An ink supply system and 3D printer

Abstract

The application discloses an ink supply system and a 3D printer, and relates to the technical field of 3D printing. The ink supply system comprises a control module, a first ink storage box, a second ink storage box, a positive pressure pump and a printing nozzle. The first ink storage box is in communication with the second ink storage box, the second ink storage box is in communication with the printing nozzle, and the positive pressure pump is in communication with the first ink storage box. The second ink storage box is provided with a first liquid level detector, and the first liquid level detector is used for detecting the storage amount of ink in the second ink storage box. The control module is electrically connected with the positive pressure pump and the first liquid level detector, respectively, and the control module is used for controlling whether the positive pressure pump works according to the detection value of the first liquid level detector. The positive pressure pump is used for increasing the pressure in the first ink storage box, so as to deliver the ink in the first ink storage box into the second ink storage box. According to the application, the positive pressure pump is in communication with the first ink storage box, the positive pressure pump provides micro-positive pressure for the first ink storage box, the ink is delivered into the second ink storage box by using a small pressure difference, and the ink in the second ink storage box is smoothly replenished.

Description

Technical Field

[0001] This application relates to the field of 3D printing technology, and in particular to an ink supply system and a 3D printer. Background Technology

[0002] Currently, full-color 3D printing technology typically uses inkjet printing. Existing ink supply systems often employ multi-stage ink storage structures, such as setting up a large-capacity primary ink cartridge and a small-capacity secondary ink cartridge, to stabilize the ink supply pressure of the print head and facilitate the management of different colors of ink.

[0003] However, when refilling small-capacity secondary ink cartridges, the traditional method is to use an ink supply pump, such as a diaphragm pump, to directly pump ink from the primary ink cartridge to the secondary cartridge. Because the secondary cartridge has a limited volume, the flow and pressure fluctuations generated by the ink supply pump are directly transmitted to the sealed cavity of the secondary cartridge, causing significant fluctuations in internal air pressure. These pressure fluctuations can further propagate to the printhead connected to the secondary cartridge, causing ink to drip unintended from the nozzle, a phenomenon known as ink dripping. This severely affects the stability of the printing process and the quality of the final printed parts. Summary of the Invention

[0004] This application provides an ink supply system and a 3D printer, which aims to solve the problem in the prior art that air pressure fluctuations are easily caused when replenishing ink to small-capacity buffer ink cartridges, resulting in unstable printing.

[0005] In a first aspect, this application provides an ink supply system, which includes a control module, a primary ink reservoir, a secondary ink reservoir, a positive pressure pump, and a printhead. The primary ink reservoir is connected to the secondary ink reservoir, the secondary ink reservoir is connected to the printhead, and the positive pressure pump is connected to the primary ink reservoir. A first level detector is provided in the secondary ink reservoir for detecting the amount of ink in the secondary ink reservoir. The control module is electrically connected to both the positive pressure pump and the first level detector, and the control module controls the operation of the positive pressure pump based on the detection signal from the first level detector. The positive pressure pump increases the pressure inside the primary ink reservoir to deliver ink from the primary ink reservoir to the secondary ink reservoir.

[0006] In this application, the primary ink cartridge serves as an ink storage unit, capable of replenishing the secondary ink cartridge. By connecting a positive pressure pump to the primary ink cartridge, the pump provides a slight positive pressure to the primary cartridge. This slight pressure difference delivers ink to the secondary ink cartridge, achieving stable ink replenishment and preventing drastic pressure fluctuations within the secondary cartridge, thus minimizing ink dripping from the printhead.

[0007] In one possible design of the first aspect, the ink supply system includes multiple primary ink cartridges and multiple secondary ink cartridges, each secondary ink cartridge corresponding to and connected to a primary ink cartridge, and a positive pressure pump connected to the multiple primary ink cartridges.

[0008] In this design, multiple primary and secondary ink cartridges are paired one-to-one, each capable of independently storing inks of different colors, adapting to the multi-material supply needs of full-color 3D printing. A positive pressure pump supplies pressure to multiple primary ink cartridges, reducing the number of positive pressure pumps required and saving costs.

[0009] In one possible design of the first aspect, a first filter is provided on the connecting pipe between the primary ink reservoir and the secondary ink reservoir, and a second filter is provided between the secondary ink reservoir and the print head.

[0010] In this design, the first filter filters out sediment particles and pipe impurities generated during ink storage in the primary ink reservoir, preventing impurities from entering the secondary ink reservoir, contaminating the ink, and clogging the pipes. The second filter is installed between the ink outlet of the secondary ink reservoir and the printhead to prevent impurities in the outside air from entering the secondary ink reservoir through the printhead, thus avoiding ink contamination.

[0011] In one possible design of the first aspect, an ink supply valve is provided on the connecting pipe between the primary ink reservoir and the secondary ink reservoir, and the ink supply valve is electrically connected to the control module.

[0012] In this design, the control module can independently control the on / off state of each ink supply valve, enabling single-channel ink replenishment. This avoids simultaneous ink replenishment of different channels when the positive pressure pump is supplying pressure, and also prevents ink leakage caused by residual pressure in the pipeline after replenishment. During color change or cleaning processes, closing the corresponding channel's ink supply valve allows for independent operation of each channel, eliminating the need for overall cleaning, reducing ink waste, and simplifying the color change process. Furthermore, the use of a filter allows for independent cleaning of individual pipelines, preventing cross-contamination between different colors of ink and enhancing the independence of multi-color ink supply.

[0013] In one possible design of the first aspect, one end of the positive pressure pump is connected to the primary ink reservoir via a connecting pipe, and the other end of the positive pressure pump is connected to an air filter.

[0014] In this design, the air filter effectively filters dust, solid particles, moisture, oil, and other impurities from the air entering the positive pressure pump, preventing these impurities from entering the primary ink reservoir and contaminating the ink. This prevents moisture from causing ink emulsification, layering, or poor ink flow, maintaining the ink's original properties such as flowability and adhesion, and ensuring the material properties of the printed parts. Simultaneously, it prevents impurities from accumulating in the primary ink reservoir and connecting pipes, ensuring the long-term smooth operation of the ink supply system and reducing equipment maintenance frequency.

[0015] In one possible design of the first aspect, multiple primary ink cartridges are connected to the same positive pressure pump.

[0016] In this design, a single positive pressure pump supplies air to multiple primary ink cartridges. Compared to a separate positive pressure pump for each ink supply branch, this reduces equipment costs and structural complexity, while also facilitating unified maintenance and pressure control.

[0017] In one possible design of the first aspect, a positive pressure pump is used to increase the pressure inside the primary ink reservoir, so that the air pressure inside the primary ink reservoir is 0.02 MPa to 0.05 MPa higher than the air pressure inside the secondary ink reservoir.

[0018] In one possible design of the first aspect, the control module controls the output pressure and flow rate of the positive pressure pump and controls the pressure fluctuation in the secondary ink reservoir to within ±0.003MPa.

[0019] In one possible design of the first aspect, a second liquid level detector is provided in the primary ink cartridge. The second liquid level detector is electrically connected to the control module. The second liquid level detector is used to detect the amount of ink in the primary ink cartridge, and the control module receives the detection signal from the second liquid level sensor.

[0020] In this design, the second level detector and the first level detector of the secondary ink cartridge form a dual-layer level detection system, enabling full-process monitoring of ink levels. The control module can use the second level detector's reading to issue an early warning of low ink levels in the primary ink cartridge, reminding staff to replenish ink promptly. This prevents ink replenishment failures and printing interruptions due to low ink levels in the primary cartridge, improving the continuity and reliability of the ink supply system. Simultaneously, it reduces the scrap of printed parts caused by sudden ink shortages, enhancing the overall production efficiency of 3D printing.

[0021] In one possible design of the first aspect, the primary ink reservoir includes an air inlet and an ink outlet, a positive pressure pump is connected to the air inlet via a connecting pipe, and the secondary ink reservoir is connected to the ink outlet via a connecting pipe, with the air inlet being higher than the ink outlet in the vertical direction.

[0022] In this design, the air inlet is higher than the liquid outlet, ensuring that the compressed gas from the positive pressure pump acts on the gas phase region of the primary ink reservoir, rather than directly impacting the ink surface. This avoids ink splashing and bubble formation, preventing bubbles from entering the secondary ink reservoir and printhead, which could lead to ink interruptions or uneven ink output. Simultaneously, the gas pressure in the gas phase region is evenly distributed across the ink surface, resulting in smoother pressure transmission and improved gas pressure stability for micro-positive pressure ink replenishment. Combined with the control module's adjustments, this more effectively prevents printhead dripping.

[0023] In one possible design of the first aspect, the ink level in the primary ink reservoir is higher than the ink level in the secondary ink reservoir in the vertical direction.

[0024] In this design, the liquid level difference between the primary and secondary ink reservoirs creates gravitational potential energy, providing gravity-assisted power for ink delivery. This, combined with the slight positive pressure of the positive pressure pump, forms a dual power supply, allowing the ink to flow more smoothly in the connecting pipes. This effectively reduces the workload of the positive pressure pump, lowers equipment energy consumption, and extends the service life of the positive pressure pump.

[0025] In one possible design of the first aspect, a plurality of primary ink storage boxes include a primary white ink storage box for storing white ink, a plurality of secondary ink storage boxes include a secondary white ink storage box, the secondary white ink storage box is connected to the primary white ink storage box, and both the primary and secondary white ink storage boxes are equipped with a stirrer.

[0026] In this design, white ink containing solid particles is prone to settling and clumping. The agitator in the primary white ink reservoir ensures that the white ink particles are uniformly suspended during storage, preventing uneven white ink concentration when delivered to the secondary ink reservoir. The agitator in the secondary white ink reservoir achieves secondary ink uniformity, ensuring the uniformity of white ink entering the printhead. The agitator effectively prevents particles from clogging the filter and printhead nozzles, working in conjunction with the filter structure to ensure uniform white ink output, improving the smoothness of the background and the color reproduction of full-color printing.

[0027] Secondly, this application provides a 3D printer that includes the ink supply system of the first aspect and any possible design thereof.

[0028] Understandably, the beneficial effects that the 3D printer described in the second aspect above can achieve can be referenced in the beneficial effects of the first aspect and any of its possible design methods, and will not be repeated here. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 This is a schematic diagram of the structure of an ink supply system provided in an embodiment of this application;

[0031] Figure 2 A schematic diagram of a primary ink storage cartridge in an ink supply system provided in an embodiment of this application;

[0032] Figure 3This is a schematic diagram of a 3D printer provided in an embodiment of this application.

[0033] In the diagram: 110 - Primary ink cartridge; 120 - Secondary ink cartridge; 130 - Positive pressure pump; 140 - Print head; 150 - First filter; 160 - Second filter; 170 - Ink supply valve; 180 - Air filter; 190 - Stirrer; 101 - First liquid level detector; 102 - Second liquid level detector; 103 - Air inlet; 104 - Liquid outlet; 111 - Level 1 white ink cartridge; 121 - Level 2 white ink cartridge. Detailed Implementation

[0034] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings, which illustrate embodiments of the present application. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of this application will be thorough and complete.

[0035] In the embodiments of this application, the terms "exemplary" or "for example" are used to indicate that something is an example, illustration, or description. Any embodiment or design that is described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design. Specifically, the use of the terms "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0036] In the embodiments of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first" and "second" may explicitly or implicitly include one or more of that feature.

[0037] It should be understood that the terminology used in the description of the various examples herein is for the purpose of describing the particular examples only and is not intended to be limiting. As used in the description of the various examples, the singular forms “a” (“a”, “an”) and “the” are intended to include the plural forms as well, unless the context explicitly indicates otherwise.

[0038] In this application, "at least one" means one, two, or more, and "more than" means two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of a single item or a plurality of items. For example, at least one of a, b, or c can mean: a, b, c, ab, ac, bc, or abc, where a, b, and c can be a single item or multiple items.

[0039] It should also be understood that, unless otherwise expressly specified and limited, the term "connection" in this application should be interpreted broadly. For example, "connection" can be a fixed connection, a sliding connection, a detachable connection, or an integral part thereof; it can be a direct connection or an indirect connection through an intermediate medium. If the connected circuits, modules, units, etc., transmit electrical signals or data to each other, it should be understood as an "electrical connection," "communication connection," etc.

[0040] It should also be understood that the term “comprising” (also referred to as “includes”, “including”, “comprises” and / or “comprising”) as used in this specification specifies the presence of the stated features, integers, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0041] It should be understood that the terms "an embodiment," "another embodiment," and "a possible design" used throughout the specification mean that a specific feature, structure, or characteristic related to an embodiment or implementation is included in at least one embodiment of this application. Therefore, phrases such as "in one embodiment of this application," "in another embodiment of this application," and "a possible design" appearing throughout the specification do not necessarily refer to the same embodiment. Furthermore, these specific features, structures, or characteristics can be combined in any suitable manner in one or more embodiments.

[0042] It should also be understood that the specific values ​​mentioned in the embodiments of this application are not intended to limit the specific dimensions of particular features or structures. The relevant values ​​may be illustrative examples for ease of understanding, or they may represent the theoretically optimal value for a certain feature. In practice, the relevant dimensions may be a range around the value, for example, the range may be ±5% of the optimal theoretical value, and the actual dimensions should be determined based on achieving the corresponding technical effect.

[0043] In this application embodiment, "parallel," "perpendicular," and "equal" include the described situation and situations similar to the described situation, where the range of similarity is within an acceptable deviation range, which is determined by those skilled in the art taking into account the measurement under discussion and errors associated with the measurement of a particular quantity (such as limitations of the measurement system). For example, "parallel" includes absolute parallelism and approximate parallelism, where the acceptable deviation range for approximate parallelism can be, for example, a deviation within 5°; "perpendicular" includes absolute perpendicularity and approximate perpendicularity, where the acceptable deviation range for approximate perpendicularity can also be, for example, a deviation within 5°. "Equal" includes absolute equality and approximate equality, where the acceptable deviation range for approximate equality can be, for example, a difference between the two equalities less than or equal to 5% of either one.

[0044] 3D printing technology, as an important means of rapid prototyping, has been widely used in industrial manufacturing, cultural and creative design, medical modeling, and other fields. Among them, full-color 3D printing technology based on inkjet principles has become a research hotspot in recent years because it can directly achieve the integrated molding of multiple materials and colors. How to stably and continuously deliver different colors of ink to the print head directly affects the color accuracy, surface quality, and structural integrity of the printed parts.

[0045] Traditional ink supply systems often employ a tiered structure consisting of a primary ink reservoir and a secondary ink reservoir. The primary reservoir acts as the main ink tank, storing a large amount of ink; the secondary reservoir serves as a buffer unit, directly supplying ink to the printhead to reduce pressure fluctuations caused by long-distance piping. In related technologies, mechanical pumps such as diaphragm pumps and gear pumps are often used to directly pump ink to the secondary reservoir. However, the piston-like motion of these mechanical pumps causes pulsed fluctuations in ink flow and pressure. Since the secondary reservoir is typically small in volume to match the printhead's ink supply rhythm, it struggles to buffer these fluctuations, leading to significant internal pressure fluctuations. This, in turn, causes ink to drip from the printhead, directly affecting the forming accuracy of 3D printing and resulting in noticeable surface textures and poor smoothness in the printed parts.

[0046] Therefore, an ink supply system is provided that can replenish ink to the secondary ink reservoir smoothly with minimal or no fluctuations, so as to ensure stable and reliable ink supply.

[0047] To address the aforementioned issues, this application proposes an ink supply system that uses gas pressure to drive ink transfer from the primary ink reservoir to the secondary ink reservoir, replacing the direct contact delivery of traditional mechanical pumps. This reduces pressure fluctuations in the secondary ink reservoir during ink replenishment, providing a stable ink supply guarantee for full-color 3D printers.

[0048] refer to Figure 1 , Figure 1 This is a schematic diagram of an ink supply system provided in an embodiment of this application. Figure 1 As shown, this application provides an ink supply system, mainly used in 3D printers, designed to solve the printing quality problems caused by air pressure fluctuations during the ink replenishment process in traditional ink supply methods. The ink supply system includes a control module (…). Figure 1The system comprises a primary ink cartridge 110 (not shown), a secondary ink cartridge 120, a positive pressure pump 130, and a printhead 140. The primary ink cartridge 110 is connected to the secondary ink cartridge 120, the secondary ink cartridge 120 is connected to the printhead 140, and the positive pressure pump 130 is connected to the primary ink cartridge 110. The secondary ink cartridge 120 is equipped with a first level detector 101, which detects the ink level in the secondary ink cartridge 120. A control module is electrically connected to both the positive pressure pump 130 and the first level detector 101, and controls the operation of the positive pressure pump 130 based on the detection value of the first level detector 101. The positive pressure pump 130 increases the pressure within the primary ink cartridge 110 to transfer ink from the primary ink cartridge 110 to the secondary ink cartridge 120.

[0049] In this embodiment, the primary ink cartridge 110 serves as the main ink storage unit, and its volume can be set according to printing needs. For example, the primary ink cartridge 110 can be designed to hold several liters of ink to reduce frequent ink refilling operations. The secondary ink cartridge 120 has a relatively small volume, generally 1 / 10 to 1 / 20 of the volume of the primary ink cartridge 110. It mainly serves as a buffer unit for the ink supply system, providing a stable ink supply directly to the printhead 140. With this hierarchical storage design, the primary ink cartridge 110 can meet the ink requirements for long-term printing, while the secondary ink cartridge 120 can quickly respond to instantaneous ink volume changes in the printhead, avoiding ink supply lag caused by the primary ink cartridge 110 being too far from the printhead.

[0050] The secondary ink cartridge 120 is equipped with a first level detector 101, which can be a float-type level switch or a photoelectric level sensor, for real-time monitoring of the ink level in the secondary ink cartridge 120. When the ink level in the secondary ink cartridge 120 is lower than a preset low level threshold, the first level detector 101 sends a low level signal to the control module. When the ink level rises to a preset high level threshold, the first level detector 101 sends a high level signal to the control module. Alternatively, when the ink level in the secondary ink cartridge 120 is lower than the preset low level threshold, a certain amount of ink is added to the secondary ink cartridge 120 according to a preset ink replenishment flow rate and a preset ink replenishment duration.

[0051] The control module is electrically connected to the positive pressure pump 130 and the first liquid level detector 101. Its function is to control the working state of the positive pressure pump 130 based on the detection signal from the first liquid level detector 101. Specifically, when a low liquid level signal is received, the control module controls the positive pressure pump 130 to start. The positive pressure pump 130 introduces a certain amount of gas into the primary ink reservoir 110 through a gas pipeline, so that the primary ink reservoir 110 is in a slightly positive pressure state (for example, the gas pressure in the primary ink reservoir 110 is 0.02MPa to 0.05MPa higher than the gas pressure in the secondary ink reservoir 120). The pressure difference is used to force the ink in the primary ink reservoir 110 into the secondary ink reservoir 120 through the connecting pipeline. When a high liquid level signal is received, the control module controls the positive pressure pump 130 to stop working, and the ink replenishment process terminates; or, after the positive pressure pump 130 has worked for a preset ink replenishment time, the control module controls the positive pressure pump 130 to stop working, and the ink replenishment process terminates.

[0052] In addition, the control module can also integrate pressure feedback function. For example, by setting a pressure sensor on the primary ink storage box 110 or the connecting pipe between the primary ink storage box 110 and the secondary ink storage box 120, the output pressure of the positive pressure pump 130 can be monitored in real time. When the pressure is abnormal (such as exceeding the safety threshold or falling below the effective ink replenishment pressure), the control module can trigger an alarm and stop the ink supply to avoid equipment damage or ink leakage.

[0053] In this embodiment, the micro-positive pressure gas provided by the positive pressure pump 130 can form a weak positive pressure field in the primary ink reservoir 110. Under this weak positive pressure, ink flows uniformly into the secondary ink reservoir 120, effectively reducing the pressure fluctuation amplitude within the secondary ink reservoir 120. In practical applications, the pressure fluctuation range within the secondary ink reservoir 120 can be controlled by adjusting the output pressure and flow rate of the positive pressure pump 130. For example, by controlling the output pressure and flow rate of the positive pressure pump 130, the pressure fluctuation within the secondary ink reservoir 120 can be controlled within ±0.003 MPa to ensure uniform ink output from the printhead 140 and reduce printing defects caused by pressure fluctuations.

[0054] It should be noted that in this embodiment, the pressure inside the primary ink cartridge 110 and the secondary ink cartridge 120 can be detected by adding a pressure sensor, or the pressure change caused by the output gas flow rate can be calculated based on the gas flow rate output by the positive pressure pump 130 and the volume of the primary ink cartridge 110 and the secondary ink cartridge 120.

[0055] In summary, this embodiment, through the coordinated operation of the control module, positive pressure pump 130, primary ink cartridge 110, secondary ink cartridge 120, and first liquid level detector 101, utilizes the positive pressure pump 130 to provide a slight positive pressure to the primary ink cartridge 110, and replenishes ink to the secondary ink cartridge 120 through pressure difference. This achieves the monitoring and stable replenishment of ink in the secondary ink cartridge 120, effectively solving the problem of large air pressure fluctuations in the secondary ink cartridge 120 in traditional ink supply methods, and improving the stability and printing quality of the 3D printer.

[0056] In one embodiment of this application, as Figure 1 As shown, the ink supply system includes multiple primary ink storage boxes 110 and multiple secondary ink storage boxes 120. Each secondary ink storage box 120 corresponds to and is connected to a primary ink storage box 110. The positive pressure pump 130 is connected to the multiple primary ink storage boxes 110.

[0057] The ink supply system includes multiple primary ink cartridges 110, multiple secondary ink cartridges 120, a positive pressure pump 130, a control module, and a print head 140. Each secondary ink cartridge 120 is connected to a primary ink cartridge 110 via an independent connecting pipe. The positive pressure pump 130 is connected to the air inlets 103 of the multiple primary ink cartridges 110 via connecting pipes.

[0058] Specifically, the number of primary ink cartridges 110 is set according to printing needs. For example, eight primary ink cartridges 110 can be set up to store different colored inks (such as cyan, magenta, yellow, black, white, etc.) or different functional printing materials (such as support materials, UV-curable resin, transparent ink, etc.). Each primary ink cartridge 110 is equipped with an independent ink outlet 104, which is connected to the corresponding secondary ink cartridge 120 through a separate connecting pipe, forming independent ink supply branches. This independent branch design can effectively avoid mixing and contamination of inks of different colors or materials during the transportation process, ensuring the accuracy of printed colors and the stability of material performance.

[0059] The positive pressure pump 130 is connected to multiple primary ink cartridges 110 via connecting pipes, enabling simultaneous supply of slightly positive pressure gas to multiple primary ink cartridges 110. Alternatively, the positive pressure pump 130 can be connected to multiple primary ink cartridges 110 via connecting pipes equipped with a diverter valve. The diverter valve is a multi-channel solenoid valve, and its channel switching is controlled by the control module. When the first level detector 101 of a secondary ink cartridge 120 sends a low level signal, the control module first controls the diverter valve to switch to the connecting pipe of the corresponding primary ink cartridge 110, and then starts the positive pressure pump 130 to introduce slightly positive pressure gas into that primary ink cartridge 110 for targeted ink replenishment. After ink replenishment is completed, the control module shuts off the positive pressure pump 130 and switches the diverter valve to the closed state, awaiting the next ink replenishment command.

[0060] In one embodiment of this application, multiple primary ink cartridges 110 are all connected to the same positive pressure pump 130. Using a single positive pressure pump 130 to supply air to multiple primary ink cartridges 110 reduces equipment cost and structural complexity compared to configuring a separate positive pressure pump 130 for each ink supply branch, while also facilitating unified maintenance and pressure control.

[0061] In this embodiment, each secondary ink cartridge 120 is equipped with a first liquid level detector 101, and the liquid level signal of each secondary ink cartridge 120 is transmitted to the control module for centralized processing and logical judgment. For example, when the liquid level of one of the secondary ink cartridges 120 is lower than the low liquid level threshold, the control module only activates the ink supply branch of the primary ink cartridge 110 corresponding to that secondary ink cartridge 120, while other branches remain closed to avoid accidental replenishment of irrelevant ink.

[0062] Furthermore, the control module can dynamically adjust the output pressure of the positive pressure pump 130 based on the rate of change of the ink level in each secondary ink cartridge 120. For example, for secondary ink cartridges 120 where the ink level drops rapidly (such as colors used extensively during printing), the air supply pressure of the corresponding primary ink cartridge 110 can be appropriately increased to accelerate ink replenishment. For secondary ink cartridges 120 where the ink level drops slowly, the air supply pressure can be reduced to decrease energy consumption.

[0063] This embodiment sets up multiple independent ink supply branches and a positive pressure pump 130 to control the positive pressure of these branches, achieving stable ink supply for multi-color and multi-material 3D printing. This ensures the independence and purity of different inks, simplifies the system structure, and reduces equipment costs, making it suitable for applications with high requirements for printing color and material diversity.

[0064] In one embodiment of this application, as Figure 1 As shown, a first filter 150 is installed on the connecting pipe between the primary ink cartridge 110 and the secondary ink cartridge 120, and a second filter 160 is installed between the secondary ink cartridge 120 and the print head 140.

[0065] The first filter 150 is installed on the connecting pipe between the primary ink reservoir 110 and the secondary ink reservoir 120. Its main function is to filter large particulate impurities in the ink of the primary ink reservoir 110. During storage or transportation, ink may develop a small amount of sediment or become mixed with impurities such as fibers and dust due to factors such as temperature changes and vibration. If it directly enters the secondary ink reservoir 120, it may clog subsequent pipelines. By installing the first filter 150 between the outlet 104 of the primary ink reservoir 110 and the secondary ink reservoir 120, the ink flowing out of the primary ink reservoir 110 first passes through the first filter 150, where large particulate impurities are trapped, and the purified ink enters the secondary ink reservoir 120. The filter element material of the first filter 150 can be polypropylene or nylon, which have good ink resistance and filtration efficiency, and are easy to replace.

[0066] During operation, the nozzles of the printhead 140 are in direct contact with the external environment. When the printhead stops spraying ink, the nozzles are open to the outside air. However, when the ink level in the secondary ink reservoir 120 drops due to printing consumption, its internal pressure may be lower than the external atmospheric pressure, allowing outside air to easily be drawn into the secondary ink reservoir 120 through the nozzles and connecting pipes. If dust, fibers, moisture, and other impurities in the air enter the secondary ink reservoir 120, they will mix with the ink to form sediment or gel, affecting not only the ink's fluidity and color stability but also potentially clogging the printhead nozzles, leading to ink gaps or printing defects. The second filter 160 is installed between the ink outlet 104 of the secondary ink reservoir 120 and the printhead 140 to prevent impurities in the outside air from entering the secondary ink reservoir 120 through the printhead 140, thus avoiding ink contamination.

[0067] This embodiment of the application filters impurities in the ink by setting a first filter 150 between the primary ink reservoir 110 and the secondary ink reservoir 120; and prevents external air impurities from back-contaminating the ink by setting a second filter 160 between the secondary ink reservoir 120 and the print head 140. The first filter 150 and the second filter 160 form a double protection, improving the anti-contamination capability of the ink supply system. It is suitable for 3D printing scenarios with complex environments such as high dust and high humidity, and helps to ensure the cleanliness of the ink and the long-term stable operation of the print head 140.

[0068] In one embodiment of this application, as Figure 1 As shown, an ink supply valve 170 is installed on the connecting pipe between the primary ink reservoir 110 and the secondary ink reservoir 120. The ink supply valve 170 is electrically connected to the control module and is used to control the on / off state of the ink supply path. The ink supply valve 170 can be a normally closed solenoid valve, which is initially closed and is triggered to open by the control module during the ink replenishment process.

[0069] When the first level detector 101 of the secondary ink cartridge 120 detects that the ink level is below the low level threshold, the control module first sends an opening signal to the ink supply valve 170, which opens the liquid channel between the primary ink cartridge 110 and the secondary ink cartridge 120. Then, the control module starts the positive pressure pump 130, introducing gas into the primary ink cartridge 110, creating a slightly positive pressure state. Under the pressure of the gas, the ink flows into the secondary ink cartridge 120 through the first filter 150 and the ink supply valve 170. When the ink level in the secondary ink cartridge 120 rises back to the high level threshold, or when the positive pressure pump 130 has operated for a preset ink replenishment time, the control module first stops the positive pressure pump 130 and then closes the ink supply valve 170, completing the ink replenishment process.

[0070] The ink supply valve 170 allows for individual control of each ink supply branch and solves the ink backflow problem that may occur after the positive pressure stops. Without the ink supply valve 170, multiple ink supply branches may be supplied with ink simultaneously, while some secondary ink cartridges 120 may not require ink supply. Furthermore, without the ink supply valve 170, when the positive pressure pump 130 stops, the pressure difference between the primary ink cartridge 110 and the secondary ink cartridge 120 disappears, and ink in the secondary ink cartridge 120 may flow back into the primary ink cartridge 110, causing fluctuations in the ink level of the secondary ink cartridge 120, and even triggering a new round of ink replenishment, resulting in energy waste and unstable ink supply. Closing the ink supply valve 170 physically isolates the ink in the secondary ink cartridge 120 from the primary ink cartridge 110, ensuring stable ink levels.

[0071] Furthermore, the control module can precisely control the ink replenishment amount by adjusting the opening duration of the ink supply valve 170 and the working pressure of the positive pressure pump 130. For example, for a smaller secondary ink cartridge 120, the opening time of the ink supply valve 170 can be shortened or the pressure of the positive pressure pump 130 can be reduced to prevent ink overflow. For printing scenarios where ink consumption is rapid, the opening time can be extended or the pressure increased to accelerate ink replenishment. This embodiment of the application, through the coordinated operation of the ink supply valve 170 and the control module, improves the controllability and stability of the ink supply system, effectively reducing ink backflow and level fluctuations.

[0072] Since the air inlet of the positive pressure pump 130 needs to draw in air, and there are certain impurities in the air, if the air with impurities is directly pumped into the primary ink storage cartridge 110, it may affect the quality of the ink in the primary ink storage cartridge 110.

[0073] To address this problem, in one embodiment of this application, as follows: Figure 1 As shown, one end of the positive pressure pump 130 is connected to the primary ink storage cartridge 110 via a connecting pipe, and the other end of the positive pressure pump 130 is connected to an air filter 180.

[0074] This application embodiment optimizes the air inlet of the positive pressure pump 130 by connecting an air filter 180 at the inlet of the positive pressure pump 130 to purify the gas entering the primary ink cartridge 110. The air filter 180 can employ a two-stage filtration structure. The first stage is a coarse filter layer, which can be made of non-woven fabric and can filter larger dust particles in the air. The second stage is a fine filter layer, which can use a HEPA filter element and can filter smaller particles, water vapor, oil, and other impurities. It should be noted that this application embodiment does not limit the specific type of air filter 180. The air filter 180 with the two-stage filtration structure described above is only a specific example; any type of air filter 180 that can filter impurities in the air can be used.

[0075] When the positive pressure pump 130 is operating, outside air first enters the air filter 180. After filtration, the clean air enters the positive pressure pump 130, is then compressed, and flows into the primary ink reservoir 110. Without the air filter 180, dust, moisture, and other impurities in the air may enter the primary ink reservoir 110 with the air, mixing with the ink to form sediment or causing ink deterioration, affecting ink flow and printing performance. Furthermore, oil stains may corrode the inner wall of the primary ink reservoir 110 or the seals of the connecting pipes, reducing the system's lifespan.

[0076] The air filter 180's filter element can be designed as a removable structure, allowing users to replace it periodically, thus reducing the maintenance cost of the air filter 180. The control module can determine whether the filter element is clogged by monitoring the pressure difference between the inlet and outlet of the air filter 180. When the pressure difference exceeds a preset threshold, the control module triggers an alarm signal to remind the user to replace the filter element.

[0077] In one embodiment of this application, as Figure 1 As shown, a second liquid level detector 102 is provided in the primary ink storage cartridge 110. The second liquid level detector 102 is electrically connected to the control module and is used to detect the amount of ink stored in the primary ink storage cartridge 110.

[0078] In the ink supply system provided in this embodiment, a second liquid level detector 102 is provided in the primary ink reservoir 110. The second liquid level detector 102 can be a capacitive liquid level sensor, an ultrasonic liquid level sensor, or a float-type liquid level switch. The second liquid level detector 102 can be installed on the side wall or bottom of the primary ink reservoir 110 and can detect the actual ink level in the primary ink reservoir 110 in real time. The second liquid level detector 102 is electrically connected to the control module and can transmit the detected liquid level signal to the control module in real time.

[0079] The control module can simultaneously receive the ink level signal from the secondary ink cartridge 120 transmitted by the first ink level detector 101 and the ink level signal from the primary ink cartridge 110 transmitted by the second ink level detector 102. When the second ink level detector 102 detects that the ink level in the primary ink cartridge 110 is lower than a preset warning threshold, the control module can issue an ink shortage warning signal to remind the operator to replenish ink in the primary ink cartridge 110 in a timely manner. If the ink level in the primary ink cartridge 110 is too low, even if the secondary ink cartridge 120 triggers an ink replenishment signal, the positive pressure pump 130 may not be able to effectively replenish ink, which will cause the printing process to be interrupted and affect the efficiency of 3D printing.

[0080] In this embodiment, the second liquid level detector 102 and the first liquid level detector 101 form a dual-layer liquid level detection system for the ink supply system, enabling the detection of ink reserves. The control module performs comprehensive regulation based on the signals from the two liquid level detectors, ensuring timely replenishment of the secondary ink cartridge 120 while proactively preventing ink replenishment failures caused by insufficient ink in the primary ink cartridge 110. This improves the continuity and reliability of the ink supply system, reduces the probability of printing interruptions due to insufficient ink, and avoids scrapped printed parts caused by failure to replenish ink in a timely manner, thereby improving the production efficiency of 3D printing.

[0081] In one embodiment of this application, reference is made to Figure 2 , Figure 2 This is a schematic diagram of a primary ink storage cartridge 110 in an ink supply system provided in an embodiment of this application. Figure 2 As shown, the primary ink cartridge 110 includes an air inlet 103 and a liquid outlet 104. The positive pressure pump 130 is connected to the air inlet 103 through a connecting pipe. The secondary ink cartridge 120 is connected to the liquid outlet 104 through a connecting pipe. The air inlet 103 is higher than the liquid outlet 104 in the vertical direction.

[0082] In this ink supply system, the primary ink reservoir 110 is equipped with an air inlet 103 and a liquid outlet 104. A positive pressure pump 130 is connected to the air inlet 103 of the primary ink reservoir 110 via a connecting pipe, and the secondary ink reservoir 120 is connected to the liquid outlet 104 of the primary ink reservoir 110 via a connecting pipe. The vertical height of the air inlet 103 is higher than that of the liquid outlet 104. The air inlet 103 corresponds to the gas phase region within the primary ink reservoir 110, and the liquid outlet 104 corresponds to the liquid phase region within the primary ink reservoir 110.

[0083] When the positive pressure pump 130 is working, compressed gas enters the gas phase region of the primary ink reservoir 110 through the air inlet 103, forming a stable pressure layer on the upper part of the primary ink reservoir 110. This pressure layer acts evenly on the surface of the ink, and the pressure difference pushes the ink out of the outlet 104 and transported to the secondary ink reservoir 120. If the air inlet 103 is at the same height as the outlet 104 or if the air inlet 103 is lower than the outlet 104, the gas input by the positive pressure pump 130 may directly impact the surface of the ink, causing ink splashing. At the same time, a large number of bubbles will be generated in the ink. After the bubbles enter the secondary ink reservoir 120 and the print head 140 with the ink, they may cause uneven ink output, ink interruption and other problems, affecting the 3D printing effect.

[0084] In this embodiment, the design of the air inlet 103 being higher than the liquid outlet 104 allows the micro-positive pressure applied by the positive pressure pump 130 to act smoothly on the ink surface. This avoids direct gas impact on the ink, preventing splashing and bubbles, ensuring no air bubbles are mixed in during ink delivery, and simultaneously allowing the air pressure within the primary ink reservoir 110 to be evenly distributed, improving the stability of ink delivery. Combined with the micro-positive pressure ink replenishment method, this makes the ink replenishment process of the secondary ink reservoir 120 more stable, minimizing ink dripping from the print head 140 and improving the forming accuracy of 3D printing.

[0085] In one embodiment of this application, in the vertical direction, the ink level in the primary ink reservoir 110 is higher than the ink level in the secondary ink reservoir 120.

[0086] During actual installation, the ink supply system ensures that the ink level in the primary ink reservoir 110 is higher than the ink level in the secondary ink reservoir 120 in the vertical direction. This utilizes the gravitational potential energy of the liquid to create a natural liquid level difference. The connecting pipe between the primary ink reservoir 110 and the secondary ink reservoir 120 is set along the direction of the liquid level difference to achieve gravity-assisted ink delivery.

[0087] In this embodiment, the ink delivery power is jointly provided by the micro-positive pressure supplied by the positive pressure pump 130 and the gravitational potential energy formed by the liquid level difference. The assist of gravity makes the ink flow more smoothly in the connecting pipe, which can effectively reduce the workload of the positive pressure pump 130, reduce the energy consumption of the positive pressure pump 130, and extend the service life of the positive pressure pump 130. At the same time, the effect of gravity can make the ink form a stable flow state in the pipe, reducing the flow rate changes caused by air pressure fluctuations.

[0088] Furthermore, when the positive pressure output by the positive pressure pump 130 is relatively low, gravitational potential energy can compensate for the insufficient pressure, avoiding the problem of untimely ink replenishment due to insufficient pressure and ensuring sufficient ink supply to the secondary ink reservoir 120. When the positive pressure pump 130 stops working, the static pressure formed by the height difference can temporarily maintain the position of the ink in the connecting pipe, preventing the formation of negative pressure cavities in the pipe. If a sudden failure of the ink supply system causes the positive pressure pump 130 to stop, gravity can also allow the ink in the primary ink reservoir 110 to continue flowing to the secondary ink reservoir 120 for a period of time, buying time for the user to handle the fault and reducing the risk of unusable printed materials.

[0089] In this embodiment, by utilizing the ink level difference between the two ink reservoirs and the slight positive pressure generated by the positive pressure pump 130, the ink delivery efficiency is effectively improved while ensuring stable air pressure and no significant fluctuations during the ink replenishment process. This allows the secondary ink reservoir 120 to respond to ink replenishment more quickly. Simultaneously, the assist of gravity makes the ink delivery process more stable, reducing fluctuations in ink output caused by pressure changes, which is beneficial for improving the forming effect of 3D printing.

[0090] In one embodiment of this application, as Figure 1 As shown, the multiple primary ink storage cartridges 110 include a primary white ink storage cartridge 111, which is used to store white ink. The multiple secondary ink storage cartridges 120 include a secondary white ink storage cartridge 121, which is connected to the primary white ink storage cartridge 111. Both the primary white ink storage cartridge 111 and the secondary white ink storage cartridge 121 are equipped with a stirrer 190.

[0091] In the ink supply system of this embodiment, the multiple primary ink cartridges 110 include a primary white ink cartridge 111, which stores the white ink required for 3D printing. The multiple secondary ink cartridges 120 include a secondary white ink cartridge 121 corresponding to the primary white ink cartridge 111, and the secondary white ink cartridge 121 is sealed and connected to the primary white ink cartridge 111. As the base color for full-color 3D printing, the uniformity of white ink directly affects the color reproduction of color printing. However, white ink usually contains solid particles (such as titanium dioxide), which are prone to sedimentation and clumping during storage, resulting in uneven ink concentration, affecting the consistency of printed colors, and even clogging the ink supply pipes and printheads.

[0092] In this embodiment, both the primary white ink storage cartridge 111 and the secondary white ink storage cartridge 121 are equipped with a stirrer 190, the stirring end of which extends into the corresponding ink storage cavity of the cartridge. The stirrer 190 may employ a magnetic stirring structure. The stirrer 190 is electrically connected to the control module, which can control the stirrer 190 to perform continuous or intermittent stirring according to actual usage requirements. When the stirrer 190 is working, it can fully stir the white ink in the cartridge, preventing solid particles in the white ink from settling to the bottom of the cartridge and avoiding particle clumping, thus maintaining a uniform ink concentration as much as possible during storage and transportation.

[0093] The agitator 190 of the primary white ink reservoir 111 ensures the overall uniformity of the stored white ink, preventing uneven particle concentration in the white ink delivered to the secondary white ink reservoir 121. The agitator 190 of the secondary white ink reservoir 121 further agitates the temporarily stored white ink, ensuring uniformity of the white ink entering the print head 140. This coordinated design of the agitator 190 and the white ink reservoir effectively solves the technical problems of white ink particle sedimentation and clumping, ensuring uniform ink output, improving color reproduction and background smoothness in full-color 3D printing, and preventing particle clogging of the filter and print head 140. Working in conjunction with the filter structure, it further ensures smooth operation of the ink supply system.

[0094] In one embodiment of this application, a 3D printer is also provided. (See reference...) Figure 3 , Figure 3 This is a schematic diagram of a 3D printer provided in an embodiment of this application. Figure 3 The 3D printer shown includes the ink supply system of any of the foregoing embodiments. The 3D printer may also include a printing platform, a motion module, a UV curing module, and a human-machine interface (the aforementioned modules). Figure 3 (Not shown in the image). The printhead 140 of the ink supply system is mounted on the motion module and can move in different directions under the drive of the control module to achieve ink jetting in three-dimensional space. The UV curing module can be installed next to the printhead 140 to cure the jetted ink in real time. The human-machine interface is used for parameter setting and printing process monitoring.

[0095] The ink supply system features multiple primary ink cartridges 110 and multiple secondary ink cartridges 120, capable of storing inks of various colors to meet the diverse material requirements of full-color 3D printing. The system employs a positive pressure pump 130 to apply a slight positive pressure for ink replenishment, ensuring stable air pressure within the secondary ink cartridges 120 and preventing ink dripping from the print head 140. Combined with filters, agitators 190, and level detectors, it achieves clean, uniform ink delivery and replenishment. This improves the printing accuracy and surface finish of 3D printed parts, reduces layer defects, and lowers the probability of warping during the printing of large or complex structures, thus reducing the need for additional support structures. The independent ink supply valve 170 design simplifies the color-changing process for 3D printers, enabling independent color changing and cleaning of individual ink streams, reducing ink waste during color changes.

[0096] The 3D printer in this embodiment combines the stable and consistent ink supply advantages of the ink supply system with the molding technology of 3D printing, which is conducive to achieving high-quality full-color 3D printing, improving the production efficiency and molding effect of 3D printing, while reducing ink consumption and equipment maintenance costs, and meeting the needs of full-color 3D printing in different scenarios.

[0097] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application.

[0098] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0099] Although preferred embodiments of the present application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the scope of protection of this application includes the preferred embodiments as well as all changes and modifications falling within the scope of the embodiments of this application.

[0100] This document uses specific examples to illustrate the working principle and implementation method of an ink supply system and a 3D printer of this application. The description of the above embodiments is only for the purpose of helping to understand the specific settings and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation method and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

[0101] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. An ink supply system, characterized in that, Includes a control module, primary ink cartridge, secondary ink cartridge, positive pressure pump, and printhead; The primary ink reservoir is connected to the secondary ink reservoir, the secondary ink reservoir is connected to the print head, and the positive pressure pump is connected to the primary ink reservoir. The secondary ink storage cartridge is equipped with a first liquid level detector, which is used to detect the amount of ink stored in the secondary ink storage cartridge. The control module is electrically connected to the positive pressure pump and the first liquid level detector respectively. The control module is used to control the operation of the positive pressure pump according to the detection signal of the first liquid level detector. The positive pressure pump is used to increase the pressure inside the primary ink reservoir to deliver the ink from the primary ink reservoir to the secondary ink reservoir.

2. The ink supply system according to claim 1, characterized in that, The ink supply system includes multiple primary ink storage boxes and multiple secondary ink storage boxes, each secondary ink storage box corresponds to and is connected to one primary ink storage box, and the positive pressure pump is connected to the multiple primary ink storage boxes.

3. The ink supply system according to claim 2, characterized in that, A first filter is installed on the connecting pipe between the primary ink reservoir and the secondary ink reservoir, and a second filter is installed between the secondary ink reservoir and the print head.

4. The ink supply system according to claim 3, characterized in that, An ink supply valve is installed on the connecting pipe between the primary ink storage box and the secondary ink storage box, and the ink supply valve is electrically connected to the control module.

5. The ink supply system according to any one of claims 2 to 4, characterized in that, One end of the positive pressure pump is connected to the primary ink storage cartridge via a connecting pipe, and the other end of the positive pressure pump is connected to an air filter.

6. The ink supply system according to claim 5, characterized in that, All of the multiple primary ink cartridges are connected to the same positive pressure pump.

7. The ink supply system according to any one of claims 1 to 4, characterized in that, The positive pressure pump is used to increase the pressure inside the primary ink reservoir, so that the air pressure inside the primary ink reservoir is 0.02 MPa to 0.05 MPa higher than the air pressure inside the secondary ink reservoir.

8. The ink supply system according to claim 7, characterized in that, The control module controls the output pressure and flow rate of the positive pressure pump, and controls the pressure fluctuation in the secondary ink storage cartridge to within ±0.003MPa.

9. The ink supply system according to claim 1, characterized in that, The primary ink cartridge is equipped with a second liquid level detector, which is electrically connected to the control module. The second liquid level detector is used to detect the amount of ink in the primary ink cartridge, and the control module receives the detection signal from the second liquid level sensor.

10. The ink supply system according to claim 1, characterized in that, The primary ink storage cartridge includes an air inlet and a liquid outlet. The positive pressure pump is connected to the air inlet via a connecting pipe. The secondary ink storage cartridge is connected to the liquid outlet via a connecting pipe. The air inlet is vertically higher than the liquid outlet.

11. The ink supply system according to claim 1, characterized in that, In the vertical direction, the ink level in the primary ink reservoir is higher than the ink level in the secondary ink reservoir.

12. The ink supply system according to claim 2, characterized in that, The plurality of primary ink storage cartridges include a primary white ink storage cartridge, which is used to store white ink. The plurality of secondary ink storage cartridges include a secondary white ink storage cartridge, which is connected to the primary white ink storage cartridge. Both the primary and secondary white ink storage cartridges are equipped with a stirrer.

13. A 3D printer, characterized in that, Including the ink supply system as described in any one of claims 1 to 9.

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