Inkway air pressure control system

Abstract

This invention provides an ink path air pressure control system, relating to the field of 3D printer technology. Through independently configured positive and negative pressure air supply devices, the ink inlet chamber is kept under positive pressure, while the ink return chamber is kept under negative pressure. Under the interaction of these two pressure states, liquid wax flows from the ink inlet chamber through the printhead into the ink return chamber. As the liquid volume in the ink return chamber increases, the ink pump operates, pumping the liquid wax from the ink return chamber back to the ink inlet chamber, forming a circulation. The positive and negative pressure air supply devices create a stable pressure difference, providing a stable circulation flow rate and ensuring sufficient liquid wax inside the printhead. This reduces the likelihood of poor printing results due to insufficient wax supply and also prevents liquid wax from dripping out of the printhead.

Description

Technical Field

[0001] This utility model relates to the field of 3D printer technology, and in particular to an ink path air pressure control system. Background Technology

[0002] With the development of 3D printing technology, multi-material 3D printing technology has gradually become a research hotspot. Among them, MJP (Multi-Jet Printing) technology has attracted much attention due to its high precision and ability to form complex structures. MJP 3D printing technology usually requires the simultaneous use of two different materials, structural materials and support materials, to complete the printing task. These two materials need to have different physical properties to meet the printing requirements.

[0003] In MJP 3D printing, the condition of the printhead plays a decisive role in print quality. To maintain optimal printhead performance, the molten wax inside the printhead needs to meet two key requirements simultaneously: maintaining optimal meniscus pressure and a stable circulation speed. Both of these requirements necessitate precise air pressure control. Therefore, an MJP 3D printing system must be equipped with a comprehensive ink path air pressure control system capable of real-time adjustment of air pressure parameters to ensure stable ink supply throughout the printing process. Simultaneously, this system must effectively handle potential issues such as ink dripping, printhead clogging, and insufficient ink supply to guarantee smooth printing and high-quality finished products. Utility Model Content

[0004] The purpose of this invention is to provide an ink path air pressure control system to alleviate the technical problem in the prior art where the nozzle circulation speed cannot be controlled during 3D printing, which affects the quality of the printed product.

[0005] The ink path air pressure control system provided by this utility model is used in a 3D printer and includes an ink inlet chamber, an ink return chamber, a printhead, an ink pump, a positive pressure air supply device, and a negative pressure air supply device.

[0006] The printhead is connected to the ink inlet chamber and the ink return chamber respectively, and the ink pump is disposed between the ink return chamber and the ink inlet chamber so that the liquid in the ink return chamber can flow back to the ink inlet chamber;

[0007] The positive pressure air supply device is connected to the ink inlet chamber, and the negative pressure air supply device is connected to the ink return chamber. The positive pressure air supply device and the negative pressure air supply device are used to create a pressure difference between the ink inlet chamber and the ink return chamber, so that the liquid in the ink inlet chamber flows back to the ink return chamber through the printhead.

[0008] In an optional implementation,

[0009] The ink-line air pressure control system also includes a first control valve and a second control valve.

[0010] The first control valve is located on the air path connecting the positive pressure air supply device and the ink inlet chamber;

[0011] The second control valve is located on the air path connecting the negative pressure air supply device and the ink return chamber.

[0012] In an optional implementation,

[0013] The positive pressure air supply device includes a first positive pressure air box, a second positive pressure air box, and a first positive pressure pump;

[0014] The first positive pressure air box is connected to the second positive pressure air box, and the second positive pressure air box is connected to the ink inlet chamber through the first control valve;

[0015] The first positive pressure pump is connected to the first positive pressure gas box, and the first positive pressure pump is used to adjust the positive pressure value in the first positive pressure gas box.

[0016] In an optional implementation,

[0017] The positive pressure air supply device also includes a positive pressure sensor and a positive pressure zeroing valve;

[0018] The positive pressure zeroing valve is installed in the gas path between the positive pressure sensor and the first positive pressure gas box. The positive pressure zeroing valve is used to control the opening and closing of the gas path between the positive pressure sensor and the first positive pressure gas box. When it is in the open state, the positive pressure sensor is used to connect to the atmosphere for zeroing. When it is in the connected state, the positive pressure sensor is used to detect the positive pressure value of the first positive pressure gas box.

[0019] In an optional implementation,

[0020] The positive pressure gas supply device also includes a positive pressure relief valve;

[0021] The positive pressure relief valve is connected to the first positive pressure gas box, and the positive pressure relief valve is used to relieve pressure on the first positive pressure gas box.

[0022] In an optional implementation,

[0023] The negative pressure air supply device includes a first negative pressure air box, a second negative pressure air box, and a negative pressure pump;

[0024] The first negative pressure air box is connected to the second negative pressure air box, and the second negative pressure air box is connected to the ink return chamber through the second control valve;

[0025] The negative pressure pump is connected to the first negative pressure gas box, and the negative pressure pump is used to adjust the negative pressure value in the first negative pressure gas box.

[0026] In an optional implementation,

[0027] The negative pressure gas supply device also includes a negative pressure sensor and a negative pressure zeroing valve;

[0028] The negative pressure zeroing valve is installed in the air path between the negative pressure sensor and the first negative pressure air box. The negative pressure zeroing valve is used to control the opening and closing of the air path between the negative pressure sensor and the first negative pressure air box. When it is in the open state, the negative pressure sensor is used to connect to the atmosphere for zeroing. When it is in the connected state, the negative pressure sensor is used to detect the negative pressure value of the first negative pressure air box.

[0029] In an optional implementation,

[0030] The negative pressure gas supply device also includes a negative pressure relief valve;

[0031] The negative pressure relief valve is connected to the first negative pressure gas box, and the negative pressure relief valve is used to relieve pressure in the first negative pressure gas box.

[0032] In an optional implementation,

[0033] The ink path air pressure control system also includes a second positive pressure pump;

[0034] The second positive pressure pump is connected to the first control valve and the second control valve respectively, and the second positive pressure pump is used to provide positive pressure to the ink inlet chamber and the ink return chamber.

[0035] In an optional implementation,

[0036] The ink-line air pressure control system also includes a connecting device;

[0037] The connecting device is connected to the positive pressure air supply device and the negative pressure air supply device respectively. The connecting device is configured to connect the positive pressure air supply device and the negative pressure air supply device when the system is powered off, so that the pressure of the ink inlet chamber and the ink return chamber are equal.

[0038] The ink path air pressure control system provided by this utility model, through independently set positive pressure air supply device and negative pressure air supply device, ensures that the ink inlet chamber is in a positive pressure state and the ink return chamber is in a negative pressure state. Under the interaction of the two pressure states, liquid wax enters the ink return chamber from the ink inlet chamber through the printhead. As the liquid volume in the ink return chamber increases, the ink pump works to pump the liquid wax in the ink return chamber back to the ink inlet chamber, forming a circulation. The setting of positive pressure air supply device and negative pressure air supply device creates a stable pressure difference, provides a stable circulation flow rate, ensures that there is sufficient liquid wax inside the printhead, reduces the situation of poor printing effect due to insufficient wax supply, and at the same time ensures that the liquid wax inside the printhead will not drip out. Attached Figure Description

[0039] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0040] Figure 1 The pneumatic circuit diagram of the ink pneumatic control system in working or standby state provided in this embodiment of the utility model;

[0041] Figure 2 This is an air path diagram of the ink path air pressure control system during the printhead cleaning state provided in an embodiment of the present utility model;

[0042] Figure 3 The pneumatic circuit diagram of the ink pneumatic control system in the power failure protection state provided in the embodiment of this utility model.

[0043] Icons: 10-Ink inlet chamber; 20-Ink return chamber; 30-Printhead; 40-Ink pump; 50-First control valve; 60-Second control valve; 110-First positive pressure air box; 120-Second positive pressure air box; 130-First positive pressure pump; 140-Positive pressure sensor; 150-Positive pressure zeroing valve; 160-Positive pressure relief valve; 170-Positive pressure boosting valve; 210-First negative pressure air box; 220-Second negative pressure air box; 230-Negative pressure pump; 240-Negative pressure sensor; 250-Negative pressure zeroing valve; 260-Negative pressure relief valve; 270-Negative pressure boosting valve; 300-Second positive pressure pump; 310-Pressure sensor; 400-Connecting device. Detailed Implementation

[0044] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0045] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0046] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0047] The specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the scope of this utility model.

[0048] like Figure 1 , Figure 2 and Figure 3 As shown, the ink path air pressure control system provided in this embodiment is used in 3D printing equipment, and is particularly suitable for printing applications of phase change materials such as liquid wax. The system includes an ink inlet chamber 10, an ink return chamber 20, a nozzle 30, an ink pump 40, a positive pressure air supply device, and a negative pressure air supply device. The nozzle 30 is connected to both the ink inlet chamber 10 and the ink return chamber 20. The ink pump 40 is connected to the nozzle 30 and circulates the ink path so that the liquid in the ink return chamber 20 can flow back to the ink inlet chamber 10, forming an ink circulation path.

[0049] A positive pressure air supply device is connected to the ink inlet chamber 10, and a negative pressure air supply device is connected to the ink return chamber 20. Through the coordinated action of the positive and negative pressure air supply devices, the ink inlet chamber 10 is under positive pressure, and the ink return chamber 20 is under negative pressure, thus creating a stable pressure difference between them. This pressure difference drives liquid wax from the ink inlet chamber 10 through the printhead 30 to the ink return chamber 20, forming a circulating flow. When the liquid wax in the ink return chamber 20 accumulates to a certain amount, the ink pump 40 starts, pumping the liquid wax back to the ink inlet chamber 10, thereby achieving the recycling of the ink.

[0050] The ink path air pressure control system provided in this embodiment, through the independent setting of positive pressure air supply device and negative pressure air supply device, forms a stable pressure difference drive between ink inlet chamber 10 and ink return chamber 20, so that liquid wax can continuously and smoothly flow from ink inlet chamber 10 through printhead 30 into ink return chamber 20, forming a closed loop circulation, avoiding the problem of uneven flow caused by pressure fluctuation in traditional ink supply systems; the printhead 30 always maintains sufficient liquid wax, ensuring that there is enough ink available for each print, avoiding problems such as ink interruption, ink splatter, and uneven spraying caused by insufficient ink supply, thereby significantly improving the stability of print quality; the liquid wax is kept in a dynamic circulation state in printhead 30, which can effectively prevent liquid wax from condensing, depositing, or accumulating air bubbles due to static placement inside printhead 30, further improving the response speed and long-term operational reliability of printhead 30.

[0051] In this embodiment, the ink path air pressure control system further includes a first control valve 50 and a second control valve 60. The first control valve 50 is located in the air path between the positive pressure air supply device and the ink inlet chamber 10, and the second control valve 60 is located in the air path between the negative pressure air supply device and the ink return chamber 20. Preferably, both the first control valve 50 and the second control valve 60 are solenoid valves, facilitating automatic on / off control via the control system.

[0052] Furthermore, the positive pressure air supply device includes a first positive pressure air box 110, a second positive pressure air box 120, and a first positive pressure pump 130. The first positive pressure air box 110 is connected to the second positive pressure air box 120, and the second positive pressure air box 120 is connected to the ink inlet chamber 10 through a first control valve 50. The second positive pressure air box 120 has a certain volume, which can reduce the air pressure fluctuations in the first positive pressure air box 110 and the ink inlet chamber 10 caused by operation, thus buffering the impact of air pressure fluctuations in the first positive pressure air box 110 on the ink inlet chamber 10, and also buffering the impact of air pressure fluctuations in the ink inlet chamber 10 on the first positive pressure air box 110.

[0053] The first positive pressure pump 130 is connected to the first positive pressure gas box 110 and is used to adjust the positive pressure value inside the first positive pressure gas box 110. The first positive pressure pump 130 is equipped with a positive pressure boosting valve 170, which is used to control the pressurization process of the first positive pressure gas box 110. The first positive pressure gas box 110 is also equipped with a positive pressure relief valve 160.

[0054] In addition, the positive pressure air supply device also includes a positive pressure sensor 140 and a positive pressure zeroing valve 150. The positive pressure zeroing valve 150 is installed in the air path between the positive pressure sensor 140 and the first positive pressure air box 110 to control the on / off state of both. Before the system is used, the positive pressure zeroing valve 150 is energized to connect the positive pressure sensor 140 to the atmosphere for zeroing. After zeroing, the positive pressure zeroing valve 150 is de-energized, and the positive pressure sensor 140 is connected to the first positive pressure air box 110 to detect the positive pressure value inside the first positive pressure air box 110. When the detected positive pressure value is too high, the positive pressure relief valve 160 is intermittently energized and opened to relieve pressure in the first positive pressure air box 110. When the positive pressure value is too low, the first positive pressure pump 130 is started, and the positive pressure boosting valve 170 is used to boost the pressure until the set value is reached.

[0055] Similarly, the negative pressure air supply device includes a first negative pressure air box 210, a second negative pressure air box 220, and a negative pressure pump 230. The first negative pressure air box 210 is connected to the second negative pressure air box 220, and the second negative pressure air box 220 is connected to the ink return chamber 20 through a second control valve 60. The second negative pressure air box 220 has a certain volume, which can reduce the air pressure fluctuations in the first negative pressure air box 210 and the ink return chamber 20 caused by operation, thus buffering the impact of air pressure fluctuations in the first negative pressure air box 210 on the ink return chamber 20, and vice versa. The first negative pressure air box 210 is also equipped with a negative pressure relief valve 260.

[0056] The negative pressure pump 230 is connected to the first negative pressure air box 210 and is used to adjust the negative pressure value in the first negative pressure air box 210. The negative pressure pump 230 is equipped with a negative pressure boosting valve 270, which is used to control the negative pressure adjustment of the first negative pressure air box 210.

[0057] The negative pressure air supply device also includes a negative pressure sensor 240 and a negative pressure zeroing valve 250. The negative pressure zeroing valve 250 is located between the negative pressure sensor 240 and the first negative pressure air box 210, and is used to control their on / off state. Before system use, the negative pressure zeroing valve 250 is energized, allowing the negative pressure sensor 240 to connect to the atmosphere for zeroing. After zeroing, the negative pressure zeroing valve 250 is de-energized, and the negative pressure sensor 240 is connected to the first negative pressure air box 210 to detect its internal negative pressure value. When the detected negative pressure value is too high, the negative pressure relief valve 260 is intermittently energized and opened to relieve pressure in the first negative pressure air box 210; when the negative pressure value is too low, the negative pressure pump 230 starts, pressurizing through the negative pressure boosting valve 270 until the set value is reached.

[0058] During system operation, precise control of the liquid wax flow state inside the nozzle 30 can be achieved by controlling the pressure values ​​of the positive and negative pressure air supply devices. This is based on the following formula:

[0059]

[0060] A stable pressure differential provides a stable circulation rate, ensuring sufficient liquid wax inside the printhead 30 and preventing print quality degradation due to insufficient wax supply. It also satisfies the following printhead 30 meniscus pressure formula:

[0061]

[0062] To achieve the best spray effect from nozzle 30, the following must be met simultaneously: and The optimal match is achieved. Therefore, this system achieves precise control of the two pressure parameters by independently adjusting the set values ​​of positive and negative pressure, thereby optimizing injection performance.

[0063] To achieve the cleaning function of nozzle 30, such as Figure 2 As shown, the ink path air pressure control system also includes a second positive pressure pump 300. A pressure sensor 310 is installed at the outlet of the second positive pressure pump 300 to detect the outlet pressure value. When the printhead 30 needs cleaning, the ink pump 40 stops working, and the first control valve 50 and the second control valve 60 are energized and connected, so that both the ink inlet chamber 10 and the ink return chamber 20 are connected to the second positive pressure pump 300. At this time, the second positive pressure pump 300 outputs a large positive pressure, and equal positive pressure is formed in both the ink inlet chamber 10 and the ink return chamber 20. Liquid wax is simultaneously forced into the printhead 30 and squeezed out from the nozzle, thereby achieving the cleaning of the printhead 30.

[0064] like Figure 3 As shown, the ink path air pressure control system also includes a connecting device 400, specifically a balancing valve. This connecting device 400 connects the positive pressure air supply device and the negative pressure air supply device, configured to connect the first positive pressure air box 110 and the first negative pressure air box 210 when the system is powered off. When the equipment is powered off, all solenoid valves are de-energized, the ink pump 40 stops working, and at this time, the balancing valve connects the first positive pressure air box 110 and the first negative pressure air box 210, making their air pressures tend to be equal. Since the initial negative pressure value of the first negative pressure air box 210 is much higher than the positive pressure value of the first positive pressure air box 110, after connection, both are in an equal negative pressure state. At this time, the ink inlet chamber 10 and the ink return chamber 20 are also in an equal negative pressure state, and the liquid wax inside the printhead 30 is absorbed by the negative pressure and will not drip due to gravity, thus realizing the power failure protection function.

[0065] In summary, the ink path air pressure control system provided by this utility model achieves pressure control of the ink inlet chamber 10 and the ink return chamber 20 through independently set positive and negative pressure air supply devices, forming a stable pressure difference to drive the liquid wax circulation, ensuring continuous ink supply to the printhead 30, improving printing quality, and also has printhead 30 cleaning and power failure protection functions. It has the advantages of reasonable structure, precise control, and stable operation, and is suitable for the ink path control needs in high-precision 3D printing equipment.

[0066] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.

Claims

1. An ink path air pressure control system for a 3D printer, characterized by, It includes an ink inlet chamber (10), an ink return chamber (20), a printhead (30), an ink pump (40), a positive pressure air supply device, and a negative pressure air supply device; The printhead (30) is connected to the ink inlet chamber (10) and the ink return chamber (20) respectively, and the ink pump (40) is disposed between the ink return chamber (20) and the ink inlet chamber (10) so that the liquid in the ink return chamber (20) can flow back to the ink inlet chamber (10); The positive pressure air supply device is connected to the ink inlet chamber (10), and the negative pressure air supply device is connected to the ink return chamber (20). The positive pressure air supply device and the negative pressure air supply device are used to create a pressure difference between the ink inlet chamber (10) and the ink return chamber (20) so that the liquid in the ink inlet chamber (10) flows back to the ink return chamber (20) through the nozzle (30).

2. The ink path air pressure control system according to claim 1, characterized in that, The inkway air pressure control system also includes a first control valve (50) and a second control valve (60); The first control valve (50) is located on the air path connecting the positive pressure air supply device and the ink inlet chamber (10); The second control valve (60) is located on the air path connecting the negative pressure air supply device and the ink return chamber (20).

3. The ink path air pressure control system according to claim 2, characterized in that, The positive pressure air supply device includes a first positive pressure air box (110), a second positive pressure air box (120), and a first positive pressure pump (130). The first positive pressure air box (110) is connected to the second positive pressure air box (120), and the second positive pressure air box (120) is connected to the ink inlet chamber (10) through the first control valve (50); The first positive pressure pump (130) is connected to the first positive pressure gas box (110), and the first positive pressure pump (130) is used to adjust the positive pressure value in the first positive pressure gas box (110).

4. The ink path air pressure control system according to claim 3, characterized in that, The positive pressure air supply device also includes a positive pressure sensor (140) and a positive pressure zeroing valve (150). The positive pressure zeroing valve (150) is disposed in the air path between the positive pressure sensor (140) and the first positive pressure air box (110). The positive pressure zeroing valve (150) is used to control the opening and closing of the air path between the positive pressure sensor (140) and the first positive pressure air box (110). When it is in the open state, the positive pressure sensor (140) is used to connect to the atmosphere for zeroing. When it is in the connected state, the positive pressure sensor (140) is used to detect the positive pressure value of the first positive pressure air box (110).

5. The ink path air pressure control system according to claim 3, characterized in that, The positive pressure air supply device also includes a positive pressure relief valve (160). The positive pressure relief valve (160) is connected to the first positive pressure gas box (110), and the positive pressure relief valve (160) is used to relieve pressure on the first positive pressure gas box (110).

6. The ink path air pressure control system according to claim 2, characterized in that, The negative pressure air supply device includes a first negative pressure air box (210), a second negative pressure air box (220), and a negative pressure pump (230). The first negative pressure air box (210) is connected to the second negative pressure air box (220), and the second negative pressure air box (220) is connected to the ink return chamber (20) through the second control valve (60); The negative pressure pump (230) is connected to the first negative pressure air box (210), and the negative pressure pump (230) is used to adjust the negative pressure value in the first negative pressure air box (210).

7. The ink path air pressure control system according to claim 6, characterized in that, The negative pressure air supply device also includes a negative pressure sensor (240) and a negative pressure zeroing valve (250). The negative pressure zeroing valve (250) is disposed in the air path between the negative pressure sensor (240) and the first negative pressure air box (210). The negative pressure zeroing valve (250) is used to control the opening and closing of the air path between the negative pressure sensor (240) and the first negative pressure air box (210). When it is in the open state, the negative pressure sensor (240) is used to connect to the atmosphere for zeroing. When it is in the connected state, the negative pressure sensor (240) is used to detect the negative pressure value of the first negative pressure air box (210).

8. The ink path air pressure control system according to claim 6, characterized in that, The negative pressure air supply device also includes a negative pressure relief valve (260). The negative pressure relief valve (260) is connected to the first negative pressure gas box (210), and the negative pressure relief valve (260) is used to relieve pressure on the first negative pressure gas box (210).

9. The ink path air pressure control system according to claim 2, characterized in that, The ink path air pressure control system also includes a second positive pressure pump (300). The second positive pressure pump (300) is connected to the first control valve (50) and the second control valve (60) respectively, and the second positive pressure pump (300) is used to provide positive pressure to the ink inlet chamber (10) and the ink return chamber (20).

10. The ink path air pressure control system according to claim 1, characterized in that, The ink-line air pressure control system also includes a connecting device (400). The connecting device (400) is connected to the positive pressure air supply device and the negative pressure air supply device respectively. The connecting device (400) is configured to connect the positive pressure air supply device and the negative pressure air supply device when the system is powered off, so that the pressure of the ink inlet chamber (10) and the ink return chamber (20) are equal.

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