A bipolar accelerated ultrasonic vibration atomized jet cooling device and operation process

Abstract

The application relates to a bipolar accelerated ultrasonic vibration atomized jet cooling device and an operation process, the device is divided into three coaxially arranged sections, and the outer shells of adjacent sections are connected through threads. Among them, a piezoelectric ceramic transducer of a first section nozzle is connected with a variable amplitude rod of a second section nozzle, a mesh nut is connected at the front end of the variable amplitude rod, and a guide vane is arranged between the second and third section nozzles and outside the mesh nut; the third section nozzle comprises a stepped inner cavity and a conical outer cavity, and an annular gap is formed between the two for guiding pressure gas. After the ultrasonic signal is connected, the piezoelectric transducer generates mechanical vibration, the variable amplitude rod amplifies and transmits the vibration to the mesh nut; the cutting fluid flows to the front end of the variable amplitude rod, and uniform atomized droplets are formed in front of the mesh nut. Under the guidance and pressurization of the guide vane and the annular gap, the high-pressure gas carries the fine atomized droplets to be uniformly, efficiently and high-speed sprayed, and the cutting processing area is effectively reached.

Description

Technical Field

[0001] This invention belongs to the fields of machining technology and cooling technology, and relates to a bipolar accelerated ultrasonic vibration atomizing jet cooling device. Background Technology

[0002] In the machining of metallic materials, especially various difficult-to-machine materials, applying good cooling and lubrication to the cutting zone can effectively reduce the temperature of the cutting zone and improve the frictional contact between the tool and the workpiece, thereby improving tool durability and enhancing machining quality and efficiency. Therefore, appropriate cooling and lubrication technologies are often used in metal cutting processes. However, at high cutting speeds, cutting fluid often struggles to penetrate the cutting zone. For ultrasonic atomization, conventional Langevin ultrasonic atomizers, with their large atomized particle diameter, low atomization efficiency, small flow rate, and low droplet velocity, can no longer meet the increasingly demanding cooling and lubrication requirements of current machining processes.

[0003] Ultrasonic atomization refers to the process where an ultrasonic power supply generates a sinusoidal excitation signal, which is then converted into mechanical vibration by an ultrasonic transducer. Under the influence of this ultrasonic vibration, the liquid undergoes cavitation, creating unstable surface tension waves at the gas-liquid interface. This causes the liquid to disperse in the gas phase, forming fine droplets. Spray cooling, on the other hand, involves mixing a small amount of liquid into a compressed airflow to create a mist-like gas-liquid two-phase fluid. This mist is then sprayed onto the cutting zone, providing sufficient cooling and lubrication for the workpiece and tool. As a novel cooling and lubrication technology, ultrasonic spraying combines both methods. The cutting fluid atomization is achieved through ultrasonic vibration, and the atomized droplets, carried by pressurized gas, become a high-velocity, highly penetrating spray, resulting in superior cooling and lubrication.

[0004] The invention patent (publication number: CN103056061A) discloses an ultrasonic vibration atomizer. This atomizer uses longitudinal ultrasonic vibration generated by a piezoelectric transducer to drive the mesh vibration plate at the front end of the amplitude transformer to bend and vibrate. It forms fine and uniform atomized droplets by relying on the combined action of the micropores on the mesh vibration plate and ultrasonic vibration. However, due to the limitation of the micropores, the initial velocity of the droplets is low, making it difficult to break through the "air barrier" in the processing area and accurately reach the processing area. In addition, the liquid delivery pipe of this atomizer runs through the entire device, which makes it difficult to manufacture and costly. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide a bipolar accelerated ultrasonic vibration atomizing jet cooling device and its operating process, which has a simple structure, good atomization effect, fast and controllable spray speed, and stable direction.

[0006] The technical solution of this invention is:

[0007] A bipolar accelerated ultrasonic vibration atomizing jet cooling device, wherein the nozzle device is mainly divided into three sections, and the three sections of the nozzle housing are connected by threads.

[0008] The first nozzle consists of a housing and a piezoelectric ceramic transducer; the second nozzle mainly consists of a housing, an amplitude transformer, a mesh nut, and a guide vane. The mesh nut is threaded to the front end of the amplitude transformer, and the guide vane is sandwiched between the housings of the second and third nozzles and located outside the mesh nut; the third nozzle mainly consists of a housing, a stepped inner cavity, and a conical outer cavity, wherein the stepped inner cavity and the conical outer cavity are respectively threaded to the housing.

[0009] The three nozzle shells are all approximately cylindrical. The first nozzle shell has a circular hole at its rear end, through which the piezoelectric ceramic transducer is connected to the ultrasonic power supply's electrical signal. The second nozzle shell has two symmetrically arranged air inlets on its side for air intake and one liquid inlet for liquid intake. The third nozzle shell has two symmetrically arranged air inlets for air intake and two internal threads for connecting to the stepped inner cavity and the conical outer cavity, respectively. The three nozzle shells are connected by internal and external threads for connection.

[0010] The rear end of the amplitude rod has a threaded hole for connecting to the piezoelectric ceramic transducer; the front half of the amplitude rod has an "L"-shaped liquid inlet pipe that runs from the side of the amplitude rod to the front end of the amplitude rod. The hose of the liquid supply device passes through the small circular hole in the second nozzle housing and is then connected to the liquid inlet pipe to deliver liquid; the center of the front end of the amplitude rod has a shallow circular hole for diffusing droplets, and the outer side is threaded for connecting to the mesh nut.

[0011] The mesh nut has several arrayed micro-mesh holes with a diameter of 20-50μm distributed at the front end where the amplitude is larger. The mesh nut has internal threads and is connected to the amplitude transformer rod through the threads.

[0012] The guide vane has a circular through hole in the middle, and oblique through holes are distributed around the through hole.

[0013] The stepped inner cavity and the conical outer cavity are connected to the third nozzle housing via external threads.

[0014] After the ultrasonic power supply inputs an electrical signal to the piezoelectric ceramic transducer, the transducer generates longitudinal mechanical vibration. The amplitude transformer amplifies the vibration and transmits it to the mesh nut, causing the mesh nut to undergo bending or torsional vibration. Simultaneously, the fluid supply device inputs cutting fluid into the delivery pipe. When the cutting fluid flows to the front end of the amplitude transformer, the vibration and deformation of the mesh nut causes the liquid in contact with the micropores to be squeezed out of the micropores under the action of inertia, surface tension, and hydrodynamics, thus forming a micro-jet, which in turn forms relatively uniform atomized droplets in front of the mesh nut. At the same time, the gas supply device injects the first-stage pressurized gas into the second-stage nozzle. Guided and constrained by the guide vanes, the flow direction and flow rate of the pressurized gas become more stable, enabling the atomized droplets to be evenly dispersed and screened by wind speed. Suitable droplets are accelerated forward into the third-stage nozzle. The second-stage high-pressure gas is injected into the third-stage nozzle. Due to the annular gap structure between the inner and outer cavities inside the third-stage nozzle, the high-pressure gas is ejected from the front end of the nozzle at a certain angle. Utilizing the pressure difference, it carries the atomized droplets to form a jet and sprays it into the cutting zone.

[0015] Beneficial effects

[0016] (1) The present invention amplifies and transmits the longitudinal vibration generated by the piezoelectric ceramic transducer to the mesh nut. The front end of the nut has an array of micro-mesh holes, and the micro-spraying effect of the vibrating mesh holes is used to form fine and uniform atomized droplets.

[0017] (2) The present invention pressurizes the ambient temperature and pressure gas twice through the second and third nozzles. The resulting two-stage pressure gas carries and filters the atomized droplets, improves and controls the spray speed of the droplets, and makes them reach the cutting area more quickly and effectively, thus improving the cooling and lubrication performance. In addition, the pressurized gas carries away the atomized droplets in time, and the direction of the gas is constrained when passing through the guide plate, which makes the carried droplets less adsorbed on the inner shell of the nozzle, improving the atomization efficiency of the cutting fluid and simplifying the subsequent cleaning process.

[0018] (3) When dealing with liquid media with high viscosity, the existing technology often requires a significant increase in vibration frequency to improve the atomization effect. The present invention uses the ultrasonic vibration of the micro-mesh of the mesh nut to generate atomized droplets, which has a good atomization effect and can improve the atomization effect without increasing the energy-consuming vibration frequency. It is suitable for atomizing various liquid media. Attached Figure Description

[0019] Figure 1 This is a cross-sectional view of the bipolar accelerated ultrasonic vibration atomizing jet cooling device of the present invention;

[0020] Figure 2 This is a sectional view of the amplitude transformer;

[0021] Figure 3 This is a schematic diagram of the structure of a mesh nut;

[0022] Figure 4 This is a cross-sectional view of the air deflector.

[0023] Figure 5 This is a schematic diagram of the second nozzle housing structure;

[0024] Figure 6 This is a schematic diagram of the third nozzle housing structure;

[0025] Figure 7 This is a comparison diagram of the diameter and distribution of atomized droplets between the present application and a conventional atomized jet cooling device;

[0026] Figure 8 This is a comparison diagram of the atomized jet effect between this application and a conventional atomized jet cooling device.

[0027] Explanation of key reference numerals in the accompanying drawings:

[0028] First section nozzle housing - 1, transducer bolt - 2, rear cover plate - 3, piezoelectric ceramic plate - 4, front cover plate - 5, amplitude transformer - 6; Second section nozzle housing - 7, mesh nut - 8, guide vane - 9; Third section nozzle housing - 10, stepped inner cavity - 11, conical outer cavity - 12, liquid inlet pipe - 13, cutting fluid diffusion zone - 14, micro-mesh - 15, oblique through hole - 16, liquid inlet hole - 17, first stage pressurized gas inlet hole - 18, second stage high-pressure gas inlet hole - 19, stepped inner cavity connecting thread - 20, conical outer cavity connecting thread - 21. Detailed Implementation

[0029] The technical solution of the present invention will be described in detail below with reference to the embodiments and accompanying drawings.

[0030] Example 1

[0031] In the description of this invention, for the sake of simplicity and ease of description of the nozzle structure, the piezoelectric ceramic transducer is a functional combination of parts such as transducer bolt 2, rear cover plate 3, piezoelectric ceramic sheet 4, and front cover plate 5. Multiple piezoelectric ceramic sheets 4 are clamped and fixed by means of transducer bolt 2. The first-stage pressurized gas inlet 18 and the second-stage high-pressure gas inlet 19 are referred to as inlet 18 and inlet 19, respectively. The stepped inner cavity connecting thread 20 and the tapered outer cavity connecting thread 21 are referred to as connecting thread 20 and connecting thread 21, respectively.

[0032] Figure 1 This is a cross-sectional view of a bipolar accelerated ultrasonic vibration atomizing jet cooling device according to the present invention. Figure 1As shown, the nozzle device is mainly composed of three interconnected sections arranged coaxially. The three adjacent nozzle housings (first nozzle housing-1, second nozzle housing-7, and third nozzle housing-10) are connected by internal and external threads. The first nozzle section consists of the first nozzle housing 1 and a piezoelectric ceramic transducer, which is connected to the ultrasonic power supply through a circular hole. The second nozzle section mainly consists of an amplitude transformer 6, a second nozzle housing 7, a mesh nut 8, and a guide vane 9. The mesh nut 8 is threaded to the front end of the amplitude transformer 6, and the guide vane is sandwiched between the second and third nozzle housings, located outside the mesh nut 8. The third nozzle section mainly consists of the third nozzle housing 10, a stepped inner cavity 11, and a conical outer cavity 12. The stepped inner cavity 11 and the conical outer cavity 12 are connected to the third nozzle housing 10 through inner and outer cavity connecting threads 20 and 21, respectively.

[0033] Figure 2 This is a cross-sectional view of the amplitude transformer 6. The amplitude transformer is designed with three stepped platforms, with the radius decreasing at each step. The three-section structure is mainly to increase the amplitude, improve the atomization effect, and allow the liquid inlet to be better distributed on the joint surface, preventing vibration from damaging the threaded structure. The threaded hole at the rear end of the amplitude transformer is used to connect to the piezoelectric ceramic transducer. The front half of the amplitude transformer has an "L"-shaped liquid inlet pipe 13, which runs from the side of the amplitude transformer to the cutting fluid diffusion zone 14 at the front end, shortening the cutting fluid delivery process. The hose of the liquid supply device passes through the small circular hole (liquid inlet 17) on the second nozzle housing and then connects to the liquid inlet pipe 13 to deliver liquid. The center of the front end of the amplitude transformer has a shallow circular cutting fluid diffusion zone 14 to diffuse the cutting fluid for subsequent atomization; the outer side is threaded to connect to the mesh nut 8.

[0034] Figure 3 This is a schematic diagram of the structure of the mesh nut 8. Several array micro-mesh holes 15 with a diameter of 20-50μm are distributed at the front end where the amplitude is large. The inside is threaded and connected to the amplitude rod 6 through the internal thread. The micro-mesh holes are distributed at the part with large amplitude, and the holes are more densely distributed at the center than at the edge.

[0035] Figure 4 This is a cross-sectional view of the guide vane 9. When the second nozzle housing 7 and the third nozzle housing 10 are connected by threads, the guide vane 9 is clamped in the middle and fixed. The inner side is a circular through hole, and oblique through holes 16 are distributed around the circular through hole. The oblique through holes 16 are used to constrain and guide the direction and flow of the first stage pressurized gas. The oblique through holes 16 are arranged in an array.

[0036] Figure 5This is a schematic diagram of the second nozzle housing 7. The rear end of housing 7 has an external thread for connecting to the first nozzle housing 1, and the front end has an internal thread for connecting to the third nozzle housing 10. Housing 7 has two symmetrically arranged air inlets 18 on its side for air intake, and a liquid inlet 17 for liquid intake. The liquid inlet 17 is located directly above the inlet of the liquid inlet pipe 13 of the amplitude transformer 6. Figure 1 As shown.

[0037] Figure 6 This is a schematic diagram of the third-stage nozzle housing 10. The rear end of housing 10 has an external thread, which connects it to the second-stage nozzle housing 7. Two symmetrically arranged air inlets 19 are used for air intake. Internally, there are two connecting threads 20 and 21, which connect to the stepped inner cavity 11 and the conical outer cavity 12, respectively. The annular gap formed between the stepped inner cavity 11 and the conical outer cavity 12 guides the pressurized gas. The angle of the annular gap between the inner and outer cavities in the horizontal direction is smaller than the angle between the oblique through-hole 16 on the guide vane and the horizontal line. This is to better pressurize the primary pressurized gas generated by the second-stage nozzle housing, forming secondary pressurized gas.

[0038] The operating process of a bipolar accelerated ultrasonic vibration atomizing jet cooling device includes the following steps:

[0039] (1) Turn on the ultrasonic generator and connect the electrical signal to the piezoelectric ceramic transducer. The transducer generates longitudinal mechanical vibration and transmits the vibration to the amplitude transformer 6. The amplitude transformer 6 amplifies the vibration and transmits it to the mesh nut 8. The mesh nut 8 then undergoes bending or torsional vibration.

[0040] (2) At the same time, the liquid supply device inputs the cutting fluid into the liquid inlet pipe 13. When the cutting fluid flows through the through hole inside the amplitude rod to the front end of the amplitude rod 6, the vibration deformation of the mesh nut 8 causes the liquid in contact with the micro hole to be squeezed out from the micro hole under the action of inertia, surface tension and hydrodynamics, thus forming a micro spray, and then forming uniform atomized droplets in front of the mesh nut 8.

[0041] (3) The gas supply device injects the first-stage pressurized gas into the second-stage nozzle through the air inlet 18. Due to the constraint of the symmetrically arranged air inlet 18 and the array of oblique through holes 16 of the guide plate 8, the gas is pressurized to form a pressurized gas. The flow direction and flow rate of the pressurized gas become uniform and stable, which can make the atomized droplets in front of the mesh nut 8 disperse evenly and perform wind speed screening. Wind speed screening specifically means that if the formed atomized droplets are not uniform, under the action of the pressurized gas, the large droplets with low speed will settle on the pipe wall, while the droplets in the suitable range have high speed and enter the third-stage nozzle. This is the first-stage acceleration. The second-stage high-pressure gas is injected into the third-stage nozzle through the air inlet 19. The annular gap formed between the stepped inner cavity 11 and the conical outer cavity 12 connected to the outer shell 10 of the third-stage nozzle makes the high-pressure gas spray out from the front end of the nozzle at a certain angle. Using the pressure difference, it carries the atomized droplets to form a jet and sprays it into the cutting area. This is the second-stage acceleration, hence it is called bipolar acceleration.

[0042] Compared to conventional and ultrasonic atomized jets, ultrasonic atomization effectively controls the jet profile. The droplet diameter follows a normal distribution, reducing the average droplet diameter by 20% and resulting in a more concentrated distribution. This facilitates more effective entry into the cutting zone for cooling and lubrication, achieving the desired effect. Figure 7 , 8 As shown.

[0043] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A bipolar accelerated ultrasonic vibration atomized jet cooling device, characterized in that, The device is a three-section structure connected in sequence, coaxially arranged, and the housings of adjacent sections are connected by threads; the nozzle is arranged at the end of the third section nozzle, and an opening is arranged at the end of the first section nozzle; the first section nozzle comprises a housing and a piezoelectric ceramic transducer, and the piezoelectric ceramic transducer is connected to an external ultrasonic generator through the opening; The second section nozzle comprises a housing, a variable amplitude rod, a mesh nut and a guide vane; the mesh nut is threadedly connected to the front end of the variable amplitude rod, and the guide vane is clamped between the housings of the second and third section nozzles and located outside the mesh nut to guide the pressure gas; the end of the variable amplitude rod is connected to the piezoelectric ceramic transducer; The third section nozzle comprises a housing, a stepped inner cavity and a conical outer cavity; the stepped inner cavity and the conical outer cavity are respectively connected to the housing by threads, and an annular gap is formed between the stepped inner cavity and the conical outer cavity for guiding the pressure gas; The housings of the three-section nozzles are all cylindrical structures; the second section nozzle housing has two symmetrically arranged air inlet holes for air inlet and another liquid inlet hole for liquid inlet; the third section nozzle housing has two symmetrically arranged air inlet holes for air inlet, and has two internal threads inside for connecting the stepped inner cavity and the conical outer cavity respectively; the housings of the three-section nozzles are connected by internal and external threads; The inner side of the guide vane is a circular through hole, and inclined through holes (16) are distributed around the circular through hole to constrain the direction and flow of the first stage pressurized gas; The angle of the annular gap formed between the stepped inner cavity (11) and the conical outer cavity (12) of the third section nozzle in the horizontal direction is smaller than the angle of the inclined through hole of the guide vane with the horizontal line, so as to better pressurize the first stage pressurized gas generated by the second section nozzle housing and form secondary pressurized gas; more than one array of micro mesh holes (15) with a diameter of 20-50 μm are distributed on the mesh nut, and the inside is threaded and connected to the variable amplitude rod (6) through the internal thread; the micro mesh holes are distributed at a larger amplitude, and the hole center is more dense than the edge distribution.

2. The bipolar accelerated ultrasonic vibrational atomized jet cooling apparatus of claim 1, wherein, A liquid inlet channel is arranged in the front section of the variable amplitude rod, one end of the liquid inlet channel is connected to an external cutting fluid supply device through a liquid inlet hole, and the other end penetrates to the front end of the variable amplitude rod and is connected to the mesh nut.

3. Bipolar accelerated ultrasonic vibration atomized jet cooling device according to claim 1 or 2, characterized in that The variable amplitude rod is arranged as three stepped platforms with gradually reduced radii, and the three-section structure is to expand the amplitude, improve the atomization effect, make the liquid inlet better distributed on the nodal surface, and prevent the damage of vibration to the threaded structure.

4. A process for operating a bipolar accelerated ultrasonic vibration atomized jet cooling device according to claim 1, characterized in that, The steps are as follows: (1) After the ultrasonic power supplies electrical signals to the piezoelectric ceramic transducer, the transducer generates longitudinal mechanical vibration and transmits the vibration to the variable amplitude rod (6), the variable amplitude rod amplifies and transmits the vibration to the mesh nut, and the mesh nut generates bending vibration or torsional vibration accordingly; (2) The cutting fluid supply device inputs the cutting fluid into the liquid supply pipeline, when the cutting fluid flows to the front end of the variable amplitude rod through the through hole in the variable amplitude rod, the vibration deformation of the mesh nut promotes the cutting fluid to form uniform atomized droplets in front of the mesh nut; (3) The gas supply device injects the first stage pressurized gas into the second section nozzle, and the guide vane guides the atomized droplets to be dispersed uniformly and subjected to wind speed screening, and the screened droplets are accelerated to enter the third section nozzle; (4) The second stage high pressure gas is injected into the third stage nozzle, the annular gap between the stepped inner cavity and the conical outer cavity guides the pressure gas, the high pressure gas is sprayed from the front end of the nozzle, and a jet is formed by using the pressure difference and carrying the atomized liquid droplets to spray to the cutting area.

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