Abrasive liquid jet nozzle with fluid self-oscillation and dielectrophoresis composite effect

Abstract

The invention discloses an abrasive liquid jet nozzle with a fluid self-excited oscillation and dielectrophoresis composite effect. The abrasive liquid jet nozzle comprises a fluid self-excited oscillation effect generation module and a dielectrophoresis effect generation module coaxially connected with the fluid self-excited oscillation effect generation module. When liquid jet flows through a fluid self-excited oscillation cavity in the fluid self-excited oscillation generation module, due to the special design of an inlet and outlet structure of the fluid self-excited oscillation cavity, entered fluid generates a fluid self-excited oscillation effect, traditional continuous jet flows are changed into pulse jet flows with higher peak velocity, and the machining efficiency is improved; besides, when the liquid jet passes through the non-uniform electric field in the dielectrophoresis effect generation module, the liquid jet can generate the dielectrophoresis effect, and the grinding material in the liquid jet moves from the middle area where the liquid jet is distributed more to the peripheral area of the liquid jet under the action of dielectrophoresis force, so that the grinding material is distributed more uniformly in the liquid jet, and the grinding effect of the grinding material is improved. The uniformity of the surface of a workpiece after abrasive liquid jet machining can be improved, and the machining precision is improved.

Description

Technical Field

[0001] The invention relates to the field of precision and ultra-precision machining, and in particular to an abrasive liquid jet nozzle with fluid self-excited oscillation and dielectrophoresis composite effect. Background Art

[0002] Abrasive liquid jet is a non-contact processing technology. The liquid is usually water as the medium. The liquid is pressurized by a high-pressure device. Then the abrasive is added to the high-pressure liquid through a feeding device and a mixing device to complete the mixing, forming a liquid-solid two-phase mixed jet. The high-speed impact and scouring of the abrasive and high-pressure fluid are used to remove the processing surface material. Compared with traditional mechanical polishing methods, abrasive liquid jet technology has the advantages of cold operation, non-contact, high process stability, and no thermal deformation of the processing surface. It has broad development prospects and has received widespread attention in the field of jet processing and cutting.

[0003] The jet nozzle consists of a liquid jet nozzle, a mixing chamber and a mixed liquid abrasive jet nozzle. In abrasive liquid jet processing, it can be divided into two types: pre-mixing and post-mixing according to the mixing time and mixing position of solid particles. Among them, in the pre-mixing method, the fluid and abrasive slurry are mixed in the mixing chamber, which has the advantages of relatively uniform particle distribution and low required hydraulic pump pressure. Its disadvantages are: the abrasive is easy to settle in the abrasive barrel, making it impossible to accurately control the abrasive concentration; the hydraulic pump has large losses; the friction cutting of abrasive particles inside the jet nozzle causes rapid nozzle wear and a short nozzle life.

[0004] In the post-mixing method, the high-pressure liquid flow generated by the hydraulic pump pressurized fluid supply system passes through the liquid jet nozzle to form a high-speed jet and then enters the mixing chamber, and the abrasive is also fed into the mixing chamber through the feeding system, and is initially mixed with the fluid in the mixing chamber, and then further accelerated in the liquid abrasive jet nozzle for secondary mixing to form a post-mixing abrasive liquid jet. Due to the advantages of relatively simple equipment, low cost, and convenient equipment maintenance, it is more widely used in liquid jet processing. However, due to the different mixing methods of abrasive addition and the lack of pre-mixing process, the mixing uniformity is slightly worse than that of the pre-mixing abrasive liquid jet. The abrasive is mainly concentrated in the middle area of ​​the jet with a faster flow rate, and the uneven distribution of abrasive leads to poor uniformity of the processed surface. In addition, in abrasive liquid jet processing, the jet beam in the impact area of ​​the workpiece surface and the reflected liquid flow on the workpiece surface will form a relatively stable holding layer (also called a blocking layer), which directly resists the jet impact force and consumes part of the jet energy. The smaller the diameter of the abrasive particles, the greater the impact of the blocking layer, which ultimately leads to a "W" shape on the processed surface with a convex middle and deeper sides. Summary of the invention

[0005] In order to overcome the deficiencies in the prior art, the present invention provides an abrasive liquid jet nozzle with a composite effect of fluid self-oscillation and dielectrophoresis. When the liquid jet passes through the fluid self-oscillation chamber in the fluid self-oscillation generating module, due to the special design of the inlet and outlet structure of the fluid self-oscillation chamber, a violent shear motion is generated on the exchange surface between the jet and the fluid in the cavity, thereby generating a large-scale vortex and colliding back and forth with the oscillation cavity wall. The liquid passing through the fluid self-oscillation chamber is changed from a traditional continuous jet to a pulse jet with a higher peak velocity, which will destroy the jet beam in the impact area of ​​the workpiece surface processing and the reflected liquid flow on the workpiece processing surface will form a blocking layer, thereby improving the processing efficiency. In addition, when the liquid jet passes through the non-uniform electric field in the dielectrophoresis effect generating module, the dielectrophoresis effect can occur, and the abrasive in the liquid pulse jet is affected by the dielectrophoresis force of the non-uniform electric field, and moves from the middle area with a larger distribution in the jet to the outer peripheral area of ​​the jet, thereby making the abrasive more evenly distributed in the jet. The use of this jet nozzle can improve the uniformity and consistency of the workpiece surface after processing and improve the processing accuracy.

[0006] The technical solution of the present invention is as follows:

[0007] An abrasive liquid jet nozzle with a composite effect of fluid self-excited oscillation and dielectrophoresis comprises a fluid self-excited oscillation effect generating module and a dielectrophoresis effect generating module coaxially connected thereto; the fluid self-excited oscillation effect generating module comprises a sand tube and a conductive slip ring sleeved on the sand tube, the front end of the sand tube is fixed in an outer cavity mounting joint; the front end surface of the sand tube is sealed with the outer cavity mounting joint by a cavity length adjustment gasket, a liquid jet flow channel I is provided in the sand tube; a piston mounting hole is provided at the front end of the outer cavity mounting joint, an outlet piston is installed in the piston mounting hole, and a liquid jet flow channel II is provided in the outlet piston; the cavity length adjustment gasket is hollow, and its two ends are respectively connected to the liquid jet flow channel I and the liquid jet flow channel II to form a fluid self-excited oscillation chamber that can make the liquid jet fluid produce a self-excited oscillation effect. During operation, the liquid jet changes from a continuous jet to a pulse jet with a higher peak velocity in the fluid self-excited oscillation chamber, and then flows out through the liquid jet flow channel II; the dielectrophoresis effect generating module includes a ceramic tube and a metal tube sleeved on the outside thereof, a sealing cover plate is fixed to the front end of the metal tube, the ceramic tube is fixed in the metal tube through the sealing cover plate, and a liquid jet outlet is arranged on the sealing cover plate; a liquid jet flow channel III is arranged in the ceramic tube, so that the liquid jet fluid flowing out of the liquid jet flow channel II flows through the liquid jet flow channel III and then is ejected through the liquid jet outlet; an insulating layer is arranged between the metal tube and the ceramic tube, and an annular positive electrode and an annular negative electrode are arranged in the insulating layer, and the annular positive electrode and the annular negative electrode are respectively electrically connected to the two output ends of the conductive slip ring, and can generate a non-uniform electric field after the power is turned on.

[0008] Compared with the prior art, the abrasive liquid jet nozzle with fluid self-oscillation and dielectrophoresis composite effect of the present invention adopts a specific structure, under the synergistic effect of fluid self-oscillation and abrasive dielectrophoresis effect, improves the processing accuracy and processing efficiency of the workpiece surface, as follows:

[0009] 1) In the present invention, after the abrasive liquid jet of the nozzle passes through the fluid self-excited oscillation chamber, it changes from a traditional continuous jet to a pulse jet with a higher peak velocity, and then enters the dielectrophoresis effect generating module. Due to the effect of the non-uniform electric field force in the dielectrophoresis effect generating module, the abrasive particles in the pulse jet will produce a dielectrophoresis effect, and the abrasive particles in the jet move from the middle area where they are more distributed to the outer periphery of the jet, so that the abrasive particles are more evenly distributed in the jet; the amount of machining removal by using this jet is more uniform, and the polishing accuracy of the workpiece is improved; the pulse jet can destroy the jet beam in the impact area of ​​the workpiece surface machining and the reflected liquid flow on the workpiece machining surface will form a blocking layer, thereby improving the machining efficiency;

[0010] 2) The present invention is suitable for abrasives that can produce dielectrophoresis effect, such as silicon carbide, cerium oxide, etc., which can improve the distribution of abrasive particles in a specified area per unit time, significantly improve the unevenness of the jet processing area, and can well solve the problems of uneven distribution of material removal on the workpiece surface and large roughness of the processed surface, significantly improve the polishing efficiency, and help to obtain better surface processing quality.

[0011] Furthermore, in the aforementioned abrasive liquid jet nozzle with fluid self-oscillation and dielectrophoresis composite effect, the fluid self-oscillation effect generating module and the dielectrophoresis effect generating module are connected to each other through a threaded connection sleeve, and internal threaded holes are provided at both ends of the threaded connection sleeve, and the two ends of the threaded connection sleeve are respectively connected to the external cavity joint and the metal tube through threads. Further, a sealing gasket I is provided between the front end face of the outlet piston and the threaded connection sleeve. A sealing gasket III is provided between the rear end face of the ceramic tube and the threaded connection sleeve. By installing the sealing gasket, a reliable seal is formed to ensure the sealing of the equipment, which has the characteristics of easy implementation.

[0012] Furthermore, in the aforementioned abrasive liquid jet nozzle with fluid self-oscillation and dielectrophoresis composite effect, the sand tube is fixed in the outer cavity fitting joint by a threaded fastening sleeve sleeved on its outer periphery. Fixing the sand tube in the outer cavity fitting joint by the threaded fastening sleeve not only achieves the position limitation of the sand tube, but also facilitates the installation and removal of the sand tube. Furthermore, the front end of the sand tube is sleeved with an inlet sand tube sleeve, and is sealed and connected to the outer cavity fitting joint and the cavity length adjustment gasket respectively through the inlet sand tube sleeve. This structural design can further fix the sand tube, avoid the phenomenon of sand tube shaking during operation, and at the same time, enhance the sealing between the sand tube and the cavity length adjustment gasket.

[0013] Furthermore, in the aforementioned abrasive liquid jet nozzle with fluid self-excited oscillation and dielectrophoresis composite effect, a sealing gasket II is provided between the ceramic tube and the sealing cover plate. This structure can not only form a reliable seal, but also has the characteristics of being easy to implement.

[0014] Furthermore, in the aforementioned abrasive liquid jet nozzle with fluid self-excited oscillation and dielectrophoresis composite effect, the widths of the annular positive electrode and the annular negative electrode are different. The annular positive and negative electrodes of different widths can generate a non-uniform electric field, so that the abrasive particles in the pulse jet can achieve the dielectrophoresis effect, so that the abrasive particles move from the middle area where they are more distributed in the jet to the outer periphery of the jet beam, so that the abrasive particles are more evenly distributed in the jet beam, thereby improving the accuracy of the workpiece surface after polishing, and it is easy to implement. Further, the annular positive electrode and the annular negative electrode are staggered and distributed at equal distances in the insulating layer.

[0015] Furthermore, in the aforementioned abrasive liquid jet nozzle with fluid self-oscillation and dielectrophoresis composite effect, the two ends of the self-oscillation chamber are conical structures. The setting of the conical structure can facilitate the formation of large-sized vortices, thereby enhancing the self-oscillation effect generated by the fluid.

[0016] Furthermore, in the aforementioned abrasive liquid jet nozzle having a composite effect of fluid self-oscillation and dielectrophoresis, the ratio of the diameter size d3 of the liquid jet flow channel II to the diameter size d2 of the liquid jet flow channel I is preferably in the range of 1.1 to 2; the ratio of the diameter size d1 of the self-oscillation chamber to the diameter size d2 of the liquid jet flow channel I is preferably in the range of 5 to 10. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic structural diagram of an abrasive liquid jet nozzle having a composite effect of fluid self-excited oscillation and dielectrophoresis of the present invention;

[0018] Figure 2 It is a structural schematic diagram of a fluid self-oscillation effect generating module in an abrasive liquid jet nozzle having a fluid self-oscillation and dielectrophoresis composite effect of the present invention;

[0019] Figure 3 It is a schematic structural diagram of a dielectrophoresis effect generating module in an abrasive liquid jet nozzle having a fluid self-excited oscillation and dielectrophoresis composite effect of the present invention;

[0020] Figure 4 It is a schematic structural diagram of the self-excited oscillation chamber of the abrasive liquid jet nozzle having the composite effect of fluid self-excited oscillation and dielectrophoresis of the present invention;

[0021] Figure 5 It is a schematic diagram of a liquid jet polishing device using an abrasive liquid jet nozzle having a fluid self-excited oscillation and dielectrophoresis composite effect of the present invention;

[0022] Figure 6 It is a surface morphology diagram of a workpiece processed by the abrasive liquid jet nozzle having the composite effect of fluid self-excited oscillation and dielectrophoresis of the present invention;

[0023] Figure 7 This is a surface morphology diagram of a workpiece after processing without using the abrasive liquid jet nozzle with fluid self-excited oscillation and dielectrophoresis composite effect of the present invention (using a commercially available ordinary liquid jet nozzle);

[0024] Figure 8 The white light interferometer is used to measure the white light interference pattern of the surface of the 316L stainless steel wafer before processing;

[0025] Fig. 9 The white light interferometer is used to measure the white light interference pattern of the surface of the 316L stainless steel disc after being processed by the abrasive liquid jet nozzle having the composite effect of fluid self-excited oscillation and dielectrophoresis of the present invention;

[0026] Fig.10 The Taylor surface roughness meter is used to measure the surface topography of the workpiece after it is processed without using the liquid jet nozzle of the present invention;

[0027] Fig.11 The Taylor surface roughness meter is used to measure the surface morphology of the workpiece after being processed by the abrasive liquid jet nozzle having the composite effect of fluid self-excited oscillation and dielectrophoresis of the present invention;

[0028] Fig.12 This is a graph of pressure changes caused by the liquid jet impacting the target at different outlet pressures measured by a high-precision pressure meter (the red curve is the impact effect with the addition of a self-excited oscillation chamber, and the black curve is the impact effect without the addition of a self-excited oscillation chamber).

[0029] Figure numerals: 1-fluid self-excited oscillation effect generating module; 101-sand pipe; 1011-liquid jet flow channel I; 102-conductive slip ring; 103-external cavity mounting joint; 104-cavity length adjustment gasket; 105-export piston; 1051-liquid jet flow channel II; 106-self-excited oscillation chamber; 107-sealing gasket I; 108-threaded fastening sleeve; 109-inlet sand pipe sleeve; 2-dielectrophoresis effect generating module; 201-ceramic tube; 2011-liquid jet flow channel III; 202-metal tube; 203-sealing cover plate; 2031-liquid jet outlet; 204-insulating layer; 205-annular positive electrode; 206-annular negative electrode; 207-sealing gasket II; 3-threaded connecting sleeve; 4-water supply system; 5-boosting system; 6-power supply; 7-workpiece; 8-mixing chamber; 9-waste recovery device; 10-abrasive supply device. DETAILED DESCRIPTION

[0030] The present invention is further described below in conjunction with the accompanying drawings and embodiments, but they are not intended to serve as the basis of the present invention.

[0031] Example (see Figure 1-12 ):

[0032] In the embodiment, the liquid jet polishing device includes an abrasive liquid jet nozzle with fluid self-excited oscillation and dielectrophoresis composite effect, a water supply system 4, a booster system 5, a power supply 6, a mixing chamber 8, a waste recovery device 9, and an abrasive supply device 10.

[0033] In the embodiment, the abrasive liquid jet nozzle having the composite effect of fluid self-excited oscillation and dielectrophoresis comprises a fluid self-excited oscillation effect generating module 1 and a dielectrophoresis effect generating module 2 coaxially connected thereto.

[0034] In the embodiment, the fluid self-excited oscillation effect generating module 1 includes a sand tube 101 and a conductive slip ring 102 sleeved on the sand tube 101. The front end of the sand tube 101 is fixed in the outer cavity fitting joint 103. The front end surface of the sand tube 101 and the outer cavity fitting joint 103 are sealed by a cavity length adjustment gasket 104. A liquid jet flow channel I 1011 is provided in the sand tube 101. A piston mounting hole is provided at the front end of the outer cavity fitting joint 103, and an outlet piston 105 is installed in the piston mounting hole. , the outlet piston 105 is provided with a liquid jet flow channel II 1051; the cavity length adjustment gasket 104 is hollow, and its two ends are respectively connected to the liquid jet flow channel I 1011 and the liquid jet flow channel II 1051, forming a fluid self-excited oscillation chamber 106 that can make the liquid jet fluid produce a self-excited oscillation effect. When working, the liquid jet fluid changes from a continuous jet to a pulse jet with a higher peak velocity in the fluid self-excited oscillation chamber 106, and then flows out through the liquid jet flow channel II 1051. The pulse jet can destroy the jet beam in the impact area of ​​the workpiece 7 surface processing and the reflected liquid flow on the workpiece 7 processing surface will form a blocking layer, thereby improving the processing efficiency;

[0035] In the embodiment, the dielectrophoresis effect generating module 2 includes a ceramic tube 201 and a metal tube 202 sleeved on the outside thereof, a sealing cover plate 203 is fixed to the front end of the metal tube 202, the ceramic tube 201 is fixed in the metal tube 202 through the sealing cover plate 203, and a liquid jet outlet 2031 is provided on the sealing cover plate 203; a liquid jet flow channel III 2011 is provided in the ceramic tube 201, so that the liquid jet fluid flowing out of the liquid jet flow channel II 1051 flows through the liquid jet flow channel III 2011 and then is ejected through the liquid jet outlet 2031; an insulating layer 204 is provided between the metal tube 202 and the ceramic tube 201, and an annular positive electrode 205 and an annular negative electrode 206 are provided in the insulating layer 204, and the annular positive electrode 205 and the annular negative electrode 206 are respectively electrically connected to the two output ends of the conductive slip ring 102, and can generate a non-uniform electric field after the power is turned on.

[0036] In the embodiment, the sand pipe 101 is fixed in the outer cavity fitting joint 103 by a threaded fastening sleeve 108 sleeved on its outer circumference. The sand pipe 101 is fixed in the outer cavity fitting joint 103 by the threaded fastening sleeve 108, which not only limits the position of the sand pipe 101, but also facilitates the installation and removal of the sand pipe 101.

[0037] In the embodiment, the front end of the sand tube 101 is sleeved with an inlet sand tube sleeve 109, and is sealed and connected to the outer cavity joint 103 and the cavity length adjustment gasket 104 respectively through the inlet sand tube sleeve 109. This structural design can further fix the sand tube 101, avoid the shaking of the sand tube 101 during operation, and at the same time, enhance the sealing between the sand tube 101 and the cavity length adjustment gasket 104.

[0038] In the embodiment, a sealing gasket II 207 is provided between the ceramic tube 201 and the sealing cover plate 203. A sealing gasket III is provided between the rear end surface of the ceramic tube 201 and the threaded connection sleeve 3. This structure can not only form a reliable seal, but also has the characteristics of being easy to implement.

[0039] In the embodiment, the widths of the annular positive electrode 205 and the annular negative electrode 206 are different. The annular positive electrode 205 and the annular negative electrode 206 are staggered and distributed at equal distances in the insulating layer. The annular positive and negative electrodes of different widths can generate a non-uniform electric field, so that the abrasive particles in the pulse jet produce a dielectrophoresis effect, so that the abrasive particles move from the middle area where they are more distributed in the jet to the outer periphery of the jet, so that the abrasive particles are more evenly distributed in the jet beam, the accuracy of the surface of the workpiece 7 after polishing is improved, and it is easy to implement (the width ratio of the positive and negative electrodes can be adjusted according to the properties of the abrasive particles).

[0040] In the embodiment, the two ends of the self-excited oscillation chamber 106 are in a conical structure. The setting of the conical structure can be conducive to the formation of a large-sized vortex, thereby enhancing the self-excited oscillation effect generated by the fluid and forming a pulse jet.

[0041] In the embodiment, Figure 4 As shown, the ratio of the diameter size d3 of the liquid jet flow channel II 1051 to the diameter size d2 of the liquid jet flow channel I 1011 is 1.2; the ratio of the diameter size d1 of the self-excited oscillation chamber 106 to the diameter size d2 of the liquid jet flow channel I 1011 is 8.

[0042] The cavity length adjustment gasket 104 can be replaced according to the cavity length L of the required fluid self-oscillation chamber 106. By replacing the cavity length adjustment gasket 104 of different lengths and adjusting the cavity length L of the self-oscillation chamber 106, different self-oscillation effects can be produced to meet different processing requirements. In order to obtain a better self-oscillation effect, when implementing the present invention, it is preferable that the cavity length L of the self-oscillation chamber 106 is smaller than the diameter size d1 of the self-oscillation chamber 106. In the embodiment, the ratio of the cavity length L of the self-oscillation chamber 106 to the diameter d1 of the self-oscillation chamber 106 is 2 / 3.

[0043] like Figure 6 , Figure 7 As shown, when the abrasive liquid jet nozzle of the present invention is not used for liquid jet polishing, the abrasive particles are mostly distributed in the central area where the liquid jet velocity is relatively high. Due to the existence of the stagnant layer, the depth and width of the pits on the surface of the processed workpiece 7 are different, and the processed surface of the workpiece 7 is in a deep "W" shape (the stagnant layer refers to the relatively stable retention layer between the jet beam in the impact area and the surface of the workpiece 7 during the abrasive liquid jet processing. It directly resists the impact of the liquid jet and consumes part of the energy of the jet. At the same time, the smaller the diameter of the abrasive particles, the greater the impact of the stagnant layer). After using the nozzle of the present invention for liquid jet polishing, the distribution of the abrasive in the liquid jet is improved, the distribution is more uniform, the level of material removal is higher, and the surface flatness of the workpiece 7 is better.

[0044] The abrasive liquid jet nozzle with the composite effect of fluid self-excited oscillation and dielectrophoresis of the present invention is used to process 316L stainless steel discs. The experimental conditions are as follows: the density of the silicon nitride substrate used is ρ (g / cm 3 ) is 7.98, Vickers hardness H (GPa) is 150, Young's modulus E (GPa) is 190, fracture toughness The abrasive material used is silicon carbide abrasive, the abrasive particle size is 3μm, and the abrasive slurry flow rate is 15ml / min. The width of the annular positive electrode 205 used is 1mm, the width of the annular negative electrode 206 is 4mm, the distance between the annular positive and negative electrodes is 4mm, and the high voltage direct current passed is 10kv; the liquid jet incident angle is 60°, the target distance is 10mm, each processing time is 10min, and a total of 4 processing times. The workpiece 7 is first polished several times and cleaned with ultrasonic waves, and then its initial roughness is measured; as Figure 8 , Fig. 9 As shown, in this embodiment, the initial surface roughness S of the 316L stainless steel disc is a The surface roughness of the 316L stainless steel disc is 155.3nm. a The surface quality is improved by 31.5%, and the original protrusions or pits on the surface of the 316L stainless steel disc are well removed.

[0045] Take two workpieces 7 with the same conditions, and use the common liquid jet polishing nozzle on the market and the abrasive liquid jet nozzle with fluid self-excited oscillation and dielectrophoresis composite effect of the present invention to perform single-point erosion on one of the workpieces 7 for 30 seconds. Fig.10 , Fig.11 As shown in the figure, after being processed by the abrasive liquid jet nozzle of the present invention, the "W" shape of the surface of the workpiece 7 is significantly improved, and the height of the middle convex peak is significantly reduced. After being processed by the ordinary liquid jet polishing nozzle, the depth difference between the convex peak and the valley bottom of the workpiece 7 is 14μm, while after being processed by the abrasive liquid jet nozzle of the present invention, the depth difference between the convex peak and the valley bottom of the workpiece 7 is 10μm.

[0046] The machining surface of workpiece 7 will produce a strong reflection pressure, namely stagnation pressure, on the continuous liquid jet, which usually does not fluctuate with time and has strong stability. The effect of self-excited oscillation is to transform the continuous jet into a pulsed jet, so that the impact pressure of the liquid jet changes at a high frequency, and produces "water hammer pressure" on the machining surface of workpiece 7, which can effectively destroy the stagnation pressure. The actual pressure change of the machining surface of workpiece 7 caused by the liquid jet generated by the jet nozzle of the self-excited oscillation chamber 106 is detected by a high-precision pressure gauge. The initial pressure of the machining surface of workpiece 7 is 4.3 N, the acquisition frequency is 50 Hz, and the single acquisition time is 10 s. Fig.12 As shown, after the abrasive liquid jet nozzle of the present invention has the composite effect of fluid self-excited oscillation and dielectrophoresis effect, the peak pressure of the liquid jet increases significantly after the jet pressure is greater than 12 MPa, and the polishing efficiency is also improved accordingly.

[0047] The above general description of the invention involved in this application and the description of its specific implementation methods should not be understood as limiting the technical solutions of the invention. Based on the disclosure of this application, those skilled in the art can, without violating the constituent elements of the invention involved, add, reduce or combine the disclosed technical features in the above general description or / and specific implementation methods (including examples) to form other technical solutions within the scope of protection of this application.

Claims

1. Abrasive liquid jet nozzle with fluid self-excited oscillation and dielectrophoresis composite effect, characterized in that: It comprises a fluid self-excited oscillation effect generating module (1) and a dielectrophoresis effect generating module (2) coaxially connected thereto; The fluid self-excited oscillation effect generating module (1) comprises a sand tube (101) and a conductive slip ring (102) sleeved on the sand tube (101); the front end of the sand tube (101) is fixed in an external cavity joint (103); the front end surface of the sand tube (101) and the external cavity joint (103) are sealed via a cavity length adjustment gasket (104); a liquid jet flow channel I (1011) is provided in the sand tube (101); a piston mounting hole is provided at the front end of the external cavity joint (103), and an outlet piston (1011) is installed in the piston mounting hole. 05), a liquid jet flow channel II (1051) is provided in the outlet piston (105); the cavity length adjustment gasket (104) is hollow, and its two ends are respectively connected to the liquid jet flow channel I (1011) and the liquid jet flow channel II (1051), so as to form a fluid self-excited oscillation chamber (106) capable of causing the liquid jet fluid to produce a self-excited oscillation effect. When working, the liquid jet changes from a continuous jet to a pulse jet with a higher peak velocity in the fluid self-excited oscillation chamber (106), and then flows out through the liquid jet flow channel II (1051); The dielectrophoresis effect generating module (2) comprises a ceramic tube (201) and a metal tube (202) sleeved on the outside of the ceramic tube (201); a sealing cover plate (203) is fixed to the front end of the metal tube (202); the ceramic tube (201) is fixed in the metal tube (202) via the sealing cover plate (203); a liquid jet outlet (2031) is provided on the sealing cover plate (203); a liquid jet flow channel III (2011) is provided in the ceramic tube (201) so that liquid jets flowing from the liquid jet flow channel II (1051) can be discharged into the ceramic tube (201); and a liquid jet flow channel III (2011) is provided in the ceramic tube (201); The liquid jet fluid flows through the liquid jet flow channel III (2011) and is ejected through the liquid jet outlet (2031); an insulating layer (204) is provided between the metal tube (202) and the ceramic tube (201); an annular positive electrode (205) and an annular negative electrode (206) are provided in the insulating layer (204); the annular positive electrode (205) and the annular negative electrode (206) are respectively electrically connected to two output ends of the conductive slip ring (102); and a non-uniform electric field can be generated after power is turned on.

2. The abrasive liquid jet nozzle with fluid self-excited oscillation and dielectrophoresis composite effect according to claim 1, characterized in that: The fluid self-excited oscillation effect generating module (1) and the dielectrophoresis effect generating module (2) are connected to each other via a threaded connection sleeve (3), both ends of the threaded connection sleeve (3) are provided with internal threaded holes, and the two ends of the threaded connection sleeve (3) are respectively connected to the outer cavity mounting joint (103) and the metal tube (202) via threads.

3. The abrasive liquid jet nozzle with fluid self-excited oscillation and dielectrophoresis composite effect according to claim 2, characterized in that: A sealing gasket I (107) is provided between the front end surface of the outlet piston (105) and the threaded connection sleeve (3); and a sealing gasket III is provided between the rear end surface of the ceramic tube (201) and the threaded connection sleeve (3).

4. The abrasive liquid jet nozzle with fluid self-excited oscillation and dielectrophoresis composite effect according to claim 1, characterized in that: The sand pipe (101) is fixed in the outer cavity joint (103) by means of a threaded fastening sleeve (108) sleeved on its outer circumference.

5. The abrasive liquid jet nozzle with fluid self-excited oscillation and dielectrophoresis composite effect according to claim 4, characterized in that: The front end of the sand pipe (101) is sleeved with an inlet sand pipe sleeve (109), and is sealedly connected to the outer cavity mounting joint (103) and the cavity length adjustment gasket (104) respectively through the inlet sand pipe sleeve (109).

6. The abrasive liquid jet nozzle with fluid self-excited oscillation and dielectrophoresis composite effect according to claim 1, characterized in that: A sealing gasket II (207) is provided between the ceramic tube (201) and the sealing cover plate (203).

7. The abrasive liquid jet nozzle with fluid self-excited oscillation and dielectrophoresis composite effect according to claim 1, characterized in that: The annular positive electrode (205) and the annular negative electrode (206) have different widths.

8. The abrasive liquid jet nozzle with fluid self-excited oscillation and dielectrophoresis composite effect according to claim 7, characterized in that: The annular positive electrodes (205) and the annular negative electrodes (206) are distributed alternately at equal distances in the insulating layer (204).

9. The abrasive liquid jet nozzle with fluid self-excited oscillation and dielectrophoresis composite effect according to claim 1, characterized in that: Both ends of the self-excited oscillation chamber (106) are in a conical structure.

10. The abrasive liquid jet nozzle having a composite effect of fluid self-excited oscillation and dielectrophoresis according to any one of claims 1 to 9, characterized in that: The ratio of the diameter size d3 of the liquid jet flow channel II (1051) to the diameter size d2 of the liquid jet flow channel I (1011) is in the range of 1.1 to 2; the ratio of the diameter size d1 of the self-excited oscillation chamber (106) to the diameter size d2 of the liquid jet flow channel I (1011) is in the range of 5 to 10.

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