a relatively large adhesive force needs to be overcome, and there is also a risk of damage to the printed layer during separation. Therefore, a release film is usually provided in the resin tank to facilitate the separation of the cured layer from the resin tank during the printing operation. However, during the operation of the 3D printing device, due to factors such as unclean cleaning, afterglow curing, and inappropriate device parameters, resin residues and other debris often appear in the resin tank during the printing process. If these debris are not removed in time, they will damage the release film during the pressing process of the component platform. For a structure in which the release film and the resin tank are integrally provided, it may even cause the entire resin tank to be scrapped, increasing the production cost and production time.

[0042] In some embodiments, filtration is carried out manually. For example, after printing one component or several components each time, the resin in the resin tank is manually poured out for filtration, and then the filtered resin is poured back into the resin tank for continued use. The filtration process is cumbersome and increases the time and labor costs, and is also not conducive to automated production.

[0043] In view of this, the present application provides a filtration system for a 3D printing device. In the embodiments provided below, the filtration system of the present application includes: a suction device, a liquid storage device, a filtration device, and a scraping device.

[0044] It should be understood that the 3D printing is a kind of rapid prototyping technology. It is a technology that constructs an object by layer-by-layer printing using bondable materials such as powdered metal or plastic based on a digital model file. During printing, the digital model file is first processed to import the 3D component model to be printed into the 3D printing device. Here, the 3D component model includes but is not limited to the 3D component model based on the CAD component, for example, an STL file, and the control device performs layout and layer slicing processing on the imported STL file. The 3D component model can be imported into the control device through a data interface or a network interface. The solid part in the imported 3D component model can be of any shape. For example, the solid part includes a tooth shape, a spherical shape, a house shape, a tooth shape, or any shape with a preset structure, etc. Among them, the preset structure includes but is not limited to at least one of the following: a cavity structure, a structure including a shape mutation, and a structure with a preset requirement for the contour accuracy in the solid part, etc. The 3D printing device prints the 3D component by layer-by-layer exposure curing of the photocurable material and accumulating each cured layer.

[0045] In the present application, the 3D printing device may be a bottom-projection or bottom-exposure 3D printing device. For example, it may be a DLP (Digital Light Procession) device that performs surface exposure using a bottom-projection optical machine, or an SLA (Stereo lithography Apparatus) device that performs laser spot scanning using a bottom laser. In other words, the optical system of the 3D printing device is located at the bottom of the container (also referred to as a resin tank in some application scenarios) and irradiates the bottom surface of the container, for irradiating the layer image in the 3D component model onto the printing reference surface to cure the photocurable material into a corresponding patterned cured layer. Among them, when using the 3D printing device to print an object, the exposure device irradiates the photocurable material at the bottom of the container to form the first cured layer. The first cured layer adheres to the build plate, and the build plate moves upward under the drive of the Z-axis drive mechanism, causing the cured layer to separate from the bottom of the container. Then, the build plate is lowered so that the bottom of the container is filled with the photocurable material to be cured between the bottom of the container and the first cured layer, and irradiated again to obtain the second cured layer adhering to the first cured layer. By analogy, through multiple filling, irradiation, and separation operations, each cured layer is accumulated on the build plate to obtain a 3D object. For a 3D printing device that manufactures 3D objects using a photocurable material with a bottom-exposure method, the layer-by-layer printing method must achieve peeling from the bottom of the container after each printing layer is cured. When forming a cured layer, the upper and lower surfaces of the cured layer adhere to the build plate and the bottom of the container respectively. Generally, the adhesion between the 3D object and the bottom of the container is relatively strong, and a large pulling force needs to be overcome during the process of the build plate driving the cured layer to rise for peeling, and there is also a risk of damage to the cured layer. Therefore, usually, a release film is covered at the bottom of the resin tank to reduce the adhesion force that needs to be overcome during peeling.

[0046] The filtration system involved in the present application is a system for filtering residues in the photocurable material used by the 3D printing device, that is, effectively filtering the residues in the photocurable material by using the filtration system to protect the release film and improve the printing accuracy, and being able to not affect its operation during the manufacturing process of the 3D printing device, facilitating the replacement of the resin tank, providing an automated operation solution for photocurable material filtration, and laying a foundation for the overall automated operation of 3D printing.

[0047] In an exemplary embodiment, please refer to Figure 1 , which shows a schematic structural diagram of the filtration system in the present application in an embodiment. As shown in the figure, the 3D printing device includes a resin tank 2, and the suction device 11 of the filtration system is arranged on one side of the resin tank for sucking the photocurable material in the resin tank. The suction device 11 is connected to the liquid storage device 12 to store the photocurable material sucked from the resin tank by means of the liquid storage device 12.

[0048] Since it is difficult to effectively suck out the photocurable material when the amount of the photocurable material in the resin tank is less than a certain amount, and the photocurable material is usually stored in the resin tank in a liquid form before being cured, while the residues in the photocurable material usually precipitate at the bottom of the resin tank in a solid form. Therefore, in order to more effectively suck the photocurable material located at the bottom of the resin tank, the filtration system of the present application further includes a scraping device adjacent to the resin tank. The scraping device can scrape the photocurable material at the bottom of the resin tank in a moving state, gather the photocurable material and scrape it towards the side where the sucking device is located, so as to facilitate the sucking device to suck the photocurable material in the resin tank.

[0049] Here, in order to filter the residues in the sucked photocurable material, a filtering device is provided between the sucking device and the liquid storage device and / or in the liquid storage device. For example, in one embodiment, as shown in Figure 1 , a filtering device 13 can be provided in the connecting pipeline between the sucking device 11 and the liquid storage device 12. The photocurable material is output to the liquid storage device 12 for storage after filtering the residues through the filtering device; in another embodiment, a filtering device can be provided at the inlet of the liquid storage device 12. When the photocurable material flows into the liquid storage device 12, it is first filtered through the filtering device, so as to filter out the residues and store the clean photocurable material in the liquid storage device 12; in still another embodiment, filtering devices can be provided both in the connecting pipeline between the sucking device 11 and the liquid storage device 12 and at the inlet of the liquid storage device 12. Thus, on the one hand, the photocurable material is output to the liquid storage device 12 after being filtered once by the filtering device in the connecting pipeline to filter the residues, and on the other hand, when it is stored in the liquid storage device 12, it is also filtered twice by the filtering device in the liquid storage device 12, so as to ensure the cleanliness of the photocurable material stored in the liquid storage device 12. The filtering device includes but is not limited to a sieve, a filter element with a pore size smaller than the thickness of the photocurable material layer, or a filter membrane that allows the photocurable material to pass through but blocks the residues outside, etc.

[0050] Among them, the liquid storage device 12 includes but is not limited to various containers such as a liquid storage bottle and a liquid storage tank that can be used to store the photocurable material. In some embodiments, the liquid storage device 12 can be selected according to the material characteristics of the photocurable material. For example, according to the chemical characteristics of the photocurable material, a container that is not easy to react with the photocurable material is selected; or, according to the storage temperature requirement of the photocurable material, the liquid storage device can also be equipped with a heat preservation device, etc.

[0051] It should be understood that the photocurable material generally refers to a material that will form a cured layer after being irradiated by light (such as ultraviolet light, laser, etc.), and it includes but is not limited to: photosensitive resin, or a mixture of photosensitive resin and other materials. The other materials are, for example, ceramic powder, pigment, etc.

[0052] In an exemplary embodiment, the squeegee device includes a squeegee and a squeegee control mechanism. The squeegee control mechanism can control the squeegee to be placed into or away from the resin tank, and drive the squeegee to move from one side of the resin tank to the opposite side to scrape the photocuring material at the bottom of the resin tank.

[0053] Please refer to Figure 2 , which shows a schematic structural diagram of the squeegee device in an embodiment of the present application. As shown in the figure, in this embodiment, the squeegee device 14 includes: a squeegee 141 and a squeegee control mechanism 142 adjacent to one side of the resin tank.

[0054] To enable the squeegee device 14 to scrape the photocuring material at the bottom of the resin tank during the operation of the filtration system to facilitate the suction device to suck, and not affect the operation of other devices in its non-operating state, such as when the 3D printing device performs a printing task or when the resin tank is replaced. The squeegee device 14 is configured to drive the squeegee to be placed into or away from the resin tank in a flipped state, and drive the squeegee to move from one side of the resin tank to the opposite side to scrape the photocuring material at the bottom of the resin tank in a scraping state.

[0055] In a possible embodiment, please refer to Figure 3 , which shows a schematic structural diagram of the squeegee in the squeegee device of the present application in an embodiment. As shown in the figure, the squeegee 141 includes a squeegee main body 1411 and a connecting arm 1412 for connecting the squeegee main body 1411 to the squeegee control mechanism. The width of the squeegee main body is equal to the width of the resin tank, so as to fully scrape the photocuring material in the resin tank. In one embodiment, the connecting arm 1412 and the squeegee main body 1411 can be integrally formed. For example, the connecting arm 1412 is integrally formed on one side of the squeegee main body 1411, and the squeegee main body 1411 is connected to the squeegee control mechanism through the connecting arm 1412; in another embodiment, the connecting arm 1412 can be connected to the squeegee main body 1411 and the squeegee control mechanism through fixing members, thereby connecting the squeegee main body 1411 to the squeegee control mechanism. The fixing members include but are not limited to screws, bolts, etc.

[0056] In one embodiment, there is a gap between the connecting arm 1412 and the blade body 1411 of the blade 141. This gap is used to ensure that when the blade body 1411 is placed in the resin tank, the connecting arm 1412 of the blade 141 is located outside the side wall of the resin tank. In other words, when the blade body 1411 is placed in the resin tank, the blade body 1411 and the connecting arm 1412 of the blade 141 are respectively located inside and outside the side wall of the resin tank. Thus, when the blade body 1411 performs a scraping motion, it can smoothly perform a linear displacement motion.

[0057] In one embodiment, to prevent the blade from damaging the release film during the scraping process, the edge of the bottom of the blade body 1411 (i.e., the part in contact with the bottom of the resin tank) is designed as an arc edge; alternatively, the edge of the bottom of the blade body 1411 can also be coated with a flexible material; or, the bottom of the blade body 1411 is made of a flexible material. Among them, examples of the flexible material include but are not limited to rubber or silicone.

[0058] Please continue to refer to Figure 2 , in Figure 2 the embodiment shown, the blade control mechanism 142 includes: a blade control motor 1421, a lead screw 1422, a displacement block 1423, and a guide rail 1424.

[0059] The blade control motor can output a driving force in the working state. The power output shaft of the blade control motor 1421 is connected to the proximal end of the lead screw 1422 (i.e., the end close to the blade control motor 1421). The distal end of the lead screw 1422 (i.e., the end far from the blade control motor 1421) is pivotally connected to a support. The lead screw 1422 is disposed adjacent to one side of the resin tank. The displacement block 1423 is connected to the connecting arm of the blade, and a connecting hole that cooperates with the lead screw 1422 is provided at the center of the displacement block 1423. The surface of the connecting hole has threads, so that when the lead screw 1422 rotates, the displacement block 1423 can drive the blade to displace between the proximal end and the distal end of the lead screw. The guide rail 1424 is disposed on the lead screw 1422. To ensure that the blade stops flipping after contacting the bottom of the resin tank and performs a translational motion in the resin tank to scrape the photocuring material at the bottom of the resin tank, the guide rail includes a flipping section and a linear displacement section that communicates with the flipping section.

[0060] In one embodiment, please refer to Figure 4, which shows a schematic structural view of the guide rail of the squeegee control mechanism in an embodiment of the present application. As shown in the figure, the guide rail includes two connected grooves, wherein the vertically oriented groove is the flipping section 1424a, and the horizontally oriented groove is the linear displacement section 1424b. A limiting portion is formed on the guide rail wall surface at the bottom of the flipping section 1424a, and this limiting portion can restrict the over-rotation of the connecting arm along with the displacement block. Please continue to refer to Figure 2 , one end of the connecting arm of the squeegee 141 is connected to the squeegee main body, and the other end passes through the flipping section of the guide rail to connect to the displacement block. When the displacement block rotates due to the rotation of the lead screw 1422, it first drives the squeegee to generate displacement within the flipping section, thereby performing a flipping motion relative to the resin tank. When the connecting arm of the squeegee 141 touches the limiting portion, restricted by the limiting portion, the squeegee is only allowed to move horizontally along the linear displacement section and cannot be further flipped.

[0061] Based on the squeegee device structure in the above embodiment, when the squeegee control motor 1421 operates, it outputs a rotational driving force to the lead screw 1422. The lead screw 1422 rotates and drives the displacement block 1423 disposed on the lead screw 1422 and the squeegee 141 on the displacement block 1423 to rotate synchronously. When the connecting arm of the squeegee 141 touches the limiting portion and / or the squeegee main body touches the bottom surface of the resin tank, the squeegee 141 is restricted by the limiting portion and / or the bottom surface of the resin tank and cannot be further flipped. Due to the continuous operation of the squeegee control motor, the squeegee 141 moves horizontally along the linear displacement section of the guide rail, thereby being able to scrape the photocuring material at the bottom of the resin tank during the movement state. After the operation of the squeegee device is completed, by reversing the squeegee control motor, the squeegee main body can be retracted along the original path outside the resin tank, without affecting the printing work of the 3D printing device or the work of replacing the resin tank.

[0062] It should be understood that the above embodiments are only examples rather than limitations of the squeegee control mechanism. In practical applications, the squeegee control mechanism can also be configured into other structures to achieve driving the squeegee to move from one side of the resin tank to the opposite side during the scraping state to scrape the photocuring material at the bottom of the resin tank. For example, the squeegee can also be connected to a linear motor and a rotary motor simultaneously, so as to achieve flipping under the drive of the rotary motor and achieve horizontal displacement under the drive of the linear motor.

[0063] In an exemplary embodiment, the squeegee device may further include a bracket located on one side of the resin tank and adjacent to the suction device. The bracket is provided with a horizontal guide rail, a vertical guide rail disposed on the horizontal guide rail, and motors respectively disposed on the vertical guide rail and the horizontal guide rail. The squeegee device includes a squeegee body and a connecting arm for connecting the squeegee body to the vertical guide rail. Driven by the motor on the vertical guide rail, the position of the squeegee in the vertical direction can be adjusted, so that the squeegee can be placed into or away from the resin tank. Driven by the motor on the horizontal guide rail, the position of the squeegee in the horizontal direction can be adjusted, so that the squeegee can move horizontally in the resin tank to scrape the photocuring material at the bottom of the resin tank. Wherein, the width of the squeegee body is equal to the width of the resin tank, which is beneficial to fully scrape the photocuring material in the resin tank.

[0064] In an exemplary embodiment, please continue to refer to Figure 1 , the suction device includes: a suction mechanism (not shown), a first transfer pump 112, and a first pipe 113.

[0065] The first transfer pump is used to provide suction power. The suction mechanism is used to suck the photocuring material in the resin tank under the suction power provided by the first transfer pump 112. The first pipe 113 communicates with the suction port of the suction mechanism, the first transfer pump 112, and the liquid storage device. In the working state of the first transfer pump 112, the suction mechanism sucks the photocuring material in the resin tank by the suction power provided by the first transfer pump 112, and the photocuring material is transported to the liquid storage device through the first pipe 113. In an embodiment, a filtering device 13 is provided in the first pipe 113, and the photocuring material is filtered through the filtering device 13 to remove residues and then output to the liquid storage device 12 for storage. The filtering device 13 includes, but is not limited to, a sieve, a filter element, or a filter membrane with a pore size smaller than the thickness of the photocuring material layer that allows the photocuring material to pass through but blocks the residues.

[0066] In an exemplary embodiment, in order to prevent the suction device from affecting the normal printing work of the 3D printing device in the non-working state and to facilitate the replacement of the resin tank, the suction device is configured to be placed into or away from the resin tank under a driving force.

[0067] In a possible embodiment, please refer to Figure 5, which shows a schematic structural view of the suction mechanism in an embodiment of the present application. As shown in the figure, the suction mechanism 111 includes: a suction cup 1111, a suction cup swing arm 1112, and a suction cup control motor 1113. Among them, the suction cup 1111 is connected to the first pipeline, the suction cup swing arm 1112 is arranged on one side of the resin tank, one end of the suction cup swing arm 1112 fixes the suction cup 1111, and the other end of the suction cup swing arm 1112 is connected to the output end of the suction cup control motor 1113. Thus, under the working state of the suction cup control motor 1113, it can be driven by the driving force of the suction cup control motor 1113 to drive the suction cup 1111 to descend into the resin tank and rise away from the resin tank.

[0068] In one embodiment, please refer to Figure 6 , which shows a schematic structural view of the suction cup in an embodiment of the present application. As shown in the figure, the lower part of the suction cup 1111 has a suction port 1111a, and the upper part of the suction cup 1111 is connected to the first pipeline. The width of the suction port 1111a of the suction cup 1111 is equal to the width inside the resin tank, and the main body width of the suction cup 1111 decreases from bottom to top to facilitate the suction of the photocuring material. In Figure 6 the structure shown, the suction cup is a duckbill suction cup structure. There is an upward notch on the front side of the suction port. During the working process of the suction mechanism, the notch forms a suction channel, that is, when the lower surface of the suction port 1111a reaches the bottom surface of the resin tank, the photocuring material is sucked into the suction port from this notch and is conveyed into the first pipeline through the upper part of the suction cup 1111. The upper part of the suction cup 1111 also has a connection seat 1111b, and the connection seat is connected to both the upper part of the suction cup 1111 and the suction cup swing arm at the same time, so as to drive the suction cup 1111 to move under the drive of the suction cup swing arm. In one embodiment, to facilitate the suction of the photocuring material and avoid possible damage to the release film caused by too hard material during suction, the suction cup 1111 is made of a soft material such as rubber or silica gel.

[0069] In this embodiment, when the suction cup mechanism works, first start the suction cup control motor to provide driving force for the suction cup swing arm. The suction cup swing arm drives the suction cup into the resin tank. When the suction port of the suction cup touches the bottom surface of the resin tank, a gap allowing the photocuring material to pass through is formed between the groove on the front side of the suction port and the bottom surface of the resin tank. The first transfer pump forms a negative pressure in the first pipeline to suck the photocuring material in the resin tank. After the photocuring material enters the first pipeline, it is filtered by the filtering device to filter out the residues in the photocuring material, and the clean photocuring material is conveyed to the liquid storage device for storage. After the suction is completed, the suction cup control motor drives the suction cup swing arm to move in the opposite direction, so as to lift the suction cup away from the resin tank.

[0070] In one embodiment, the filtered photocuring material in the liquid storage device can also be recycled. To this end, the filtration system further includes a conveying device, which is adjacent to the resin tank and communicates with the liquid storage device, so as to convey the photocuring material in the liquid storage device into the resin tank. Wherein, a filtering device may be further provided between the liquid storage device and the conveying device to perform secondary filtration on the photocuring material output from the liquid storage device.

[0071] In an exemplary embodiment, please refer to Figure 7 , which shows a schematic structural diagram of the filtration system in another embodiment of the present application. As shown in the figure, the conveying device includes: a conveying mechanism (not shown), a second conveying pump 152, and a second pipeline 153.

[0072] Wherein, the conveying mechanism is used to convey the photocuring material stored in the liquid storage device 12 into the resin tank 2, the second conveying pump 152 is used to provide suction power, and the second pipeline 153 communicates the second conveying pump 152 and the liquid storage device 12, so as to convey the photocuring material in the liquid storage device 12 into the resin tank 2 through the conveying mechanism under the suction power provided by the second conveying pump 152. A filtering device 13 is further provided in the second pipeline 153 to perform secondary filtration on the photocuring material output from the liquid storage device.

[0073] In some cases, to ensure that the conveying device does not affect the normal printing operation of the 3D printing device in the non-working state and to facilitate the replacement of the resin tank, the conveying device is configured to be able to move closer to or away from the resin tank under driving force.

[0074] In an exemplary embodiment, please refer to Figure 8 , which shows a schematic structural diagram of the conveying mechanism in one embodiment of the present application. As shown in the figure, the conveying mechanism 151 includes: a conveying port 1511, a conveying swing arm 1512, and a conveying control motor 1513.

[0075] The conveying control motor 1513 is used to provide driving force for the conveying swing arm 1512 in the working state. The conveying swing arm 1512 is arranged on one side of the resin tank. One end of the conveying swing arm 1512 is connected to the output end of the conveying control motor 1513, and the other end of the conveying swing arm 1512 is connected to the conveying port 1511. In the working state of the conveying control motor 1513, the conveying control motor 1513 drives the conveying swing arm 1512 to swing, and the conveying swing arm 1512 further drives the conveying port 1511 to move downward to be placed in or close to the resin tank. The conveying port 1511 communicates with the second pipeline to convey the photocuring material stored in the liquid storage device into the resin tank. In the embodiment, the conveying port 1511 is, for example, the pipe orifice of a conduit.

[0076] Among them, the delivery port 1511 can be placed in the resin tank and output the photocuring material to the resin tank, or can be close to the resin tank and output the photocuring material to the resin tank by hydraulic pressure or gravity. For example, the delivery port can be located in the resin tank under the action of the delivery swing arm 1512, and the photocuring material flowing out of the delivery port accumulates in the resin tank; another example is that the delivery port can be located above the resin tank under the action of the delivery swing arm 1512, and the photocuring material flowing out of the delivery port flows down into the resin tank by gravity; still another example is that the delivery port can be located on one side of the resin tank under the action of the delivery swing arm 1512 and the liquid outlet direction of the delivery port faces the resin tank, and the photocuring material flowing out of the delivery port can flow out to the resin tank by the hydraulic pressure provided by the second delivery pump to accumulate in the resin tank.

[0077] In this embodiment, when the delivery device works, first start the delivery control motor to provide driving force for the delivery swing arm. The delivery swing arm drives the delivery port to approach or be placed in the resin tank, and the photocuring material in the liquid storage device is filtered by the filtering device in the second pipeline and then delivered to the resin tank by the suction power provided by the second delivery pump. After the delivery is completed, the delivery control motor drives the delivery swing arm to move in the opposite direction, so as to raise and turn the delivery port to be away from the resin tank.

[0078] In an exemplary embodiment, in order to detect the remaining amount of the photocuring material in the resin tank in real time or at regular intervals, a liquid level sensor is provided in or near the resin tank.

[0079] In one embodiment, please refer to Figure 9, which shows a schematic structural diagram of the filtration system in another embodiment of the present application. As shown in the figure, a liquid level sensor 16 is provided above the resin tank 2, and the liquid level sensor 16 can be configured to detect the remaining amount of the photocuring material in the resin tank in real time or at regular intervals. For example, during the printing operation of a 3D printing device, to ensure the cleanliness of the photocuring material in the resin tank 2, the remaining photocuring material can be filtered after a certain amount of the photocuring material is used. Therefore, when the liquid level sensor 16 detects that the photocuring material in the resin tank 2 is less than the third threshold, the suction mechanism of the filtration system can be activated to suck the photocuring material in the resin tank 2 and filter it through the filtration device in the first pipeline 113, and then store the clean photocuring material in the liquid storage device 12. Another example is that during the process of the suction mechanism sucking the photocuring material in the resin tank 2, to prevent the residue in the resin tank from not being completely sucked due to sedimentation at the bottom of the resin tank, when the liquid level sensor 16 detects that the photocuring material in the resin tank 2 is less than the first threshold, the scraper control mechanism flips the scraper device to place its scraper into the resin tank 2 and scrape the photocuring material at the bottom of the resin tank 2, so as to facilitate scraping all the photocuring material at the bottom of the resin tank 2 to the vicinity of the suction port of the suction device 11 for suction. Another example is that when the liquid level sensor 16 detects that the photocuring material in the resin tank 2 is less than the fourth threshold, the conveying device can also be commanded to input clean photocuring material into the resin tank 2. Another example is that during the process of the conveying device inputting clean photocuring material into the resin tank 2, when the liquid level sensor 16 detects that the photocuring material in the resin tank 2 is greater than the second threshold, the conveying is stopped. Among them, the values of the first threshold, the second threshold, the third threshold, and the fourth threshold can be determined according to the actual situation. For example, the values of the first threshold and the fourth threshold can include but are not limited to 0% - 20% of the resin tank capacity, such as 0%, 0.1%, 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, etc.; the value of the second threshold can be determined according to the number and size of the components to be printed or the expected amount of photocuring material required for printing, and it includes but is not limited to 1% - 100% of the resin tank capacity, such as 1%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 100%, etc.The value of the third threshold can be determined according to the amount of photocuring material in the resin tank before printing, the frequency of filtering required for the photocuring material during actual printing operations, and the amount of photocuring material consumed by each component during printing. For example, if the remaining amount of photocuring material in the resin tank before printing is 80% of the overall capacity of the resin tank, and printing the current component requires 10% of the photocuring material and filtering is required after each component is printed, and filtering of the photocuring material is required once after each component is printed, then the liquid level sensor can start the suction mechanism of the filtering system to suck the photocuring material in the resin tank for filtering after detecting a 10% reduction in the photocuring material.

[0080] Among them, the liquid level sensor can be selected according to its installation position or actual needs. For example, when the liquid level sensor is installed in the resin tank, a float type liquid level sensor can be selected; when the liquid level sensor is installed above the resin tank or to avoid the influence of the liquid level sensor on printing operations, a photoelectric liquid level sensor can be selected, etc.

[0081] In an exemplary embodiment, please refer to Figure 10, which shows a schematic structural diagram of the filtration system and the applicable 3D printing device in an embodiment of the present application. As shown in the figure, the 3D printing device includes a resin tank 2 and a member platform 17 located above the resin tank. A suction device 11, a scraper device 14, a conveying device 15, and a liquid level sensor 16 are respectively provided around the resin tank 2. The liquid level sensor 16 is used to detect the remaining amount of the photocurable material in the resin tank, so as to trigger different devices of the filtration system to perform work tasks according to different remaining amount detection results. When it is necessary to filter the photocurable material in the resin tank, the suction cup control motor is started to provide driving force for the suction cup swing arm. The suction cup swing arm drives the suction cup to be placed into the resin tank. When the suction port of the suction cup touches the bottom surface of the resin tank, a gap allowing the photocurable material to pass through is formed between the notch on the front side of the suction port and the bottom surface of the resin tank. The first transfer pump forms a negative pressure in the first pipeline to suck the photocurable material in the resin tank. After the photocurable material enters the first pipeline, it is filtered by the filtering device to filter out the residues in the photocurable material, and the clean photocurable material is transported to the liquid storage device for storage. When the amount of the photocurable material in the resin tank 2 is less than the first threshold, the scraper device is driven to work to scrape the photocurable material at the bottom of the resin tank 2. The scraper control motor outputs a rotational driving force to the lead screw. The lead screw rotates and drives the displacement block arranged on the lead screw and the scraper on the displacement block to rotate synchronously. When the connecting arm of the scraper touches the limiting part and / or the main body of the scraper touches the bottom surface of the resin tank, the scraper is restricted by the limiting part and / or the bottom surface of the resin tank and cannot be further turned over. Due to the continuous operation of the scraper control motor, the scraper moves horizontally along the linear displacement section of the guide rail, so that the photocurable material at the bottom of the resin tank can be scraped in the moving state, and the scraped photocurable material accumulates on the side close to the suction cup. Then, the suction device 11 is made to suck the scraped photocurable material, so that the remaining photocurable material in the resin tank is sucked clean. After the suction is completed, the suction cup control motor drives the suction cup swing arm to move in the opposite direction, so as to lift the suction cup away from the resin tank, and the scraper device is reset by reversing the lead screw. When it is necessary to add photocurable material to the resin tank 2, first, the conveying control motor is started to provide driving force for the conveying swing arm. The conveying swing arm drives the conveying port to approach or be placed into the resin tank, and the photocurable material in the liquid storage device is filtered by the filtering device in the second pipeline and then transported into the resin tank by the suction power provided by the second transfer pump. When the liquid level sensor detects that the remaining amount of the photocurable material in the resin tank is greater than the second threshold, it is prompted that the conveying is completed. The conveying control motor drives the conveying swing arm to move in the opposite direction, so as to lift the conveying port and turn it away from the resin tank.

[0082] In summary, the filtration system of the present application can timely filter the photocuring material in the resin tank in the first aspect, thereby avoiding damage to the release film caused by residues in the photocuring material while improving the printing accuracy. Moreover, during the suction process, the lower surface of the suction cup adheres to the release film at the bottom of the resin tank, and the scraper device cooperates to scrape the photocuring material remaining in the resin tank to the edge of the suction cup to ensure that the photocuring material in the resin tank can be completely sucked out. On the other hand, each device of the filtration system does not affect the normal operation of the 3D printing device in the non-working state, does not interfere with the workpiece manufacturing process, and does not affect the replacement of the resin tank.

[0083] The present application also provides a filtration method, which can be executed by a computer system, and the computer system is implemented through the combination of its hardware and software.

[0084] The computer system at least includes: one or more memories, one or more processors, I / O interfaces, network interfaces, input structures, etc.

[0085] Among them, the memory contains programs. The types of the memory include: high-speed random access memory, and may also include non-volatile memory, such as one or more disk storage devices, flash memory devices, or other non-volatile solid-state storage devices.

[0086] In some embodiments, the memory may further include a memory remote from the one or more processors, such as a network-attached memory accessed via an RF circuit or an external port and a communication network, where the communication network may be the Internet, one or more internal networks, a local area network (LAN), a wide area network (WLAN), a storage area network (SAN), etc., or a suitable combination thereof. The controller of the memory can control other components of the device, such as the CPU and the peripheral interface, to access the memory. The one or more processors are operably coupled to the network interface to communicatively couple the computing device to the network. For example, the network interface can connect the computing device to a local area network (such as a LAN) and / or a wide area network (such as a WAN). The processor is also operably coupled to the I / O port and the input structure. The I / O port is connected to a 3D printing device, a liquid level sensor, a suction device, a scraper device, or a conveying device, etc., which enables the computing device to interact with the 3D printing device, the liquid level sensor, the suction device, the scraper device, or the conveying device, etc. The input structure enables the user to interact with the computing device. Optionally, the input structure may include buttons, a keyboard, a mouse, a touchpad, etc. Additionally optionally, the electronic display may include a touch component, which facilitates user input by detecting the occurrence and / or position of an object touching its screen.

[0087] The filtration method involved in this application can be applied to a 3D printing device with a resin tank to filter the photocurable material in the resin tank of the 3D printing device, remove the residues in the photocurable material, ensure the cleanliness of the photocurable material in the resin tank, and thus improve the printing accuracy while protecting the release film.

[0088] In an exemplary embodiment, please refer to Figure 11 , which shows a schematic diagram of the filtration method in this application in one embodiment.

[0089] In step S110, a suction device is used to suck the photocurable material in the resin tank into a liquid storage device. A filtration device is provided between the suction device and the liquid storage device and / or in the liquid storage device. The filtration device filters the residues in the sucked photocurable material.

[0090] Among them, the suction device may include a suction mechanism, a first transfer pump, and a first pipeline. The first transfer pump is used to provide suction power. The suction mechanism is used to suck the photocurable material in the resin tank under the suction power provided by the first transfer pump. The first pipeline connects the suction port of the suction mechanism, the first transfer pump, and the liquid storage device. In the working state of the first transfer pump, the suction mechanism sucks the photocurable material in the resin tank by the suction power provided by the first transfer pump, and the photocurable material is transported to the liquid storage device through the first pipeline.

[0091] In one implementation manner, a filtration device can be provided in the connection pipeline between the suction device and the liquid storage device. The photocurable material is filtered through the filtration device to remove residues and then output to the liquid storage device for storage. In another implementation manner, a filtration device can be provided at the inlet of the liquid storage device. When the photocurable material flows into the liquid storage device, it is first filtered through the filtration device to remove the residues, and the clean photocurable material is stored in the liquid storage device. In yet another implementation manner, filtration devices can be provided both in the connection pipeline between the suction device and the liquid storage device and at the inlet of the liquid storage device. Thus, on the one hand, the photocurable material is filtered once through the filtration device in the connection pipeline to remove residues and then output to the liquid storage device, and on the other hand, when it is stored in the liquid storage device, it is also filtered a second time through the filtration device in the liquid storage device, so as to ensure the cleanliness of the photocurable material stored in the liquid storage device. The filtration device includes but is not limited to a sieve, a filter element, or a filter membrane with a pore size smaller than the thickness of the photocurable material layer that allows the photocurable material to pass through but blocks the residues outside.

[0092] In step S120, when it is detected that the liquid level of the photocurable material in the resin tank is lower than a threshold, a scraping device is used to scrape the photocurable material at the bottom of the resin tank to facilitate the suction device to continue sucking the photocurable material in the resin tank.

[0093] It should be understood that when the amount of photocuring material in the resin tank is large, the liquid level of the photocuring material is higher than the suction port of the suction device, and the photocuring material is relatively easy to be sucked by the suction device. However, when the amount of photocuring material in the resin tank is small, the photocuring material deposited at the bottom of the resin tank is difficult to be directly sucked by the suction device. Therefore, a detection device such as a liquid level sensor can be set to detect the remaining amount of photocuring material in the resin tank. When the detected liquid level of the photocuring material is lower than a threshold value, the scraping device is used to scrape the photocuring material at the bottom of the resin tank, so as to sweep the photocuring material to the side close to the suction device, so that the suction device can continue to suck the photocuring material in the resin tank.

[0094] Among them, the scraping device includes a scraper and a scraper control mechanism. The scraper control mechanism can control the scraper to be placed into or away from the resin tank, and drive the scraper to move from one side of the resin tank to the opposite side to scrape the photocuring material at the bottom of the resin tank.

[0095] In a possible implementation manner, when it is detected that the liquid level of the photocuring material in the resin tank is lower than the first threshold value, the scraper control mechanism can be made to flip the scraping device to place its scraper into the resin tank, make the lower edge of the scraper contact the bottom of the resin tank, and make the scraper control mechanism drive the scraper to move from one side of the resin tank to the side of the suction device to scrape the photocuring material at the bottom of the resin tank.

[0096] It should be understood that the resin tank is usually of a rectangular structure, and the suction device is arranged on one side of the resin tank. To fully scrape the photocuring material, the scraper is configured to scrape from the direction opposite to the suction device to the direction where the suction device is arranged.

[0097] Here, the value of the first threshold can be determined according to the actual situation, including but not limited to 0% - 20% of the resin tank capacity, such as 0%, 0.1%, 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, etc.

[0098] In one embodiment, the squeegee includes a squeegee body and a connecting arm for connecting the squeegee body to the squeegee control mechanism. The width of the squeegee body is equal to the width of the resin tank, so as to fully scrape the photocuring material in the resin tank. The squeegee control mechanism includes: a squeegee control motor, a lead screw, a displacement block, and a guide rail. The squeegee control motor can output a driving force in the working state. The power output shaft of the squeegee control motor is connected to the proximal end of the lead screw (i.e., the end close to the squeegee control motor), and the distal end of the lead screw (i.e., the end far from the squeegee control motor) is axially connected to a support. The lead screw is arranged adjacent to one side of the resin tank. The displacement block is connected to the connecting arm of the squeegee, and a connecting hole matching with the lead screw is provided in the center of the displacement block. The surface of the connecting hole has threads, so that the displacement block can drive the squeegee to displace between the proximal end and the distal end of the lead screw when the lead screw rotates. The guide rail is arranged on the lead screw. In order to make the squeegee stop flipping after contacting the bottom of the resin tank and move horizontally in the resin tank to scrape the photocuring material at the bottom of the resin tank, the guide rail includes a flipping section and a linear displacement section communicating with the flipping section. When the squeegee control motor works, it outputs a rotational driving force to the lead screw. The lead screw rotates and drives the displacement block arranged on the lead screw and the squeegee on the displacement block to rotate synchronously. When the connecting arm of the squeegee touches the limiting part and / or the squeegee body touches the bottom surface of the resin tank, the squeegee is restricted by the limiting part and / or the bottom surface of the resin tank and cannot be further flipped. Due to the continuous operation of the squeegee control motor, the squeegee moves horizontally along the linear displacement section of the guide rail, so as to scrape the photocuring material at the bottom of the resin tank in the moving state.

[0099] Please continue to refer to Figure 11 , in step S130, the suction device is made to suck the photocuring material scraped by the squeegee device.

[0100] Here, since the squeegee moves from one side of the resin tank towards the side of the suction device, the photocuring material is collected to the side of the resin tank close to the suction device. Therefore, making the suction device suck the photocuring material scraped by the squeegee device can suck the photocuring material in the resin tank clean. In some embodiments, steps S120 and S130 can also be repeated to make the scraping and suction effects better.

[0101] In one embodiment, after receiving the signal that the suction device has completed its work, the suction cup of the suction device is controlled to be lifted away from the resin tank; and, the squeegee control mechanism is controlled to flip the squeegee device to make it away from the resin tank, so as not to affect the printing work of the 3D printing device and the replacement of the resin tank, etc.

[0102] In an exemplary embodiment, the filtering method further includes the step of adding clean photocurable material to the resin tank. To this end, upon receiving an instruction to add the photocurable material, a conveying device conveys the photocurable material in the liquid storage device to the resin tank, and when it is detected that the liquid level of the photocurable material in the resin tank is higher than a second threshold, the conveying device is instructed to stop working.

[0103] In a possible implementation, the conveying device includes: a conveying mechanism, a second delivery pump, and a second pipeline. The conveying mechanism is used to convey the photocurable material stored in the liquid storage device to the resin tank. The second delivery pump is used to provide suction power. The second pipeline connects the second delivery pump and the liquid storage device, so that under the suction power provided by the second delivery pump, the photocurable material in the liquid storage device is conveyed to the resin tank through the conveying mechanism. In some embodiments, a filtering device is further provided between the liquid storage device and the conveying device to perform secondary filtering on the photocurable material output from the liquid storage device.

[0104] Among them, the instruction can be issued based on the detection result of the liquid level sensor or based on the user's operation instruction. For example, when the liquid level sensor detects that the remaining amount of the photocurable material in the resin tank is too small and needs to be added, an instruction to add the photocurable material is issued; another example is that the user selects to add the photocurable material to drive the conveying device to work; another example is that when the liquid level sensor detects that the remaining amount of the photocurable material in the resin tank is too small and needs to be added, the computer device that executes the filtering method communicates with the 3D printing device, and when it is determined that the 3D printing device is not performing a printing task or receives a signal indicating that the 3D printing device has completed printing, the conveying device is driven to work.

[0105] Here, the value of the second threshold can be determined according to the number and size of the components to be printed or the expected amount of photocurable material required for printing, including but not limited to 1% - 100% of the resin tank capacity, such as 1%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 100%, etc.

[0106] In an embodiment, after receiving a signal indicating that the conveying device has completed its work, the conveying device is controlled to move away from the resin tank, so as not to affect the printing work of the 3D printing device and the replacement of the resin tank, etc.

[0107] In an exemplary embodiment, please refer to Figures 12a to 12c which shows a schematic structural diagram of the working process of the filtering system in this application in an embodiment. As shown in the figure, in Figure 12aAmong them, the liquid level sensor 16 is used to detect the remaining amount of the photocuring material in the resin tank 2. When it is necessary to filter the photocuring material in the resin tank, for example, Figure 12a The suction device is placed into the resin tank in the direction of the arrow in the figure, and the first transfer pump forms a negative pressure in the first pipeline to suck the photocuring material in the resin tank. As shown in Figure 12b and Figure 12c When the photocuring material in the resin tank 2 is less than the first threshold value, the scraper device is driven to work and scrape the photocuring material at the bottom of the resin tank 2 in the direction of the arrow in Figure 12b so that the scraped photocuring material accumulates on one side close to the suction device, and then the suction device sucks the scraped photocuring material, so that the remaining photocuring material in the resin tank is sucked clean. After the photocuring material enters the first pipeline, it is filtered by the filtering device to filter out the residues in the photocuring material, and the clean photocuring material is transported to the liquid storage device for storage. After the suction is completed, the sucker control motor drives the sucker swing arm to move in the opposite direction, so as to lift the suction device away from the resin tank and reset the scraper device, so as not to affect the printing work of the 3D printing device. When it is necessary to add photocuring material into the resin tank 2, the conveying mechanism of the conveying device is made to approach or be placed into the resin tank, and the photocuring material in the liquid storage device is filtered by the filtering device in the second pipeline and then transported into the resin tank by the suction power provided by the second transfer pump. When the liquid level sensor detects that the remaining amount of the photocuring material in the resin tank is greater than the second threshold value, it prompts that the conveying is completed, and the conveying mechanism is lifted away from the resin tank to avoid affecting the printing work of the 3D printing device.

[0108] In summary, the filtering method in the present application can fully and effectively filter the photocuring material in the resin tank through the cooperation of the suction device and the scraper device, and realizes the automation of the photocuring material filtering.

[0109] Among them, for the specific structures of the suction device, the liquid storage device, the scraper device, and the conveying device involved in the filtering method in the present application, reference can be made to the structures in the corresponding embodiment part, which will not be repeated here. Figures 1 to 10

[0110] The present application also provides a 3D printing device.

[0111] ​The 3D printing device may be a bottom projection or bottom exposure 3D printing device. For example, it can be a DLP (Digital Light Procession) device that performs surface exposure using a bottom projection optical machine, or an SLA (Stereo lithography Apparatus) device that scans laser spots using a bottom laser. In other words, the optical system of the 3D printing device is located at the bottom of a container (also referred to as a resin tank in some application scenarios) and irradiates the bottom surface of the container, so as to irradiate the layered images in the 3D component model onto the printing reference surface to cure the photocurable material into a corresponding patterned cured layer. Among them, when using the 3D printing device to print an object, the exposure device irradiates the photocurable material at the bottom of the container to form the first cured layer. The first cured layer adheres to the building plate. The building plate moves upward driven by the Z-axis drive mechanism, so that the cured layer is separated from the bottom of the container. Then, the building plate is lowered so that the photocurable material to be cured is filled between the bottom of the container and the first cured layer, and irradiated again to obtain the second cured layer adhering to the first cured layer. And so on. After multiple filling, irradiation, and separation operations, the cured layers are accumulated on the building plate to obtain a 3D object. For a 3D printing device that manufactures 3D objects using a photocurable material with a bottom exposure method, the layer-by-layer printing method must be adopted to achieve peeling from the bottom of the container after each printing layer is cured. When forming a cured layer, the upper and lower surfaces of the cured layer adhere to the building plate and the bottom of the container respectively. Generally, the adhesion between the 3D object and the bottom of the container is relatively strong. During the process of the building plate driving the cured layer to rise for peeling, a relatively large pulling force needs to be overcome, and there is also a risk of damage to the cured layer. Therefore, usually, a release film is covered at the bottom of the resin tank to reduce the adhesion force that needs to be overcome during peeling.

[0112] In an exemplary embodiment, please refer to Figure 13 , which shows a schematic structural diagram of the 3D printing device in an embodiment of the present application. As shown in the figure, the 3D printing device includes: a frame (not shown), a resin tank 2, an energy radiation device (not shown), a component platform 17, a Z-axis drive mechanism (not shown), a filtration system, and a control device (not shown).

[0113] The frame is used to carry the resin tank 2, the energy radiation device, the component platform 17, and the Z-axis drive mechanism. The resin tank is used to hold the photocurable material to be cured. Among them, the photocurable material generally refers to a material that will form a cured layer after being irradiated by light (such as ultraviolet light, laser, etc.), and it includes but is not limited to: photosensitive resin, or a mixture of photosensitive resin and other materials. The other materials are, for example, ceramic powder, pigment, etc. The Z-axis drive mechanism is connected to the component platform and is configured to adjust the distance between the component platform and the bottom surface of the resin tank according to the printing instruction to fill the photocurable material to be cured. The component platform is located in the resin tank during the printing state and is used to attach the pattern cured layer obtained after energy radiation, so as to accumulate the 3D component through the pattern cured layer. During the printing process, the Z-axis drive mechanism drives the component platform to descend into the resin tank, and the photocurable material after passing through the energy radiation device forms a pattern cured layer, and the 3D component is formed after the pattern cured layers are accumulated layer by layer.

[0114] Among them, the energy radiation device is arranged at a preset position on one side of the bottom of the resin tank, and the energy radiation device is configured to radiate energy in a projection mode or a dot matrix scanning mode to the bottom surface of the resin tank when receiving a printing instruction, so as to cure the liquid photocurable material on the preset curing surface in the resin tank.

[0115] In a DLP device, the energy radiation device includes, for example, a DMD chip, a controller, and a storage module. Among them, the storage module stores the layered images obtained by slicing the 3D component model. After receiving the control signal from the controller, the DMD chip irradiates the light sources of each pixel on the corresponding layered image onto the component platform. In fact, the DMD chip looks like just a small piece of mirror and is encapsulated in a sealed space composed of metal and glass. In fact, this mirror is composed of hundreds of thousands or even millions of micromirrors, and each micromirror represents a pixel, and the projected image is composed of these pixels. The DMD chip can be simply described as a semiconductor optical switch and a micromirror corresponding to the pixel points. The controller allows / forbids each microchip to reflect light by controlling the optical switches in the DMD chip, thereby irradiating the corresponding layered image onto the photocurable material, so that the photocurable material with the corresponding image shape is cured to obtain a patterned cured layer.

[0116] For an SLA device, the energy radiation device includes a laser emitter, a lens group located on the optical path of the laser beam emitted by the laser emitter, and a galvanometer scanning unit located on the light output side of the lens group. Among them, the laser emitter is controlled to adjust the energy of the output laser beam. For example, the laser emitter is controlled to emit a laser beam with a preset power and stop emitting the laser beam. Also, for example, the laser emitter is controlled to increase the power of the laser beam and decrease the power of the laser beam. The lens group is used to adjust the focusing position of the laser beam, and the galvanometer scanning unit is used to scan the laser beam in a two-dimensional space on the component platform in a controlled manner. The photocurable material scanned by the laser beam is cured into a corresponding patterned cured layer.

[0117] The filtration system is adjacent to the resin tank and is used to filter the residues in the photocurable material in the resin tank. The specific structure of the filtration system is as Figures 1 to 10 described in the corresponding embodiments and will not be repeated here. When it is necessary to filter the photocurable material in the resin tank, the suction device is placed into the resin tank, and the first transfer pump forms a negative pressure in the first pipeline to suck the photocurable material in the resin tank. When the amount of photocurable material in the resin tank is less than the first threshold, the scraper device is driven to work and scrape the photocurable material at the bottom of the resin tank to facilitate the suction of the suction device. After the photocurable material enters the first pipeline, it is filtered by the filtration device to filter out the residues in the photocurable material, and the clean photocurable material is transported to the liquid storage device for storage. After the suction is completed, the suction cup control motor drives the suction cup swing arm to move in the opposite direction, so as to lift the suction device away from the resin tank and reset the scraper device, so as not to affect the printing work of the 3D printing device. When it is necessary to add photocurable material into the resin tank, the conveying mechanism of the conveying device is moved close to or placed into the resin tank, and the photocurable material in the liquid storage device is filtered by the filtration device in the second pipeline and then transported into the resin tank by the suction power provided by the second transfer pump. When the liquid level sensor detects that the remaining amount of photocurable material in the resin tank is greater than the second threshold, it prompts that the conveying is completed, and the conveying mechanism is lifted away from the resin tank to avoid affecting the printing work of the 3D printing device.

[0118] Among them, the scraper in the filtration device can be configured to: during the filtration work of the 3D printing device, it is used to scrape the photocurable material at the bottom of the resin tank in a moving state to facilitate the suction device to suck the photocurable material in the resin tank.

[0119] The control device is electrically connected to the energy radiation device, the Z-axis drive mechanism, and the filtration system, and is used to control the working states of the energy radiation device, the Z-axis drive mechanism, and the filtration system.

[0120] The control device is, for example, a control board (a circuit board provided with electronic devices), and the control board includes a storage unit, a processing unit, and a drive reservation interface unit. Among them, the storage unit includes a non-volatile memory, a volatile memory, etc. Among them, the non-volatile memory is exemplified by a solid-state drive or a USB flash drive, etc. The storage unit is connected to the processing unit through a system bus. The processing unit includes at least one of a CPU or a chip integrated with a CPU, a programmable logic device (FPGA), and a multi-core processor. The drive reservation interface unit includes a plurality of drive reservation interfaces, and each of the drive reservation interfaces is electrically connected to devices such as an energy radiation device, a Z-axis drive mechanism, and a filtration system, for controlling devices that are independently packaged and transmit data or drive work through interfaces in a 3D printing device such as the energy radiation device, the Z-axis drive mechanism, and the filtration system. The device further includes at least one of the following: a prompting device, a human-machine interaction device, etc. The drive reservation interface unit determines its interface type according to the connected device, and it includes, but is not limited to: a universal serial interface, a video interface, an industrial control interface, etc. For example, the drive reservation interface includes: a USB interface, an HDMI interface, and an RS232 interface. Among them, there are multiple USB interfaces and RS232 interfaces. The USB interface can be connected to a human-machine interaction device, etc., and the RS232 interface is connected to the energy radiation device, the Z-axis drive mechanism, and the filtration system, for controlling the energy radiation device, the Z-axis drive mechanism, and the filtration system, etc.

[0121] In an exemplary embodiment, the 3D printing device includes a printing state and a filtering state. The control device may include control programs for the energy radiation device, the Z-axis drive mechanism, and the filtering system to start the corresponding devices or mechanisms to perform corresponding operations according to the control programs. For example, in the printing state, the control device drives the Z-axis drive mechanism to lower the component platform into the resin tank, and the control device sends a printing instruction to the energy radiation device, and radiates energy to the bottom surface of the resin tank in a projection manner or a dot matrix scanning manner through the control program to cure the liquid photocuring material on the preset curing surface in the resin tank. The lower surface of the component platform adheres to the pattern curing layer obtained after energy radiation, and a 3D component is formed by accumulating through the pattern curing layer. Again, for example, in the filtering state, when the filtered photocuring material in the resin tank is required, the control device drives the Z-axis drive mechanism to raise the component platform and sends a filtering instruction to the suction filtering device. The suction device in the filtering system is placed into the resin tank to suck the photocuring material. When the amount of photocuring material in the resin tank is less than the first threshold, the control device drives the scraper device to be placed into the resin tank and scrape the photocuring material in the direction of the suction device to facilitate the suction device to suck the photocuring material in the resin tank clean. The photocuring material sucked by the suction device is filtered by the filtering device and then stored in the liquid storage device. After the suction device and the scraper device complete their operations, they are respectively controlled to move away from the resin tank. When it is necessary to add photocuring material to the resin tank, the control device drives the conveying device to extract the photocuring material from the liquid storage device into the resin tank. When the amount of photocuring material in the resin tank is greater than the second threshold, the conveying device is controlled to stop adding photocuring material to the resin tank and move away from the resin tank. In one implementation manner, the control device may also be configured to drive the filtering device to work after one or more printed components are printed to filter the photocuring material in the resin tank, so as to avoid damage to the release film caused by residues in the photocuring material.

[0122] In summary, the 3D printing device of the present application can filter the photocuring material in the resin tank, thereby improving the printing accuracy while avoiding damage to the release film caused by residues in the photocuring material. Moreover, during the process of the filtering system sucking the photocuring material, the scraper device cooperates to scrape the photocuring material remaining in the resin tank to the edge of the suction cup of the suction device to ensure that the photocuring material in the resin tank can be completely sucked clean. On the other hand, each device of the filtering system in the 3D printing device does not affect the normal operation of the printing system of the 3D printing device in the non-working state, does not interfere with the component manufacturing process, and does not affect the replacement of the resin tank.

[0123] The above embodiments are only illustrative of the principles and effects of the present application and are not intended to limit the present application. Any person familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present application. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the technical field without departing from the spirit and technical idea disclosed by the present application should still be covered by the claims of the present application.

Claims

1. A filtration system for a 3D printing device, the 3D printing device being a bottom exposure or bottom projection 3D printing device, the 3D printing device including a resin tank, characterized in that, the filtration system includes: A suction device, disposed on one side of the resin tank, configured to be placed into or away from the resin tank under a driving force, for sucking the photocuring material in the resin tank; A liquid storage device, communicating with the suction device, for storing the photocuring material sucked from the resin tank; A filtration device, disposed between the suction device and the liquid storage device and / or in the liquid storage device, for filtering residues in the photocuring material output from the resin tank; A scraper device, adjacent to the resin tank, for scraping the photocuring material at the bottom of the resin tank in a moving state to facilitate the suction device to suck the photocuring material in the resin tank; wherein, the scraper device includes a scraper and a scraper control mechanism adjacent to one side of the resin tank; the scraper includes a scraper body and a connecting arm for connecting the scraper body to the scraper control mechanism; the scraper control mechanism is used to drive the scraper to be placed into or away from the resin tank in a flipping state, and to drive the scraper to move from one side of the resin tank to the opposite side in a scraping state to scrape the photocuring material at the bottom of the resin tank; the scraper control mechanism includes: a scraper control motor, for outputting a driving force in a working state; a lead screw, adjacent to one side of the resin tank, with the proximal end connected to the power output shaft of the scraper control motor and the distal end pivotally connected to a support; a displacement block, helically engaged with the lead screw and connected to the connecting arm of the scraper, for displacing between the proximal end and the distal end of the lead screw when the lead screw rotates; a guide rail, disposed on the lead screw, including a flipping section and a linear displacement section communicating with the flipping section, the flipping section including a limiting portion for restricting the excessive rotation of the connecting arm along with the displacement block.

2. The filtration system for a 3D printing device according to claim 1, characterized in that, the width of the scraper body is equal to the width of the resin tank.

3. The filtration system for a 3D printing device according to claim 1, characterized in that, the suction device includes: A suction mechanism, for sucking the photocuring material in the resin tank; A first delivery pump, for providing suction power; A first pipeline, communicating the suction mechanism, the first delivery pump, and the liquid storage device; the filtration device is disposed in the first pipeline.

4. The filtration system for a 3D printing device according to claim 3, characterized in that, the suction mechanism includes: A suction cup, communicating with the first pipeline, for sucking the photocuring material scraped by the scraper device by the suction power provided by the first delivery pump when placed into the resin tank; A suction cup swing arm, disposed on one side of the resin tank to fix the suction cup, for driving the suction cup to be placed into or away from the resin tank; A suction cup control motor, for providing a driving force for the suction cup swing arm in a working state.

5. The filtration system for a 3D printing device according to claim 4, characterized in that, The suction width of the suction cup is equal to the width of the resin tank.

6. The filtration system of the 3D printing device according to claim 1, wherein, it further includes a conveying device communicating with the liquid storage device for conveying the photocuring material in the liquid storage device into the resin tank, and a filtering device is arranged between the liquid storage device and the conveying device.

7. The filtration system of the 3D printing device according to claim 6, wherein, the conveying device includes: a conveying mechanism for conveying the photocuring material stored in the liquid storage device into the resin tank; a second conveying pump for providing suction power; a second pipeline communicating with the second conveying pump and the liquid storage device; and the filtering device is arranged in the second pipeline.

8. The filtration system of the 3D printing device according to claim 7, wherein, the conveying mechanism includes: a conveying port communicating with the second pipeline for conveying the photocuring material stored in the liquid storage device into the resin tank; a conveying swing arm arranged on one side of the resin tank to fix the conveying port and used for driving the conveying port to be inserted into or away from the resin tank; a conveying control motor for providing driving force for the conveying swing arm in the working state.

9. The filtration system of the 3D printing device according to claim 1, wherein, the filtration system further includes a liquid level sensor arranged in or adjacent to the resin tank for detecting the remaining amount of the photocuring material in the resin tank.

10. The filtration system of the 3D printing device according to claim 1, wherein, the 3D printing device is a 3D printing device including a DLP system or a 3D printing device including an SLA system.

11. A filtration method applied to a 3D printing device having a resin tank, and the 3D printing device is a 3D printing device with bottom exposure or bottom projection, wherein, the filtration method includes the following steps: Let a suction device suck the photocuring material in the resin tank into a liquid storage device, and a filtering device is arranged between the suction device and the liquid storage device and / or in the liquid storage device, and the filtering device filters the residues in the sucked photocuring material; wherein, the suction device is configured to be inserted into or away from the resin tank under the driving force. When it is detected that the liquid level of the photocuring material in the resin tank is lower than a threshold value, a scraping device is made to scrape the photocuring material at the bottom of the resin tank to facilitate the suction device to continue sucking the photocuring material in the resin tank; wherein, the scraping device includes a scraper and a scraper control mechanism adjacent to one side of the resin tank; the scraper includes a scraper body and a connecting arm for connecting the scraper body to the scraper control mechanism; the scraper control mechanism is used to drive the scraper to be placed into or away from the resin tank in a flipped state, and to drive the scraper to move from one side of the resin tank to the opposite side in a scraping state to scrape the photocuring material at the bottom of the resin tank; the scraper control mechanism includes: a scraper control motor for outputting a driving force in a working state; a lead screw adjacent to one side of the resin tank, with its proximal end connected to the power output shaft of the scraper control motor and its distal end pivotally connected to a support; a displacement block spirally wound on the lead screw and connected to the connecting arm of the scraper for displacing between the proximal end and the distal end of the lead screw when the lead screw rotates; a guide rail provided on the lead screw, including a flipping section and a linear displacement section communicating with the flipping section, and the flipping section includes a limiting portion for restricting the excessive rotation of the connecting arm along with the displacement block; the step of making a scraping device scrape the photocuring material at the bottom of the resin tank when it is detected that the liquid level of the photocuring material in the resin tank is lower than a threshold value includes: when it is detected that the liquid level of the photocuring material in the resin tank is lower than a first threshold value, making a scraper control mechanism flip the scraping device to place its scraper into the resin tank and making the lower edge of the scraper contact the bottom of the resin tank; making the scraper control mechanism drive the scraper to move from one side of the resin tank to the side of the suction device to scrape the photocuring material at the bottom of the resin tank; Making the suction device suck the photocuring material scraped by the scraping device.

12. According to the filtering method described in claim 11, characterized in that it further includes the step of adding photocuring material into the resin tank: when receiving an instruction to add photocuring material, making a conveying device convey the photocuring material in the liquid storage device to the resin tank, and a filtering device is provided between the liquid storage device and the conveying device; when it is detected that the liquid level of the photocuring material in the resin tank is higher than a second threshold value, making the conveying device stop working.

13. A 3D printing device, characterized in that it includes: a frame; a resin tank for containing the photocuring material to be cured; an energy radiation device provided at a preset position on one side of the bottom of the resin tank, configured to radiate energy in a projection manner or a dot matrix scanning manner to the bottom surface of the resin tank when receiving a printing instruction, so as to cure the liquid photocuring material on a preset curing surface in the resin tank; a component platform located in the resin tank in a printing state, for attaching a pattern curing layer obtained after energy radiation, so as to form a 3D component through the accumulation of the pattern curing layer; A Z-axis driving mechanism, connected to the component platform, is configured to adjust the distance between the component platform and the bottom surface of the resin tank according to a printing instruction to fill a photocurable material to be cured; The filtration system according to any one of claims 1 to 10, adjacent to the resin tank, for filtering residues in the photocurable material in the resin tank; A control device, electrically connected to the energy radiation device, the Z-axis driving mechanism, and the filtration system, for controlling the working states of the energy radiation device, the Z-axis driving mechanism, and the filtration system.

14. The 3D printing device according to claim 13, wherein, the 3D printing device is a 3D printing device including a DLP system or a 3D printing device including an SLA system.

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