Liquid drop generator based on liquid bridge tensile fracture

Abstract

The invention relates to the technical field of ink-jet printing, and discloses a liquid drop generator based on liquid bridge tensile fracture, which comprises a box body, a guide rail is arranged at the bottom of the box body, a first rack and a second rack which are respectively meshed with a driving gear and a driven gear are arranged on the guide rail in a relatively sliding manner, and the driving gear is connected with a stepless speed change mechanism; the stepless speed change mechanism is installed on the motor, and the first needle head and the second needle head are correspondingly fixed to the lower portions of the first rack and the second rack respectively. Test liquid forms a liquid bridge between the two needle heads, the needle heads are driven to move along with the rack, the liquid bridge is stretched and fractured to form liquid drops with controllable sizes, and the influence of different test liquid, flow and stretching speed on the liquid drops can be obtained through the control terminal. The transmission ratio can be adjusted by controlling the diameter of a friction wheel of the stepless speed change mechanism, and acceleration scaling of gear transmission is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of inkjet printing, and more particularly to a droplet generator based on liquid bridge stretching and breaking. Background Art

[0002] The jet breakup method is currently the main method for generating droplet targets. By applying disturbances at the nozzle to make the jet unstable and break, the main droplets and satellite droplets are generated. However, there are three problems with the jet breakup method: ① The size of the main droplet has approached the limit and cannot be further reduced; ② The satellite droplets cannot be effectively removed; ③ The main droplet is spatially unstable when it exists. Therefore, it is necessary to explore a method to generate smaller and more stable droplet targets.

[0003] The droplets generated by the liquid bridge stretching fracture method have the advantages of small size, no satellite droplets, and stability in time and space. It can effectively solve the current shortcomings of the jet fracture method. It has important scientific value and broad application prospects in applications involving micro-nanoscale droplet generation, such as extreme ultraviolet light sources and micro-nanoscale additive manufacturing.

[0004] Therefore, it is necessary to design a droplet generator based on tensile fracture. Summary of the invention

[0005] In order to solve the technical problems existing in the prior art, the present invention provides a droplet generator based on liquid bridge stretching and breaking, which has a novel structure and ingenious design and can realize the control of the size and initial velocity of the droplets.

[0006] To achieve the above object, the present invention adopts the following technical solution:

[0007] A droplet generator based on liquid bridge tensile fracture comprises a box body, a guide rail extending in the left and right directions is installed at the bottom of the box body as a bottom structure, a first rack and a second rack are installed on the left and right sides of the guide rail for relative sliding, a driving gear is installed in the box body above the first rack, the driving gear is connected to a continuously variable transmission mechanism, the continuously variable transmission mechanism is installed on a motor, and the motor is fixed inside the box body; a driven gear adapted to mesh with the driving gear is installed in the box body above the second rack; the upper parts of the first rack and the second rack located in the box body are toothed and are respectively connected to their respective upper parts. The corresponding driving gear and the driven gear are meshed; the lower parts of the first rack and the second rack extend downwardly out of the box body, and are respectively fixed with a first needle and a second needle; the needle ends of the first needle and the front end of the second needle are placed concentrically, and the liquid inlet ends at the ends are respectively connected to a micro-injection pump through corresponding infusion pipelines; the test liquid in the micro-injection pump is injected into the two infusion pipelines, and a liquid bridge is formed between the first needle and the second needle; a control terminal is installed on the outer wall of the box body, and the control terminal controls the motor, the continuously variable transmission mechanism and the micro-injection pump through the line.

[0008] Preferably, a first L-shaped fixing plate is installed on the lower side of the first rack, a second L-shaped fixing plate is installed on the lower side of the second rack, the first needle head is installed at the center of the lower vertical plate of the first L-shaped fixing plate, and the second needle head is installed at the center of the lower vertical plate of the second L-shaped fixing plate.

[0009] Preferably, the guide rail is mounted on the box body by bolts, the first L-shaped fixing plate is mounted on the lower side of the first rack by bolts, and the second L-shaped fixing plate is mounted on the lower side of the second rack by bolts.

[0010] Preferably, a threaded hole 1 for screwing the first needle head is formed on the lower vertical plate of the first L-shaped fixing plate, and a threaded hole 2 for screwing the second needle head is formed on the lower vertical plate of the second L-shaped fixing plate, and the threaded hole 1 is opposite to the threaded hole 2.

[0011] Preferably, the driving gear and the driven gear have the same size.

[0012] Preferably, a positioning plate is installed on each of the side portions of the first rack and the second rack that are opposite to each other, and anti-collision rubber is fixed on the outer side of the positioning plate; and lubricating oil is coated on the guide rail.

[0013] Preferably, the infusion pipeline is made of transparent hard material.

[0014] Preferably, the infusion pipeline is also equipped with a flow measurement device and a temperature measurement device connected to the input end of the control terminal, and a temperature adjustment device and a throttle valve connected to the output end of the control terminal.

[0015] Preferably, a liquid recovery device is installed at the lower part of the box.

[0016] Preferably, a PLC controller is installed inside the control terminal, and a display screen, a micro-injection pump control port, a motor control port, a continuously variable transmission mechanism control port, a knob, left and right buttons and an input panel are installed outside the control terminal. The knob is used to control and adjust various numerical values, the left and right buttons are used to select motor control and micro-injection pump control, and the input panel is used to input parameters.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] 1) The present invention injects the test liquid between the first needle and the second needle on the left and right sides through a micro-injection pump to form a liquid bridge; the way to generate droplets is that the motor drives the continuously variable transmission mechanism to rotate, and the continuously variable transmission mechanism controls the gear to rotate, driving the racks to move away from each other on the left and right sides, so that the liquid bridge breaks to form droplets, and then the PLC controller is programmed and controlled. Under the program setting, the motor speed and rotation cycle are automatically controlled, the transmission ratio of the continuously variable transmission mechanism and the infusion flow rate of the test liquid through the micro-injection pump are adjusted. The speed of generating droplets can be adjusted according to experimental requirements, and the influence of different stretching speeds and discharge speeds on the droplets generated by the breaking of the liquid bridge can be obtained.

[0019] 2) The present invention automatically controls the micro-injection pump to adjust the flow of the infusion pipeline through the PLC controller, and monitors the flow of the test liquid through the flow measuring device arranged at the end of the infusion pipeline, and inputs the collected information into the PLC controller. The PLC controller displays the information on the display screen of the control terminal after processing, and adjusts the micro-injection pump through the control terminal to achieve flow adjustment, which can avoid flow fluctuations of the infusion pipeline to the needle part.

[0020] 3) The present invention automatically controls the diameter of the friction wheel of the stepless speed change mechanism to adjust the transmission ratio through the PLC controller, thereby realizing the acceleration scaling of the gear transmission. Compared with the traditional mechanical transmission, the stepless speed change has the advantages of high transmission efficiency, smooth transmission ratio change, and stable power output.

[0021] 4) The present invention generates a stable torque by controlling the input current of the motor, ensuring that the torque acting on the object remains constant, thereby achieving a uniform angular acceleration, so that the sliding speeds of the two needles can be controlled to be the same when the liquid bridge is stretched, thereby avoiding non-uniform breakage of the liquid bridge and obtaining droplets with adjustable sizes within a certain range. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0023] Figure 1 A schematic diagram of the overall structure of a droplet generator based on liquid bridge tensile fracture provided in an embodiment of the present invention.

[0024] Figure 2 A schematic structural diagram of a droplet generator (excluding a housing) based on liquid bridge tensile fracture provided in an embodiment of the present invention.

[0025] Figure 3 A schematic structural diagram of an L-shaped fixing plate provided in an embodiment of the present invention.

[0026] Figure 4 A schematic diagram of the structure of a needle provided in an embodiment of the present invention.

[0027] Figure 5 A schematic diagram of the external structure of a control terminal provided in an embodiment of the present invention.

[0028] Figure 6 , Figure 7 A diagram of the experimental results of a cross-scale satellite droplet test using the stretching method controlled by the present invention.

[0029] In the figure: 1-box, 2-guide rail, 3-first rack, 4-second rack, 5-driving gear, 6-motor, 7-driven gear, 8-first needle, 9-second needle, 10-infusion pipeline, 11-control terminal, 12-first L-shaped fixing plate, 13-second L-shaped fixing plate, 14-positioning plate, 15-anti-collision rubber, 16-gear shaft, 17-display screen, 18-micro injection pump control port, 19-motor control port, 20-knob, 21-left and right buttons, 22-input panel, 23-continuously variable transmission mechanism, 24-continuously variable transmission mechanism control port. DETAILED DESCRIPTION

[0030] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0031] In the description of the present invention, it is necessary to understand that the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention 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, and therefore cannot be understood as a limitation on the present invention.

[0032] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0033] Example:

[0034] See also Figures 1 to 5 The present invention provides a droplet generator based on liquid bridge tensile fracture, including a box body 1, a guide rail 2 extending in the left and right directions is installed at the bottom of the box body as a bottom structure (that is, the bottom of the guide rail coincides with the bottom of the box body, and the box body takes the guide rail as the bottom), a first rack 3 and a second rack 4 are relatively slidably installed on the left and right sides of the guide rail 2, a driving gear 5 is installed in the box body 1 above the first rack 3, the driving gear 5 is connected to a continuously variable transmission mechanism 23, the continuously variable transmission mechanism 23 is installed on a motor 6, and the motor 6 is fixed inside the box body 1; a driven gear 7 adapted to mesh with the driving gear 5 is installed in the box body 1 above the second rack 4, specifically, the driving gear 5 is rotatably connected to the continuously variable transmission mechanism 23 through a gear shaft 16 installed thereon.

[0035] The upper parts of the first rack 3 and the second rack 4 located in the housing 1 are tooth-shaped, and are respectively meshed with the corresponding driving gear 5 and the driven gear 7 above them; the lower parts of the first rack 3 and the second rack 4 extend downwardly out of the housing 1, and are respectively fixed with the first needle 8 and the second needle 9; the needle ends of the front ends of the first needle 8 and the second needle 9 are placed concentrically, and the liquid inlet ends at the ends are respectively connected to a micro-injection pump (not shown in the figure) through corresponding infusion pipelines 10; the test liquid in the micro-injection pump is injected into the two infusion pipelines 10, and a liquid bridge is formed between the first needle 8 and the second needle 9 placed opposite each other.

[0036] A control terminal 11 is installed on the outer wall of the box body 1. The control terminal 11 controls the motor 6, the continuously variable transmission mechanism 23 and the micro-injection pump through the line, so that the generation of droplets by breaking the liquid bridge is completely controllable, and droplets with adjustable sizes within a certain range are obtained.

[0037] Specifically, the control terminal 11 can control the moving direction and speed of the two racks by controlling the rotation direction and speed of the motor 6. At the same time, the control terminal 11 can also control the injection speed of the micro-injection pump, thereby controlling the flow rate of the test liquid in the infusion pipeline 10.

[0038] In the present invention, the test liquid forms a liquid bridge between the two needles. As the rack drives the needles to move, the liquid bridge is stretched and broken to form droplets of controllable size. The effects of different test liquids, flow rates, and stretching speeds on the occurrence of droplets can be obtained through the control terminal 11.

[0039] In the present invention, a continuously variable transmission mechanism 23 and a motor 6 are installed inside the box 1. The control terminal 11 can adjust the transmission ratio by controlling the diameter of the friction wheel in the continuously variable transmission mechanism 23 to achieve acceleration scaling of the gear transmission, and obtain droplets with adjustable sizes within a certain range to meet the requirements of inkjet printing; the control terminal 11 can also generate a stable torque by controlling the input current of the motor 6 to ensure that the torque acting on the object remains constant, thereby achieving uniform angular acceleration, so that when the liquid bridge is stretched, the sliding speeds of the two needles can be controlled to be the same, achieving uniform and symmetrical breaking of the liquid bridge, and obtaining droplets with adjustable sizes within a certain range.

[0040] Furthermore, the present invention can obtain droplets whose size can be controlled within a certain range, which is a specific interval that can be pre-set, providing great convenience and more precise operation possibilities for related application scenarios.

[0041] In a further specific embodiment, a first L-shaped fixing plate 12 is installed on the lower side of the first rack 3, a second L-shaped fixing plate 13 is installed on the lower side of the second rack 4, a first needle 8 is installed at the center of the lower vertical plate of the first L-shaped fixing plate 12, and a second needle 9 is installed at the center of the lower vertical plate of the second L-shaped fixing plate 13.

[0042] The L-shaped fixing plate is provided to more conveniently fix the needle and the infusion line 10 on the rack. One end of the L-shaped fixing plate is connected to the infusion line 10, and the other end is connected to the corresponding needle, so that the test liquid enters the needle from the micro-injection pump through the infusion line 10 and the L-shaped fixing plate. The two needles are placed concentrically to prevent abnormal liquid bridge breakage due to spatial deviation.

[0043] Furthermore, the guide rail 2 is mounted on the box body 1 by means of bolts, and a threaded hole matching with the box body 1 is provided on the top of the guide rail. This structure can facilitate the installation and removal of the guide rail 2.

[0044] The first L-shaped fixing plate 12 is installed on the lower side of the first rack 3 by bolts, and the second L-shaped fixing plate 13 is installed on the lower side of the second rack 4 by bolts to facilitate installation and disassembly between the L-shaped fixing plate and the rack.

[0045] At the same time, a threaded hole 1 for screwing the first needle 8 is formed on the lower vertical plate of the first L-shaped fixing plate 12, and a threaded hole 2 for screwing the second needle 9 is formed on the lower vertical plate of the second L-shaped fixing plate 13. The threaded hole 1 is opposite to the threaded hole 2, and this structure can facilitate the installation and removal of the needle on the L-shaped fixing plate.

[0046] In this embodiment, the driving gear 5 has the same size as the driven gear 7. In actual experiments, different transmission effects can be achieved by replacing gears and adjusting the motor speed, so that the sliding speeds of the two needles can be controlled to be different when the liquid bridge is stretched, thereby achieving asymmetric fracture of the liquid bridge.

[0047] In a further specific embodiment, a positioning plate 14 is installed on the side parts opposite to the first rack 3 and the second rack 4, and an anti-collision rubber 15 is fixed on the outer side of the positioning plate 14 to prevent collision caused by misoperation. At the same time, lubricating oil is also applied on the guide rail 2 to facilitate smooth sliding of the rack.

[0048] In a further specific embodiment, the infusion line 10 is made of a transparent hard material, which facilitates observation of the flow of the test liquid in the infusion line 10 .

[0049] In a further specific embodiment, a flow measurement device and a temperature measurement device connected to the input end of the control terminal and a temperature adjustment device and a throttle valve connected to the output end of the control terminal are also installed on the infusion pipeline 10. At the same time, a liquid recovery device is installed at the lower part of the box 1.

[0050] In a further specific embodiment, a PLC controller is installed inside the control terminal 11, such as Figure 5 As shown, the control terminal 11 is externally installed with a display screen 17, a micro-injection pump control port 18 (two), a motor control port 19, a continuously variable transmission mechanism control port 24, a knob 20, left and right buttons 21 and an input panel 22; each control port is respectively connected to the left and right gears and related components in the left and right infusion pipelines, and each component is controlled by a PLC controller. For example, the control terminal 11 controls the micro-injection pump through the micro-injection pump control port 18 to adjust the flow rate; the knob 20 is used to control and adjust various values, the left and right buttons 21 are used to select motor control and micro-injection pump control, and the input panel 22 is used to input parameters.

[0051] The present invention provides a method for using a droplet generator based on liquid bridge tensile fracture:

[0052] When the present invention is used, the test liquid in the micro-injection pump is input into the infusion pipeline 10, and the flow rate is controlled by the micro-injection pump to form a liquid bridge between the first needle 8 and the second needle 9. The motor 6 is controlled to rotate by the control terminal 11, which drives the continuously variable transmission mechanism 23 to rotate, and drives the two racks to move relative to each other, so that the liquid bridge breaks to form droplets with adjustable sizes within a certain range.

[0053] The micro-injection pump is adjusted through the control terminal 11 to control the flow rate so that different test liquid flows affect the occurrence and rupture of the liquid bridge; and the micro-injection pump control port 18 is adjusted through the control terminal 11 to achieve uniform entry of the test liquid into the infusion pipeline 10.

[0054] The torque is stabilized by adjusting the current of the motor 6 through the control terminal 11, so that the sliding speed of the left and right gear racks is the same, and the speed and direction of the motor 6 are adjusted to achieve the periodic reciprocating motion of the rack.

[0055] The transmission ratio of the continuously variable transmission mechanism 23 is adjusted by the control terminal 11 to achieve acceleration scaling of the gear transmission.

[0056] Motor control, stepless speed control and micro-injection pump control are selected by the left and right buttons 21 on the control terminal 11, and the corresponding numerical changes are controlled by the control knob 20 and displayed on the display screen 17. Parameters can also be input through the input panel 22 for precise control.

[0057] The method of controlling the generation of cross-scale satellite droplets by stretching proposed in the present invention has been experimentally verified by the applicant. Using V50 silicone oil and a needle with a tube diameter of 1.5 mm, satellite droplets with a span of 4 to 280 μm were obtained by adjusting the stretching acceleration on both sides. The results are detailed in Figure 6 , Figure 7 .

[0058] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0059] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A droplet generator based on liquid bridge tensile fracture, characterized in that: The invention comprises a box body, a guide rail extending in the left-right direction is installed at the bottom of the box body as a bottom structure, a first rack and a second rack are installed on the left and right sides of the guide rail for relative sliding, a driving gear is installed in the box body above the first rack, the driving gear is connected to a continuously variable transmission mechanism, the continuously variable transmission mechanism is installed on a motor, and the motor is fixed inside the box body; a driven gear adapted to mesh with the driving gear is installed in the box body above the second rack; the upper parts of the first rack and the second rack located in the box body are tooth-shaped, and are respectively connected to the corresponding driving gear above each of them The wheel and the driven gear are meshed; the lower parts of the first rack and the second rack extend downwardly out of the box body, and respectively correspond to the first needle and the second needle; the needle ends of the front ends of the first needle and the second needle are placed concentrically, and the liquid inlet ends at the ends are respectively connected to a micro injection pump through corresponding infusion pipelines; the test liquid in the micro injection pump is injected into the two infusion pipelines, and a liquid bridge is formed between the first needle and the second needle; a control terminal is installed on the outer wall of the box body, and the control terminal controls the motor, the continuously variable transmission mechanism and the micro injection pump through the line.

2. A droplet generator based on liquid bridge tensile fracture according to claim 1, characterized in that: A first L-shaped fixing plate is installed at the lower side of the first rack, a second L-shaped fixing plate is installed at the lower side of the second rack, the first needle head is installed at the center of the lower vertical plate of the first L-shaped fixing plate, and the second needle head is installed at the center of the lower vertical plate of the second L-shaped fixing plate.

3. A droplet generator based on liquid bridge tensile fracture according to claim 2, characterized in that: The guide rail is mounted on the box body by bolts, the first L-shaped fixing plate is mounted on the lower side of the first rack by bolts, and the second L-shaped fixing plate is mounted on the lower side of the second rack by bolts.

4. A droplet generator based on liquid bridge tensile fracture according to claim 2, characterized in that: A threaded hole 1 for screwing the first needle head is formed on the lower vertical plate of the first L-shaped fixing plate, and a threaded hole 2 for screwing the second needle head is formed on the lower vertical plate of the second L-shaped fixing plate, and the threaded hole 1 is opposite to the threaded hole 2.

5. A droplet generator based on liquid bridge tensile fracture according to claim 1, characterized in that: The driving gear and the driven gear have the same size.

6. A droplet generator based on liquid bridge tensile fracture according to claim 1, characterized in that: A positioning plate is installed on the side parts of the first rack and the second rack that are opposite to each other, and anti-collision rubber is fixed on the outer side of the positioning plate; and lubricating oil is coated on the guide rail.

7. A droplet generator based on liquid bridge tensile fracture according to claim 1, characterized in that: The infusion pipeline is made of transparent hard material.

8. The droplet generator based on liquid bridge tensile fracture according to claim 1, characterized in that: The infusion pipeline is also equipped with a flow measurement device and a temperature measurement device connected to the input end of the control terminal, and a temperature adjustment device and a throttle valve connected to the output end of the control terminal.

9. The droplet generator based on liquid bridge tensile fracture according to claim 1, characterized in that: A liquid recovery device is installed at the lower part of the box.

10. A droplet generator based on liquid bridge tensile fracture according to any one of claims 1 to 9, characterized in that: A PLC controller is installed inside the control terminal, and a display screen, a micro-injection pump control port, a motor control port, a continuously variable transmission mechanism control port, a knob, left and right buttons, and an input panel are installed outside the control terminal. The knob is used to control and adjust various numerical values, the left and right buttons are used to select motor control and micro-injection pump control, and the input panel is used to input parameters.

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