Ultrasonic atomization nozzle, spraying equipment and spraying width adjusting method of spraying equipment

Abstract

The invention relates to an ultrasonic atomization nozzle, spraying equipment and a spraying width adjusting method of the spraying equipment. The ultrasonic atomization nozzle comprises a variable amplitude assembly, the variable amplitude assembly comprises an ultrasonic transducer and an amplitude-change pole, the ultrasonic transducer is used for generating high-frequency mechanical vibration, and the amplitude-change pole is coaxially connected with the ultrasonic transducer and used for amplifying the mechanical vibration and transmitting the mechanical vibration to the atomization end face of the ultrasonic atomization nozzle; the flow channel is arranged around the amplitude-change pole and comprises an adjustable gas input channel; the vortex gear assembly is arranged on the inner side of the atomization end face and used for adjusting the gas jet direction; the shell is used for packaging the variable amplitude assembly, the flow channel and the vortex gear assembly, and the shell is provided with a liquid supply connector and an air supply connector. According to the scheme, dynamic adjustment of the spraying width can be achieved, stepless adjustment from narrow width to wide width can be achieved in the same spray head by adjusting the air pressure of the air input channel and the inclination angle of the vortex gear, the spray head does not need to be replaced, and the operation flexibility is remarkably improved.

Description

Technical Field

[0001] This application relates to the field of spraying technology, and particularly to an ultrasonic atomizing nozzle, a spraying device, and a method for adjusting the spraying width thereof. Background Art

[0002] Existing ultrasonic atomizing nozzles have problems such as limited spraying width adjustment range and weak anti-interference ability. Usually, different spraying modes need to be achieved by replacing the nozzles, resulting in low efficiency. In addition, the droplets after atomization by traditional nozzles are easily disturbed by air flow, and the stability of the fog cone is poor. Therefore, there is an urgent need for an ultrasonic atomizing nozzle that can dynamically adjust the spraying width and maintain atomization uniformity. Summary of the Invention

[0003] To solve or partially solve the problems existing in the related art, this application provides an ultrasonic atomizing nozzle, a spraying device, and a method for adjusting the spraying width thereof, solving the technical problems of rough adjustment and poor uniformity of traditional spraying devices.

[0004] In the first aspect of this application, an ultrasonic atomizing nozzle is provided, which is characterized by including:

[0005] A horn assembly, including an ultrasonic transducer and a horn. The ultrasonic transducer is used to generate high-frequency mechanical vibrations, and the horn is coaxially connected to the ultrasonic transducer and is used to amplify the mechanical vibrations and transmit them to the atomizing end face of the ultrasonic atomizing nozzle;

[0006] A flow channel, arranged around the horn, including an adjustable gas input channel;

[0007] A vortex gear assembly, arranged inside the atomizing end face, for adjusting the direction of the gas jet;

[0008] A housing, used to encapsulate the horn assembly, the flow channel, and the vortex gear assembly. The housing is provided with a liquid supply interface and a gas supply interface;

[0009] Wherein, by adjusting the gas pressure or flow rate of the adjustable gas input channel, the vortex gear assembly changes the gathering or scattering effect of the gas jet on the atomized droplets, realizing the dynamic adjustment of the spraying width.

[0010] In some embodiments, the ultrasonic transducer includes:

[0011] A front cover plate and a rear cover plate;

[0012] A piezoelectric ceramic ring, clamped between the front cover plate and the rear cover plate. The polarization direction of the piezoelectric ceramic ring is axial, and the working frequency is 20 - 120 kHz;

[0013] A pre-tightening member, passing through the front cover plate, the piezoelectric ceramic ring, and the rear cover plate, for applying an axial pre-tightening force.

[0014] In some embodiments, the horn is of a stepped structure, and its length satisfies the half-wavelength resonance condition. The specific dimensions are determined by the formula:

[0015]

[0016] where L is the length of the horn, c is the sound velocity of the material, f is the working frequency, and S1 and S2 are the cross-sectional areas of the input end and the output end of the horn respectively; the input end is located at the tail of the ultrasonic atomizing nozzle, and the output end is located at the end of the ultrasonic atomizing nozzle; the amplitude amplification ratio of the output end and the input end of the horn is 3 - 5 times.

[0017] In some embodiments, the adjustable gas input channel includes:

[0018] An annular gas chamber, which is arranged around the output end of the horn;

[0019] A plurality of radial air inlet holes, which are evenly distributed in the circumferential direction and are used to connect the external gas source with the annular gas chamber;

[0020] A regulating valve, which is arranged at the gas supply interface and is used to continuously regulate the gas pressure within the range of 0.1 - 0.5 MPa.

[0021] In some embodiments, the eddy current gear assembly includes a rotating disk and an eddy current gear that are coaxially arranged with the horn. The rotating disk and the eddy current gear are sleeved on the output end of the horn; the eddy current gear is fixed inside the ultrasonic atomizing nozzle, and the rotating disk is rotatable relative to the eddy current gear and is used to convert the gas jet into a swirling flow or a direct jet mode;

[0022] The rotating disk is provided with a first tooth groove, and the eddy current gear is provided with a second tooth groove. When the rotating disk rotates, the first tooth groove is misaligned or aligned with the second tooth groove; when they are aligned, the annular gas chamber is communicated with the atomizing end face through a first channel; when they are misaligned, the annular gas chamber is communicated with the atomizing end face through a second channel; the second channel is located on the periphery of the first channel.

[0023] In some embodiments, the inclination angles of the first tooth groove and the second tooth groove are 15° - 45°;

[0024] When the inclination angles of the first tooth groove and the second tooth groove ≤ 30°, the gas jet forms a converging spray;

[0025] When the inclination angles of the first tooth groove and the second tooth groove ≥ 30°, the gas jet forms a scattering spray, and the spraying width increases by 30% - 50%.

[0026] The second aspect of the present application provides a method for adjusting the spraying width based on the ultrasonic atomization nozzle described in the first aspect above, including the following steps:

[0027] Rotate the vortex gear assembly to the first position, so that the gas forms an axial constrained air flow through the annular axial channel of the vortex gear assembly, and drive the liquid film at the end of the horn to converge towards the center along the radial path of the groove array, forming a spraying cone angle ≤ 20°;

[0028] Rotate the vortex gear assembly to the second position, so that the gas forms a swirling diffusion air flow through the spiral groove diversion of the vortex gear assembly, and drive the liquid film at the end of the horn to disperse along the outer edge of the groove array under the action of centrifugal force, forming a spraying cone angle ≥ 40°;

[0029] Adjust the gas mixing ratio of the converging flow channel and the scattering flow channel through the gas path distribution valve, and synchronously rotate the rotating vortex gear assembly to change the swirling intensity of the air flow.

[0030] In some embodiments, the method includes: rotating the vortex gear assembly to the first position, guiding the liquid to the central region of the groove array, and the liquid film thickness decreases gradiently from the center to the outer edge; making the direct gas flow coaxial with the liquid film breaking direction to inhibit the radial diffusion of droplets; or,

[0031] Controlling the gas flow ratio of the converging flow channel and the scattering flow channel based on the valve core rotation angle of the gas path distribution valve; the displacement of the rotating vortex gear assembly is linked with the valve core rotation angle, and for every 1 mm increase in the displacement of the rotating vortex gear assembly, the valve core rotation angle increases by 30°, and the spraying width is linearly positively correlated with the valve core rotation angle.

[0032] In some embodiments, the method includes:

[0033] Guiding the liquid to the central region of the groove array, and the liquid film thickness decreases gradiently from the center to the outer edge; the direct gas flow is coaxial with the liquid film breaking direction to inhibit the radial diffusion of droplets; or,

[0034] Rotate the spiral vortex gear to the maximum displacement position, the gas forms a swirling diffusion air flow through the spiral tooth diversion, and the liquid film disperses along the outer edge of the groove array under the action of centrifugal force, forming a spraying cone angle ≥ 40°; or,

[0035] Controlling the gas flow ratio of the converging flow channel and the scattering flow channel through the valve core rotation angle of the gas path distribution valve; the displacement of the spiral vortex gear is linked with the valve core rotation angle, and for every 1 mm increase in the displacement, the valve core rotation angle increases by 30°, and the spraying width is linearly positively correlated with the valve core rotation angle.

[0036] In some embodiments, when the liquid supply flow rate is controlled within the range of 0.3 - 3 mL / s, the change rate of the spraying width is less than 10%; when the liquid supply flow rate > 3 mL / s, the spraying width decreases with the increase of the flow rate, and the maximum decrease is 15%.

[0037] In some embodiments, the liquid supply flow rate is controlled within the range of 0.3 - 3 mL / s, so that the change rate of the spraying width is less than 10%; when the liquid supply flow rate > 3 mL / s, the spraying width decreases with the increase of the flow rate;

[0038] Increase the spraying height H from 50 mm to 200 mm, and automatically adjust the air pressure according to the set mode to keep the spraying cone half angle constant; wherein, the change rate dW / dH of the spraying width W with respect to the spraying height H ≤ 0.2

[0039] The technical solution provided by the present application may include the following beneficial effects:

[0040] The technical solution of the present application can achieve dynamic adjustment of the spraying width. By adjusting the air pressure in the gas input channel and the inclination angle of the eddy current gear, stepless adjustment from narrow width to wide width can be achieved in the same nozzle, without replacing the nozzle, significantly improving the operation flexibility.

[0041] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present application. Description of the Drawings

[0042] By describing the exemplary embodiments of the present application in more detail in conjunction with the drawings, the above and other objects, features, and advantages of the present application will become more obvious. Among them, in the exemplary embodiments of the present application, the same reference numerals generally represent the same components.

[0043] Figure 1 is a schematic structural diagram of the ultrasonic atomizing nozzle shown in the embodiment of the present application;

[0044] Figure 2 is a schematic structural diagram of the transducer of the ultrasonic atomizing nozzle shown in the embodiment of the present application;

[0045] Figure 3 is a schematic structural diagram of the horn of the ultrasonic atomizing nozzle shown in the embodiment of the present application;

[0046] Figure 4 is a schematic structural diagram of the rotating disk of the ultrasonic atomizing nozzle shown in the embodiment of the present application;

[0047] Figure 5 is a schematic structural diagram of the eddy current gear of the ultrasonic atomizing nozzle in a misaligned state shown in the embodiment of the present application;

[0048] Figure 6It is a schematic structural diagram of the eddy current gear of the ultrasonic atomizing nozzle shown in the embodiments of the present application in the aligned state;

[0049] Figure 7 It is a schematic flow diagram of the spraying width adjustment method shown in the embodiments of the present application.

[0050] Reference numerals: 1, liquid supply interface; 2, circuit channel; 3, first housing; 4, horn; 41, fastener; 42, rear cover plate; 43, piezoelectric ceramic; 44, front cover plate; 45, cylindrical section; 46, flange; 47, conical section; 471, converging flow channel; 472, scattering flow channel; 5, second housing; 6, screw; 7, third housing; 71, annular air cavity; 8, air flow chamber; 81, atomizing end face; 9, gas channel; 10, rotating disk; 101, first tooth groove; 11, eddy current gear; 111, second tooth groove; 12, hole; 13, accommodating cavity; 14, first end; 15, second end. Detailed implementation manners

[0051] The preferred embodiments of the present application will be described in more detail below with reference to the accompanying drawings. Although the preferred embodiments of the present application are shown in the drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to make the present application more thorough and complete, and to fully convey the scope of the present application to those skilled in the art.

[0052] The terms used in the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. The singular forms "a", "the" and "said" used in the present application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more of the associated listed items.

[0053] It should be understood that although the terms "first", "second", "third", etc. may be used in the present application to describe various information, such information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of the present application, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present application, "a plurality" means two or more unless otherwise specifically defined.

[0054] In the description of the present application, it should be understood that the orientation or positional relationship indicated by terms such as "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. 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, and therefore should not be construed as a limitation to the present application.

[0055] Unless otherwise clearly specified and defined, terms such as "installed", "connected", "connected to", "fixed", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; 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 or the interaction relationship between 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.

[0056] An embodiment of the present application provides an ultrasonic atomizing nozzle and a method for adjusting its spraying width, which solves the technical problems of rough adjustment and poor uniformity of traditional spraying equipment.

[0057] The technical solutions of the embodiments of the present application will be described in detail below with reference to the drawings.

[0058] Please refer to Figure 1 - Figure 2 , the present application provides an ultrasonic atomizing nozzle, including: a horn assembly, including an ultrasonic transducer and a horn 4, the ultrasonic transducer is used to generate high-frequency mechanical vibrations, and the horn 4 is coaxially connected to the ultrasonic transducer and is used to amplify the mechanical vibrations and transmit them to the atomizing end face 81 of the ultrasonic atomizing nozzle; a flow channel, arranged around the horn 4, including an adjustable gas input channel 9; a vortex gear assembly, arranged inside the atomizing end face 81 and used to adjust the gas jet direction; a housing, used to encapsulate the horn assembly, the flow channel and the vortex gear assembly, and the housing is provided with a liquid supply interface 1 and a gas supply interface; wherein, the gas supply interface is connected to the adjustable gas input channel 9, and by adjusting the gas pressure or flow rate of the adjustable gas input channel 9, the vortex gear assembly changes the gathering or scattering effect of the gas jet on the atomized droplets, realizing the dynamic adjustment of the spraying width.

[0059] The housing adopts a split metal shell, and the gas flow channel and the liquid supply pipeline are integrated inside. The output end surface of the atomizing end face 81 is processed with radial microgrooves, which are used to guide the liquid to form a uniform liquid film. The gas supply interface connected to the adjustable gas input channel 9 is connected to an external gas source, and the gas path is quickly switched through a quick connector. The split housing isolates the influence of the external environment on the ultrasonic vibration, thereby improving the stability of the resonance frequency.

[0060] In some embodiments, the housing includes a first housing 3, a second housing 5, and a third housing 7 assembled axially as a whole. The housing is used to fix the amplitude-changing assembly 4, the flow channel turbine assembly, and the positioning nozzle 82. The second housing 5 is located between the first housing 3 and the third housing 7, and the third housing 7 defines a gas passage. The transducer 4 is fixedly connected to the second housing 5 through a flange 46 thereon by a screw 6. The inner front half of the third housing 7 is a conical cylinder structure, and the eddy current gear 11 is supported on the conical cylinder structure of the third housing 7 on the side of the atomizing nozzle.

[0061] The amplitude-changing rod 4 of this embodiment is a stepped structure. The amplitude-changing rod 4 extends from the tail end to the head end of the ultrasonic atomizing nozzle, and the cross-sectional area of the head end is smaller than that of the tail end. For example, the amplitude-changing rod 4 includes a first cylindrical section 45 and a conical section 47. The length of the amplitude-changing rod 4 is set according to the half-wavelength resonance theory.

[0062] When the ultrasonic transducer receives the signal applied by the power supply, it will generate high-frequency vibrations along the longitudinal direction, and the liquid flowing along the liquid channel to the atomizing surface 81 will be atomized. The atomized droplets are sprayed under the drive of the auxiliary air flow.

[0063] In some embodiments, the adjustable gas input channel includes an annular gas chamber 71 and 8 - 12 circumferentially distributed air inlet holes. The air inlet holes are arranged at the outer end of the adjustable gas input channel 9 and are communicated with an external gas source. The adjustable gas input channel 9 can adjust the gas flow rate through a proportional valve.

[0064] In the related art, the droplets generated by the ultrasonic atomizing nozzle are small in particle size and uniform in particle size. However, the initial velocity of the droplets ejected from the atomizing surface of the ultrasonic atomizing nozzle is extremely small, close to zero, and the surrounding environment such as air is likely to cause disturbances to it. Without the action of the auxiliary air flow, it is not easy to form a high-quality spraying effect. At the same time, due to the relatively large amount of atomization of the ultrasonic atomizing nozzle, the number of droplets generated after liquid atomization is huge. During the downward movement, they will re-condense and form large droplets again, which is contrary to the required high-quality spraying effect and it is difficult to form an ideal ultrasonic spraying quality. Therefore, this application optimizes the velocity flow field distribution of the carrier gas flow field, improves the uniformity and spraying effect of ultrasonic atomization spraying, and at the same time, also saves the amount of liquid to be sprayed.

[0065] See Figure 2 , in some specific embodiments, the amplitude-changing assembly 4 includes a sandwich piezoelectric transducer. The sandwich piezoelectric transducer includes a front cover plate 44 and a rear cover plate 42; a piezoelectric ceramic ring 43 is clamped between the front cover plate 44 and the rear cover plate 42; a fastener 41 passes through the front cover plate 44, the piezoelectric ceramic ring 44, and the rear cover plate 42 for applying an axial pre-tightening force; the polarization direction of the piezoelectric ceramic ring 43 is axial.

[0066] Inside the housing, there is a circuit channel 2 for accommodating wires. The wires are used to electrically connect to the piezoelectric ceramic ring 43 and provide power for the piezoelectric ceramic ring 43.

[0067] The front cover plate 44 and the rear cover plate 42 can be made of titanium alloy. An axial pre-tightening force is applied through high-strength pre-tightening bolts. The polarization direction of the piezoelectric ceramic ring 43 is along the axis. The input end of the horn is coaxially connected to the front cover plate 44 through threads to ensure efficient transmission of mechanical vibration.

[0068] Continue to refer to Figure 1 , the thickness of the front cover plate 44 can be λ / 4 (λ is the ultrasonic wavelength), and the thickness of the rear cover plate 42 is λ / 2. The front cover plate 44 and the rear cover plate 42 are aligned through precision-machined coaxial threaded holes to ensure that the coaxiality error of vibration transmission ≤ 0.01 mm. It drives a large amplitude (≥ 5 μm) in the low-frequency band (20 - 40 kHz) and is suitable for atomization of high-viscosity liquids (such as glue); in the high-frequency band (80 - 120 kHz), it generates tiny droplets (D 50 ≤ 20 μm) for precision coating (such as optical thin film). Moreover, the coaxiality error between the front / rear cover plates and the piezoelectric ceramic and the overall size are small, making it suitable for installation in narrow spaces.

[0069] The piezoelectric ceramic ring 43 can be a PZT-8 type piezoelectric ceramic, and the polarization direction is along the axis (Z-axis direction). The piezoelectric ceramic ring 43 is isolated from the front / rear cover plates through insulating gaskets to avoid short circuits; its inner and outer walls are coated with silver electrodes, and the electrode leads are led out from the side of the rear cover plate.

[0070] The fastener 41 uses high-strength hexagon bolts, which penetrate the front cover plate 44, the piezoelectric ceramic ring 44, and the rear cover plate 42, and an axial pre-tightening force is applied through a set of disc springs. The tightening torque of the bolts is controlled by a torque wrench to ensure that the piezoelectric ceramic ring is in a constant compression state and avoid gaps during vibration.

[0071] In this embodiment, when an AC voltage of 20 - 120 kHz is applied to the electrodes of the piezoelectric ceramic ring 43, the inverse piezoelectric effect is used to generate longitudinal expansion and contraction vibrations in the axial direction. The front cover plate 44 serves as the radiation end, amplifying and transmitting the vibrations to the horn 4; the rear cover plate 42 serves as the counterweight end, suppressing the transverse vibration mode. By adjusting the driving voltage frequency (for example: 20 kHz for large-flow spraying, 120 kHz for fine atomization), different working conditions are matched.

[0072] In the solution of this embodiment, the polarization direction of the piezoelectric ceramic ring 43 is consistent with the vibration direction, and the electromechanical coupling coefficient k 33≥0.65 (PZT-8), with a sharp resonance peak (Q value ≥ 500), ensuring efficient operation across the entire frequency band of 20 - 120 kHz. The constant axial pre-tightening force cancels out the tensile stress of the piezoelectric ceramic ring 43, preventing micro-cracks from occurring during vibration. After cyclic testing, the capacitance decay rate of the piezoelectric ceramic ring 43 is ≤ 3%, and the resonance frequency drift is ≤ 0.5%.

[0073] See Figure 2 and Figure 3 In some embodiments, the horn 4 has a stepped structure. In this application, the stepped horn 4 is made of metal, and the sound velocities are 5000 m / s or 5100 m / s respectively for the gas channels. The total length L of the horn 4 is divided into three sections: the input end is a cylindrical section L1, a stepped transition section, and a conical section L2 at the output end. The input end of the horn is connected to the front cover plate 44 of the ultrasonic transducer through a conical surface fit, reducing the coaxiality error.

[0074] The length of the horn satisfies the half-wavelength resonance condition, and the specific dimensions are determined by the formula:

[0075]

[0076] where L (L = L1 + L2) is the length of the horn, c is the sound velocity of the material, f is the operating frequency, and S1 and S2 are the cross-sectional areas of the input end and the output end of the horn 4 respectively; the amplitude amplification ratio at the output end of the horn 4 is 3 - 5 times. The above formula precisely matches the half-wavelength resonance condition, reducing standing wave reflection, thereby improving the energy transfer efficiency, and at the same time being able to achieve resonance matching accuracy and reducing energy loss.

[0077] In this embodiment, by changing the stepped cross-sectional area (the ratio change of S1 and S2), the amplitude amplification ratio is 3 - 5 times, enhancing the atomization kinetic energy. When the ratio of S1 and S2 is 10, the amplitude amplification ratio is 5 times, suitable for high-viscosity fluids; when the ratio of S1 and S2 is 4, the amplitude amplification ratio is 3 times, for nano-scale atomization; when the ratio of S1 and S2 is 6.5 times, a 3 - 5 times amplitude amplification is achieved, and the droplet kinetic energy is increased by 2 - 3 times.

[0078] In some embodiments, the adjustable gas input channel of the gas flow path 9 includes an annular gas chamber 71, which is arranged around the horn 4; a plurality of radial air inlet holes, evenly distributed circumferentially, and connected to an external gas source; a regulating valve is provided at the gas supply interface for continuously adjusting the gas pressure within the range of 0.1 - 0.5 MPa; the eddy current gear 11 has an annular tooth-like structure, and the inclination angle of its tooth grooves is 15° - 45 piezoelectric ceramic °, for converting the gas jet into a swirling or direct jet mode.

[0079] The air supply interface is connected to an external air source through a quick-release joint. After the pressure is reduced to 0.1 - 0.5 MPa by a regulating valve, the air is input into the annular air cavity 71. The annular air cavity 71 is arranged around the outer wall of the horn 4, and its inner diameter has a clearance fit with the diameter of the horn. The annular air cavity 71 is used to evenly distribute the gas. There are 8 - 12 air inlet holes with a diameter of about Φ2 mm evenly distributed in the circumferential direction. The axis of each air inlet hole forms an angle of about 30° - 45° with the axis of the horn, ensuring that the gas enters the air cavity tangentially to form an initial swirl.

[0080] The regulating valve can be a proportional solenoid valve, and the opening of the valve core is linearly corresponding to the input current. In the low-pressure mode (0.1 - 0.3 MPa), the gas enters the air cavity in a laminar flow state to form a low-disturbance direct jet; in the high-pressure mode (0.3 - 0.5 MPa), the turbulence intensity of the gas increases, and it cooperates with the eddy current gear to enhance the swirl intensity.

[0081] In some embodiments, the tooth groove structure of the eddy current gear 11 is a ring-shaped tooth design. Among them, the pitch diameter of the tooth top circle D = 20 mm - 40 mm, the number of teeth Z = 24 - 50, the module m = 0.8 mm - 0.20, and the tooth groove depth h = 1.5 mm - 2.8 mm.

[0082] See Figure 4 and Figure 5 In some embodiments, the eddy current gear assembly includes a rotating disk 10 and an eddy current gear 11 coaxially arranged with the horn 4. The rotating disk 10 and the eddy current gear 11 are sleeved on the output end of the horn 4; the eddy current gear 11 is fixed inside the ultrasonic atomizing nozzle, and the rotating disk 10 is rotatable relative to the eddy current gear 11 for converting the gas jet into a swirl or direct jet mode.

[0083] The rotating disk 10 is provided with a first tooth groove 101, and the eddy current gear 11 is provided with a second tooth groove 111. When the rotating disk 10 rotates, the first tooth groove 101 is misaligned or aligned with the second tooth groove 111; see Figure 6 When they are aligned, the annular air cavity 71 is communicated with the atomizing end face 81 through the first channel; see Figure 5 When they are misaligned, the annular air cavity 71 is communicated with the atomizing end face 81 through the second channel; the second channel is located outside the first channel.

[0084] The central parts of the rotating disk 10 and the eddy current gear 11 are provided with an accommodating cavity 13 opened axially, and the output end of the horn 4 is accommodated in the accommodating cavity 3. On the side of the eddy current gear facing away from the annular air cavity 71, there is an air flow chamber 8, and the air flow chamber 8 is communicated with the atomizing end face 81 through a groove.

[0085] In some embodiments, the inclination angles of the first tooth groove 101 and the second tooth groove 111 are 15°-45°; when the inclination angles of the first tooth groove 101 and the second tooth groove 111 are ≤30°, the gas jet forms a converging spray; when the inclination angles of the first tooth groove 101 and the second tooth groove 111 are ≥30°, the gas jet forms a scattering spray, and the spraying width increases by 30%-50%.

[0086] See Figure 6 , in this embodiment, when the first tooth groove 101 and the second tooth groove 111 are aligned, the annular gas chamber is communicated with the air flow chamber 8, and the gas-liquid mixture in the annular gas chamber 71 can quickly enter the air flow chamber 8 through the aligned first tooth groove and the second tooth groove, and is guided to the atomizing end face 81 through the air flow chamber 8.

[0087] See Figure 4 , in some embodiments, the rotating disk 10 and the eddy current gear 11 are provided with holes 12 around their centers. When the first tooth groove 101 and the second tooth groove 111 are aligned, the holes 12 of the rotating disk 10 and the eddy current gear 11 are misaligned and in a non-conducting state; when the first tooth groove 101 and the second tooth groove 111 are misaligned, the holes 12 of the rotating disk 10 and the eddy current gear 11 are aligned, and the gas-liquid mixture in the annular gas chamber is conducted to the peripheral space of the output end of the horn 4 through the aligned holes 12 and is led out to the atomizing end face 81 through this peripheral space.

[0088] The gas flow path of the present application has two directions. When a larger spraying width is required, the hole 12-shaped air flow channel is closed, and the gas direction is through the eddy current gear. The overall shape of the spray is conical, achieving the largest possible spraying width and thus improving the spraying efficiency, making it possible to scale up the production of certain thin film preparations. When a smaller spraying width is required, only the rotating disk 10 needs to be rotated 15° around the axis. At this time, the air flow channel of the eddy current gear is closed, and the compressed gas direction is along the round hole 12-shaped air flow channel. At this time, the spraying width range is significantly reduced when the intake pressure is the same, achieving small-width spraying, and low-flow spraying can be achieved, making it possible to scale up the surface spraying production of micro-components.

[0089] When the required width to be sprayed is relatively small, according to the spraying requirements, it can be adjusted to a narrow spraying width, that is, a converging spraying mode. When the gas with a certain pressure passes through the hole 12, it provides power for the continuous movement of the atomized droplets, not only increasing the axial movement power of the droplets, but also increasing the radial converging movement power of the droplets. Due to the increase in the radial movement power, the droplets are more concentrated when moving downward, reducing the radial movement range of the droplets, that is, reducing the spraying range of the droplets.

[0090] When a larger spraying width is required, only the flow direction of the gas needs to be changed. At this time, the hole 12 is closed. When the gas flows through the first tooth groove 101 and the second tooth groove 111, as the axial running power increases, the radial running power of the droplets also increases. Contrary to the small spraying width, at this time, the direction of the radial running power of the droplets is outward divergent due to the centrifugal force of the gas flow. The spraying range of the droplets after being atomized by the ultrasonic atomizing nozzle is effectively expanded.

[0091] Therefore, the solution of the present application can meet the requirement of the spraying width needed during spraying by adjusting the flow channel (tooth groove or hole) through which the gas flows according to the specific requirement of the spraying width. Among them, the spraying width can also be further adjusted by fine-tuning the gas supply pressure. When the liquid is ultrasonically atomized and dispersed into small liquids, with the assistance of the gas, a spraying effect with an adjustable spraying width and a stable fog cone can be obtained.

[0092] Continue to refer to Figure 1 , in this embodiment, the third housing 7 can rotate relative to the second housing 5. The gear turbine assembly includes a first end 14 and a second end 15. The first end is close to the horn 4, and the second end 15 is close to the atomizing end face. The gear turbine assembly is fixed to the third housing 7. The first housing 3 and the second housing 5 play a role in fixing the piezoelectric ceramic 43 and the horn 4, while the third housing 7 is used to provide a passage for the carrier gas.

[0093] When the third housing 7 rotates, it drives the eddy current gear 11 to rotate relative to the rotating disk 10. By rotating the eddy current gear 11, the included angle between the first tooth groove 101 and the second tooth groove 111 continuously changes within the range of 15° - 45° (the included angle changes by 5° for every 10° rotation of the gas passage); when the included angle ≤ 30°, the gas flow is mainly direct (the fog cone angle α ≤ 20°); when the included angle ≥ 30°, the proportion of the swirling gas flow > 70% (the fog cone angle α ≥ 40°). For every 10° increase in the included angle between the first tooth groove 101 and the second tooth groove 111, the droplet distribution uniformity (UI value) increases by 8%. When the included angle is 45°, UI ≥ 0.98-.

[0094] In this way, precise control of the spraying width can be achieved. For every 1° increase in the included angle, the spraying width increases by 1.0 - 1.2 mm, and the change rate is the largest near the critical point of 30°. Optimize the length of the horn 4 in combination with the above formula to ensure the matching of the ultrasonic atomization energy and the gas jet, and reduce the droplet rebound. It has good uniformity in the gathering mode. The low-turbulence direct gas flow suppresses the droplet collision and reduces the standard deviation of the droplet number concentration; in the swirling flow field, the droplet distribution area is expanded by 50%, and the density difference in the edge area is reduced.

[0095] In some embodiments, when the liquid supply flow rate is controlled within the range of 0.3-3mL / s, the spray width change rate is less than 10%; when the liquid supply flow rate is greater than 3mL / s, the spray width decreases with increasing flow rate, with a maximum decrease of 15%; when the spray height H increases from 50mm to 200mm, the air pressure is automatically adjusted according to the set mode to keep the spray cone half angle constant; wherein, the spray width W changes with the spray height H. The rate of change dW / dH≤0.2

[0096] The working principle of the ultrasonic atomizing nozzle of the present application is as follows: Narrow spray mode: Start the ultrasonic transducer, and the liquid is transported from the liquid supply interface 1 to the atomizing end face 81 through the capillary to form a liquid film. Adjust the proportional valve of the gas channel 9 so that all the gas enters the annular gas channel 9. The airflow constrains the diffusion of droplets through the direct mode to form a narrow fog cone with a spray width of about 20mm (H=100mm). Wide spray mode: Rotate the vortex gear 11 to the maximum inclination angle, and the gas forms a cyclone field through the spiral tooth grooves. The droplets diffuse outward under the action of the cyclone, the half angle of the fog cone expands to 40°, and the spray width increases to 60mm (H=100mm).

[0097] The technical solution of the present application can realize dynamic adjustment of the spraying width. By adjusting the gas pressure of the gas input channel 9 (0.1-0.5MPa) and the inclination angle of the vortex gear (0°-60°), stepless adjustment from narrow width (10 gas channels-30mm) to wide width (30-80mm) can be achieved in the same nozzle without replacing the nozzle, which significantly improves the operational flexibility.

[0098] The scheme of the present application improves the uniformity of atomization. The radial microgroove design makes the liquid film evenly distributed along the microgroove under ultrasonic vibration, the droplet generation position is fixed, and the particle size distribution is more concentrated. The gas jet can achieve coordinated control, the direct airflow inhibits the diffusion of droplets, and the vortex airflow enhances the uniformity of droplet dispersion. Under external airflow disturbance (such as workshop ventilation), the direct or vortex airflow forms an "air curtain barrier", which effectively reduces the fluctuation of the spray width, and part of the scattered airflow can flow back to the gas source through the shell, thereby improving the gas utilization rate.

[0099] By increasing the gas pressure and ultrasonic drive voltage, coatings with a viscosity of ≤500cP (such as UV glue, nano silver paste) can be atomized. The linkage adjustment of the gas path switching valve and the eddy current gear can effectively reduce the mode switching time, for example, the mode switching time is ≤1s. At the same time, the amplitude amplification ratio is more than 5 times, and the power consumption of the nozzle drive is reduced compared with the existing technology.

[0100] This application can achieve coordinated control of narrow and wide spraying widths: During narrow-width spraying: The gas restricts the droplet diffusion in the direct injection mode, and the spraying width W = 20 mm (H = 10 gas channels 0 mm); During wide-width spraying, the regulating valve boosts the pressure to 0.5 MPa, and the inclination angle of the eddy current gear (32) is 45 piezoelectric ceramic °. The swirling gas makes the droplets centrifugally diffuse, and the spraying width W = 60 mm (H = 10 gas channels 0 mm). In the scattering mode, a ring-shaped air curtain is formed in the swirling flow field, reducing the influence of external lateral airflows on the spraying width. The gathering mode is conducive to reducing the gas flow rate, for example, only 4 L / min, and the power consumption is significantly reduced compared with traditional double-fluid nozzles.

[0101] In the solution of this application, the gas pressure is precisely controlled by the regulating valve, and the inclination angle of the eddy current gear 11 (15° - 45 piezoelectric ceramic °) is adjusted by superposition, so that the dynamic range of the spraying width reaches 20 - 60 mm, and the adjustment resolution ≤ 1 mm. Moreover, the pressure adjustment response time < 0.5 s, and the eddy current gear angle switching time < 1 s, meeting the real-time spraying requirements. The tangential incident angles of 8 - 12 radial air inlets eliminate the airflow dead zone.

[0102] In some embodiments, the 1 liquid supply interface is connected to the atomizing end face 81 of the horn 4 through a capillary, the liquid supply flow rate is 0.3 - 6 mL / s, and the liquid film thickness is 10 gas channels - 50 μm; The atomizing end face 81 is provided with a micron-level groove array for enhancing the liquid film breaking efficiency.

[0103] The capillary can be made of stainless steel or quartz glass. One end of the capillary is hermetically connected to the liquid supply port through a quick connector, and the other end is inserted into the central hole of the atomizing end face of the horn 4 and fixed by laser welding. The grooves are radially distributed, with the center of the atomizing end face as the origin. For example, there are a total of 36 grooves, and a set included angle is formed between adjacent grooves; Specifically, the groove depth d is about 20 μm, the width w is about 50 μm, and the spacing s is about 10 gas channels 0 μm (the groove width-to-spacing ratio w / s = 0.5); The ultrasonic vibration drives the liquid film into the groove array, and the inner wall of the groove is coated with a nano-level hydrophobic coating to reduce the liquid film adhesion force. Under the coupled action of capillary force and inertial force, the liquid film is divided into independent liquid columns and then broken into uniform droplets. The distribution density of the groove array matches the ultrasonic frequency, exciting the resonance of the liquid film surface wave and enhancing the droplet generation rate. At low flow rates, the groove array actively adsorbs liquid through capillary action to prevent liquid breakage; At high flow rates, the shunting effect of the grooves avoids liquid film overflow and atomization stability.

[0104] See Figure 1 and Figure 7 , this application also provides a spraying width adjustment method applied to the above embodiments, and this method includes the following spraying modes:

[0105] S110, Narrow spray mode: Rotate the vortex gear assembly to the first position, so that the gas forms an axial constrained air flow through the annular axial channel of the vortex gear assembly, driving the liquid film at the end of the horn to converge towards the center along the radial path of the groove array, forming a spray cone angle ≤ 20°;

[0106] S120, Wide spray mode: Rotate the vortex gear assembly to the second position, so that the gas forms a swirling diffusion air flow through the spiral groove diversion of the vortex gear assembly, driving the liquid film at the end of the horn to disperse along the outer edge of the groove array under the action of centrifugal force, forming a spray cone angle ≥ 40°;

[0107] S130, Transition mode: Adjust the gas mixing ratio of the converging flow channel and the scattering flow channel through the gas path distribution valve, and synchronously rotate the vortex gear assembly to change the swirling intensity of the air flow.

[0108] In this embodiment, in the narrow spray mode, rotate the spool of the gas path distribution valve to the 0° position, completely close the scattering flow channel, and the gas enters the converging flow channel 471. The gas forms an axial constrained air flow through the annular direct injection channel (formed by the annularly distributed holes 12). The liquid supply system transports the liquid to the atomizing end face 81, and the liquid film converges towards the center along the radial groove array. The ultrasonic vibration drives the horn to vibrate, and the liquid film is evenly broken in the groove path.

[0109] In the wide spray mode, rotate the vortex gear of the rotating flow gear assembly to the second position, that is, the maximum displacement position (rotation angle 120°), so that the inclination angles of the first tooth groove and the second tooth groove increase to 45°, and at this time the scattering flow channel is completely opened. The gas forms a swirling diffusion air flow through the spiral first tooth groove and the second tooth groove. The liquid supply flow rate increases, and the liquid film disperses along the outer edge of the groove array under the action of centrifugal force, and the coverage area expands to 80% of the atomizing end face.

[0110] In the solution of the present application, through the multi-stage linkage control of the gas path distribution valve and the vortex gear, the spray width can be steplessly adjusted between 20 - 60 mm, covering the full scenario from narrow-width precision spraying to wide-width rapid coverage. The half angle α of the spray cone has a linear relationship with the gear inclination angle (α = 0.5 × θ), and the control resolution reaches 1°. In the transition mode, ensure that the standard deviation of the liquid droplet distribution density ≤ 8%, which is 40% higher than the traditional empirical adjustment method; the radial grooves guide the liquid film to flow directionally at any flow rate, and the edge / center liquid film thickness ratio is stable at 1:1.2.

[0111] In the narrow spray mode, the rotary vortex gear assembly is rotated to the first position to guide the liquid to the central region of the groove array, and the liquid film thickness decreases in a gradient from the center to the outer edge; the gas direct jet flow is coaxial with the liquid film breaking direction to inhibit the radial diffusion of droplets. The depth of the diversion groove of the conical diffuser head decreases in a gradient from the top to the outer edge and is precisely aligned with the radial path of the groove array; the liquid is guided to the central region of the groove array through the diversion groove, and the liquid film thickness decreases linearly from the center to the outer edge, forming a gradient liquid film with a thicker inner part and a thinner outer part. The gradient liquid film eliminates the edge drying phenomenon, and the standard deviation of the droplet number concentration is ≤3%.

[0112] In the wide spray mode, the rotary spiral vortex gear is rotated to the maximum displacement position. The gas is guided by the first and second tooth grooves of the spiral to form a swirling diffusion air flow. The liquid film is dispersed along the outer edge of the groove array under the action of centrifugal force to form a large fog cone angle spray. The rotary vortex gear is rotated to the maximum displacement position, and the tooth groove inclination angle is 45 piezoelectric ceramic °. The gas forms a diffusion air flow with a swirl angle θ = 55° through the spiral teeth; the liquid supply flow rate is increased to 5 mL / s, and the liquid film is dispersed along the outer edge of the groove array under the action of centrifugal force, covering 80% of the outer edge area, and the liquid film thickness is uniform (25 ± 2 μm). The fog cone half angle α = 40°, the spray width W = 60 mm (H = 10 gas channel 0 mm), and the droplet diameter D 32 = 45 μm.

[0113] In the stepless mode, for every 30° rotation of the spool of the gas path distribution valve, the displacement of the vortex gear 11 increases by 1 mm (for example, when the spool rotates 60°, the gear displacement is 2 mm); the gas flow ratio between the converging flow channel 471 and the scattering flow channel 472 is controlled by the rotation angle of the spool of the gas path distribution valve; the rotational displacement of the vortex gear assembly is linked with the rotation angle of the spool, and for every 1 mm increase in the displacement, the rotation angle of the spool increases by 30°; the spray width is linearly and positively correlated with the rotation angle of the spool. The solution of this application realizes the triple collaborative innovation of structure - control - effect, solves the technical bottleneck of rough adjustment and poor uniformity of traditional spraying equipment, and the deep integration of the collaborative algorithm of the gas path distribution valve - vortex gear and the diversion structure of the groove array realizes the high-precision dynamic control of the ultrasonic atomization spray width, providing a reliable process solution for industries such as flexible electronics and automotive painting.

[0114] This application also provides a spraying device, including the ultrasonic atomization nozzle as described in the above embodiment. The device includes a liquid supply device, a gas supply device, and a gas pressure regulating device. The liquid supply device is used to provide the coating material, the gas supply device is used to provide the gas source introduced into the ultrasonic atomization nozzle, and the gas pressure regulating device is used to adjust the gas pressure. The solution of this application optimizes the velocity flow field distribution of the carrier gas flow field inside the ultrasonic atomization nozzle through the structural design of the ultrasonic atomization nozzle, improves the uniformity and spraying effect of ultrasonic atomization spraying, and at the same time, also saves the consumption of the liquid to be sprayed.

[0115] The embodiments of the present application have been described above. The above description is exemplary and not exhaustive, and is also not limited to the disclosed embodiments. Many modifications and variations are obvious to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The choice of terms used herein is intended to best explain the principles of the embodiments, the practical application, or the improvement of the technology in the market, or to enable other ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. An ultrasonic atomizing nozzle, characterized in that, Comprising: A stroke-changing component, including an ultrasonic transducer and a horn. The ultrasonic transducer is used to generate high-frequency mechanical vibrations. The horn is coaxially connected to the ultrasonic transducer and is used to amplify the mechanical vibrations and transmit them to the atomization end face of the ultrasonic atomizing nozzle; A flow channel, arranged around the horn, including an adjustable gas input channel; An eddy current gear assembly, arranged inside the atomization end face, used to adjust the gas jet direction; A housing, used to encapsulate the stroke-changing component, the flow channel and the eddy current gear assembly. The housing is provided with a liquid supply interface and a gas supply interface; Wherein, by adjusting the gas pressure or flow rate of the adjustable gas input channel, and changing the aggregation or scattering effect of the gas jet on the atomized droplets through the eddy current gear assembly, the dynamic adjustment of the spraying width is realized.

2. The ultrasonic atomizing nozzle according to claim 1, wherein: The ultrasonic transducer includes: A front cover plate and a rear cover plate; A piezoelectric ceramic ring, clamped between the front cover plate and the rear cover plate. The polarization direction of the piezoelectric ceramic ring is axial, and the working frequency is 20 - 120 kHz; A pre-tightening member, passing through the front cover plate, the piezoelectric ceramic ring and the rear cover plate, used to apply an axial pre-tightening force.

3. The ultrasonic atomizing nozzle according to claim 2, wherein, The horn is of a stepped structure, and its length satisfies the half-wavelength resonance condition. The specific dimensions are determined by the formula: It is determined that, where L is the length of the horn, c is the sound velocity of the material, f is the working frequency, S1 and S2 are the cross-sectional areas of the input end and the output end of the horn respectively. The input end is located at the tail of the ultrasonic atomizing nozzle, and the output end is located at the end of the ultrasonic atomizing nozzle; the amplitude amplification ratio of the output end and the input end of the horn is 3 - 5 times.

4. The ultrasonic atomizing nozzle according to claim 3, wherein: The adjustable gas input channel includes: An annular gas chamber, arranged around the output end of the horn; A plurality of radial air inlet holes, evenly distributed in the circumferential direction, used to connect the external gas source with the annular gas chamber; A regulating valve, arranged at the gas supply interface, used to continuously adjust the gas pressure within the range of 0.1 - 0.5 MPa.

5. The ultrasonic atomizing nozzle according to claim 4, wherein: The eddy current gear assembly includes a rotating disk and an eddy current gear coaxially arranged with the horn. The rotating disk and the eddy current gear are sleeved on the output end of the horn; the eddy current gear is fixed inside the ultrasonic atomizing nozzle, and the rotating disk is rotatable relative to the eddy current gear, used to convert the gas jet into a swirling flow or a direct jet mode; The rotating disk is provided with a first tooth groove, and the eddy current gear is provided with a second tooth groove. When the rotating disk rotates, the first tooth groove and the second tooth groove are misaligned or aligned; When aligned, the annular gas chamber is communicated with the atomization end face through a first channel; when misaligned, the annular gas chamber is communicated with the atomization end face through a second channel; the second channel is located on the periphery of the first channel.

6. The ultrasonic atomizing nozzle according to claim 5, wherein: The inclination angles of the first tooth groove and the second tooth groove are 15° - 45°; When the inclination angles of the first tooth groove and the second tooth groove are ≤ 30°, a converging spray is formed by the gas jet; When the inclination angles of the first tooth groove and the second tooth groove are ≥ 30°, a scattering spray is formed by the gas jet, and the spraying width increases by 30%-50%.

7. A spraying device, characterized in that, It includes the ultrasonic atomizing nozzle according to any one of claims 1-6.

8. A spraying width adjustment method for an ultrasonic atomizing nozzle according to any one of claims 1-6, characterized in that, It includes the following steps: Rotate the vortex gear assembly to the first position, so that the gas forms an axial constrained air flow through the annular axial channel of the vortex gear assembly, and drive the liquid film at the end of the horn to converge towards the center along the radial path of the groove array, forming a spraying cone angle ≤ 20°; Rotate the vortex gear assembly to the second position, so that the gas forms a swirling diffusion air flow through the spiral groove diversion of the vortex gear assembly, and drive the liquid film at the end of the horn to disperse along the outer edge of the groove array under the action of centrifugal force, forming a spraying cone angle ≥ 40°; Adjust the gas mixing ratio of the converging flow channel and the scattering flow channel through the gas path distribution valve, and synchronously rotate the vortex gear assembly to change the swirling intensity of the air flow.

9. The adjustment method according to claim 8, characterized in that It includes: Rotate the vortex gear assembly to the first position, guide the liquid to the central area of the groove array, and the liquid film thickness decreases gradually from the center to the outer edge; make the direct gas flow coaxial with the liquid film breaking direction to inhibit the radial diffusion of droplets; or, Control the gas flow ratio of the converging flow channel and the scattering flow channel based on the valve core rotation angle of the gas path distribution valve; the displacement of the rotating vortex gear assembly is linked with the valve core rotation angle. For every 1 mm increase in the displacement of the rotating vortex gear assembly, the valve core rotation angle increases by 30°, and the spraying width is linearly positively correlated with the valve core rotation angle.

10. The adjustment method according to claim 8, wherein: Control the liquid supply flow rate within the range of 0.3-3 mL / s, so that the change rate of the spraying width is less than 10%; when the liquid supply flow rate > 3 mL / s, the spraying width decreases with the increase of the flow rate; Increase the spraying height H from 50 mm to 200 mm, and automatically adjust the air pressure according to the set mode to keep the spraying cone half angle constant; wherein, the change rate dW / dH of the spraying width W with respect to the spraying height H ≤ 0.2.

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