Micro-droplet spraying device

Abstract

The utility model relates to a micro-droplet jetting device, which is used for jetting fluid and comprises a chamber main body, at least one micro-droplet jetting device, at least one micro-droplet jetting device and at least one micro-droplet jetting device, the fluid cavity is communicated with the fluid path, and at least one spray hole is formed in the fluid cavity; an actuator configured to perform a mechanical motion in response to the pulse signal; the linear actuating piece is linearly inserted into the fluid cavity; the motor is connected with the actuator; the linear actuator is configured to do reciprocating linear motion along a linear path relative to the chamber main body under the action of the actuator so as to form fluctuation acting on the fluid in the fluid chamber; the linear actuating piece is provided with a first central shaft, and the linear path is parallel to the first central shaft; the spray hole is provided with a second central shaft; and the first central shaft is aligned with the second central shaft. According to the utility model, the spraying precision is improved, and the accuracy and the consistency of the dropping position of liquid drops are improved.

Description

Technical Field

[0001] The utility model relates to a spraying device, in particular to a micro-drop spraying device. Background Art

[0002] Using the principle of traditional droplet generators, such as the traditional pressure pulse extrusion principle, the diameter of the generated droplets is usually close to or equal to the size of the nozzle. Based on the existing manufacturing process and cost, it is still difficult to spray ultra-precise micron or nanometer droplets. Even if the spraying of tiny droplets is achieved, it is difficult to achieve more accurate droplet positioning and control. Summary of the invention

[0003] The utility model aims at the problems existing in the prior art and provides a micro-droplet injection device, which improves the injection precision and the accuracy and consistency of the droplet landing position.

[0004] The utility model discloses a micro-droplet injection device for injecting fluid, comprising:

[0005] A chamber body, which has a fluid path and at least one fluid chamber therein; the fluid chamber is connected to the fluid path, and at least one spray hole is provided in the fluid chamber;

[0006] an actuator configured to perform mechanical motion in response to the pulse signal;

[0007] A linear actuator is linearly inserted in the fluid chamber; connected to the actuator; configured to perform reciprocating linear motion along a linear path relative to the chamber body under the action of the actuator, so as to form waves acting on the fluid in the fluid chamber; and the linear actuator has a first central axis, the linear path is parallel to the first central axis; the spray hole has a second central axis; the first central axis and the second central axis are aligned.

[0008] As an implementation mode, one of the fluid chambers is correspondingly inserted with one of the linear actuators; the inner wall of the fluid chamber is symmetrically arranged around the third center axis, and the first center axis is aligned with the third center axis.

[0009] As an embodiment, at least a portion of the inner wall of the fluid chamber is a continuously changing arc surface.

[0010] As an implementation manner, the inner wall of the fluid path and the inner wall of the fluid chamber are connected via the continuously changing arc surface.

[0011] As an embodiment, the fluid chamber has a first cross-section at the end away from the nozzle and a second cross-section at the end close to the nozzle; the continuously changing arc surface includes a radially converging inner wall that gradually decreases from the first cross-section to the second cross-section.

[0012] As an implementation manner, the linear actuator has a radially convergent structure.

[0013] As an implementation manner, the linear actuator is adapted to the shape of the fluid chamber; and a consistent gap distance is maintained between the radially converging structure and the opposite surfaces of the radially converging inner wall.

[0014] As an implementation manner, the maximum cross-section of the spray hole is smaller than or equal to the second cross-section.

[0015] As an embodiment, it also includes a sealing ring; an insertion hole is set on the chamber body, and the sealing member is set between the linear actuator and the insertion hole.

[0016] After adopting the above structure, the utility model has the following advantages compared with the prior art:

[0017] The utility model adopts the actuation principle of the linear actuator making reciprocating linear motion along the linear path, which can form micron-level or nanometer-level droplets with a droplet diameter smaller than the diameter of the nozzle hole, thereby improving the injection accuracy. The central axis is aligned to improve the accuracy and consistency of the droplet landing position. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a partial structural diagram of the first embodiment of the utility model.

[0019] Figure 2 It is a cross-sectional view of the first embodiment of the present utility model.

[0020] Figure 3 It is a schematic diagram of the structure of the actuator and the linear actuator of the first embodiment of the utility model.

[0021] Figure 4 It is a cross-sectional view of the second embodiment of the present utility model.

[0022] Figure 5 It is a cross-sectional view of the chamber body of the second embodiment of the present utility model.

[0023] Figure 6 This is a first state diagram of the fluid at the spray hole of the utility model.

[0024] Figure 7 This is a second state diagram of the fluid at the nozzle of the utility model.

[0025] 1. Chamber body, 11. Fluid path, 12. Fluid chamber, 13. Spray hole, 14. Insert hole, 15. Second center axis, 16. Third center axis;

[0026] 2. Actuator;

[0027] 3. Linear actuator, 31. First central axis;

[0028] 4. Sealing ring. DETAILED DESCRIPTION

[0029] The utility model is further described below in conjunction with the accompanying drawings and specific embodiments.

[0030] Droplet generator technology began in the 1970s with the emergence of piezoelectric jet technology, which used piezoelectric ceramics to form droplets. In the 1980s, capillary ejectors solved the problem of nozzle spacing. In the 1990s, thermal bubble jet technology used electric heat to cause pressure increase. In 2000, piezoelectric jet technology was further developed, and through more advanced ceramic processing and innovative shared wall drive solutions, nozzle 13 spacing was achieved with a smaller spacing. Jetting technology has experienced a development process from continuous, piezoelectric to thermal bubble, continuously improving the accuracy of nozzle 13 and the compatibility of fluid components, laying the foundation for the ejection of tiny droplets.

[0031] However, due to the limitation mechanism of droplet injection, the accuracy of traditional injection is limited by the size of its nozzle; and due to the limitations of processing technology and cost, it is difficult to achieve ultra-fine micron (less than 10 microns) or nanometer size or even smaller droplet volume.

[0032] The utility model systematically studies that a driving pulse stimulates the fluid to produce damped oscillation in the liquid, thereby triggering the fluid to form droplets through the liquid surface constraint of the nozzle 13. Under the premise of achieving a droplet diameter printing accuracy of micrometer or nanometer size or even smaller, the manufacturing cost is effectively reduced.

[0033] like Figure 2 and Figure 4 A micro-droplet ejection device is provided for ejecting a fluid, comprising:

[0034] The chamber body 1 is provided with a fluid path 11 and at least one fluid chamber 12; the fluid chamber 12 is connected to the fluid path 11, and at least one spray hole 13 is provided in the fluid chamber 12;

[0035] An actuator 2, configured to perform mechanical motion in response to a pulse signal;

[0036] The linear actuator 3 is linearly inserted in the fluid chamber 12; connected to the actuator 2; configured to perform reciprocating linear motion along a linear path relative to the chamber body 1 under the action of the actuator 2, so as to form waves acting on the fluid in the fluid chamber 12; and the linear actuator 3 has a first central axis 31, and the linear path is parallel to the first central axis 31; the spray hole 13 has a second central axis 15; the first central axis 31 and the second central axis 15 are aligned.

[0037] The specific principle of the utility model is described as follows. First, under the driving action of the actuator 2, the linear actuator 3 moves along a linear path away from the spray hole 13, such as Figure 6 As shown, the fluid surface at the nozzle 13 contracts slightly to form a curved liquid surface. Under the action of the reverse drive applied by the actuator 2, the linear actuator 3 moves back and forth along a linear path toward the nozzle 13, and the vibration wave propagates axially along the first center axis 31 of the linear actuator 3, generating a pressure wave at the nozzle 13, causing the liquid surface to bulge outward. The linear actuator 3 moves in a linear manner toward or away from the nozzle 13, driving the liquid surface at the nozzle 13 to extend outward until it reaches the deformation peak. The linear actuator 3 moves along a linear path away from the nozzle 13, and the viscous force and inertial force hinder the backflow of the fluid outside the hole. The newly formed liquid surface continues to expand outward under the action of residual energy, and small droplets detach from the curved liquid surface due to the surface vibration, and under the action of the flow field in the fluid chamber 12, as shown Figure 7 As shown, the liquid surface shrinks from the edge of the nozzle hole 13 to form a droplet. In order to better understand this solution, reference may be made to the Worthington jet principle.

[0038] The chamber body 1, as Figure 5 As shown, the fluid path 11 includes an inlet and an outlet, and the fluid enters from the inlet and passes through the internal space to guide the fluid at a constant pressure. The fluid chamber 12 contains the fluid within a range and helps the fluid to be accurately ejected from the nozzle 13. The chamber body 1 is usually designed with a filtering function to prevent impurities from clogging the nozzle 13. In terms of material selection, polymers are widely used because of their lightness and chemical stability, while metals or ceramics are used in applications that require higher heat resistance and chemical resistance. The manufacture of the chamber body 1 usually relies on injection molding and machining, both of which can efficiently produce components with precise structures and reliable performance. Overall, the optimized design of the chamber body 1 is crucial to improving the performance of the nozzle head, improving the injection quality, and ensuring the long-term stable operation of the equipment. Among them, the fluid can be ink, additives, liquid metal or other fluid liquids that need to be sprayed.

[0039] The actuator 2 is used to realize the energy conversion from pulse signal to mechanical energy. For example, the piezoelectric actuator 2 will change shape and produce displacement due to the action of the electrical signal; the stepper motor or servo motor will move precisely according to the received electrical pulse. The signal generating module applies the energy driving pulse, and the actuator 2 is the component that responds to these pulses and performs mechanical movement. Among them, the signal generating module can be an arbitrary waveform generator, a direct digital synthesizer, a microcontroller, a phase-locked loop, etc., which generate voltage or current pulses according to a predetermined program or algorithm. The signal generating module generates appropriate electrical signals according to the required control strategy. The electrical signal is transmitted to the actuator 2 via a cable. The actuator 2 receives the pulse signal and converts it into mechanical movement to perform the required task.

[0040] For example, the actuator 2 may be a piezoelectric actuator 2, which drives a piezoelectric material to deform by voltage, thereby generating mechanical motion. Their response time can be very fast, reaching microseconds or even shorter. The piezoelectric actuator 2 not only has a fast response speed, but also has very high position accuracy and repeatability, and is suitable for applications requiring high-precision control. In addition, other materials may also be used, for example, when photosensitive materials or structures are used, some photoactuators 2 can achieve very fast responses. These materials deform rapidly under the stimulation of light; shape memory alloy materials (such as nickel-titanium alloys) can rapidly change shape under the influence of temperature or current to generate mechanical motion. Although the response time of a general electromagnetic actuator 2 (such as a solenoid valve or relay) may be in the millisecond range, a high-performance electromagnetic actuator 2 can be designed to have an extremely short response time.

[0041] The linear actuator 3, such as Figure 1-4 As shown, it can be a piston or a push rod, and its shape can be circular, conical, or other parts that can achieve linear reciprocating motion. More preferably, the structure of the linear actuator 3 is symmetrical around the first central axis 31. The material can be a metal alloy, or piezoelectric ceramics, piezoelectric polymers, composite materials or silicon-based materials. When the linear actuator 3 and the actuator 2 are made of the same material, they can be a whole. When the linear actuator 3 and the actuator 2 are made of different materials, an adhesive can be used for bonding; other flexible materials can also be arranged between the linear actuator 3 and the actuator 2, for example, to help seal the chamber body 1.

[0042] Thus, the linear actuator 3 has a first central axis 31, and the linear path is parallel to the first central axis 31; so as to form a vibration wave transmitted along the direction of the linear path, and the vibration wave propagates axially along the first central axis 31 of the linear actuator 3. Wherein, the endpoints of the linear path are the first position and the second position. The larger the distance between the first position and the second position, the larger the amplitude of the reciprocating movement of the linear actuator 3 between the first position and the second position, and the larger the amplitude of the vibration wave when other conditions remain unchanged. The spray hole 13 has a second central axis 15; the first central axis 31 and the second central axis 15 are aligned. The vibration wave propagates axially along the first central axis 31, that is, the pressure wave of the fluid can be propagated axially along the second central axis 15. The fluid at the spray hole 13 generates pressure waves uniformly distributed along the circumference of the second central axis 15, causing the fluid liquid surface to bulge outward uniformly with the second central axis 15 as the center. Under the action of the flow field into the fluid chamber 12, the liquid surface uniformly shrinks from the edge of the spray hole 13 with the second central axis 15 as the center to form droplets. This is conducive to achieving the accuracy and consistency of the droplet drop position, and can be particularly applied to application scenarios with extremely high precision requirements. In addition, the pressure wave of the fluid propagates axially along the second central axis 15, so that the kinetic energy component along the axial direction of the second central axis 15 is maximized, thereby improving energy utilization efficiency.

[0043] In some embodiments, one of the fluid chambers 12 is correspondingly inserted with one of the linear actuators 3 ; the inner wall of the fluid chamber is arranged symmetrically around the third center axis 16 , and the first center axis 31 is aligned with the third center axis 16 .

[0044] Among them, the fluid chamber 12 is for the linear actuator 3, and the vibration wave propagates axially along the first central axis 31 of the linear actuator 3, generating a pressure wave at the nozzle 13, causing the liquid surface to bulge outward. At this time, the fluid chamber 12 plays a role in reflecting the pressure wave to enhance the energy of the synthetic wave along the second central axis 15. The inner wall of the fluid is arranged symmetrically around the third central axis 16, and the first central axis 31 is aligned with the third central axis 16, so that the reflected pressure wave uniformly distributed along the circumference of the second central axis 15 can be obtained, so as to obtain the synthetic wave uniformly distributed along the circumference of the third central axis 16.

[0045] As an implementation manner, at least a portion of the inner wall of the fluid chamber 12 is a continuously changing cambered surface.

[0046] The fluid chamber 12 has a circular cross section, for example, the diameter of the circular cross section gradually increases from 1 mm at the bottom to 2 mm at the top. The streamlined cavity design formed by the continuously changing arc surface and the smooth inner surface can make the fluid flow smoothly with minimal resistance. It may also include the use of special coatings to reduce internal friction.

[0047] As an implementation method, it is better to Figure 5 As shown, the inner wall of the fluid path 11 and the inner wall of the fluid chamber 12 are connected via the continuously changing cambered surface.

[0048] The geometric shapes of the fluid chamber 12 and the fluid path 11 are intended to optimize the streamlined flow of the fluid. In order to optimize the fluid flow characteristics, the fluid chamber 12 and the fluid path 11 are designed with an arcuate structure, wherein the arcuate surface helps to guide the fluid flow and reduce turbulence. The arcuate fluid chamber 12 and the fluid path 11 are designed to optimize fluid dynamics performance, maintaining the uniformity and stability of the fluid flow through their surfaces with continuous curvature. The design of the arcuate fluid chamber 12 and the fluid path 11 is intended to reduce fluid dynamics losses through geometric shapes and improve the overall efficiency of the system. The arcuate surfaces of the fluid chamber 12 and the fluid path 11 gradually change from the inlet to the outlet, forming a smooth transition to promote the smooth flow of the fluid.

[0049] As an embodiment, more preferably, the fluid chamber 12 has a first cross-section at the end away from the nozzle 13 and a second cross-section at the end close to the nozzle 13; the continuously changing arc surface includes a radially converging inner wall that gradually decreases from the first cross-section to the second cross-section.

[0050] The arc-shaped structures of the fluid chamber 12 and the fluid path 11 are defined by specific radii and center angles, and these parameters can be carefully selected according to requirements to achieve the best fluid dynamics effect.

[0051] As an implementation manner, in order to match the above-mentioned embodiment, the linear actuator 3 has a radially convergent structure.

[0052] As an implementation mode, the linear actuator 3 is adapted to the shape of the fluid chamber 12; and a consistent gap distance is maintained between the radially converging structure and the opposite surface of the radially converging inner wall.

[0053] The linear actuator 3 has a first center axis 31, which is aligned with the third center axis 16 of the inner wall center axis of the fluid chamber 12, and a predetermined gap is maintained between the linear actuator 3 and the inner wall of the fluid chamber 12, and the gap allows the fluid to flow between the linear actuator 3 and the inner wall of the fluid chamber 12.

[0054] As an implementation manner, the maximum cross section of the spray hole 13 is smaller than or equal to the second cross section.

[0055] As an embodiment, it further includes a sealing ring 4 ; an insertion hole 14 is provided on the chamber body 1 , and the sealing member is provided between the linear actuator 3 and the insertion hole 14 .

[0056] The linear actuator 3 is inserted into the insertion hole 14 to form a seal, maintain a constant pressure in the fluid path 11, and protect the actuator 2 from the influence of the fluid, thereby further improving the consistency of the injection. The seal may include, for example, a sealing ring or a rubber gasket.

[0057] In another embodiment, a plurality of linear actuators 3 and nozzle holes 13 are combined to form an array. The fluid chambers 12 are spaced apart from each other to avoid crosstalk between adjacent chambers.

[0058] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0059] Although the embodiments of the utility model have been shown and described above, they cannot be understood as limiting the claims. The utility model is not limited to the above embodiments, and its specific structure is allowed to be changed. All changes made within the protection scope of the independent claims of the utility model are within the protection scope of the utility model.

Claims

1. A droplet ejection device for ejecting a fluid, characterized in that: include: A chamber body (1) is provided with a fluid path (11) and at least one fluid chamber (12); the fluid chamber (12) is connected to the fluid path (11), and at least one spray hole (13) is provided in the fluid chamber (12); An actuator (2) configured to perform mechanical movement in response to a pulse signal; The linear actuator (3) is linearly inserted into the fluid chamber (12) and connected to the actuator (2); it is configured to perform reciprocating linear motion along a linear path relative to the chamber body (1) under the action of the actuator (2) to form waves acting on the fluid in the fluid chamber (12); and the linear actuator (3) has a first central axis (31), and the linear path is parallel to the first central axis (31); the spray hole (13) has a second central axis (15); the first central axis (31) and the second central axis (15) are aligned.

2. A droplet ejection device according to claim 1, characterized in that: One of the fluid chambers (12) is correspondingly inserted with one of the linear actuators (3); the inner wall of the fluid chamber (12) is arranged symmetrically around the third center axis (16), and the first center axis (31) is aligned with the third center axis (16).

3. A droplet ejection device according to claim 1 or 2, characterized in that: At least a portion of the inner wall of the fluid chamber (12) is a continuously changing cambered surface.

4. A droplet ejection device according to claim 3, characterized in that: The inner wall of the fluid path (11) and the inner wall of the fluid chamber (12) are connected via the continuously changing arc surface.

5. A droplet ejection device according to claim 3, characterized in that: The fluid chamber (12) has a first cross section at the end away from the spray hole (13) and a second cross section at the end close to the spray hole (13); the continuously changing cambered surface comprises a radially converging inner wall that gradually decreases from the first cross section to the second cross section.

6. A droplet ejection device according to claim 5, characterized in that: The linear actuator (3) has a radially convergent structure.

7. A droplet ejection device according to claim 6, characterized in that: The linear actuator (3) is adapted to the shape of the fluid chamber (12); and a consistent gap distance is maintained between the radially converging structure and the opposite surface of the radially converging inner wall.

8. A droplet ejection device according to claim 5, characterized in that: The maximum cross section of the spray hole (13) is smaller than or equal to the second cross section.

9. A droplet ejection device according to claim 1, characterized in that: It also includes a sealing ring (4); an insertion hole (14) is provided on the chamber body (1), and the sealing ring (4) is provided between the linear actuator (3) and the insertion hole (14).

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