Circulating ink supply device and control method thereof

Abstract

The present invention provides a circulating ink supply device and a control method thereof, which relate to the field of 3D printing ink supply technology. By arranging an ink return chamber, an ink inlet chamber, a pump placement chamber and a nozzle placement chamber in a heating chamber, the pump circulation component is placed in the pump placement chamber, and the nozzle component is placed in the nozzle placement chamber, so that the nozzle component and the pump circulation component can be integrated in the heating chamber, with a compact structure and smaller volume. Moreover, since the communication channels between the various components are all opened in the side walls of the heating chamber, there is no need to set up additional pipelines, which further reduces the volume. When the heating chamber as a whole is heated, the heat can be transferred to each chamber to ensure that the entire device operates at a uniform temperature, thereby alleviating the technical problems of poor integration of the ink supply system and large overall volume in the prior art.

Description

Technical Field

[0001] The present invention relates to the technical field of 3D printing ink supply, and in particular to a circulating ink supply device and a control method thereof. Background Art

[0002] In the current 3D printing industry, the ink supply system, including the ink pump and filter, is independently configured and connected to the printhead via pipes. However, this arrangement results in a large overall ink supply system. Therefore, a highly integrated, compact printhead circulation ink supply system is urgently needed to accommodate 3D printers that are highly efficient, compact, easy to move, and easy to maintain. Summary of the Invention

[0003] The object of the present invention is to provide a circulating ink supply device and a control method thereof, so as to alleviate the technical problems existing in the prior art of poor integration and large overall volume of the ink supply system.

[0004] The circulating ink supply device provided by the present invention comprises: a heating cavity, a nozzle component, and a pump circulation component;

[0005] The heating cavity is configured to be heated as a whole, and an ink return cavity, an ink inlet cavity, a pump placement cavity, and a nozzle placement cavity are formed in the heating cavity;

[0006] The pump circulation assembly is arranged in the pump placement cavity;

[0007] The ink return chamber is connected to the ink inlet chamber through the pump circulation assembly, and the communication channel between the ink return chamber and the pump circulation assembly, and the communication channel between the pump circulation assembly and the ink inlet chamber are both opened in the heating chamber;

[0008] The nozzle component is arranged in the nozzle placement cavity, the ink inlet cavity is connected to the ink inlet end of the nozzle component, and the ink return end of the nozzle component is connected to the ink return cavity. The liquid in the ink inlet cavity can flow into the nozzle component, and the liquid in the nozzle component can flow back into the ink return cavity. In an optional embodiment,

[0009] The pump circulation assembly includes an ink pump body, an ink pump one-way valve and an ink pump connector;

[0010] The ink pump one-way valve and the ink pump connector are both arranged in the pump placement cavity, and the bottom of the ink pump body extends into the pump placement cavity;

[0011] The ink return cavity is communicated with the ink pump body through the ink pump one-way valve, and the ink pump body is communicated with the ink inlet cavity through the ink pump joint.

[0012] In an alternative embodiment,

[0013] The circulating ink supply device further includes a cavity end cover;

[0014] The cavity end cover is provided on the heating cavity, and the cavity end cover is configured to be connected to an ink inlet tube, and the ink inlet tube is used to transport liquid to the ink return cavity;

[0015] The communication channel between the ink inlet tube and the ink return cavity is opened in the cavity end cover.

[0016] In an alternative embodiment,

[0017] The circulating ink supply device also includes an ink path adapter block;

[0018] The ink path adapter block is mounted on the cavity end cover, and the nozzle component has an ink path ink inlet end and an ink path ink return end, and both the ink path ink inlet end and the ink path ink return end are connected to the ink path adapter block;

[0019] The ink inlet cavity is connected to the nozzle component through the ink path adapter block and the ink inlet end of the ink path;

[0020] The nozzle component is communicated with the ink return cavity through the ink return end of the ink path and the ink path adapter block.

[0021] In an alternative embodiment,

[0022] The ink path adapter block is provided with a first ink path channel and a second ink path channel. The first ink path channel and the second ink path channel respectively extend from the bottom surface of the ink path adapter block to the top of the ink path adapter block, bend from the top of the ink path adapter block, and then extend toward the bottom surface of the ink path adapter block. The first ink path channel and the second ink path channel are independent of each other.

[0023] The ink inlet cavity is communicated with the nozzle component through the first ink path through the ink inlet end of the ink path; the nozzle component is communicated with the ink return cavity through the second ink path through the ink return end of the ink path.

[0024] In an alternative embodiment,

[0025] The circulating ink supply device includes a filter. A filter placement cavity is formed in the heating cavity. The filter is arranged in the filter placement cavity. The filter is arranged between the ink pump connector and the ink inlet cavity.

[0026] In an alternative embodiment,

[0027] The ink pump one-way valve includes a valve seat, a valve core and a valve head;

[0028] An inner cavity is formed in the valve seat, the valve head is connected to the valve seat by a set screw, and the bottom end of the valve seat extends into the inner cavity of the valve seat, and the valve core is telescopically connected to the bottom of the valve head to control the flow of liquid in the valve seat through the valve core;

[0029] The valve seat has an ink inlet. Liquid entering the valve seat from the ink inlet pushes up the valve core, and the valve core moves in a direction extending into the valve head. The liquid in the valve seat flows out from the ink outlet of the ink pump connector.

[0030] In an alternative embodiment,

[0031] The circulating ink supply device further comprises a first air box and a second air box;

[0032] The first air box is connected to the ink inlet cavity through a first air path, a first switching valve is provided on the first air path, and the first air box is connected to a first negative pressure pump so that the first air box provides negative pressure for the ink inlet cavity;

[0033] The second air box is connected to the ink return chamber through a second air path, a second switching valve is provided on the second air path, and the second air box is connected to a second negative pressure pump so that the second air box provides negative pressure for the ink return chamber;

[0034] The first switching valve and the second switching valve are respectively communicated with two ends of a third air path, and the third air path is connected to a positive pressure pump so that the third air path provides positive pressure to the ink inlet chamber and the ink return chamber respectively.

[0035] A control method for a circulating ink supply device:

[0036] When the circulating ink supply device is in a printing state, the negative pressure value provided by the second air box to the ink return chamber is greater than the negative pressure value provided by the first air box to the ink inlet chamber;

[0037] The first switching valve switches the first air path to a state of communication with the ink inlet chamber, and the second switching valve switches the second air path to a state of communication with the ink return chamber, so that the pressure difference generated by the first air cartridge and the second air cartridge causes the liquid to circulate among the ink return chamber, the pump circulation assembly, the filter, the ink inlet chamber, and the nozzle assembly;

[0038] When the circulating ink supply device is in the power-on protection state, the temperature of the ink return chamber, the ink inlet chamber and the nozzle component is detected. When the detected liquid temperature is greater than or equal to the temperature that ensures the fluid is in a liquid state, the circulating ink supply device switches to the printing state;

[0039] When the detected liquid temperature is lower than the temperature that ensures the fluid is in liquid state, the heating cavity is heated;

[0040] When the circulating ink supply device is in a dormant state, the negative pressure value provided by the second air box to the ink return chamber is equal to the negative pressure value provided by the first air box to the ink inlet chamber, so that the nozzle component does not drip ink;

[0041] When the circulating ink supply device is in the ink pressing state, the first switching valve switches to the state where the third air path is connected to the ink inlet chamber, and the second switching valve switches to the state where the third air path is connected to the ink return chamber, so as to provide positive pressure to the ink inlet chamber and the ink return chamber through the positive pressure pump and the third air path to pressurize the ink on the nozzle component.

[0042] In an alternative embodiment,

[0043] The first gas box and the second gas box are connected through a fourth gas path, and a balancing valve is provided on the fourth gas path;

[0044] When the circulating ink supply device is in a power-off state, the balancing valve opens, the first switching valve switches to a state where the first air path is connected to the ink inlet chamber, and the second switching valve switches to a state where the second air path is connected to the ink return chamber.

[0045] The circulating ink supply device provided by the present invention arranges an ink return chamber, an ink inlet chamber, a pump placement chamber and a nozzle placement chamber in the heating chamber, places the pump circulation component in the pump placement chamber, and places the nozzle component in the nozzle placement chamber cavity, so that the nozzle component and the pump circulation component can be integrated in the heating chamber. The structure is compact and the volume is smaller. Moreover, since the connecting channels between the various components are opened in the side walls of the heating chamber, there is no need to set up additional pipes, which further reduces the volume. When the heating chamber as a whole is heated, the heat can be transferred to each chamber to ensure that the entire device operates at a uniform temperature, thereby alleviating the technical problems of poor integration of the ink supply system and large overall volume in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0047] Figure 1 An exploded view of the overall structure of the circulating ink supply device provided in an embodiment of the present invention;

[0048] Figure 2 A schematic diagram of the overall structure of the circulating ink supply device provided in an embodiment of the present invention;

[0049] Figure 3 A schematic diagram of the liquid flow direction of the circulating ink supply device provided in an embodiment of the present invention;

[0050] Figure 4A schematic diagram of the principle of an ink circulation supply device provided in an embodiment of the present invention;

[0051] Figure 5 A cross-sectional view of the structure of a one-way valve of an ink pump in an ink circulating supply device provided by an embodiment of the present invention;

[0052] Figure 6 A cross-sectional view of the installation structure of the ink pump one-way valve and the ink pump connector in the circulating ink supply device provided by an embodiment of the present invention.

[0053] Icons: 11-first air box; 12-second air box; 21-first air circuit; 22-second air circuit; 23-third air circuit; 24-fourth air circuit; 31-first negative pressure pump; 32-second negative pressure pump; 33-positive pressure pump; 41-first switching valve; 42-second switching valve; 43-balancing valve; 51-first pressure relief pipe; 52-second pressure relief pipe; 61-first air pressure sensor; 62-second air pressure sensor; 63-third air pressure sensor; 71-first temperature sensor; 81-first liquid level switch; 82-second liquid level switch; 100-heating chamber; 110-ink inlet chamber; 120-ink return chamber; 130-filter placement chamber ;140-pump placement cavity;150-nozzle placement cavity;200-nozzle component;210-ink inlet end of ink path;220-ink return end of ink path;300-pump circulation assembly;310-ink pump body;320-ink pump one-way valve;321-valve seat;322-valve core;323-valve head;324-first ED sealing ring;325-second ED sealing ring;326-O-ring;327-setting screw;328-ink inlet;330-ink pump connector;331-third ED sealing ring;332-ink outlet;400-filter;500-cavity end cover;510-sealing gasket;600-ink inlet tube;700-ink path adapter block. DETAILED DESCRIPTION

[0054] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0055] In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0056] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0057] The following describes the specific embodiments of the present invention in detail with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention and are not intended to limit the present invention.

[0058] like Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 As shown, the arrow in the figure indicates the direction of liquid flow. The circulating ink supply device provided in this embodiment includes: a heating chamber 100, a nozzle component 200, a pump circulation component 300 and a filter 400; the heating chamber 100 is configured to be heated as a whole and to conduct heat to ensure the temperature consistency of the entire device. An ink return chamber 120, an ink inlet chamber 110, a filter placement chamber 130, a pump placement chamber 140, and a nozzle placement chamber 150 are formed in the heating chamber 100. The filter 400 is arranged in the filter placement chamber 130, and the pump circulation component 300 is arranged in the pump placement chamber 140, and the nozzle component 200 is arranged in the nozzle placement chamber 150, wherein the ink return chamber 120, the ink inlet chamber 110 and the pump placement chamber 140 are all formed by the downward depression of the top surface of the heating chamber 100, and the filter placement chamber 130 is formed by the upward depression of the bottom surface of the heating chamber 100. The nozzle placement chamber 150 is located in the middle of the heating chamber 100 and passes through from top to bottom. The ink return chamber 120, the ink inlet chamber 110, the filter placement chamber 130, the pump placement chamber 140 and the nozzle placement chamber 150 are all independently arranged relative to each other.

[0059] External liquid enters the ink return chamber 120, and the liquid in the ink return chamber 120 can enter the ink inlet chamber 110 through the pump circulation component 300 and the filter 400 in sequence. The connecting channel between the ink return chamber 120 and the pump circulation component 300, the connecting channel between the pump circulation component 300 and the filter 400, and the connecting channel between the filter 400 and the ink inlet chamber 110 are all opened in the heating cavity 100, so that the liquid can flow in the heating cavity 100 to ensure the temperature stability of the liquid.

[0060] The nozzle component 200 is arranged in the heating cavity 100. The temperature of the nozzle component 200 is provided by the heating cavity 100 through heat conduction. The liquid in the ink inlet cavity 110 can flow into the ink inlet end IN of the nozzle component 200. After the nozzle component 200 sprays ink, the liquid in the nozzle component 200 that is not sprayed can flow back to the ink return cavity 120 through the ink return end OUT.

[0061] It should be noted that the number of the ink return chamber 120, the ink inlet chamber 110, the filter 400 and the pump circulation assembly 300 depends on the type and model of the nozzle component 200. For example, if the nozzle component 200 uses a two-color nozzle and requires two different colors of ink, the ink return chamber 120, the ink inlet chamber 110, the filter 400 and the pump circulation assembly 300 are each provided with two groups to deliver two different colors of ink to the nozzle component 200.

[0062] The circulating ink supply device provided in this embodiment provides an ink return chamber 120, an ink inlet chamber 110, a filter placement chamber 130, a pump placement chamber 140, and a nozzle placement chamber 150 in the heating chamber 100, the filter 400 is placed in the filter placement chamber 130, the pump circulation component 300 is placed in the pump placement chamber 140, and the nozzle component 200 is placed in the nozzle placement chamber 150, so that the nozzle component 200, the filter 400 and the pump circulation component 300 can be integrated in the heating chamber 100, with a compact structure and smaller volume. Moreover, since the connecting channels between the various components are all opened in the side walls of the heating chamber 100, no additional pipes are required, which further reduces the volume. When the heating chamber 100 is heated as a whole, the heat can be transferred to each chamber to ensure that the entire device operates at a uniform temperature, thereby alleviating the technical problems of poor integration of the ink supply system and large overall volume in the prior art.

[0063] Regarding the structure and shape of the pump circulation component 300, specifically:

[0064] The pump circulation assembly 300 includes an ink pump body 310, an ink pump one-way valve 320 and an ink pump connector 330; the ink pump one-way valve 320 and the ink pump connector 330 are both arranged in the pump placement cavity 140, the bottom of the ink pump body 310 extends into the pump placement cavity 140, and the top of the ink pump body 310 extends out of the pump placement cavity 140. The setting of the ink pump one-way valve 320 restricts the flow direction of the liquid. When the ink pump one-way valve 320 is opened, the liquid in the ink return cavity 120 enters the ink pump body 310 through the ink pump one-way valve 320, and the liquid in the ink pump body 310 flows to the filter 400 through the ink pump connector 330.

[0065] It should be noted that the ink pump one-way valve 320 and the ink pump connector 330 are both connected to the ink pump body 310, the ink pump one-way valve 320 is connected to the inlet end of the ink pump body 310, and the ink pump connector 330 is connected to the outlet end of the ink pump body 310. The communication channel between the ink return cavity 120 and the ink pump one-way valve 320 is opened inside the heating cavity 100, and the communication channel between the ink pump connector 330 and the filter 400 is opened inside the heating cavity 100. No additional pipelines are set up, which reduces the volume of the overall device and ensures that the liquid will not lose temperature and become solid when it flows.

[0066] Optional, such as Figure 5 、 Figure 6 As shown, the arrow in the figure indicates the direction of liquid flow. The one-way valve specifically includes a valve seat 321, a valve core 322, a valve head 323, a first ED sealing ring 324, a second ED sealing ring 325, an O-ring 326, and a set screw 327. Specifically, the one-way valve is placed in the pump placement cavity 140 of the heating cavity 100. An inner cavity is formed in the middle of the valve seat 321. The valve head 323 is connected to the valve seat 321 by a set screw 327, and the bottom end of the valve head 323 extends into the inner cavity of the valve seat 321. The valve core 322 is telescopically connected. At the bottom of the valve head 323, the flow of liquid in the valve seat 321 is controlled by the valve core 322. When the liquid enters from the ink inlet of the valve seat 321 and enters the inner cavity of the valve seat 321 from bottom to top through the ink inlet 328 on the valve seat 321, the valve core 322 is pushed open, and the liquid flows out from bottom to top into the ink pump body 310. When the liquid flows into the inner cavity of the valve seat 321 from top to bottom, the valve core 322 blocks the flow hole in the middle of the valve seat 321 by its own weight, and the liquid inside the valve seat 321 cannot flow out, thereby realizing unidirectional flow of the liquid.

[0067] A first ED sealing ring 324 , a second ED sealing ring 325 and an O-ring 326 are provided on the valve seat 321 . The second ED sealing ring 325 serves to seal between the valve seat 321 and the valve head 323 , and the first ED sealing ring 324 and the O-ring 326 serve to seal between the valve seat 321 and the heating cavity 100 .

[0068] In addition, the one-way valve can also be replaced by a solenoid valve, which can be selected according to specific circumstances.

[0069] like Figure 6 As shown, the ink pump connector 330 is provided with a third ED sealing ring 331, which serves to seal between the ink pump connector 330 and the heating cavity 100, and an ink outlet 332 is opened at the ink pump connector 330. After the liquid flowing out of the ink pump body 310 enters the ink pump connector 330, it flows out through the ink outlet 332.

[0070] In an optional embodiment, the circulating ink supply device also includes a cavity end cover 500; the cavity end cover 500 is covered on the heating cavity 100, and a connecting channel is opened inside the cavity end cover 500, the inlet end of the connecting channel is connected to the ink inlet tube 600, and the outlet end of the connecting channel is connected to the ink return chamber 120, and the external liquid enters the connecting channel inside the cavity end cover 500 through the ink inlet tube 600 and flows into the ink return chamber 120.

[0071] In addition, a sealing gasket 510 is provided between the cavity end cover 500 and the top surface of the heating cavity 100 to seal the cavity end cover 500 and the heating cavity 100 , thereby ensuring the sealing of the ink return cavity 120 and the ink inlet cavity 110 .

[0072] In an optional embodiment, the circulating ink supply device also includes an ink path adapter block 700; the ink path adapter block 700 is installed on the cavity end cover 500, and the ink path adapter block 700 has an ink path channel inside, and the nozzle component 200 has an ink path ink inlet end 210 and an ink path ink return end 220, and the ink path ink inlet end 210 and the ink path ink return end 220 are both connected to the ink path adapter block 700, and the liquid in the ink inlet cavity 110 enters the first ink path channel, flows in the first ink path channel, enters the nozzle component 200 through the ink path ink inlet end 210, and part of the liquid in the nozzle component 200 enters the second ink path channel through the ink path ink return end 220, and enters the ink return cavity 120 through the second ink path channel. The first ink path extends from the bottom surface of the ink path adapter block 700 to the top of the ink path adapter block 700, bends from the top of the ink path adapter block 700, and then extends to the bottom surface of the ink path adapter block 700. The second ink path similarly extends from the bottom surface of the ink path adapter block 700 to the top of the ink path adapter block 700, bends from the top of the ink path adapter block 700, and then extends to the bottom surface of the ink path adapter block 700. The first ink path and the second ink path are independent of each other. Through the design of the first ink path and the second ink path, the height of the ink inlet and outlet of the nozzle component can be increased. The ink inlet cavity adopts the siphon principle to supply ink to the nozzle. The positions of the ink inlet and outlet of the nozzle are higher than the liquid levels of the ink inlet cavity and the ink return cavity. There will be no liquid leakage when replacing the nozzle component.

[0073] In an optional embodiment, if Figure 4As shown, the circulating ink supply device also includes a first air box 11 and a second air box 12; the first air box 11 is connected to the ink inlet chamber 110 through a first air path 21, and a first switching valve 41 is provided on the first air path 21. The first air box 11 is connected to a first negative pressure pump 31, and the first negative pressure pump 31 generates negative pressure in the first air box 11, so that the first air box 11 provides negative pressure for the ink inlet chamber 110.

[0074] The second air box 12 is connected to the ink return chamber 120 through the second air path 22. A second switching valve 42 is provided on the second air path 22. The second air box 12 is connected to a second negative pressure pump 32. The second negative pressure pump 32 generates negative pressure in the second air box 12 so that the second air box 12 provides negative pressure for the ink return chamber 120.

[0075] The first switching valve 41 and the second switching valve 42 are respectively connected to the two ends of the third air path 23. The first switching valve 41 is used to control the ink inlet chamber 110 to be connected to the first air path 21 or the third air path 23. The second switching valve 42 is used to control the ink return chamber 120 to be connected to the second air path 22 or the third air path 23.

[0076] The third air path 23 is connected to a positive pressure pump 33 , which generates positive pressure so that the third air path 23 provides positive pressure to the ink inlet cavity 110 and the ink return cavity 120 .

[0077] In addition, a first temperature sensor 71, a first liquid level switch 81 and a first air pressure sensor 61 are provided on the ink inlet chamber 110, and a second liquid level switch 82 and a second air pressure sensor 62 are provided on the ink return chamber 120. The first liquid level switch 81 and the second liquid level switch 82 extend through the cavity end cover 500 into the ink inlet chamber 110 and the ink return chamber 120 respectively. The installation method of the temperature sensor, the liquid level switch and the air pressure sensor is well known in the art and will not be repeated here.

[0078] In addition, the first gas box 11 is connected to a first pressure relief line 51 , on which a pressure relief valve is provided. The second gas box 12 is connected to a second pressure relief line 52 , on which a pressure relief valve is provided.

[0079] When the circulating ink supply device is in the printing state, the first switching valve 41 switches to the state in which the first air path 21 is connected to the ink inlet chamber 110, and the second switching valve 42 switches to the state in which the second air path 22 is connected to the ink return chamber 120, and the negative pressure value provided by the second air box 12 to the ink return chamber 120 is greater than the negative pressure value provided by the first air box 11 to the ink inlet chamber 110, thereby generating a pressure difference, so that the pressure difference generated by the first air box 11 and the second air box 12 causes the liquid to circulate between the ink return chamber 120, the pump circulation component 300, the filter 400, the ink inlet chamber 110 and the nozzle assembly 200.

[0080] The liquid entering the ink chamber 110 during circulation enters the ink return chamber 120 through circulation, triggering the second liquid level switch 82 , thereby triggering the ink pump body 310 to work, open the one-way valve, and pass through the filter 400 .

[0081] The first gas box 11 and the second gas box 12 are designed to eliminate air pressure fluctuations, remove bubbles in the fluid, and ensure the temperature stability of the fluid at high speed. When the upper limit value set by the second liquid level switch 82 is triggered, the air pressure difference is adjusted to zero, and the software reports an error protection.

[0082] Figure 3 This is an ink path diagram, where the arrows indicate the ink path direction. As shown in the figure, the ink path process is: ink inlet tube 600 - cavity end cover 500 - ink return chamber 120 - ink pump one-way valve 320 - ink pump body 310 - ink pump connector 330 - filter 400 - ink inlet chamber 110 - ink path adapter block 700 - ink inlet end 210 of the ink path - nozzle component 200 - ink return end 220 of the ink path adapter block 700 - nozzle return ink chamber 120, forming a cycle.

[0083] By circulating the nozzle assembly 200, the pressure difference between the ink inlet chamber 110 and the ink return chamber 120 is utilized, and the absolute value of the negative pressure in the ink return chamber 120 is greater than that in the ink inlet chamber 110. This allows ink to be siphoned from the ink inlet chamber 110 into the ink inlet end of the nozzle assembly 200. The ink is then discharged from the ink outlet end of the nozzle assembly into the ink return chamber 120. The ink pump body 310 then transfers the ink from the ink return chamber 120 to the ink inlet chamber 110, maintaining a balanced liquid level in the ink return chamber 120 and the ink inlet chamber 110. This entire ink circuit operates continuously, removing sediment near the nozzles of the nozzle assembly 200 and improving nozzle clogging.

[0084] When the circulating ink supply device is in the power-on protection state, the temperature of the ink return chamber 120, the ink inlet chamber 110 and the nozzle assembly 200 is detected. When the detected liquid temperature is greater than or equal to the temperature that ensures the fluid is in liquid state, the circulating ink supply device switches to the printing state, the first negative pressure pump 31 and the second negative pressure pump 32 start working, the air pressure difference increases slowly, and the circulation is slowly carried out.

[0085] When the detected liquid temperature is lower than the temperature required to ensure that the fluid is in liquid state, the heating cavity 100 needs to be heated. Specifically, the heating time required for the ink cavity fluid and the nozzle is dynamically determined based on the solid-liquid heating curve of the fluid, the heating and heat transfer design of the ink cavity and nozzle, and related empirical parameters. Generally, the set temperature Ta is reached first and the temperature is maintained for a certain period of time to ensure that the fluid is in liquid state.

[0086] When the circulating ink supply device is in a dormant state, the negative pressure value provided by the second air box 12 to the ink return chamber 120 is equal to the negative pressure value provided by the first air box 11 to the ink inlet chamber 110, and the liquid does not circulate, so that the nozzle component 200 does not drip ink.

[0087] When the circulating ink supply device is in the ink pressing state, the first switching valve 41 switches to the third air path 23 and is connected to the ink inlet chamber 110, and the second switching valve 42 switches to the third air path 23 and is connected to the ink return chamber 120. Positive pressure is provided to the ink inlet chamber 110 and the ink return chamber 120 through the positive pressure pump 33 and the third air path 23. The working speed of the positive pressure pump 33 is adjusted according to the value of the third air pressure sensor 63 on the third air path 23 to ensure a certain pressure, so as to press ink on the nozzle component 200.

[0088] Optionally, a fourth air circuit 24 is also provided, through which the first air box 11 and the second air box 12 are connected, and a balancing valve 43 is provided on the fourth air circuit 24; when the circulating ink supply device is in a power-off state, the balancing valve 43 is opened, the first switching valve 41 is switched to a state in which the first air circuit 21 is connected to the ink inlet chamber 110, and the second switching valve 42 is switched to a state in which the second air circuit 22 is connected to the ink return chamber 120, so that the pressure difference is zero and the circulation is stopped, and the nozzle component 200 also maintains an appropriate negative pressure so that ink will not drip, thereby preventing waste of materials.

[0089] The circulating ink supply device provided in this embodiment has an integrated design and a more compact structure, and can be applied to various 3D printing equipment. In addition, the nozzle component 200 is integrated in the heating cavity 100, and there is no need to heat the nozzle component 200 separately, which shortens the flow channel length and further reduces the occupied space. The nozzle component 200 does not leak when disassembled and assembled, has a low cost, reduces the size of the entire machine, and is easy to maintain.

[0090] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A circulating ink supply device, characterized in that: include: Heating cavity (100), nozzle component (200), pump circulation component (300); The heating cavity (100) is configured to be heated as a whole, and an ink return cavity (120), an ink inlet cavity (110), a pump placement cavity (140), and a nozzle placement cavity (150) are formed in the heating cavity (100); The pump circulation component (300) is disposed in the pump placement cavity (140); The ink return chamber (120) is connected to the ink inlet chamber (110) via the pump circulation assembly (300), and the communication channel between the ink return chamber (120) and the pump circulation assembly (300), and the communication channel between the pump circulation assembly (300) and the ink inlet chamber (110) are both provided in the heating chamber (100); The nozzle component (200) is arranged in the nozzle placement cavity (150), the ink inlet cavity (110) is communicated with the ink inlet end of the nozzle component (200), and the ink return end of the nozzle component (200) is communicated with the ink return cavity (120); The circulating ink supply device further comprises a cavity end cover (500); The cavity end cover (500) is provided on the heating cavity (100); The circulating ink supply device further comprises an ink path adapter block (700); The ink path adapter block (700) is mounted on the cavity end cover (500); the nozzle component (200) has an ink path ink inlet end (210) and an ink path ink return end (220); and both the ink path ink inlet end (210) and the ink path ink return end (220) are in communication with the ink path adapter block (700); The ink inlet cavity (110) is connected to the nozzle component (200) through the ink path adapter block (700) and the ink path ink inlet end (210); The nozzle component (200) is connected to the ink return chamber (120) via the ink return end (220) through the ink path adapter block (700); The ink path adapter block (700) is provided with a first ink path channel and a second ink path channel, the first ink path channel and the second ink path channel respectively extending from the bottom surface of the ink path adapter block (700) to the top of the ink path adapter block (700) and then bending from the top of the ink path adapter block (700) and then extending toward the bottom surface of the ink path adapter block (700), the first ink path channel and the second ink path channel being independent of each other; The ink inlet cavity (110) is communicated with the nozzle component (200) through the ink inlet end (210) of the ink path via the first ink path channel; the nozzle component (200) is communicated with the ink return cavity (120) through the ink return end (220) of the ink path via the second ink path channel.

2. The circulating ink supply device according to claim 1, characterized in that: The pump circulation assembly (300) comprises an ink pump body (310), an ink pump one-way valve (320), and an ink pump connector (330); The ink pump one-way valve (320) and the ink pump connector (330) are both arranged in the pump placement cavity (140), and the bottom of the ink pump body (310) extends into the pump placement cavity (140); The ink return chamber (120) is communicated with the ink pump body (310) via the ink pump one-way valve (320), and the ink pump body (310) is communicated with the ink inlet chamber (110) via the ink pump connector (330).

3. The circulating ink supply device according to claim 2, characterized in that: The cavity end cover (500) is configured to be connectable to an ink inlet tube (600), and the ink inlet tube (600) is used to transport liquid to the ink return cavity (120); A communication channel between the ink inlet tube (600) and the ink return cavity (120) is opened in the cavity end cover (500).

4. The circulating ink supply device according to claim 2, characterized in that: The circulating ink supply device comprises a filter (400), a filter placement cavity (130) is formed in the heating cavity (100), the filter (400) is arranged in the filter placement cavity (130), and the filter (400) is arranged between the ink pump connector (330) and the ink inlet cavity (110).

5. The circulating ink supply device according to claim 2, characterized in that: The ink pump one-way valve (320) comprises a valve seat, a valve core and a valve head; An inner cavity is formed in the valve seat (321), the valve head (323) is connected to the valve seat (321) via a set screw (327), and the bottom end of the valve seat (321) extends into the inner cavity of the valve seat (321), and the valve core (322) is telescopically connected to the bottom of the valve head (323) to control the flow of liquid in the valve seat (321) through the valve core (322); The valve seat (321) has an ink inlet (328), and the liquid entering the valve seat (321) from the ink inlet (328) pushes the valve core (322) open, and the valve core (322) moves in a direction extending into the valve head (323), and the liquid in the valve seat (321) flows out from the ink outlet (332) of the ink pump connector (330).

6. The circulating ink supply device according to any one of claims 1 to 5, characterized in that: The circulating ink supply device further comprises a first air box (11) and a second air box (12); The first air box (11) is in communication with the ink inlet chamber (110) via a first air path (21), a first switching valve (41) is provided on the first air path (21), and the first air box (11) is connected to a first negative pressure pump (31) so that the first air box (11) provides negative pressure for the ink inlet chamber (110); The second air box (12) is in communication with the ink return chamber (120) via a second air path (22), a second switching valve (42) is provided on the second air path (22), and the second air box (12) is connected to a second negative pressure pump (32) so that the second air box (12) provides negative pressure for the ink return chamber (120); The first switching valve (41) and the second switching valve (42) are respectively connected to the two ends of the third air path (23), and the third air path (23) is connected to a positive pressure pump (33) so that the third air path (23) provides positive pressure to the ink inlet chamber (110) and the ink return chamber (120).

7. A control method for the circulating ink supply device according to any one of claims 1 to 6, characterized in that: When the circulating ink supply device is in a printing state, the negative pressure value provided by the second air box (12) to the ink return chamber (120) is greater than the negative pressure value provided by the first air box (11) to the ink inlet chamber (110); The first switching valve (41) switches to a state where the first air path (21) is in communication with the ink inlet chamber (110), and the second switching valve (42) switches to a state where the second air path (22) is in communication with the ink return chamber (120), so that the pressure difference generated by the first air box (11) and the second air box (12) causes the liquid to circulate among the ink return chamber (120), the pump circulation assembly (300), the filter (400), the ink inlet chamber (110), and the nozzle assembly (200); When the circulating ink supply device is in a power-on protection state, the temperatures of the ink return chamber (120), the ink inlet chamber (110), and the nozzle assembly (200) are detected, and when the detected liquid temperature is greater than or equal to a temperature that ensures that the fluid is in a liquid state, the circulating ink supply device switches to a printing state; When the detected liquid temperature is lower than the temperature for ensuring that the fluid is in a liquid state, heating the heating cavity (100); When the circulating ink supply device is in a dormant state, the negative pressure value provided by the second air box (12) to the ink return chamber (120) is equal to the negative pressure value provided by the first air box (11) to the ink inlet chamber (110), so that the nozzle component (200) does not drip ink; When the circulating ink supply device is in the ink pressing state, the first switching valve (41) switches to a state in which the third air path (23) is connected to the ink inlet chamber (110), and the second switching valve (42) switches to a state in which the third air path (23) is connected to the ink return chamber (120), so as to provide positive pressure to the ink inlet chamber (110) and the ink return chamber (120) through the positive pressure pump (33) and the third air path (23), thereby pressing ink on the nozzle component (200).

8. The control method of the circulating ink supply device according to claim 7, characterized in that: The first gas box (11) and the second gas box (12) are connected via a fourth gas path (24), and a balancing valve (43) is provided on the fourth gas path (24); When the circulating ink supply device is in a power-off state, the balancing valve (43) is opened, the first switching valve (41) is switched to a state where the first air path (21) is connected to the ink inlet chamber (110), and the second switching valve (42) is switched to a state where the second air path (22) is connected to the ink return chamber (120).

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