Photo-curing three-dimensional printing system and centralized liquid supplementing system thereof

Abstract

The invention discloses a centralized liquid replenishing system for liquid replenishing of photocuring three-dimensional printing equipment, which comprises a total liquid replenishing tank, a liquid outlet end of the total liquid replenishing tank is respectively communicated with resin tanks of N photocuring three-dimensional printing equipment through corresponding first liquid replenishing channels, and each first liquid replenishing channel is provided with a first control valve; the N resin consumption detection devices are respectively used for detecting the resin consumption in the resin tanks; the control module is used for obtaining a liquid supplementing instruction and acquisition signals of the resin consumption detection devices and sending a driving instruction to the first control valves to control liquid supplementing, and the number of the first control valves in the open state at the same time enables the flow speed of resin flowing into the resin tank through the first liquid supplementing channels to at least meet the expected flow speed; according to the photocuring three-dimensional printing equipment, centralized liquid supplementing control is achieved on the photocuring three-dimensional printing equipment, the cost and the size of the photocuring three-dimensional printing equipment are reduced, the liquid supplementing efficiency is improved, and correspondingly, the invention further discloses a photocuring three-dimensional printing system.

Description

Technical Field

[0001] The present invention relates to the technical field of 3D printing, and in particular to a centralized fluid replenishment system for fluid replenishment of a light-curing 3D printing device and a light-curing 3D printing system. Background Art

[0002] Photosensitive resin is generally in liquid form. It immediately causes a polymerization reaction under the irradiation of ultraviolet light of a certain wavelength and completes curing. Photocuring molding mainly uses photosensitive resin as raw material. It takes advantage of the property that liquid photosensitive resin will quickly cure under the irradiation of ultraviolet laser beam. By focusing ultraviolet light of specific wavelength and intensity onto the surface of the photocurable material, it solidifies from point to line and from line to surface in sequence, thereby completing the drawing of a layer cross-section. In this way, layer by layer, a three-dimensional solid printing is completed.

[0003] like Figure 1 The figure shows a structural diagram of a light-curing 3D printing device in the prior art, which includes a body 1, in which a controller 11, a transmission system 12, a printing platform 13, a material trough 14 and a projection device 15 are arranged. The material trough 14 is arranged at the bottom of the body 1, the transmission system 12 is arranged on one side of the material trough 14, the printing platform 13 is arranged directly above the material trough 14 and is connected to the transmission system 12, the controller 11 is arranged on one side of the transmission system 12 and is respectively connected to the transmission system 12 and the projection device 15, the projection device 15 is arranged on the upper part of the body 1, and the projection device 15 includes a projection head 151. The projection head 151 is arranged at the lower end of the projection device 15 and corresponds to the material trough 14. The working process of the 3D printing molding machine is as follows: 1) an external PC performs layered processing on the 3D model to be molded in the device to obtain a series of 2D images of the 3D model, and at the same time imports the 2D images into the controller 11; 2) the controller 11 controls the transmission system 12 to drive the liftable printing platform 13 to move up and down in the material trough 14, and the projection device 15 uses the projection head arranged at its lower end to solidify the light and shadow projected by the 2D image on the printing platform 13 to form a layer of resin of a certain precise thickness; 3) step 2) is repeated until the 3D workpiece 300 to be molded is completely formed.

[0004] In the aforementioned patent, the resin in the tank 14 solidifies from a liquid state to a solid state during the printing process, and is gradually consumed. During the printing process, if the resin in the tank fails to reach the set working plane, the user needs to replenish the tank to bring the resin back to the set working plane before printing can continue. Therefore, adding resin is an indispensable step in the light-curing printing process.

[0005] To achieve fluid replenishment, the 3D printing machine of the aforementioned patent further includes a fluid replenishment tank 16, which is connected to the material tank 14 for replenishing liquid therein. This method of fluid replenishment requires that each light-curing 3D printing device be equipped with a fluid replenishment tank 16. This increases the cost of the light-curing 3D printing device, especially for a light-curing 3D printing system with multiple light-curing 3D printing devices. Each light-curing 3D printing device requires a separate fluid replenishment system, which significantly increases the cost. In addition, each light-curing 3D printing device requires space for the fluid replenishment system, which increases the size of the light-curing 3D printing device and, therefore, the space required for each light-curing 3D printing device. Furthermore, each separately configured fluid replenishment system also requires manual replenishment of fluid to achieve continuous printing, which still incurs high labor costs. Summary of the Invention

[0006] The main purpose of the present invention is to propose a light-curing 3D printing system and its centralized fluid replenishment system, aiming to achieve efficient centralized fluid replenishment for each printing device in the light-curing 3D printing system, reduce the cost and volume of the light-curing 3D printing equipment, and improve the overall printing efficiency of the system.

[0007] To achieve the above objectives, an embodiment of the present invention provides a centralized fluid replenishment system for fluid replenishment of a light-curing 3D printing device, comprising:

[0008] A main liquid replenishment tank for containing photosensitive resin material, having at least one liquid outlet, the liquid outlet being connected to the liquid inlet of each resin tank of N light-curing 3D printing devices through corresponding first liquid replenishment channels, each of the first liquid replenishment channels being provided with a first control valve, where N is greater than or equal to 5;

[0009] N resin consumption detection devices, each provided corresponding to each resin tank, for detecting the resin consumption in the corresponding resin tank;

[0010] A control module is configured to obtain a refill instruction from each light-curing 3D printing device and a collection signal from each resin consumption detection device, and send a corresponding drive instruction to the corresponding first control valve to control the refill;

[0011] The number of first control valves that are simultaneously in the open state should be such that the flow rate of the resin flowing into the corresponding resin tank through each first liquid replenishing channel at least meets the designed expected flow rate.

[0012] Optionally, the expected flow rate is the liquid outlet flow rate or an approximate value thereof obtained based on detection of the liquid outlet end of the total liquid infusion tank, or the expected flow rate is the expected liquid infusion flow rate designed based on a liquid infusion strategy.

[0013] Optionally, the maximum number M of the first control valves that are simultaneously in the open state is determined based on the liquid outflow rate of the liquid outlet end of the total liquid replenishment tank and the liquid replenishment flow rate flowing into the liquid inlet of each resin tank at the expected flow rate.

[0014] Optionally, the rehydration instruction is generated based on a printing cycle end signal of each light-curing 3D printing device at the end of the mth printing cycle, where m is an integer greater than 1.

[0015] Optionally, the rehydration instructions of at most M light-curing three-dimensional printing devices are generated based on the m-th printing cycle end signal with the same m value.

[0016] Optionally, m is less than or equal to 5.

[0017] Optionally, when (N / m) is greater than the maximum number of first control valves that are in the open state at the same time, which is determined based on the resin flow rate at the liquid outlet of the total liquid replenishment tank and the liquid replenishment flow rate flowing into the liquid inlet of each resin tank at the expected flow rate, the expected flow rate is adjusted so that the maximum number M of the first control valves that are in the open state at the same time satisfies the configuration of generating liquid replenishment instructions for all light-curing three-dimensional printing devices based on m different rounds of printing cycle end signals, or the liquid replenishment instructions set for M*(m-1) light-curing three-dimensional printing devices are generated based on the printing cycle end signal of the (m-1)th round among the m rounds, and the liquid replenishment instructions set for (NM*(m-1)) light-curing three-dimensional printing devices are generated based on the printing cycle end signals of the remaining rounds.

[0018] Optionally, the rehydration instruction is generated based on the collection signal of each resin consumption detection device. When the control module determines that the liquid level in the current resin tank is close to or reaches the set minimum working liquid level based on the collection signal of the resin consumption detection device, a rehydration instruction is generated to replenish the current resin tank.

[0019] Optionally, the lowest working liquid levels of at most M light-curing 3D printing devices are the same or close to each other.

[0020] Optionally, when the control device receives the fluid replenishment instruction, it controls the first control valve corresponding to the current fluid replenishment instruction to open or add it to a queue to be opened based on the number of first control valves currently in the fluid replenishment state and the maximum value M.

[0021] Optionally, the control device generates a driving instruction for closing the corresponding first control valve based on the collected signal of the resin consumption detection device.

[0022] Optionally, if the number t of the first control valves currently in the fluid replenishing state is less than M, the control device drives (Mt) first control valves to open according to the order of the first control valves entering the queue to be opened.

[0023] Optionally, when the control module receives the fluid replenishment instruction, it determines whether the number of the first control valves currently in the fluid replenishment state has reached the maximum value M. If it has not reached the maximum value M, it directly drives the first control valve corresponding to the fluid replenishment instruction to open; if it has reached M, it further determines whether the resin tank of the light-curing 3D printing device corresponding to the current fluid replenishment instruction has reached the minimum working liquid level. If it has not reached the minimum working liquid level, it sends a fluid replenishment rejection instruction to the light-curing 3D printing device, instructing the light-curing 3D printing device to continue the next round of printing; if it has reached the minimum working liquid level, it adds the first control valve corresponding to the current fluid replenishment instruction to the queue to be opened.

[0024] Optionally, if the number of first control valves currently in the rehydration state is less than M and the difference from the maximum value M is less than the number of rehydration instructions currently received, the priority of each rehydration instruction is determined based on the actual number of rounds of printing cycle end signals corresponding to each rehydration instruction, and the first control valve corresponding to the corresponding rehydration instruction is driven to open based on the priority of each rehydration instruction. For other rehydration instructions that fail to drive the first control valve to open, a rehydration rejection instruction is sent to the corresponding light-curing three-dimensional printing device or the first control valve is added to the queue to be opened, depending on whether the resin tank of the corresponding light-curing three-dimensional printing device has reached the lowest working liquid level.

[0025] Optionally, when the expected liquid replenishment flow rate is the ideal flow rate of the resin tank liquid inlet of each light-curing 3D printing device, the number of the first control valves that are simultaneously in the open state is the maximum value M.

[0026] Optionally, when the control module receives a refill instruction corresponding to each light-curing 3D printing device, it adds the first control valve corresponding to each refill instruction to a queue to be opened based on the order of receipt, and opens M first control valves in sequence according to the first-in-first-out principle to simultaneously refill the resin tanks of the M corresponding light-curing 3D printing devices.

[0027] Optionally, the rehydration instruction is generated based on a printing cycle end signal of each light-curing 3D printing device at the end of the mth printing cycle, where m is an integer greater than or equal to 1.

[0028] Optionally, the liquid replenishment instruction for each M light-curing 3D printing devices among the N light-curing 3D printing devices is generated based on an m-th printing cycle end signal having the same value m.

[0029] Optionally, the rehydration instruction is generated based on the collection signal of each resin consumption detection device. When the control module determines that the liquid level in the current resin tank is close to or lower than the set minimum working liquid level based on the collection signal of the resin consumption detection device, a rehydration instruction is generated to replenish the current resin tank.

[0030] Optionally, the lowest working liquid levels of the resin tanks of each M light-curing 3D printing devices among the N light-curing 3D printing devices are the same or close to each other.

[0031] Optionally, when the number of the first control valves in the queue to be opened is less than M within a preset time, the control module directly drives to open all the first control valves in the queue to be opened.

[0032] Optionally, the centralized fluid replenishment system is further provided with a resin quantity detection device for monitoring the resin quantity in the total fluid replenishment tank. The control module determines whether it is necessary to add fluid to the total fluid replenishment tank based on the signal detected by the resin quantity detection device. When it is determined that fluid addition is required, fluid is added to the total fluid replenishment tank through the liquid inlet end of the total fluid replenishment tank.

[0033] Optionally, a stirring mechanism is provided in the main liquid replenishing tank, and the stirring mechanism includes at least a driving device, a stirring shaft and a stirring rod. The driving device is connected to the stirring shaft located in the main liquid replenishing tank, and the stirring shaft sleeve is provided with several fixing frames, and the stirring rod is fixed on the outer wall of the fixing frame.

[0034] To achieve the above-mentioned object, the present invention further provides a light-curing three-dimensional printing system, comprising:

[0035] N sets of photocuring 3D printing devices, each of which includes a printing device, an image exposure device, and an automatic workpiece collection device, wherein the printing device includes: a resin tank for accommodating photosensitive resin; a lifting platform including a workpiece carrier and a lifting mechanism, wherein the workpiece carrier is used to carry a printed workpiece, and the lifting mechanism drives the workpiece carrier to move up and down relative to the resin tank; an image exposure system located above the resin tank for projecting a preset light beam onto the workpiece carrier to form the printed workpiece on the surface of the workpiece carrier; and an automatic workpiece collection device for automatically collecting the printed workpiece from the workpiece carrier after the printed workpiece is formed on the workpiece carrier;

[0036] As in the aforementioned centralized fluid replenishment system, the main fluid replenishment tank of the centralized fluid replenishment system is connected to each resin tank of the N light-curing 3D printing devices through the first fluid replenishment channel.

[0037] Compared with the prior art, the light-curing 3D printing system and the centralized fluid replenishment system of the present invention have the following beneficial effects:

[0038] 1. The present invention utilizes a central fluid replenishment tank to replenish the resin tanks of N light-curing 3D printing devices through N first fluid replenishment channels. By controlling the number of first control valves that are simultaneously open, the flow rate of resin flowing into the corresponding resin tank through each first fluid replenishment channel reaches at least the designed desired flow rate. This achieves efficient centralized fluid replenishment for each printing device in the light-curing 3D printing system, reduces the cost and size of the light-curing 3D printing devices, and improves the overall printing efficiency of the light-curing printing system.

[0039] 2. The present invention controls the number of first control valves that are simultaneously open so that the flow rate of resin flowing into the corresponding resin tank through each first refill channel approaches the ideal flow rate of the resin tank inlet of each light-curing 3D printing device. This minimizes the waiting time for the liquid level to stabilize while ensuring the refill speed, thereby improving the efficiency of the light-curing printing system.

[0040] 3. The present invention drives the first control valve corresponding to the current refill instruction to open according to the maximum value of the first control valve that is simultaneously in the open state when receiving a refill instruction. For a refill instruction that cannot be immediately driven to open, the present invention determines whether to send a refill rejection instruction or add it to the queue to be opened based on the lowest working liquid level of the corresponding resin tank. This allows the light-curing three-dimensional printing device that has not reached the lowest working liquid level to continue printing and avoid entering the queue to be opened and waiting.

[0041] 4. The present application improves the refill efficiency by controlling the refill instructions of at most M light-curing three-dimensional printing devices to be generated based on the m-th round printing cycle end signal with the same m value, or when the refill instruction is generated by the collection signal of the resin consumption detection device, the lowest working liquid levels of at most M light-curing three-dimensional printing devices are the same or close, thereby minimizing the waiting time caused by the control device adding the corresponding first control valve to the queue to be opened after receiving the refill instruction, thereby minimizing the waiting time caused by the control device adding the corresponding first control valve to the queue to be opened.

[0042] 5. This application provides a first stirring mechanism in the main liquid replenishing tank to stir the photosensitive resin in the main liquid replenishing tank, thereby avoiding precipitation of the photosensitive resin and improving the liquid replenishing efficiency and printing effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] One or more embodiments are exemplarily described by the figures in the corresponding drawings, and these exemplified descriptions do not constitute limitations on the embodiments.

[0044] Figure 1 A schematic diagram of the structure of a conventional light-curing 3D printing device;

[0045] Figure 2 This is a structural schematic diagram of a centralized fluid replenishment system for fluid replenishment of a photo-curing 3D printing device according to another embodiment of the present application;

[0046] Figure 3 This is a schematic structural diagram of a centralized fluid replenishment system for fluid replenishment of a light-curing 3D printing device according to another embodiment of the present application;

[0047] Figure 4 This is a structural diagram of a photo-curing 3D printing device in a photo-curing 3D printing system according to another embodiment of the present application. DETAILED DESCRIPTION

[0048] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0049] 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 that mechanical, structural, 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 limited only by the claims of the published patents. The terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the present application. Spatially related terms, such as "upper", "lower", "left", "right", "below", "below", "lower", "above", "upper", etc., may be used in the text to illustrate the relationship between one element or feature shown in the figure and another element or feature.

[0050] Although in some instances the terms first, second, etc. are used to describe various elements or parameters in this article, these elements or parameters should not be limited by these terms. These terms are only used to distinguish one element or parameter from another element or parameter. For example, the first mobile assembly can be referred to as the second mobile assembly, and similarly, the second mobile assembly can be referred to as the first mobile assembly, without departing from the scope of the various described embodiments. The first mobile assembly and the second mobile assembly are both describing a mobile assembly, but unless the context clearly indicates otherwise, they are not the same mobile assembly. Similar situations also include the first guide rail and the second guide rail, or the first drive component and the second drive component.

[0051] Furthermore, as used herein, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context indicates otherwise. It should be further understood that the terms "comprise", "include" indicate the presence of the described features, steps, operations, elements, components, items, kinds, and / or groups, but do not exclude the presence, occurrence, or addition of one or more other features, steps, operations, elements, components, items, kinds, and / or groups. The terms "or" and "and / or" used herein are interpreted as inclusive, or mean 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". Exceptions to this definition occur only when the combination of elements, functions, steps, or operations is inherently mutually exclusive in some way.

[0052] As can be seen from the background technology, the current liquid replenishment method of light-curing 3D printing equipment generally requires that each light-curing 3D printing device be equipped with a liquid replenishment system. Firstly, this increases the cost of the light-curing 3D printing device. In particular, for a light-curing 3D printing system with a large number of light-curing 3D printing devices, each light-curing 3D printing device needs to be equipped with a separate liquid replenishment system, which adds a lot of cost. In addition, each light-curing 3D printing device needs to be equipped with a storage space for the liquid replenishment system, which increases the volume of the light-curing 3D printing device and thus increases the space occupied by each light-curing 3D printing device. Secondly, each separately configured liquid replenishment system also needs to be further replenished with liquid manually to achieve continuous printing, which still requires high labor costs.

[0053] The following will be used in conjunction with specific embodiments to describe the implementation details of the light-curing 3D printing system and its centralized fluid replenishment system described in this application. The following content is only provided for ease of understanding and is not required for the implementation of this solution.

[0054] like Figure 2 As shown, one embodiment of the present application proposes a centralized fluid replenishment system for replenishing fluid for each light-curing 3D printing device in a light-curing 3D printing system, including: a main fluid replenishment tank 101 for containing photosensitive resin material, which has at least one liquid outlet 101e, and the liquid outlet 101e is connected to the liquid inlets of the resin tanks 201 of the N light-curing 3D printing devices through N first fluid replenishment channels 102, respectively. At least one first control valve 103 is provided on each of the first fluid replenishment channels 102 to replenish the resin in the main fluid replenishment tank 101 into the corresponding resin tank 201 through the corresponding first fluid replenishment channel 102 according to the opening and closing of each first control valve 103. In this embodiment, the number N of light-curing 3D printing devices in the light-curing 3D printing system is greater than or equal to 5, and preferably, N is greater than or equal to 10.

[0055] N resin consumption detection devices 104 are respectively provided corresponding to each resin tank 201 to detect the resin consumption in the corresponding resin tank 201. Each resin consumption detection device 104 can be used to detect the resin consumption in the resin tank 201 of the corresponding light-curing three-dimensional printing device in real time during the light-curing printing process. The resin consumption detection device 104 can be a liquid level sensor provided above the resin tank 201. The liquid level sensor can be used to collect the liquid level height information in the resin tank 201 in real time and transmit the liquid level height information to the control module 105. The control module 105 can obtain the resin consumption of the current printing task of the current resin tank 201 based on the liquid level height difference before and after printing and the cross-sectional area of ​​the resin tank 201. Consumption. In this embodiment, the liquid level sensor can be one or more of an ultrasonic liquid level sensor, an optical liquid level sensor, and a capacitive liquid level sensor; of course, the resin consumption detection device 104 can also be a weighing sensor arranged in the corresponding resin tank 201. The weighing sensor can be used to collect the resin weight signal in the resin tank 201 in real time and transmit it to the control module 105. The control module 105 can obtain the resin consumption of the current printing task in the current resin tank 201 according to the resin weight signals before and after printing. Among them, the weighing sensor can be one or more of a photoelectric weighing sensor, a hydraulic weighing sensor, a capacitive weighing sensor, a vibration weighing sensor, a resistance strain weighing sensor, etc.

[0056] The control module 105 is used to obtain the refill instructions of each light-curing 3D printing device and the collected signals of the corresponding resin consumption detection device 104, and send corresponding drive instructions to the corresponding first control valve 103 based on the refill instructions and the collected signals of the corresponding resin consumption detection device 10 to control the refill. In particular, the control module 105 controls the number of first control valves 103 that are in the open state at the same time so that the resin flow rate flowing into the corresponding resin tank 201 through each first refill channel reaches at least the pre-designed expected flow rate.

[0057] In this embodiment, the control module 105 is an electronic device including a processor. For example, the control module 105 may be a computer device, an embedded device, or an integrated circuit integrated with a CPU. For example, the control module 105 includes a processing unit, a storage unit, and multiple interface units. The processing unit of the control module 105 is connected to each first resin consumption detection device 104 via the interface unit to obtain the acquisition signal of each resin consumption detection device 104 via the interface unit. The control module 105 also controls each first control valve 103 via the interface unit. The processing unit includes at least one of a CPU or a chip integrated with a CPU, a field programmable logic device (FPGA), and a multi-core processor. The processing unit also includes memory, registers, and other storage devices for temporarily storing data.

[0058] During the printing process, each photocuring 3D printing device may require refilling when the resin liquid in its resin tank 201 is too low. The refilling instruction is a trigger instruction for each photocuring 3D printing device to trigger the control module 105 to refill the resin. In some embodiments, the refilling instruction may be generated by each photocuring 3D printing device based on a print cycle end signal generated upon completion of each print cycle. Each print cycle refers to the cycle in which the photocuring 3D printing device 201 completes a print cycle of a workpiece, generally including the layout, printing, and retrieval processes of the photocuring 3D printing device. The layout process is to layout the 3D model to be printed, the printing process is to print the layouted 3D model, and the retrieval process is to retrieve the printed workpiece after printing. When the retrieval process is completed, a print cycle is completed. Generally, when a print cycle is completed, the control module 105 receives the print cycle end signal to proceed to the next print cycle. In some embodiments, the rehydration instruction can be generated based on the print cycle end signal at the end of the mth round of printing cycle of each light-curing three-dimensional printing device, where m is greater than or equal to 1 and less than or equal to 5. For a light-curing three-dimensional printing device, after completing each mth round of printing, the control module 105 determines that a rehydration instruction has been generated when receiving the mth round of printing cycle end signal, and the light-curing three-dimensional printing device needs to be rehydrating. That is to say, the rehydration instructions of different light-curing three-dimensional printing devices can be generated based on print cycle end signals with different m values. For example, the rehydration instruction of device A can be generated based on the print cycle end signal of the first round, and the rehydration instruction of device B can be generated based on the print cycle end signal of the second or third round. For each light-curing 3D printing device, in order to enable normal printing, the resin working liquid level in the resin tank 201 generally cannot be too low. When it is lower than the minimum working liquid level required for normal printing, the light-curing 3D printing device cannot print normally. Of course, the resin working liquid level cannot be too high either. When it is higher than the maximum working liquid level, the resin is likely to overflow. Therefore, the amount of resin between the maximum working liquid level and the minimum working liquid level needs to be sufficient for the light-curing 3D printing device to perform m rounds of printing. In some embodiments, to avoid the setting of the minimum working liquid level being too low and affecting printing, m is selected to be less than or equal to 5, thereby ensuring that the minimum working liquid level of the resin tank 201 does not need to be set too low. In other words, the refill instruction of the light-curing 3D printing device in the system is generated based on the end signal of the fifth printing cycle at most, but the present invention is not limited to this.

[0059] In other embodiments, the refill instruction may also be generated based on the collected signals from each resin consumption detection device 104. For example, when the control module 105 determines, based on the collected signals from the resin consumption detection device 104, that the liquid level in the current resin tank 201 has approached or reached a set minimum working liquid level, a refill instruction is generated to refill the corresponding resin tank 201. Approaching the set minimum working liquid level means that the difference between the current resin tank level and the set minimum working liquid level is insufficient to complete a printing cycle. In this embodiment, the timing of refill instructions for different photocuring 3D printing devices can also be varied. For example, if the minimum working liquid levels of the resin tanks of device A and device B are set differently, the timing of refill instructions generated by device A and device B will also be different. This allows printing requests from the different photocuring 3D printing devices to be staggered, reducing waiting time for refills and ensuring timely refills.

[0060] The stereolithography 3D printing system of the present invention includes N stereolithography 3D printing devices, where N is greater than or equal to 5. However, in some cases, N may be greater than 30 or even more. Generally, the flow rate at the liquid outlet of the total liquid refilling tank 101 is limited. If liquid refilling is required for N stereolithography 3D printing devices simultaneously, this is generally not a problem when N is small. However, when the number N of stereolithography 3D printing devices is large, the resin flow rate flowing into the corresponding stereolithography 3D printing device through each first liquid refilling channel is inevitably small. Furthermore, the high viscosity of the photosensitive resin results in a very slow refilling speed for each stereolithography 3D printing device. During the printing process, each stereolithography 3D printing device needs to maintain a relatively stable working liquid level in its resin tank. Therefore, simultaneous printing cannot be performed during the refilling process. Therefore, when N is large, if the control module 105 controls all first control valves 103 to refill all stereolithography 3D printing devices simultaneously, the refilling speed for all stereolithography 3D printing devices will inevitably be slow, resulting in low printing efficiency for each stereolithography 3D printing device, and thus low printing efficiency for the entire system. Therefore, in this embodiment, the number of first control valves that are simultaneously open should ensure that the flow rate of the resin flowing into the corresponding resin tank through each first refill channel at least meets the designed expected flow rate, thereby ensuring the refill efficiency of each light-curing 3D printing device as much as possible. The expected flow rate is the liquid outlet flow rate obtained based on the detection of the liquid outlet end of the main refill tank, or its approximate value, or the expected flow rate can also be the expected refill flow rate designed based on the refill strategy. In some preferred embodiments, during the refill process, the control module 105 controls the number of first control valves 103, for example, controlling the number of first control valves 103 that can be simultaneously open, so that the flow rate of the resin flowing into the corresponding resin tank 201 through each first refill channel is at least not less than the liquid outlet flow rate flowing out of the liquid outlet end of the main refill tank 101, or its approximate value. Specifically, in order to ensure that the flow rate of the resin flowing into the corresponding resin tank 201 through each first liquid replenishing channel is at least not less than the liquid flow rate flowing out of the liquid outlet end of the main liquid replenishing tank 101, the maximum number M of the first control valves 103 that can be in the open state at the same time can be determined based on the cross-sectional area of ​​the liquid outlet end of the main liquid replenishing tank 101 and the cross-sectional area of ​​the liquid inlet of the corresponding resin tank 201. In this embodiment, it is assumed that the cross-sectional area of ​​the liquid outlet end of the main liquid replenishing tank 101 is S 总 , the cross-sectional area of ​​the liquid inlet of each resin tank 201 is S0, and the maximum number M of the first control valves 103 that can be in the open state at the same time can be obtained by the following formula:

[0061]

[0062] Of course, the phrase "the flow rate of the resin flowing into the corresponding resin tank 201 through each first refill channel is at least not less than the flow rate of the liquid flowing out of the liquid outlet of the main refill tank 101" in this embodiment can also be an approximate value of the flow rate of the liquid flowing out of the liquid outlet of the main refill tank 101, and does not necessarily have to be the value obtained by detecting the flow rate of the liquid flowing out of the liquid outlet of the main refill tank 101 using a flow monitoring device. Therefore, the maximum number M of first control valves 103 that can be open simultaneously can also be calculated as follows:

[0063]

[0064] It can be seen that this embodiment can determine the maximum number M of first control valves that can be in the open state at the same time based on the cross-sectional area of ​​the liquid outlet end of the total liquid replenishing tank and the cross-sectional area of ​​the liquid inlet of the corresponding resin tank, so that the liquid replenishing flow rate of each resin tank during liquid replenishment is not less than the liquid outlet flow rate of the liquid outlet end of the total liquid replenishing tank, thereby ensuring the liquid replenishing speed of at least M light-curing three-dimensional printing devices so that subsequent printing can be carried out as soon as possible, thereby improving the overall printing efficiency of the light-curing three-dimensional printing system of the present invention.

[0065] Of course, designers can also design their own rehydration strategies as needed, so that the flow rate of the resin flowing into the corresponding resin tank 201 through each first rehydration channel is not less than the expected rehydration flow rate designed based on the rehydration strategy. In some embodiments, the expected rehydration flow rate can be the minimum rehydration flow rate designed based on the rehydration strategy. In this regard, the maximum value M of the number of first control valves that are simultaneously in the open state can be obtained based on the resin flow rate flowing out of the liquid outlet of the total rehydration tank 101 and the rehydration flow rate flowing into the resin tank inlet of each light-curing three-dimensional printing device at the minimum rehydration flow rate. The flow rate refers to the amount of fluid flowing through the effective cross-section of the closed pipe per unit time, that is, V=Sv, where V represents the flow rate, S represents the effective cross-section of the closed pipe, and v represents the flow rate. Specifically, assuming that the cross-sectional area of ​​the liquid outlet of the total rehydration tank 101 is S 总 The liquid flow rate at the outlet of the total liquid replenishment tank 101 is v 总 The size of the liquid inlet of the resin tank of each light-curing 3D printing device is the same, and the cross-sectional area is S0. The minimum rehydration flow rate obtained by each light-curing 3D printing device based on the rehydration strategy is ν 低 , the maximum value M of the first control valve 103 in the open state is calculated as follows:

[0066]

[0067] Of course, the minimum infusion flow rate can also be a value within a certain range, and the maximum value M of the first control valve 103 in the open state can also be calculated as follows:

[0068]

[0069] As can be seen, this embodiment can also determine the maximum number M of first control valves that can be simultaneously open by using the resin flow rate at the outlet of the total refill tank and the refill flow rate flowing into the corresponding resin tank's inlet at a minimum refill flow rate determined based on the refill strategy. This ensures that the refill flow rate of each resin tank during refill is no less than the minimum refill flow rate, thereby ensuring the refill speed and printing efficiency of at least M light-curing 3D printing devices. Since the maximum number of first control valves that can be simultaneously open in the present invention is M, upon receiving a refill instruction corresponding to each light-curing 3D printing device, the control module 105 needs to control the first control valve corresponding to the current refill instruction to open or add it to a queue Q to be opened based on the number of first control valves currently in the refill state. Specifically, when the control module 105 receives each refilling instruction, it is necessary to first determine whether the number of the first control valves currently in the refilling state has reached M. If the number of the first control valves currently in the refilling state has not reached M, the first control valve 103 corresponding to the current refilling instruction is directly driven to open to refill the resin tank 201 corresponding to the current refilling instruction; if the number of the first control valves currently in the refilling state is already M, the first control valve 103 corresponding to the refilling instruction is added to the queue Q to be opened, and after the resin tanks corresponding to the first control valves in the open state are refilled, the first control valves 103 in the queue Q to be opened are opened in sequence according to the order of the first control valves 103 entering the queue Q to be opened, so as to control the number of the first control valves 103 in the refilling state to always be at most M, thereby ensuring that the refilling speed of each resin tank in the refilling state is not less than the liquid outlet flow rate of the liquid outlet end of the total refilling tank 101.

[0070] Regarding the closing control of the first control valve 103, the control module 105 can generate a driving instruction for closing the corresponding first control valve 103 based on the collected signals from the resin consumption detection device 104 corresponding to the resin tank of each photo-curing 3D printing device. For example, after sending an opening driving instruction to a first control valve 103, the control module 105 calculates the current refill volume based on the collected signals from the resin consumption detection device 104 corresponding to the photo-curing 3D printing device corresponding to that first control valve 103. When the calculated current refill volume equals the resin consumption of the photo-curing 3D printing device, the control module 105 generates a driving instruction for closing the first control valve 103 to close it. After closing, the control module 105 then drives the subsequent first control valves according to the waiting-to-open queue Q to open.

[0071] Generally speaking, even if the refill efficiency of each light-curing 3D printing device in the refill state is guaranteed by ensuring that the flow rate of the resin flowing into the corresponding resin tank through each first refill channel at least meets the designed expected flow rate, if refill instructions are received from all light-curing 3D printing devices at the same time, in order to ensure that the flow rate of the resin flowing into the corresponding resin tank through each first refill channel at least meets the designed expected flow rate, some refill instructions will inevitably need to wait before entering the refill state. Therefore, it is also necessary to minimize the possible waiting time of each light-curing 3D printing device.

[0072] In some preferred embodiments, one method of reducing the potential waiting time of each stereolithography 3D printing device can be to control the startup time of each stereolithography 3D printing device. Assuming that the refill instructions for each stereolithography 3D printing device are generated based on the mth printing cycle signal with the same value m, or that the refill instructions for each stereolithography 3D printing device are generated based on monitoring the same minimum working liquid level, then at most M stereolithography 3D printing devices are controlled to start at the same time. By staggering the startup times of the stereolithography 3D printing devices, and thus the refill instructions for the stereolithography 3D printing devices, it is possible to minimize the simultaneous receipt of excessive refill instructions, which would increase the waiting time of the stereolithography 3D printing devices. As previously described, the refill instructions for each stereolithography 3D printing device can be generated based on the print cycle end signal at the end of the mth printing cycle of each stereolithography 3D printing device. If the refill instructions of all the light-curing 3D printing devices are generated based on the print cycle end signal of the same round (that is, the m value corresponding to each light-curing 3D printing device is the same), and the printing work is started at the same time, then obviously there will be multiple light-curing 3D printing devices entering the waiting queue Q to wait for refilling, thereby wasting the waiting time of these light-curing 3D printing devices. Therefore, in other embodiments, the refill instructions of at most M light-curing 3D printing devices can be generated based on the print cycle end signal of the same m value. For example, for a light-curing 3D printing system with 30 light-curing 3D printing devices, For example, in a digital printing system, assuming that the number M of first control valves 103 that can be simultaneously open is 10, the refill instructions for up to 10 of the stereolithography 3D printing devices can be generated based on the end-of-print cycle signal of one print cycle. For the remaining 20 stereolithography 3D printing devices (no more than 10) the refill instructions are generated based on the end-of-print cycle signals of two, three, four, or five print cycles. This minimizes the control module 105 from receiving more than M refill instructions simultaneously, thus preventing the stereolithography 3D printing devices from being placed in the waiting queue Q and impacting printing efficiency. Of course, although this embodiment allows some of the stereolithography 3D printing devices in the system to generate refill instructions based on different end-of-print cycle signals, preventing any stereolithography 3D printing devices from initially entering the waiting queue Q, as the printing process progresses, refill instructions generated based on different end-of-print cycle signals may still require refilling simultaneously. In this case, the first control valves of the stereolithography 3D printing devices that received the refill instructions later need to be added to the waiting queue Q to ensure the refill speed of each stereolithography 3D printing device in the refill state.

[0073] It can be seen that this embodiment allows at most M photocuring 3D printing devices to generate refill instructions based on the printing cycle end signal with the same value m, so that the control module will try not to receive more than M refill instructions at the same time, thereby avoiding placing the photocuring 3D printing device in the waiting queue Q and affecting the printing efficiency.

[0074] In some preferred embodiments, in order to avoid setting the minimum working liquid level of the resin tank 201 too low, the print cycle end signal generally used to generate the refill instruction is limited to a print cycle end signal of no more than the fifth round, that is, m is less than When the maximum value M of the number of first control valves that are simultaneously in the open state is determined, it is inevitable that some light-curing 3D printing devices cannot be configured with the corresponding printing cycle end signal to generate the liquid replenishment instruction. Therefore, when this situation occurs, a method is to adjust the expected flow rate so that the maximum value of the number of first control valves that are simultaneously in the open state satisfies the configuration of generating the liquid replenishment instruction based on the m different rounds of printing cycle end signals for all light-curing 3D printing devices, for example, reducing the expected flow rate so that Among them, ν 期 Indicates the expected flow rate; or, another method can also be selected to generate the liquid replenishment instruction set for M*(m-1) light-curing 3D printing devices based on the (m-1) round printing cycle end signal, and generate the liquid replenishment instruction set for (NM*(m-1)) light-curing 3D printing devices based on the remaining rounds of printing cycle end signals. For example, assuming that there are 30 light-curing 3D printing devices in the system, the maximum number of the first control valves that can be in the open state at the same time is 5, when the maximum value of m is 5, then one way is to adjust the expected flow rate so that The maximum value M of the number of first control valves in the open state at the time of the reset can be 6, and the refilling instructions of each of the 6 light-curing 3D printing devices are generated based on the printing cycle end signal of the same wheel; another way is to set every 5 of the M*(m-1)=20 light-curing 3D printing devices to be based on the printing cycle end signal of (m-1)=4 wheels (which can be 1, 2, 3, 4, or 1, 2, 3, 5), and the other 10 devices are based on the printing cycle end signal of the remaining wheels (the 5th wheel or the 4th wheel or other wheels).

[0075] As previously mentioned, the refill instructions for each photocuring 3D printing device can also be obtained based on the collected signals from each resin consumption detection device 104. In this case, if all photocuring 3D printing devices have the same minimum working liquid level, then if printing begins simultaneously, refill instructions will inevitably be generated simultaneously. Similarly, multiple photocuring 3D printing devices will inevitably enter the waiting queue Q waiting for refilling, thereby wasting the waiting time of these photocuring 3D printing devices. Therefore, in other embodiments, to avoid this situation, the minimum working liquid level of the refill tank 201a of at most M photocuring 3D printing devices can be made the same. In this way, when printing begins simultaneously, at most M photocuring 3D printing devices will generate refill instructions simultaneously, and there will be no significant number of photocuring 3D printing devices that need to enter the waiting queue Q waiting for refilling, thereby reducing the overall printing efficiency of the photocuring 3D printing system. For example, for a stereolithography printing system with 30 stereolithography 3D printing devices, the minimum working liquid levels of 10 of the stereolithography 3D printing devices can be made the same, and the minimum working liquid levels of another 10 of the stereolithography 3D printing devices can be made slightly lower than the minimum working liquid levels of the aforementioned 10 devices (the amount of resin by this liquid level difference can be used for at least one round of printing), and the minimum working liquid levels of the remaining 10 stereolithography 3D printing devices can be made even lower than the minimum working liquid levels of the remaining 10 devices. In this way, the first control valve corresponding to the stereolithography 3D printing device that needs to be replenished does not need to enter the waiting queue Q for opening, thereby improving the overall printing efficiency.

[0076] In some embodiments, in order to minimize the possible waiting time of each light-curing 3D printing device, the refill instruction is generated based on the printing cycle end signal at the end of the mth printing cycle of each light-curing 3D printing device, and the resin tank of each light-curing 3D printing device has a corresponding minimum working liquid level. When the control module 105 receives the refill instruction, it first determines whether the number of first control valves currently in the refill state has reached a maximum value M. If not, the first control valve corresponding to the refill instruction can be directly driven to open (at this time, there must be no first control valve in the queue to be opened in the queue Q, because if there is a first control valve in the queue, the number of first control valves in the refill state must have reached M). If the number of first control valves currently in the refill state has reached the maximum value M, it means that waiting is required if refilling is to be performed. At this time, the control module 105 will further determine the number of first control valves in the queue Q of the light-curing 3D printing device corresponding to the current refill instruction. The control module 105 determines whether the resin tank 201 has approached or reached its set minimum working liquid level. If it has not approached or reached the minimum working liquid level, the stereolithography 3D printing device does not need to be immediately replenished with liquid and can perform at least one more round of printing. Therefore, the control module 105 sends a refill rejection instruction to the stereolithography 3D printing device, instructing the stereolithography 3D printing device to continue with the next round of printing. If it is determined that the resin tank 201 of the stereolithography 3D printing device corresponding to the current refill instruction has reached the minimum working liquid level, this indicates that the current stereolithography 3D printing device must be replenished with liquid. Therefore, the first control valve corresponding to the current refill instruction needs to be added to the waiting queue Q for opening to wait for refill. It should be noted that in this embodiment, for the stereolithography 3D printing device that receives the refill rejection instruction, at the end of each subsequent printing cycle, a new refill request is generated based on the print cycle end signal to obtain refill as soon as possible. The new refill request carries the actual number of rounds of the current print cycle end signal.

[0077] Furthermore, if the control module 105 determines that the number of the first control valves currently in the refill state has not reached the maximum value M, and the difference between the number of the first control valves currently in the refill state and the maximum value M is less than the number of refill instructions currently received, then the priority of each refill instruction will be determined based on the actual number of rounds of the printing cycle end signal corresponding to each refill instruction, and the first control valve corresponding to the corresponding refill instruction will be driven to open based on the priority of each refill instruction. That is to say, the refill instruction with a larger actual number of rounds indicates that its refill demand is more urgent, and thus the priority is higher. For example, the maximum value M is 8, and the number of the first control valves currently in the refill state is 7. When two refill instructions are received at the same time, the actual number of rounds corresponding to the two refill instructions will be used. For other refill instructions that fail to drive the first control valve to open, the corresponding light-curing three-dimensional printing device will be used. If the resin tank of the corresponding photocuring 3D printing device has reached the minimum working liquid level, a refill rejection instruction is sent to the corresponding photocuring 3D printing device or the first control valve is added to the queue to be opened. Assuming that one refill instruction is generated based on the third printing cycle end signal and the other refill instruction is generated based on the second printing cycle end signal, the first control valve corresponding to the refill instruction generated based on the third printing cycle end signal is driven to open. At the same time, for the other refill instruction (generated based on the second printing cycle end signal), it is determined whether the resin tank 201 of the corresponding photocuring 3D printing device has approached or reached the set minimum working liquid level. If not, a refill rejection instruction is sent to instruct the photocuring 3D printing device to perform another printing operation. If the resin tank has approached or reached the set minimum working liquid level, the corresponding first control valve is added to the queue to be opened. Of course, it is understandable that if the actual number of printing cycle signals corresponding to the refill instructions received by the control module 105 is the same, the first control valve can be randomly selected to be opened. This is not detailed here.

[0078] On the one hand, in order to ensure the refilling speed of each light-curing 3D printing device, the present application ensures that the flow rate of the resin flowing into the corresponding resin tank 201 through each first refilling channel is not less than the expected refilling flow rate designed based on the refilling strategy; on the other hand, if the number of light-curing 3D printing devices that are refilling at the same time is too small, although the refilling speed of each light-curing 3D printing device can be guaranteed, it may cause the refilling flow rate at the liquid inlet of the resin tank 201 of the light-curing 3D printing device that is being refilled to be too high. Due to the high viscosity of the photosensitive resin, the excessive refilling flow rate entering the resin tank 201 will make the liquid level of the resin tank 201 during refilling extremely unstable. In this way, more waiting time is required after refilling for the liquid level of the resin tank to stabilize, which will also affect the overall printing efficiency. Therefore, in some embodiments, to ensure the refill speed of each light-curing 3D printing device without causing the liquid level to be excessively unstable during refilling, the control module 105 controls the number of first control valves 103, and controls the number M of first control valves 103 that are simultaneously open, so that the refill flow rate of the resin flowing into the corresponding resin tank 201 through each first refill channel meets the ideal refill flow rate. The ideal refill flow rate refers to the ideal flow rate at the liquid inlet of the resin tank of each light-curing 3D printing device. Refilling the resin tank 201 with this ideal flow rate can both ensure the refill speed and make the liquid level in the resin tank as stable as possible after refilling. In a specific embodiment, the ideal refill flow rate of the light-curing 3D printing device can be obtained in advance through multiple experiments, or can be directly determined by the designer based on experience. It should also be noted that the phrase "the flow rate of the resin flowing into the corresponding resin tank 201 through each first refill channel satisfies the ideal refill flow rate" does not require that the refill flow rate of the resin flowing into the corresponding resin tank 201 through each first refill channel be completely equal to the ideal refill flow rate. It is sufficient as long as the difference between the refill flow rate of the resin flowing into the corresponding resin tank 201 through each first refill channel and the ideal refill flow rate is within a certain threshold range.

[0079] Specifically, assuming that the cross-sectional area of ​​the liquid outlet end of the total liquid replenishment tank 101 is S 总 The liquid flow rate at the outlet of the total liquid replenishment tank 101 is v 总 The liquid inlets of the resin tanks of the various light-curing 3D printing devices have the same size and a cross-sectional area of ​​S0. The ideal liquid replenishment flow rate of each light-curing 3D printing device is ν0. The number of first control valves 103 that are simultaneously open is calculated as follows:

[0080] or

[0081] It can be seen that this number is the maximum number of first control valves that can be simultaneously opened in the aforementioned embodiment. Since this embodiment limits the number of light-curing 3D printing devices that can be simultaneously refilled, when the control module 105 receives a refill instruction corresponding to each light-curing 3D printing device, it will add the first control valves 103 corresponding to each light-curing 3D printing device to the queue Q to be opened according to the order in which the refill instructions were received. The corresponding first control valves 103 are opened in the queue Q to refill the resin tank 201 of the corresponding light-curing 3D printing device. The number of first control valves 103 in the refill state controlled by the control module 105 is M. That is to say, when receiving each rehydration instruction, the control module 105 does not directly send a driving instruction to open the first control valve 103 corresponding to the rehydration instruction, but adds the first control valve 103 corresponding to the rehydration instruction to the queue Q to be opened, and then opens them in sequence according to the order of the first control valves entering the queue Q to be opened, so as to control the number of first control valves 103 in the rehydration state to always be M. For example, the control module 105 opens the first M first control valves 103 in the queue Q to be opened in sequence. When the resin tank 201 of a certain light-curing three-dimensional printing device is rehydrated, a closing driving instruction is sent to drive the corresponding first control valve 103 to close, and at the same time drives the first control valve 103 added to the queue Q to be opened to open. It should be noted that, for the fluid replenishment instructions received at the same time, the control module 105 can randomly add the first control valve 103 corresponding to the light-curing 3D printing device corresponding to the fluid replenishment instruction to the queue Q to be opened, or adopt a certain strategy, such as processing the fluid replenishment instructions received at the same time based on the priority set for each light-curing 3D printing device, as long as the first control valve corresponding to each fluid replenishment instruction can be added to the queue Q to be opened.

[0082] In addition, it should be noted that when the number of first control valves 103 in the queue Q to be opened is less than M, in order to ensure the fluid replenishment speed, the control module 105 will not wait until the number of first control valves 103 in the queue Q to be opened is greater than or equal to M before driving M first control valves at the same time. Instead, if the number of first control valves 103 in the queue Q to be opened is still less than M within the preset time, all the first control valves 103 in the queue Q to be opened will be directly driven. When a first control valve 103 corresponding to a new fluid replenishment instruction is added to the queue Q to be opened, an opening drive instruction is sent to open the first control valve 103 corresponding to the fluid replenishment instruction.

[0083] Similarly, in this embodiment, the control module 105 can generate a drive instruction for closing the corresponding first control valve 103 based on the collected signals from the resin consumption detection device 104 corresponding to the resin tank of each light-curing 3D printing device. For example, after sending an open drive instruction to a first control valve 103, the control module 105 calculates the current fluid replenishment volume based on the collected signals from the first resin consumption detection device 104 corresponding to the light-curing 3D printing device corresponding to that first control valve 103. When the calculated current fluid replenishment volume equals the resin consumption of that light-curing 3D printing device, the control module 105 generates a drive instruction for closing the first control valve 103 to close it.

[0084] Similarly, since the refill instructions for each stereolithography 3D printing device can be generated based on the print cycle end signal at the end of the mth print cycle of each stereolithography 3D printing device, if the refill instructions for all stereolithography 3D printing devices are generated based on the print cycle end signal of the same round (i.e., the value of m corresponding to each stereolithography 3D printing device is the same), there will inevitably be multiple stereolithography 3D printing devices entering the waiting queue Q waiting for refilling, thereby significantly wasting the waiting time of these stereolithography 3D printing devices. Therefore, in some embodiments, the refill instructions for each of the M stereolithography 3D printing devices among the N stereolithography 3D printing devices can be generated based on the print cycle end signal with the same value of m. When the refill instructions for each of the stereolithography 3D printing devices are refill instructions generated based on the collected signals of each resin consumption detection device, the lowest working liquid levels of the resin tanks of each of the M stereolithography 3D printing devices among the N stereolithography 3D printing devices are the same or close. It is understood that if N cannot divide M evenly, then the number of stereolithography 3D printing devices in the final group will inevitably be less than M. In this case, the refill instructions for each of the M stereolithography 3D printing devices are still generated based on the end-of-print cycle signal of the same value m. For example, assuming that there are 35 stereolithography 3D printing devices in the system and the number of first control valves that are simultaneously open is 8, then 8 of 32 of them generate end-of-print cycle signals based on the same wheel, while the number of the other 3 is less than 8. In this case, the other 3 generate end-of-print cycle signals based on the same wheel. In this case, the minimum working liquid level of the resin tank of each of the M stereolithography 3D printing devices in the N stereolithography 3D printing devices is still considered to be the same or close. It can be seen that the present invention can control the number of first control valves that are simultaneously open so that the flow rate of resin flowing into the corresponding resin tank through each first refill channel is close to the ideal flow rate at the resin tank inlet of each stereolithography 3D printing device. This minimizes the waiting time for the liquid level to stabilize while ensuring the refill speed, thereby improving the overall efficiency of the stereolithography printing system of the present application.

[0085] In this application, in order to continuously replenish the liquids of each light-curing 3D printing device, the main liquid replenishing tank 101 itself also needs to be replenished in time. Therefore, in some embodiments, a liquid inlet end 101f is provided at the top of the main liquid replenishing tank 101 for replenishing the liquids of the main liquid replenishing tank 101, such as Figure 3 As shown, in this embodiment, the total liquid replenishment tank 101 is provided with a resin quantity detection device 106 for monitoring the resin quantity in the total liquid replenishment tank 101, and the control module 105 determines whether it is necessary to add liquid to the total liquid replenishment tank 101 according to the signal detected by the resin quantity detection device. When it is determined that liquid needs to be added, liquid is added to the total liquid replenishment tank 101 through the liquid inlet end. Similarly, the total liquid replenishment tank can be a liquid level sensor located above the total liquid replenishment tank 101, which determines whether liquid replenishment is needed based on the liquid level in the total liquid replenishment tank 101. Of course, it can also be a weighing sensor arranged at the bottom of the total liquid replenishment tank 101. That is to say, when it is monitored that the resin liquid level in the total liquid replenishment tank 101 is lower than the set liquid level lower limit threshold or the resin weight in the total liquid replenishment tank 101 is less than the set resin lower limit threshold, the total liquid replenishment tank 101 is replenished, and when the resin liquid level in the total liquid replenishment tank 101 reaches the set liquid level upper limit threshold or the resin weight in the total liquid replenishment tank 101 reaches the set resin upper limit threshold, replenishment of the total liquid replenishment tank 101 is stopped.

[0086] Due to the special properties of photosensitive resin materials, they are prone to precipitation after being unused for a long time. This not only makes the liquid flow difficult, but also makes the texture of the printed model uneven. Therefore, in some embodiments, the centralized refilling system further includes a first stirring mechanism to stir the photosensitive resin in the main refilling tank 101 to prevent precipitation of the photosensitive resin, thereby improving the printing effect. Specifically, Figure 3 As shown, the first stirring mechanism includes at least a first driving device 101a, a first stirring shaft 101c and a first stirring rod 101b. The first driving device 101a can be arranged on the top of the total liquid replenishment tank 101 (for example, the top of the total liquid replenishment tank 101 has a top cover, the first driving device 101a is placed on the top cover, and is connected to the stirring shaft 101c located in the total liquid replenishment tank 101. In some preferred embodiments, the first driving device 101a is a servo motor, and its output shaft is connected to the first stirring shaft 101c through a coupling. The stirring shaft 101c is provided with a plurality of fixing frames 101d and fixed by bolts. The first stirring rod 101b is welded on the outer wall of the fixing frame 101d to stir the resin in the total liquid replenishment tank 101 by driving the stirring rod 101b to prevent the resin from solidifying.

[0087] like Figure 4 As shown, another embodiment of the present invention further provides a light-curing three-dimensional printing system, comprising:

[0088] N sets of photocuring 3D printing devices, each photocuring 3D printing device 200 includes a printing device, an image exposure device, and an automatic workpiece collection device. The printing device includes: a resin tank 201 for accommodating photosensitive resin; a lifting platform including a workpiece carrier platform and a lifting mechanism, the workpiece carrier platform 202 for carrying a printed workpiece, and the lifting mechanism 203 drives the workpiece carrier platform 202 to move up and down relative to the resin tank 201; an image exposure system 204 located above the resin tank 201 to project a preset light beam onto the workpiece carrier platform 202 to form the printed workpiece 300 on the upper surface of the workpiece carrier platform 202; an automatic workpiece collection device 210 for automatically collecting the printed workpiece 300 from the workpiece carrier platform 202 after the printed workpiece 300 is formed on the workpiece carrier platform 202; except for the fluid replenishment system, the other structures of each photocuring 3D printing device in this embodiment are the same as those of the prior art photocuring 3D printing device, and their working principles are also the same. Therefore, the specific structure of the photocuring 3D printing device is not described in detail here;

[0089] The centralized fluid replenishment system is a centralized fluid replenishment system implemented in the aforementioned embodiments. The liquid outlet end of the main fluid replenishment tank 101 of the centralized fluid replenishment system is connected to the liquid inlet end of the resin tank 201 of the N light-curing 3D printing devices through the corresponding first fluid replenishment channel. Each of the first fluid replenishment channels is provided with a first control valve 103 for controlling fluid replenishment. The centralized fluid replenishment system has been described in detail in the aforementioned embodiments and will not be repeated here.

[0090] Those skilled in the art will appreciate that the above embodiments are specific embodiments for implementing the present application, and that in actual applications, various changes may be made thereto in form and detail without departing from the spirit and scope of the present application.

Claims

1. A centralized fluid replenishment system for light-curing 3D printing equipment, characterized in that: include: A main liquid replenishment tank for containing photosensitive resin material, having at least one liquid outlet, the liquid outlet being connected to the liquid inlet of each resin tank of N light-curing 3D printing devices through corresponding first liquid replenishment channels, each of the first liquid replenishment channels being provided with a first control valve, where N is greater than or equal to 5; N resin consumption detection devices, each provided corresponding to each resin tank, for detecting the resin consumption in the corresponding resin tank; A control module is configured to obtain a refill instruction from each light-curing 3D printing device and a collection signal from each resin consumption detection device, and send a corresponding drive instruction to the corresponding first control valve to control the refill; The number of first control valves that are simultaneously in the open state should be such that the flow rate of the resin flowing into the corresponding resin tank through each first liquid replenishing channel at least meets the designed expected flow rate.

2. The centralized fluid replenishment system for fluid replenishment of a light-curing 3D printing device according to claim 1, characterized in that: The expected flow rate is the liquid outlet flow rate or an approximate value thereof obtained based on detection of the liquid outlet end of the total liquid infusion tank, or the expected flow rate is the expected liquid infusion flow rate designed based on the liquid infusion strategy.

3. The centralized fluid replenishment system for fluid replenishment of a light-curing 3D printing device according to claim 2, characterized in that: The maximum number M of the first control valves that are simultaneously in the open state is determined based on the liquid outflow rate of the liquid outlet end of the total liquid replenishment tank and the liquid replenishment flow rate flowing into the liquid inlet of each resin tank at the expected flow rate.

4. The centralized fluid replenishment system for fluid replenishment of a light-curing 3D printing device according to claim 3, characterized in that: The rehydration instruction is generated based on a printing cycle end signal of each light-curing 3D printing device at the end of the mth printing cycle, where m is an integer greater than 1.

5. The centralized fluid replenishment system for fluid replenishment of a light-curing 3D printing device according to claim 4, characterized in that: The refill instructions of at most M light-curing three-dimensional printing devices are generated based on the m-th printing cycle end signal with the same m value.

6. The centralized fluid replenishment system for fluid replenishment of a light-curing 3D printing device according to claim 5, characterized in that: m is less than or equal to 5.

7. The centralized fluid replenishment system for fluid replenishment of a light-curing 3D printing device according to claim 6, characterized in that: When (N / m) is greater than the maximum number of first control valves that are simultaneously in the open state, which is determined based on the resin flow rate at the liquid outlet of the total liquid replenishment tank and the liquid replenishment flow rate flowing into the liquid inlet of each resin tank at the expected flow rate, the expected flow rate is adjusted so that the maximum number M of the first control valves that are simultaneously in the open state satisfies the configuration of generating liquid replenishment instructions for all light-curing three-dimensional printing devices based on m different rounds of printing cycle end signals, or generating the liquid replenishment instructions set for M*(m-1) light-curing three-dimensional printing devices based on the printing cycle end signal of the (m-1)th round among the m rounds, and generating the liquid replenishment instructions set for (NM*(m-1)) light-curing three-dimensional printing devices based on the printing cycle end signals of the remaining rounds.

8. The centralized fluid replenishment system for fluid replenishment of a light-curing 3D printing device according to claim 3, characterized in that: The rehydration instruction is generated based on the collection signal of each resin consumption detection device. When the control module determines that the liquid level in the current resin tank is close to or reaches the set minimum working liquid level based on the collection signal of the resin consumption detection device, a rehydration instruction is generated to replenish the current resin tank.

9. The centralized fluid replenishment system for fluid replenishment of a light-curing 3D printing device according to claim 8, characterized in that: The lowest working liquid levels of at most M light-curing 3D printing devices are the same or close to each other.

10. The centralized fluid replenishment system for fluid replenishment of a light-curing 3D printing device according to any one of claims 1 to 9, characterized in that: When the control device receives the fluid replenishment instruction, it controls the first control valve corresponding to the current fluid replenishment instruction to open or add it to a queue to be opened according to the number of first control valves currently in the fluid replenishment state and the maximum value M.

11. The centralized fluid replenishment system for fluid replenishment of a light-curing 3D printing device according to claim 10, characterized in that: The control device generates a driving instruction for closing the corresponding first control valve based on the collected signal of the resin consumption detection device.

12. The centralized fluid replenishment system for fluid replenishment of a light-curing 3D printing device according to claim 10, characterized in that: If the number t of the first control valves currently in the fluid replenishing state is less than M, the control device drives (Mt) first control valves to open according to the order of the first control valves entering the queue to be opened.

13. The centralized fluid replenishment system for fluid replenishment of a light-curing 3D printing device according to any one of claims 3 to 7, characterized in that: When the control module receives the fluid replenishment instruction, it determines whether the number of the first control valves currently in the fluid replenishment state has reached the maximum value M. If the number has not reached the maximum value M, it directly drives the first control valve corresponding to the fluid replenishment instruction to open. If the number has reached M, it further determines whether the resin tank of the light-curing 3D printing device corresponding to the current fluid replenishment instruction has reached the minimum working liquid level. If the minimum working liquid level has not been reached, it sends a fluid replenishment rejection instruction to the light-curing 3D printing device, instructing the light-curing 3D printing device to continue the next round of printing. If the minimum working liquid level has been reached, it adds the first control valve corresponding to the current fluid replenishment instruction to a queue to be opened.

14. The centralized fluid replenishment system for fluid replenishment of a light-curing 3D printing device according to claim 13, characterized in that: If the number of first control valves currently in the rehydration state is less than M and the difference from the maximum value M is less than the number of rehydration instructions currently received, the priority of each rehydration instruction is determined based on the actual number of print cycle end signals corresponding to each rehydration instruction, and the first control valve corresponding to the corresponding rehydration instruction is driven to open based on the priority of each rehydration instruction. For other rehydration instructions that fail to drive the first control valve to open, a rehydration rejection instruction is sent to the corresponding light-curing three-dimensional printing device or the first control valve is added to the queue to be opened, depending on whether the resin tank of the corresponding light-curing three-dimensional printing device has reached the lowest working liquid level.

15. The centralized fluid replenishment system for fluid replenishment of a light-curing 3D printing device according to claim 3, characterized in that: When the expected liquid replenishment flow rate is the ideal flow rate of the resin tank liquid inlet of each light-curing 3D printing device, the number of the first control valves that are simultaneously in the open state is the maximum value M.

16. The centralized fluid replenishment system for fluid replenishment of a light-curing 3D printing device according to claim 15, characterized in that: When the control module receives a fluid replenishment instruction corresponding to each light-curing 3D printing device, the control module adds the first control valve corresponding to each fluid replenishment instruction to a queue to be opened based on the order of receipt, and sequentially opens M first control valves according to a first-in-first-out principle to simultaneously replenish the resin tanks of the M corresponding light-curing 3D printing devices.

17. The centralized fluid replenishment system for fluid replenishment of a light-curing 3D printing device according to claim 16, characterized in that: The rehydration instruction is generated based on a printing cycle end signal of each light-curing 3D printing device at the end of the mth printing cycle, where m is an integer greater than or equal to 1.

18. The centralized fluid replenishment system for fluid replenishment of a light-curing 3D printing device according to claim 17, characterized in that: The liquid replenishing instruction of each M light-curing 3D printing device among the N light-curing 3D printing devices is generated based on the m-th printing cycle end signal with the same m value.

19. The centralized fluid replenishment system for fluid replenishment of a light-curing 3D printing device according to claim 16, wherein: The rehydration instruction is generated based on the collection signal of each resin consumption detection device. When the control module determines that the liquid level in the current resin tank is close to or lower than the set minimum working liquid level based on the collection signal of the resin consumption detection device, a rehydration instruction is generated to replenish the current resin tank.

20. The centralized fluid replenishment system for fluid replenishment of a light-curing 3D printing device according to claim 19, characterized in that: The lowest working liquid levels of the resin tanks of each of the M light-curing 3D printing devices among the N light-curing 3D printing devices are the same or close to each other.

21. The centralized fluid replenishment system for fluid replenishment of a light-curing 3D printing device according to claim 16, characterized in that: When the number of the first control valves in the queue to be opened is less than M within a preset time, the control module directly drives to open all the first control valves in the queue to be opened.

22. The centralized fluid replenishment system for fluid replenishment of a light-curing 3D printing device according to any one of claims 1-9 and 14-21, characterized in that: The centralized liquid replenishment system is also provided with a resin quantity detection device for monitoring the resin quantity in the total liquid replenishment tank. The control module determines whether it is necessary to add liquid to the total liquid replenishment tank based on the signal detected by the resin quantity detection device. When it is determined that liquid addition is required, liquid is added to the total liquid replenishment tank through the liquid inlet end of the total liquid replenishment tank.

23. The centralized fluid replenishment system for fluid replenishment of a light-curing 3D printing device according to any one of claims 1-9 and 14-21, characterized in that: A stirring mechanism is provided in the total liquid replenishing tank, and the stirring mechanism includes at least a driving device, a stirring shaft and a stirring rod. The driving device is connected to the stirring shaft located in the total liquid replenishing tank, the stirring shaft sleeve is provided with several fixing frames, and the stirring rod is fixed on the outer wall of the fixing frame.

24. A light-curing three-dimensional printing system, characterized in that: include: N sets of photocuring 3D printing devices, each of which includes a printing device, an image exposure device, and an automatic workpiece collection device, wherein the printing device includes: a resin tank for accommodating photosensitive resin; a lifting platform including a workpiece carrier and a lifting mechanism, wherein the workpiece carrier is used to carry a printed workpiece, and the lifting mechanism drives the workpiece carrier to move up and down relative to the resin tank; an image exposure system located above the resin tank for projecting a preset light beam onto the workpiece carrier to form the printed workpiece on the surface of the workpiece carrier; and an automatic workpiece collection device for automatically collecting the printed workpiece from the workpiece carrier after the printed workpiece is formed on the workpiece carrier; The centralized fluid replenishment system according to any one of claims 1 to 23, wherein the main fluid replenishment tank of the centralized fluid replenishment system is connected to each resin tank of the N light-curing 3D printing devices through a first fluid replenishment channel.

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