Electrofluid nozzle flexible in ink supply, jet printing device and ink-jet printing system

Abstract

The invention relates to an electrofluid nozzle flexible in ink supply, a jet printing device and an ink-jet printing system, and the electrofluid nozzle comprises a main body part which is internally provided with a liquid outlet hole; the needle head is detachably connected to the bottom end of the main body part, and the needle head communicates with the liquid outlet hole; the conveying assembly comprises a conveying driving assembly and a spiral conveying shaft, the spiral conveying shaft penetrates through the liquid outlet hole, a spiral conveying channel is formed between the spiral conveying shaft and the hole wall of the liquid outlet hole, and the conveying driving assembly drives the spiral conveying shaft to rotate; the liquid supply assembly comprises a liquid supply cylinder and an air supply mechanism, the liquid supply cylinder is used for storing functional liquid and communicates with the spiral conveying channel, and the air supply mechanism is used for supplying air into the liquid supply cylinder; and the power supply assembly is electrically connected with the needle head. The speed of the functional liquid supplied to the needle head is adjusted by changing the rotating speed of the spiral conveying shaft, meanwhile, the air pressure in the air supply cylinder is adaptively adjusted, the voltage applied to the needle head is adjusted and controlled in combination with the power supply assembly, and therefore the injection requirements of needle heads with different needle tip sizes are met.

Description

Technical Field

[0001] This application relates to the field of inkjet printing technology, and particularly to an electrohydrodynamic nozzle with flexible ink supply, a printing device, and an inkjet printing system. Background Art

[0002] Inkjet printing devices have been widely used in recent years due to advantages such as material saving, environmental friendliness, and simple operation. Traditional inkjet printing technology has disadvantages such as low printing resolution, droplet size limited by nozzle diameter, easy nozzle clogging, and complex nozzle manufacturing process. Compared with traditional inkjet printing technology, electrohydrodynamic inkjet printing technology can generate finer droplets and liquid filaments with diameters reaching the nanometer level. At the same time, electrohydrodynamic printing technology can print more materials such as polymer organic compounds, making its application range wider, such as flexible electronics manufacturing, ceramic component manufacturing, tissue engineering, etc.

[0003] Electrohydrodynamic printing technology applies the mechanism of electrohydrodynamics. An electric field is used to pull the liquid out of the nozzle orifice to form a Taylor cone. Since the nozzle has a relatively high electric potential, the liquid at the nozzle is subjected to an electrohydrodynamic shear stress. When the local charge force exceeds the liquid surface tension, the charged liquid is ejected from the nozzle and then breaks into liquid columns or small droplets. By changing the flow rate, voltage, liquid properties, and nozzle structure, electrohydrodynamic printing modes with different jet shapes and breakup mechanisms can be formed, namely electrospinning, electro-droplet spraying, and electrospraying.

[0004] In related technologies, an external liquid supply component supplies a functional liquid into the main body of the nozzle. The functional liquid in the main body is sent into the needle, and under the action of the electric field force, the functional liquid in the needle is ejected. The inner diameter of the tip of the nozzle determines the droplet diameter printed by the nozzle. When droplets with different diameters need to be printed, by replacing the needle with a corresponding inner diameter of the tip and correspondingly adjusting the voltage applied to the tip of the nozzle, the adjustment of the printed droplet diameter can be achieved.

[0005] However, since the inner diameter of the main body of the nozzle is consistent, and the main body of the nozzle is connected to the needle, the flow of the functional liquid in the main body to the needle is the same, that is, the speed of supplying the functional liquid to the needle is the same. When droplets with a larger diameter need to be printed, after replacing the needle with a larger inner diameter of the tip, the functional liquid flowing into the needle is difficult to fill the needle, resulting in the easy appearance of air bubbles inside the needle, which affects the printing quality. When droplets with a smaller diameter need to be printed, after replacing the needle with a smaller inner diameter of the tip, the needle cannot discharge the functional liquid in time, easily causing clogging at the liquid inlet end of the needle, and the pressure inside the needle is too high, resulting in some functional liquid being ejected incidentally when the functional liquid is ejected under the action of the electric field force, which affects the printing quality.

[0006] Therefore, for the electrohydrodynamic inkjet printhead in the related art, it is impossible to achieve high-precision and high-quality printing processing of different droplet diameters only by replacing the needle. When droplets of different diameters need to be printed, the entire electrohydrodynamic inkjet printhead needs to be replaced. Therefore, it is difficult for the printhead in the related art to print droplets of different diameters, and its applicability is poor. Summary of the Invention

[0007] The embodiments of the present application provide an electrohydrodynamic inkjet printhead, a printing device, and an inkjet printing system with flexible ink supply to solve the technical problem that it is difficult for the printhead in the related art to print droplets of different diameters and its applicability is poor.

[0008] In a first aspect, an electrohydrodynamic inkjet printhead with flexible ink supply is provided, including:

[0009] A main body portion, in which a liquid outlet hole is provided;

[0010] A needle, which is detachably connected to the bottom end of the main body portion, and the needle is communicated with the liquid outlet hole;

[0011] A conveying assembly, which includes a conveying driving assembly and a spiral conveying shaft. The spiral conveying shaft penetrates through the liquid outlet hole, and the outer circumferential surface of the spiral conveying shaft abuts against the hole wall of the liquid outlet hole to form a spiral conveying channel between the spiral conveying shaft and the hole wall of the liquid outlet hole. The outlet of the spiral conveying channel is arranged close to the needle, and the conveying driving assembly drives the spiral conveying shaft to rotate;

[0012] A liquid supply assembly, which includes a liquid supply cylinder and a gas supply mechanism. The liquid supply cylinder is used to store the functional liquid, the liquid supply cylinder is communicated with the spiral conveying channel, and the gas supply mechanism is used to supply gas into the liquid supply cylinder;

[0013] A power supply assembly, which is electrically connected to the needle to apply a voltage to the needle.

[0014] In some embodiments, the spiral conveying shaft includes a conveying section and a shielding section. The shielding section is connected to the top of the conveying section, the outer diameter of the shielding section is larger than the outer diameter of the conveying section, and the spiral conveying channel is formed between the conveying section and the hole wall of the liquid outlet hole;

[0015] The main body portion further includes a leakage prevention hole, which is located above the liquid outlet hole and communicated with the liquid outlet hole. The shielding section is located in the leakage prevention hole, and the circumferential side surface of the shielding section fits with the hole wall of the leakage prevention hole.

[0016] In some embodiments, a sealing ring is embedded on the outer circumferential surface of the shielding section, and the sealing ring abuts tightly against the hole wall of the leakage prevention hole.

[0017] In some embodiments, the conveying assembly further includes a bearing. An installation hole is formed at the top of the main body portion. The installation hole communicates with the liquid outlet hole. The outer ring of the bearing is installed in the installation hole, and the top of the bolt conveying shaft is connected to the inner ring of the bearing.

[0018] In some embodiments, the conveying drive assembly includes:

[0019] A conveying drive member;

[0020] A coupling. The input end of the coupling is connected to the drive end of the conveying drive member, and the output end of the coupling is connected to the screw conveyor shaft;

[0021] A protective sleeve. The protective sleeve is fixed to the top of the main body portion, and the coupling is located inside the protective sleeve.

[0022] In some embodiments, the liquid supply assembly further includes a liquid supply pipe. The two ends of the liquid supply pipe are respectively communicated with the screw conveying channel and the liquid outlet end of the liquid supply cylinder;

[0023] The flow channel inside the liquid supply pipe is arranged obliquely. The end of the flow channel inside the liquid supply pipe that communicates with the liquid supply cylinder is higher than the end of the flow channel inside the liquid supply pipe that communicates with the screw conveying channel.

[0024] In some embodiments, the electrohydrodynamic inkjet head with flexible ink supply further includes a connector. The connector is inserted into the bottom end of the liquid outlet hole to be connected to the main body portion. A through connection hole is formed at the top of the connector, and the connection hole communicates with the liquid outlet hole; an annular groove is formed on the bottom surface of the connector, and the needle head is detachably connected to the connector by being inserted into the annular groove, and the needle head communicates with the connection hole.

[0025] In some embodiments, the power supply assembly includes a conductive ring and a magnetic member. Both the conductive ring and the magnetic member are arranged at the bottom of the annular groove. The magnetic member is adapted to magnetically adsorb the needle head so that the needle head abuts against the conductive ring and is electrically connected to the conductive ring, and the conductive ring is electrically connected to an external power supply;

[0026] Wherein, the connector is made of an insulating material or the part of the connector in contact with the conductive ring and the needle head is made of an insulating material.

[0027] The beneficial effects brought by the technical solutions provided in this application include:

[0028] The embodiment of the present application provides an electrohydrodynamic inkjet printhead with flexible ink supply. By changing the rotation speed of the spiral conveying shaft, the speed of the functional liquid supplied to the nozzle is adjusted. At the same time, the air pressure in the air supply cylinder is adaptively adjusted, and the voltage applied to the nozzle is regulated in combination with the power supply component, so as to meet the jetting requirements of nozzles with different tip sizes.

[0029] Specifically, when printing droplets with a smaller diameter, replace the nozzle with a smaller tip size, slow down the rotation speed of the spiral conveying shaft, and reduce the functional liquid sent into the nozzle through the spiral conveying channel. At the same time, the air pressure in the air supply cylinder is reduced by the air supply mechanism, which not only slows down the speed of the functional liquid sent into the spiral conveying channel, but also reduces the air pressure applied to the functional liquid at the nozzle. After the inner diameter of the tip of the nozzle is reduced, the force received by the functional liquid at the tip of the nozzle remains unaffected, that is, regardless of the size of the tip of the nozzle, the state of the functional liquid at the tip of the nozzle is consistent, so as to ensure printing consistency and printing quality. It is also necessary to adaptively adjust the voltage applied to the nozzle by the power supply component to achieve the printing of small droplets. Since the amount of functional liquid entering the nozzle is reduced, the nozzle can normally consume the functional liquid in the nozzle, and the functional liquid is not easily accumulated and blocked, and the functional liquid is not easily ejected incidentally during jetting, ensuring printing quality and accuracy.

[0030] When printing droplets with a larger diameter, replace the nozzle with a larger tip size, increase the rotation speed of the spiral conveying shaft, and increase the functional liquid sent into the nozzle through the spiral conveying channel. At the same time, the air pressure in the air supply cylinder is increased by the air supply mechanism, which not only speeds up the speed of the functional liquid sent into the spiral conveying channel, but also increases the air pressure applied to the functional liquid at the nozzle. After the inner diameter of the tip of the nozzle is increased, the force received by the functional liquid at the tip of the nozzle remains unaffected, that is, regardless of the size of the tip of the nozzle, the state of the functional liquid at the tip of the nozzle is consistent, so as to ensure printing consistency and printing quality. It is also necessary to adaptively adjust the voltage applied to the nozzle by the power supply component to achieve the printing of large droplets. Since the amount of functional liquid entering the nozzle is increased, the demand for the amount of functional liquid required for jetting by the nozzle is met, and air bubbles are not easily generated in the nozzle due to insufficient functional liquid, ensuring printing quality and accuracy.

[0031] Therefore, by adaptively adjusting the air pressure in the liquid supply cylinder through the air supply mechanism, not only the speed of the functional liquid sent into the spiral conveying channel is adaptively adjusted, but also when the rotation speed of the spiral conveying shaft is adjusted, the air pressure is used to push the functional liquid to ensure that the functional liquid sent to the nozzle is not easily bubbled and the air pressure of the functional liquid in the nozzle is stable. By changing the rotation speed of the spiral conveying shaft, the speed of the functional liquid sent to the nozzle is adjusted, and the outputs of the power supply component and the liquid supply component are adaptively adjusted to meet the jetting requirements of nozzles with different tip sizes, ensuring printing quality and accuracy and improving the applicability of the electrohydrodynamic inkjet printhead.

[0032] In a second aspect, a printing device is provided, which includes the electrohydrodynamic inkjet printhead with flexible ink supply as described above.

[0033] Another embodiment of the present application provides a printing device. Since this printing device includes the electrohydrodynamic inkjet printhead with flexible ink supply as described above, the beneficial effects of this printing device are the same as those of the electrohydrodynamic inkjet printhead with flexible ink supply described above, and thus will not be elaborated here.

[0034] In a third aspect, an inkjet printing system is provided, which includes the electrohydrodynamic inkjet printhead with flexible ink supply as described above, and / or the printing device as described above.

[0035] Another embodiment of the present application provides an inkjet printing system. Since this inkjet printing system includes the electrohydrodynamic inkjet printhead with flexible ink supply as described above, and / or the printing device as described above, the beneficial effects of this inkjet printing system are the same as those of the electrohydrodynamic inkjet printhead with flexible ink supply and the printing device as described above, and thus will not be elaborated here. Description of the Drawings

[0036] To more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0037] Figure 1 Schematic diagram of the electrohydrodynamic inkjet printhead with flexible ink supply provided by the embodiment of the present application;

[0038] Figure 2 Internal schematic diagram of the electrohydrodynamic inkjet printhead with flexible ink supply provided by the embodiment of the present application;

[0039] Figure 3 Partial internal schematic diagram of the electrohydrodynamic inkjet printhead with flexible ink supply provided by the embodiment of the present application;

[0040] Figure 4 Partial exploded view of the electrohydrodynamic inkjet printhead with flexible ink supply provided by the embodiment of the present application;

[0041] Figure 5 Schematic diagram of the spiral conveyor shaft provided by the embodiment of the present application;

[0042] Figure 6 Cross-sectional view of the connector, needle head and power supply assembly provided by the embodiment of the present application;

[0043] Figure 7 Exploded view of the connector, needle head and power supply assembly provided by the embodiment of the present application.

[0044] In the figure: 1. Main body; 1a. Liquid outlet hole; 1b. Leak-proof hole; 1c. Mounting hole; 2. Needle; 3. Delivery assembly; 31. Delivery drive assembly; 311. Delivery drive member; 312. Coupling; 313. Protective sleeve; 32. Screw conveyor shaft; 321. Delivery section; 322. Shielding section; 323. Mounting section; 324. Sealing ring; 33. Bearing; 4. Liquid supply assembly; 41. Liquid supply cylinder; 42. Liquid supply pipe; 5. Power supply assembly; 51. Conductive ring; 52. Magnetic member; 6. Connector; 6a. Annular groove; 6b. Conductive hole; a. Screw conveyor channel. Detailed implementation manners

[0045] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Apparently, the described embodiments are some, but not all, of the embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the protection scope of the present application.

[0046] The embodiments of the present application provide an electrohydrodynamic inkjet printhead with flexible ink supply, a printing device, and an inkjet printing system. The electrohydrodynamic inkjet printhead with flexible ink supply adjusts the speed of the functional liquid supplied to the needle by changing the rotation speed of the screw conveyor shaft, and simultaneously adaptively adjusts the air pressure in the air supply cylinder, and combines with the power supply assembly to control the voltage applied to the needle, so as to meet the jetting requirements of needles with different tip sizes. The present application solves the technical problem that it is difficult for the printhead in the related art to print liquid droplets with different dot diameters and has poor applicability.

[0047] Referring to Figures 1-3 , an electrohydrodynamic inkjet printhead with flexible ink supply includes a main body 1, a needle 2, a delivery assembly 3, a liquid supply assembly 4, and a power supply assembly 5. The needle 2 is detachably connected to the main body 1. The liquid supply assembly 4 supplies the functional liquid into the main body 1. The functional liquid in the main body 1 is sent to the needle 2 through the delivery assembly 3. At the same time, the liquid supply assembly 4 makes the pressure of the functional liquid at the needle 2 the pressure required by the process, and then the power supply assembly 5 applies a voltage to the needle 2, so that the functional liquid can be ejected from the needle 2.

[0048] With such a setting, when replacing the needle 2 with different inner diameters of the needle tip, by adjusting the speed at which the delivery assembly 3 delivers the functional liquid to the needle 2 and adjusting the outputs of the liquid supply assembly 4 and the power supply assembly 5, the jetting requirements of the needle 2 with different tip sizes can be met to support the jetting of liquid droplets with different dot diameters. The applicability of the electrohydrodynamic inkjet printhead is provided.

[0049] Referring to Figures 1-3, wherein, the main body 1 is tubular, and a liquid outlet hole 1a is provided inside the main body 1. The liquid supply component 4 supplies the functional liquid into the liquid outlet hole 1a. The needle 2 is detachably connected to the bottom of the main body 1, and different needles 2 are replaced to adapt to printing liquid droplets with different dot diameters. The needle 2 is communicated with the liquid outlet hole 1a to support the functional liquid in the liquid outlet hole 1a to enter the needle 2. The conveying component 3 works in the liquid outlet hole 1a to send the functional liquid in the liquid outlet hole 1a to the needle 2, and by adjusting the output of the conveying component 3, the speed of sending the functional liquid to the needle 2 is adjusted.

[0050] With such a setting, the speed of the functional liquid being sent to the needle 2 can be changed through the conveying component 3, that is, the speed of the functional liquid entering the needle 2 can be adaptively increased or decreased. When the tip sizes of the needles 2 are different and the needles 2 with different tip sizes consume the functional liquid at different speeds, through the regulation of the speed of the functional liquid entering the needle 2 by the conveying component 3, it is ensured that the functional liquid in the needle 2 will not accumulate too much and will not be too little to cause ink shortage in printing, thus ensuring the printing quality.

[0051] Refer to Figures 2-4 , wherein, the conveying component 3 includes a conveying driving component 31 and a spiral conveying shaft 32. The spiral conveying shaft 32 is disposed through the liquid outlet hole 1a, and the outer circumferential surface of the spiral conveying shaft 32 abuts against the hole wall of the liquid outlet hole 1a to form a spiral conveying channel a between the spiral conveying shaft 32 and the hole wall of the liquid outlet hole 1a. The outlet of the spiral conveying channel a is arranged close to the needle 2, and the conveying driving component 31 drives the spiral conveying shaft 32 to rotate.

[0052] It can be understood that as the spiral conveying shaft 32 rotates, the functional liquid in the spiral conveying channel a can be conveyed to send the functional liquid in the liquid outlet hole 1a to the position of the needle 2.

[0053] Refer to Figures 2-4 , specifically, the communication position between the liquid supply component 4 and the liquid outlet hole 1a is located at the hole wall of the liquid outlet hole 1a, and the liquid supply component 4 is communicated with the spiral conveying channel a through the communication with the liquid outlet hole 1a.

[0054] With such a setting, the liquid supply component 4 sends the functional liquid into the spiral conveying channel a. As the spiral conveying shaft 32 rotates, the functional liquid is sent to the position of the needle 2 along the spiral conveying channel a. On the one hand, during the conveying process of the functional liquid, it all flows along the spiral conveying channel a, and the flow process of the functional liquid is relatively stable and not easy to generate bubbles, so as to ensure the printing quality. On the other hand, by changing the rotation speed of the spiral conveying shaft 32, the speed of the functional liquid being sent to the position of the needle 2 can be changed, so as to adjust the speed of supplying the functional liquid to the needle 2, ensure the sufficient supply of the functional liquid to the needle 2 with a large inner diameter of the tip, and avoid the situation of functional liquid accumulation and blockage inside the needle 2 with a small inner diameter of the tip.

[0055] Refer to Figures 2-5, specifically, the screw conveyor shaft 32 includes a conveying section 321 and a shielding section 322. The shielding section 322 is connected to the top of the conveying section 321. In this embodiment, the shielding section 322 and the conveying section 321 are integrally formed. The outer diameter of the shielding section 322 is larger than that of the conveying section 321, and a screw conveying channel a is formed between the conveying section 321 and the pore wall of the liquid outlet hole 1a.

[0056] Referring to Figures 2-5 , correspondingly, the main body 1 includes a leak-proof hole 1b, which is located above the liquid outlet hole 1a and communicates with the liquid outlet hole 1a. The aperture of the leak-proof hole 1b is larger than that of the liquid outlet hole 1a. The shielding section 322 is located within the leak-proof hole 1b, and the circumferential side surface of the shielding section 322 is in contact with the pore wall of the leak-proof hole 1b. The height of the leak-proof hole 1b is higher than the connection point between the liquid supply assembly 4 and the liquid outlet hole 1a.

[0057] With such a setting, by making the shielding section 322 fit against the pore wall of the leak-proof hole 1b, the top of the liquid outlet hole 1a is blocked, preventing the functional liquid in the liquid outlet hole 1a from overflowing from the top of the liquid outlet hole 1a. When the functional liquid supplied by the liquid supply assembly 4 to the screw conveying channel a is more than that in the screw conveying channel a, and the functional liquid accumulates in the screw conveying channel a and fills the screw conveying channel a, the functional liquid will not overflow from the liquid outlet hole 1a to contaminate the components above the liquid outlet hole 1a.

[0058] Referring to Figures 2-5 , preferably, a sealing ring 324 is embedded on the outer circumferential side surface of the shielding section 322, and the sealing ring 324 abuts against the pore wall of the leak-proof hole 1b.

[0059] With such a setting, the gap between the shielding section 322 and the pore wall of the leak-proof hole 1b is eliminated by the sealing ring 324, improving the sealing performance of the liquid outlet hole 1a.

[0060] Referring to Figures 2-5 , wherein, the conveying assembly 3 further includes a bearing 33. An installation hole 1c is formed at the top of the main body 1, and the installation hole 1c communicates with the liquid outlet hole 1a. In this embodiment, the installation hole 1c, the leak-proof hole 1b, and the liquid outlet hole 1a are arranged and communicated in sequence from top to bottom. Preferably, the aperture of the installation hole 1c is larger than that of the leak-proof hole 1b.

[0061] Referring to Figures 2-5 , the outer ring of the bearing 33 is installed within the installation hole 1c. The outer ring of the bearing 33 is embedded within the installation hole 1c, and the outer ring of the bearing 33 is supported by the bottom of the installation hole 1c. The top installation section 323 of the bolt conveyor shaft passes through the inner ring of the bearing 33 to be connected to the inner ring of the bearing 33. In this embodiment, the installation section 323, the shielding section 322, and the conveying section 321 are integrally formed.

[0062] With such a setting, the spiral conveyor shaft 32 is rotatably connected to the main body 1 by means of bearings 33. This facilitates the installation of the spiral conveyor shaft 32 and makes the rotation of the spiral conveyor shaft 32 smoother.

[0063] Referring to Figures 2-5 , in which the conveying drive assembly 31 includes a conveying drive member 311, a coupling 312 and a protective sleeve 313.

[0064] The protective sleeve 313 is fixed to the top of the main body 1, and the conveying drive member 311 is installed on the top of the protective sleeve 313. In this embodiment, the conveying drive member 311 includes a servo motor.

[0065] The coupling 312 is located inside the protective sleeve 313. The input end of the coupling 312 is connected to the drive end of the conveying drive member 311, and the output end of the coupling 312 is connected to the spiral conveyor shaft 32. In this embodiment, the output end of the coupling 312 is connected to the installation portion of the spiral conveyor shaft 32. The power of the conveying drive member 311 is transmitted to the spiral conveyor shaft 32 through the coupling 312 to drive the spiral conveyor shaft 32 to rotate.

[0066] With such a setting, the protective sleeve 313 protects the installation positions of the coupling 312, the spiral conveyor shaft 32 and the drive end of the conveying drive member 311, and avoids adverse effects of the external environment on the power transmission process. The arrangement of the coupling 312 facilitates the connection between the conveying drive member 311 and the spiral conveyor shaft 32, and also facilitates the installation and disassembly of the spiral conveyor shaft 32 and the coupling 312, that is, it facilitates the assembly of the electrohydrodynamic nozzle. In addition, by removing the protective sleeve 313, the coupling 312 and the conveying drive member 311 together from the main body 1, it is convenient to repair the inside of the main body 1.

[0067] Referring to Figures 2-4 , in which the liquid supply assembly 4 includes a liquid supply cylinder 41 and a gas supply mechanism (not shown in the figure). The liquid supply cylinder 41 is used to store the functional liquid. The liquid supply cylinder 41 is communicated with the liquid outlet hole 1a to be communicated with the spiral conveying channel a, and the gas supply mechanism is used to supply gas into the liquid supply cylinder 41. In this embodiment, the gas supply mechanism includes a positive pressure gas source.

[0068] With such a setting, air is supplied into the liquid supply cylinder 41 by the air supply mechanism, and the functional liquid in the liquid supply cylinder 41 is sent into the spiral conveying channel a by using air pressure, so as to realize the liquid supply to the spiral conveying channel a. When the rotation speed of the spiral conveying shaft 32 increases, the air pressure applied to the liquid supply cylinder 41 by the air supply assembly also increases synchronously, ensuring that a sufficient amount of functional liquid is supplied into the spiral conveying channel a. Moreover, the liquid supply cylinder 41, the spiral conveying channel a and the needle 2 are all connected. The air pressure applied by the air supply mechanism to the functional liquid will also synchronously push the functional liquid to flow in the spiral conveying channel a, making the flow of the functional liquid in the spiral conveying channel a smoother. And under the push of the air pressure, during the process of functional liquid transportation, gaps are not likely to appear in the spiral conveying channel a, so bubbles are not likely to be generated in the functional liquid either.

[0069] In addition, when it is necessary to print liquid droplets with a small dot diameter and the needle 2 with a larger inner diameter of the needle tip is replaced, the air supply mechanism reduces the pressure applied to the functional liquid in the liquid supply cylinder 41, which not only reduces the functional liquid sent into the spiral conveying channel a, but also adjusts the pressure received by the functional liquid in the needle 2. After the inner diameter of the needle tip of the needle 2 is reduced, the force received by the functional liquid at the needle tip of the needle 2 is not affected, that is, no matter what the size of the needle tip of the needle 2 is, the state of the functional liquid at the needle tip of the needle 2 is the same, so as to ensure printing consistency and ensure the printing quality.

[0070] When it is necessary to print liquid droplets with a large dot diameter and the needle 2 with a larger inner diameter of the needle tip is replaced, the air supply mechanism increases the pressure applied to the functional liquid in the liquid supply cylinder 41, which not only increases the functional liquid sent into the spiral conveying channel a, but also adjusts the pressure received by the functional liquid in the needle 2. After the inner diameter of the needle tip of the needle 2 is increased, the force received by the functional liquid at the needle tip of the needle 2 is not affected, that is, no matter what the size of the needle tip of the needle 2 is, the state of the functional liquid at the needle tip of the needle 2 is the same, so as to ensure printing consistency and ensure the printing quality.

[0071] It can be understood that when the needle tip sizes of different needles 2 are different, when the same pressure is applied to the inside of the needle 2, the functional liquid in the needle 2 with a smaller needle tip size receives a greater pressure, and the functional liquid in the needle 2 with a larger needle tip size receives a smaller pressure. Therefore, if the same pressure is applied to the needles 2 with different needle tip sizes, the pressures received by the functional liquids in different needles 2 are inconsistent, which affects the printing consistency.

[0072] In addition, it should be understood that the viscosity of the functional liquid is relatively large, and the needle tip of the needle 2 is usually very small, at the micron level. Therefore, it is difficult to eject the functional liquid only by air pressure, and it is even more impossible to achieve precise quantitative spraying. Therefore, the pressure applied by the air supply mechanism to the functional liquid in the needle 2 will not cause the functional liquid to be ejected.

[0073] Refer to Figures 2-4, Further, the liquid supply assembly 4 further includes a liquid supply pipe 42. The two ends of the liquid supply pipe 42 are respectively communicated with the spiral conveying channel a and the liquid outlet end of the liquid supply cylinder 41. The liquid supply pipe 42 is fixed on the side wall of the main body portion 1. The liquid supply cylinder 41 is inserted into the liquid supply pipe 42, and the liquid supply cylinder 41 supplies liquid to the spiral conveying channel a by means of the liquid supply pipe 42.

[0074] With such a setting, it is convenient to replace the liquid supply cylinder 41 so as to replace the exhausted liquid supply cylinder 41 in time.

[0075] Refer to Figure 2 and Figure 3 , Preferably, the flow channel inside the liquid supply pipe 42 is arranged obliquely. The end of the flow channel inside the liquid supply pipe 42 that communicates with the liquid supply cylinder 41 is higher than the end of the flow channel inside the liquid supply pipe 42 that communicates with the spiral conveying channel a.

[0076] With such a setting, the obliquely arranged flow channel in the liquid supply pipe 42 makes it easier for the functional liquid to flow from the liquid supply pipe 42 into the spiral conveying channel a. The possibility of the functional liquid accumulating in the flow channel and even causing blockage is reduced.

[0077] Refer to Figure 3 , Figure 6 and Figure 7 , wherein, the electrohydrodynamic inkjet head with flexible ink supply further includes a connector 6. The connector 6 is inserted into the bottom end of the liquid outlet hole 1a to be connected with the main body portion 1. A through connection hole is opened at the top of the connector 6, and the connection hole is communicated with the liquid outlet hole 1a.

[0078] An annular groove 6a is opened on the bottom surface of the connector 6. The needle 2 is detachably connected with the connector 6 by being inserted into the annular groove 6a, and the needle 2 is communicated with the connector 6. Therefore, the needle 2 is communicated with the liquid outlet hole 1a through the connector 6.

[0079] With such a setting, the needle 2 is connected with the main body portion 1 by means of the connector 6. When the needle 2 is replaced subsequently, the needle 2 can be removed from the connector 6, which will not cause damage to the main body portion 1 and ensures the service life of the main body portion 1.

[0080] In other embodiments, the needle 2 is threadedly connected with the connector 6.

[0081] Refer to Figure 3 , Figure 6 and Figure 7 , wherein, the power supply assembly 5 includes a conductive ring 51 and a magnetic member 52. The conductive ring 51 and the magnetic member 52 are both arranged at the bottom of the annular groove 6a. In this embodiment, the magnetic member 52 includes an annular magnet, and the annular magnet is located inside the conductive ring 51. The magnetic member 52 is adapted to magnetically adsorb the needle 2 so that the needle 2 abuts against the conductive ring 51 and is electrically connected to the conductive ring 51, and the conductive ring 51 is electrically connected to an external power supply.

[0082] Refer toFigure 3 , Figure 6 and Figure 7 , in this embodiment, a conductive hole 6b is formed in the side wall of the connector 6, and a wire of an external power supply is adapted to pass through the conductive hole 6b to be electrically connected to the conductive ring 51.

[0083] With such an arrangement, by disposing the connector 6, it is convenient to supply power to the needle 2. Moreover, the arrangement of the conductive ring 51 and the magnetic member 52 facilitates power supply to the needle 2 when the needle 2 is mounted on the connector 6, realizing the quick-disassembly function of the needle 2. The arrangement of the magnetic member 52 makes the electrical connection between the needle 2 and the conductive ring 51 more stable, ensuring normal printing.

[0084] Among them, the needle 2 is made of a magnetic conductive material. The connector 6 is made of an insulating material or the part of the connector 6 in contact with the conductive ring 51 and the needle 2 is made of an insulating material.

[0085] With such an arrangement, only the voltage is supplied to the needle 2, making the electric field ejected by the needle 2 more stable, ensuring the printing accuracy and quality.

[0086] The embodiment of the present application provides an electrohydrodynamic inkjet head with flexible ink supply. By changing the rotation speed of the spiral conveying shaft 32, the speed of the functional liquid supplied to the needle 2 is adjusted, and at the same time, the air pressure in the air supply cylinder is adaptively adjusted, and in combination with the power supply assembly 5, the voltage applied to the needle 2 is regulated, so as to adapt to the jetting requirements of needles 2 with different tip sizes.

[0087] Specifically, when it is necessary to print droplets with a smaller dot diameter, the needle 2 with a smaller tip size is replaced, the rotation speed of the spiral conveying shaft 32 is slowed down, and the functional liquid sent from the spiral conveying channel a to the needle 2 is reduced. At the same time, the air pressure in the air supply cylinder is reduced by the air supply mechanism, which not only slows down the speed of the functional liquid sent into the spiral conveying channel a, but also reduces the air pressure applied to the functional liquid at the needle 2, so that after the inner diameter of the tip of the needle 2 is reduced, the force received by the functional liquid at the tip of the needle 2 is not affected, that is, regardless of the size of the tip of the needle 2, the state of the functional liquid at the tip of the needle 2 is the same, so as to ensure printing consistency and printing quality. It is also necessary to adaptively adjust the voltage applied to the needle 2 by the power supply assembly 5 to realize the printing of small droplets. Since the amount of the functional liquid entering the needle 2 is reduced, the needle 2 can normally consume the functional liquid in the needle 2, the functional liquid is not easily accumulated and blocked, and the functional liquid is not easily ejected along with the jetting, ensuring the printing quality and accuracy.

[0088] When it is necessary to print droplets with a larger dot diameter, replace the needle 2 with a larger needle tip size, increase the rotation speed of the screw conveyor shaft 32, and increase the functional liquid sent from the screw conveyor channel a into the needle 2. At the same time, increase the air pressure in the air supply cylinder through the air supply mechanism, which not only speeds up the speed of the functional liquid sent into the screw conveyor channel a, but also increases the air pressure applied to the functional liquid at the needle 2. After the inner diameter of the needle tip of the needle 2 becomes larger, the force received by the functional liquid at the needle tip of the needle 2 is not affected, that is, regardless of the size of the needle tip of the needle 2, the state of the functional liquid at the needle tip of the needle 2 is consistent, so as to ensure printing consistency and printing quality. It is also necessary to adaptively adjust the voltage applied by the power supply component 5 to the needle 2, and then the printing of large droplets can be realized. Since the amount of functional liquid entering the needle 2 is increased, the demand for the amount of functional liquid required to be ejected by the needle 2 is met, and it is not easy to generate air bubbles in the needle 2 due to insufficient functional liquid, ensuring printing quality and accuracy.

[0089] Therefore, by adaptively adjusting the air pressure in the liquid supply cylinder 41 through the air supply mechanism, not only the speed of the functional liquid sent into the screw conveyor channel a is adaptively adjusted, but also when the rotation speed of the screw conveyor shaft 32 is adjusted, the air pressure is used to push the functional liquid to ensure that the functional liquid sent to the needle 2 is not easy to generate air bubbles and the air pressure of the functional liquid in the needle 2 is stable. By changing the rotation speed of the screw conveyor shaft 32, the speed of the functional liquid sent to the needle 2 is adjusted, and the outputs of the power supply component 5 and the liquid supply component 4 are adaptively adjusted to adapt to the spraying requirements of the needle 2 with different needle tip sizes, ensuring printing quality and accuracy and improving the applicability of the electrohydrodynamic inkjet printhead.

[0090] In a second aspect, an inkjet printing device is provided, including the electrohydrodynamic inkjet printhead with flexible ink supply as described above.

[0091] Another embodiment of the present application provides an inkjet printing device. Since this inkjet printing device includes the electrohydrodynamic inkjet printhead with flexible ink supply as described above, the beneficial effects of this inkjet printing device are the same as those of the electrohydrodynamic inkjet printhead with flexible ink supply as described above, and will not be elaborated here.

[0092] In a third aspect, an inkjet printing system is provided, including the electrohydrodynamic inkjet printhead with flexible ink supply as described above, and / or the inkjet printing device as described above.

[0093] Another embodiment of the present application provides an inkjet printing system. Since this inkjet printing system includes the electrohydrodynamic inkjet printhead with flexible ink supply as described above, and / or the inkjet printing device as described above, the beneficial effects of this inkjet printing system are the same as those of the electrohydrodynamic inkjet printhead with flexible ink supply and the inkjet printing device as described above, and will not be elaborated here.

[0094] In the description of the present application, it should be noted that the orientation or positional relationship indicated by terms such as "upper" and "lower" is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present application. Unless otherwise clearly specified and defined, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0095] It should be noted that in the present application, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising a..." does not exclude the existence of additional identical elements in the process, method, article or device comprising the said element.

[0096] The above are only specific embodiments of the present application, enabling those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to these embodiments shown herein, but rather to the broadest scope consistent with the principles and novel features claimed herein.

Claims

1. An electrofluidic nozzle with flexible ink supply, characterized in that: It includes: A main body, wherein a liquid outlet is provided inside the main body; A needle, the needle is detachably connected to the bottom end of the main body, and the needle is communicated with the liquid outlet; A conveying assembly, the conveying assembly comprising a conveying drive assembly and a spiral conveying shaft, the spiral conveying shaft is penetrated through the liquid outlet, and the circumferential outer side surface of the spiral conveying shaft abuts against the hole wall of the liquid outlet to form a spiral conveying channel between the hole wall of the liquid outlet, the outlet of the spiral conveying channel is arranged close to the needle head, and the conveying drive assembly drives the spiral conveying shaft to rotate; A liquid supply assembly, the liquid supply assembly comprising a liquid supply cylinder and an air supply mechanism, the liquid supply cylinder is used to store functional liquid, the liquid supply cylinder is communicated with the spiral conveying channel, and the air supply mechanism is used to supply air into the liquid supply cylinder; A power supply component is electrically connected to the needle to apply voltage to the needle.

2. The electrofluidic nozzle with flexible ink supply according to claim 1, characterized in that: The spiral conveying shaft comprises a conveying section and a shielding section, wherein the shielding section is connected to the top of the conveying section, the outer diameter of the shielding section is larger than the outer diameter of the conveying section, and a spiral conveying channel is formed between the conveying section and the hole wall of the liquid outlet hole; The main body also includes an anti-leakage hole, which is located above the liquid outlet and connected to the liquid outlet. The shielding section is located in the anti-leakage hole, and the circumferential side surface of the shielding section is in contact with the hole wall of the anti-leakage hole.

3. The electrofluidic nozzle with flexible ink supply according to claim 2, characterized in that: A sealing ring is embedded in the circumferential outer side surface of the shielding section, and the sealing ring is tightly pressed against the hole wall of the anti-leakage hole.

4. The electrofluidic nozzle with flexible ink supply according to claim 1, characterized in that: The conveying assembly also includes a bearing. A mounting hole is opened at the top of the main body, the mounting hole is connected to the liquid outlet, the outer ring of the bearing is installed in the mounting hole, and the top of the bolt conveying shaft is connected to the inner ring of the bearing.

5. The electrofluidic nozzle with flexible ink supply according to claim 1, characterized in that: The conveying drive assembly comprises: Conveyor drive components; A coupling, the input end of which is connected to the driving end of the conveying drive member, and the output end of which is connected to the screw conveying shaft; A protective sleeve is fixed to the top of the main body, and the coupling is located inside the protective sleeve.

6. The electrofluidic nozzle with flexible ink supply according to claim 1, characterized in that: The liquid supply assembly further comprises a liquid supply pipe, both ends of which are respectively connected to the spiral conveying channel and the liquid outlet end of the liquid supply cylinder; The flow channel inside the liquid supply tube is arranged obliquely, and one end of the flow channel inside the liquid supply tube connected to the liquid supply cylinder is higher than one end of the flow channel inside the liquid supply tube connected to the spiral conveying channel.

7. The electrofluidic nozzle with flexible ink supply according to claim 1, characterized in that: It also includes a connecting head, which is inserted at the bottom end of the liquid outlet to be connected to the main body, and a penetrating connecting hole is opened at the top of the connecting head, and the connecting hole is connected to the liquid outlet; an annular groove is opened on the bottom surface of the connecting head, and the needle is inserted in the annular groove to be detachably connected to the connecting head, and the needle is connected to the connecting hole.

8. The electrofluidic nozzle with flexible ink supply according to claim 7, characterized in that: The power supply assembly includes a conductive ring and a magnetic member, both of which are arranged at the bottom of the annular groove, and the magnetic member is suitable for magnetically adsorbing the needle so that the needle is pressed against the conductive ring and electrically connected to the conductive ring, and the conductive ring is electrically connected to an external power source; Wherein, the connector is made of insulating material or the portion of the connector that contacts the conductive ring and the needle is made of insulating material.

9. A printing device, characterized in that: The invention comprises an electrofluidic nozzle having a flexible ink supply as claimed in any one of claims 1 to 8.

10. An inkjet printing system, characterized in that: It comprises an electrofluid nozzle with flexible ink supply as claimed in any one of claims 1 to 8, and / or a printing device as claimed in claim 9.

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