A targeted ultrasonic focused dispersion nanofluid heat pipe grinding wheel and its use method

Abstract

The present invention relates to a targeted ultrasonic focused dispersion nanofluid heat pipe grinding wheel and a method for using the same. The wheel comprises a handle, a condensation portion is provided below the handle, an insulation portion is provided below the condensation portion, an evaporation portion is provided below the insulation portion, a heat pipe cavity loaded with nanofluid is provided within the condensation portion, the insulation portion and the evaporation portion, and a focusing dispersion device for disturbing the nanofluid is provided within the heat pipe cavity. The wheel solves the problem of nanofluid deposited in the contact area between the grinding wheel and a workpiece, which hinders heat exchange, and promotes the application of nanofluid as a working fluid in the formed heat pipe grinding wheel.

Description

Technical Field

[0001] The invention relates to a targeted ultrasonic focusing dispersion nanofluid heat pipe grinding wheel and a use method thereof, belonging to the technical field of grinding heat pipes. Background Art

[0002] Creep-feed grinding and high-efficiency deep-cut grinding have become mainstream in the grinding industry. The pursuit of higher material removal rates in grinding technology leads to increased grinding heat generation. This heat is continuously generated and accumulated in the grinding arc. If not promptly channeled away, it can burn the workpiece and damage the grinding wheel, thus limiting the development of grinding technology.

[0003] Rotating heat pipes are widely used as high-performance heat transfer components. A growing number of researchers are discovering that nanofluids can improve the heat transfer capacity of heat pipe grinding wheels by replacing traditional working fluids. Nanofluids are formed by dispersing nanoparticles in a base liquid. Compared to the base liquid, nanoparticles exhibit a small size effect, leading to their random motion and disrupting the stability of the fluid flow layer, thereby reducing thermal resistance and improving the heat transfer capacity of the heat pipe grinding wheel. However, the heat transfer efficiency of nanofluid rotating heat pipes is inhibited by the tendency of nanoparticles to agglomerate, the poor dispersion stability of nanofluids, and the tendency of nanoparticles to partially deposit on the evaporator wall under high centrifugal forces. At present, extensive research at home and abroad has confirmed that ultrasonic vibration has significant advantages in improving the surface quality of workpieces, increasing material removal rate, reducing cutting force and workpiece surface damage, and extending tool life. Among them, the ultrasonic transducer is an energy conversion device that converts alternating high-frequency electrical signals into high-frequency mechanical vibration signals. Focusing the ultrasonic energy vibration signal of the ultrasonic transducer on a fixed area can effectively disperse the deposition of nanofluids. Therefore, there is an urgent need for a forming heat pipe grinding wheel device that can disperse nanoparticles in nanofluids in real time, solve the problem of nanofluid inside the forming heat pipe grinding wheel being deposited in the contact area between the grinding wheel and the workpiece, which hinders heat exchange, and will promote the application of nanofluids as working fluids in forming heat pipe grinding wheels. Summary of the Invention

[0004] Based on the above problems, a forming heat pipe grinding wheel device is designed, which can disperse nanoparticles in nanofluids in real time. It solves the problem that nanofluid inside the forming heat pipe grinding wheel is deposited in the contact area between the grinding wheel and the workpiece, which hinders heat exchange. It will promote the application of nanofluids as working fluids in forming heat pipe grinding wheels.

[0005] The present invention achieves the above-mentioned purpose through the following technical scheme: a targeted ultrasonic focused dispersion nanofluid heat pipe grinding wheel, comprising a handle, a condensation part is provided below the handle, an insulating part is provided below the condensation part, an evaporation part is provided below the insulating part, a heat pipe cavity loaded with nanofluid is provided in the condensation part, the insulating part and the evaporation part, and a focusing dispersion device for disturbing the nanofluid is provided in the heat pipe cavity.

[0006] Furthermore, the focusing and dispersion device includes a stepped hollow shaft, the top and bottom of which are rotatably connected to the condensation part and the evaporation part respectively, and a plurality of miniature ultrasonic transducers are arranged on the same side of the stepped hollow shaft. The miniature ultrasonic transducer leads connected to the miniature ultrasonic transducers pass through the stepped hollow shaft and are connected to an external power supply. The bottom end of the stepped hollow shaft is also provided with a directional device.

[0007] Furthermore, the orientation device includes a strong magnetic needle, a nut is provided at the bottom of the strong magnetic needle, the nut is threadedly connected to the stepped hollow shaft, and an indicator recess is provided on the stepped hollow shaft outside the heat pipe cavity, and the indicator recess is in the same direction as the miniature ultrasonic transducer.

[0008] Furthermore, the top and bottom of the stepped hollow shaft are respectively connected to the evaporation part and the evaporation part is rotatably connected through rolling bearings. An oil retaining ring is provided above the rolling bearing at the bottom, and a bearing end cover is provided below. A trapezoidal felt ring is also provided below the bearing end cover.

[0009] Furthermore, a sealing ring is provided at the connection between the miniature ultrasonic transducer and the stepped hollow shaft.

[0010] Furthermore, the cross-sectional diameter of the heat pipe cavity in the evaporation portion is larger than the cross-sectional diameters of the heat pipe cavity in the condensation portion and the insulation portion.

[0011] Furthermore, the side wall of the evaporation portion is provided with an arc structure, and the position where the miniature ultrasonic transducer is installed on the stepped hollow shaft is also provided with an arc structure corresponding to the arc structure.

[0012] Furthermore, heat dissipation fins are evenly distributed around the condensation part.

[0013] Furthermore, the insulating portion is composed of an upper and a lower part which are fixedly connected by bolts.

[0014] A method for using a targeted ultrasonic focused dispersion nanofluid heat pipe grinding wheel comprises the following steps: installing a tool holder on a machine tool spindle, rotating a stepped hollow shaft so that an indicating concave point on the stepped hollow shaft points to the area where the outer wall of the evaporation portion and the workpiece are ground, thereby aligning all micro-ultrasonic transducers with the area where the outer wall of the evaporation portion and the workpiece are ground, tightening a nut after a strong magnetic needle at the end reaches an equilibrium position, thereby fixing the positional relationship between the strong magnetic needle and the stepped hollow shaft, then turning on an external power supply for the micro-ultrasonic transducer, starting the machine tool to drive the tool holder to rotate, and the strong magnetic needle always maintains the same direction due to the action of the earth's magnetic field, so that the stepped hollow shaft remains stationary, thereby causing the ultrasonic transducer on the stepped hollow shaft to always focus on the grinding arc area corresponding to the heat pipe cavity, thereby achieving targeted dispersion of nanofluid in a local area of ​​the grinding arc area and accelerating the heat exchange cycle.

[0015] The beneficial effects of the present invention are:

[0016] 1. The beneficial effect of the present invention is that the external strong magnetic needle is driven by magnetic force to keep the micro ultrasonic transducer on the built-in step shaft focused on the nanofluid deposition arc area where the grinding wheel and the workpiece are in contact. The external magnetic force and the built-in ultrasonic transducer device are small in size, save space and are easy to install, and do not affect the normal heat exchange work of the formed heat pipe.

[0017] 2. The ultrasonic energy is always focused on the arc area where the workpiece and the grinding wheel are in contact through an external strong magnetic needle, which enables the forming heat pipe grinding wheel to work. At the same time, the nanofluid deposits in the arc area of ​​the grinding wheel-workpiece contact are dispersed through the built-in ultrasonic transducer, thereby dispersing the nanoparticles accumulated in the contact arc area, ensuring the heat exchange capacity and grinding performance of the nanofluid forming heat pipe grinding wheel.

[0018] 3. The rotating heat pipe device for ultrasonic focusing and dispersion of nanofluids uses magnetic force to keep the ultrasonic energy targeted and focused on a certain area, realizing real-time dispersion of nanofluids in the grinding arc area, which can ensure the heat exchange effect and save energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a cross-sectional view of the overall structure of the present invention.

[0020] Figure 2 for Figure 1 Enlarged view of point A in the middle.

[0021] Figure 3 This is a schematic diagram of the stepped hollow shaft structure of the present invention.

[0022] Figure 4 for Figure 3 Enlarged view of point B in the middle.

[0023] Figure 5 for Figure 3 Enlarged view of point C in the middle.

[0024] In the figure: tool handle 1, rolling bearing 2, stepped hollow shaft 3, micro ultrasonic transducer 4, nanofluid 5, strong magnetic needle 6, nut 7, indicator pit 8, bolt 9, micro ultrasonic transducer lead 10, oil retaining ring 11, bearing end cover 12, sealing ring 13, trapezoidal felt ring 14, condensation part 15, insulation part 16, evaporation part 17. DETAILED DESCRIPTION

[0025] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0026] See also Figure 1-5As shown, a targeted ultrasonic focusing and dispersing nanofluid heat pipe grinding wheel includes a handle 1, a condensation portion 15 is provided below the handle 1, an insulating portion 16 is provided below the condensation portion 15, an evaporation portion 17 is provided below the insulating portion 16, a heat pipe cavity for loading nanofluid 5 is provided in the condensation portion 15, the insulating portion 16 and the evaporation portion 17, a focusing and dispersing device for disturbing the nanofluid 5 is provided in the heat pipe cavity; the focusing and dispersing device includes a stepped hollow shaft 3, the top and bottom of the hollow shaft 3 are rotatably connected to the condensation portion 15 and the evaporation portion 17 respectively, and the stepped hollow shaft 3 is provided with a plurality of holes. A plurality of miniature ultrasonic transducers 4 are provided on the same side of the shaft 3. The miniature ultrasonic transducer leads 10 connected to the miniature ultrasonic transducers 4 pass through the stepped hollow shaft 3 and are connected to an external power supply. The bottom end of the stepped hollow shaft 3 is also provided with an orientation device; the orientation device includes a strong magnetic needle 6, a nut 7 is provided at the bottom of the strong magnetic needle 6, the nut 7 is threadedly connected to the stepped hollow shaft 3, and an indicator concave point 8 is provided on the stepped hollow shaft 3 outside the heat pipe cavity, and the indicator concave point 8 is in the same direction as the miniature ultrasonic transducer 4; the top and bottom of the stepped hollow shaft 3 are respectively The evaporation part 17 and the evaporation part 17 are rotatably connected through the rolling bearing 2. An oil retaining ring 11 is provided above the rolling bearing 2 at the bottom, and a bearing end cover 12 is provided below. A trapezoidal felt ring 14 is also provided below the bearing end cover 12; a sealing ring 13 is provided at the connection between the micro ultrasonic transducer 4 and the stepped hollow shaft 3; the cross-sectional diameter of the heat pipe cavity in the evaporation part 17 is larger than the cross-sectional diameter of the heat pipe cavity in the condensation part 15 and the insulation part 16; the side wall of the evaporation part 17 is provided with an arc structure, and the position of the micro ultrasonic transducer 4 is installed on the stepped hollow shaft 3. The corresponding arc structure is also provided with an arc structure, so that the micro ultrasonic transducer 4 installed on the arc area of ​​the second-level step shaft is in a curved structure. The ultrasonic wave emitted by the micro ultrasonic transducer 4 can effectively cover the long and narrow arc area inside the grinding arc area. Compared with installing the micro ultrasonic transducer 4 on a shaft without an arc area, it can disperse the nanoparticles deposited on the internal wall surface corresponding to the grinding arc area with higher energy; the condensation part 15 is evenly distributed with heat dissipation fins on all sides; the insulating part 16 is composed of two parts, the upper and lower parts, and is fixedly connected by bolts 9.

[0027] See also Figure 3The stepped hollow shaft 3 is provided with a four-step shaft. The rolling bearing 2 is installed in the groove at the top of the condensation section 15 and cooperates with the shoulder of the second-step shaft of the stepped hollow shaft 3. The rolling bearing 2 is slightly higher than the groove to facilitate the removal of the rolling bearing 2. A gap of 1-2mm is left between the top of the stepped shaft 3 and the groove to prevent the top of the stepped hollow shaft 3 from being worn. The oil retaining ring 11 is fitted between the bottom end of the second-step shaft of the stepped hollow shaft 3 and the rolling bearing 2. The bearing end cover 12 is installed on the third-step shaft 3 and leaves a certain gap with the step shaft. In order to prevent the nanofluid 5 from flowing into the bearing and the leakage of the nanofluid 5, an oil retaining ring 11 is added between the rolling bearing 2 and the shoulder of the second-step shaft of the stepped hollow shaft 3, and a bearing end cover 12 and a felt ring 14 are added between the rolling bearing 2 and the bottom of the evaporation section 17 for dynamic sealing to ensure the vacuum degree of the heat pipe cavity.

[0028] In the embodiment, the stepped hollow shaft 3 is designed with four steps, and the curvature of the second-step stepped shaft is designed to be consistent with the curvature of the grinding arc zone. The miniature ultrasonic transducer lead 10 passes through the hole in the arc zone of the second-step stepped hollow shaft 3 and the cavity of the stepped hollow shaft 3 and is then connected to the power supply externally.

[0029] In this embodiment, the nanofluid 5 in the heat pipe cavity rapidly expands along the inner wall of the evaporation section 17 under the action of centrifugal force, forming a smooth liquid film. Simultaneously, the outer wall of the evaporation section 17 grinds the workpiece, generating a large amount of grinding heat in the grinding arc. This heat is transferred to the nanofluid 5 in the heat pipe cavity through the wall of the evaporation section 17. The nanofluid 5 exchanges heat with the wall, absorbing heat and evaporating, increasing the pressure inside the evaporation section 17. Driven by the axial pressure difference between the heat pipe condenser section 15, the insulation section 16, and the evaporation section 17, the vapor flows to the cooler condenser section 15. There, it releases heat and condenses into a liquid phase. Under the action of centrifugal force and gravity, it flows back to the evaporation section 17 along the wall. The heat released by evaporation is then transferred through the fins of the condenser section 15 to exchange heat with the external environment. This cycle repeats continuously, and the grinding heat is continuously carried from the grinding surface of the grinding wheel to the condenser end by the heat pipe, achieving the purpose of dissipating heat and controlling the arc zone temperature.

[0030] The ultrasonic waves generated by the transducer cause cavitation in the nanofluid base liquid. The instantaneous collapse of the cavitation bubbles generates a strong impact force, which can create disturbances within the nanosolution, thereby maintaining a uniform and stable dispersion of the nanoparticles. Furthermore, the convection created by the acoustic cavitation effect can effectively improve the convective heat transfer efficiency of the nanofluid. Specifically, the high-energy mechanical oscillations and cavitation effects generated by high-intensity focused ultrasound can stir the nanofluid interior, achieving dispersion of the nanofluid. Nanoparticles can trigger a "cavitation chain reaction," causing the cavitation bubbles to collapse and preventing the accumulation of cavitation bubbles, which can cause cavitation shielding. The interaction between ultrasound and nanofluids forms a complementary heat transfer mechanism, greatly improving heat transfer capacity.

[0031] The specific method of using the heat pipe grinding wheel in this embodiment is as follows: install the tool handle 1 on the main shaft of the machine tool, rotate the stepped hollow shaft 3 so that the indicating concave point 8 on the stepped hollow shaft 3 points to the area where the outer wall of the evaporation part 17 and the workpiece are ground, so that the miniature ultrasonic transducer 4 is aligned with the area where the outer wall of the evaporation part 17 and the workpiece are ground. After the end strong magnetic needle 6 reaches the equilibrium position, tighten the nut 7 to fix the positional relationship between the strong magnetic needle 6 and the stepped hollow shaft 3, then turn on the external power supply of the miniature ultrasonic transducer 4, start the machine tool to drive the tool handle 1 to rotate, and the strong magnetic needle 6 always maintains the same direction under the action of the earth's magnetic field, so that the stepped hollow shaft 3 remains stationary, so that the ultrasonic transducer 4 on the stepped hollow shaft 3 is always focused on the grinding arc area corresponding to the heat pipe cavity, thereby realizing the targeted dispersion of nanofluids in the local area of ​​the grinding arc area and accelerating the heat exchange cycle.

[0032] The present invention drives an external strong magnetic needle through magnetic force to keep the micro ultrasonic transducer on the built-in stepped shaft focused on the nanofluid deposition arc area where the grinding wheel contacts the workpiece. The external magnetic force and built-in ultrasonic transducer device is small in size, saves space and is easy to install, and does not affect the normal heat exchange work of the formed heat pipe; the external strong magnetic needle keeps the ultrasonic energy always focused on the arc area where the workpiece contacts the grinding wheel, thereby realizing the operation of the formed heat pipe grinding wheel and at the same time breaking up the nanofluid deposition in the grinding wheel-workpiece contact arc area through the built-in ultrasonic transducer, thereby dispersing the nanoparticles accumulated in the contact arc area, ensuring the heat exchange capacity and grinding performance of the nanofluid formed heat pipe grinding wheel; the rotating heat pipe device for ultrasonically focusing and dispersing nanofluid uses magnetic force to keep the ultrasonic energy targeted and focused on a certain area, realizing real-time dispersion of the nanofluid in the grinding arc area, which can both ensure the heat exchange effect and save energy.

[0033] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims, not the foregoing description, and all variations within the meaning and range of equivalents of the claims are intended to be included therein. Any reference sign in a claim should not be construed as limiting the claim to which it relates.

[0034] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A targeted ultrasonic focused dispersion nanofluid heat pipe grinding wheel, characterized by: The invention comprises a knife handle (1), wherein a condensation portion (15) is provided below the knife handle (1), an insulation portion (16) is provided below the condensation portion (15), an evaporation portion (17) is provided below the insulation portion (16), a heat pipe cavity loaded with a nanofluid (5) is provided in the condensation portion (15), the insulation portion (16) and the evaporation portion (17), and a focusing dispersion device for disturbing the nanofluid (5) is provided in the heat pipe cavity; the focusing dispersion device comprises a stepped hollow shaft (3), the top and bottom of the stepped hollow shaft (3) are rotatably connected to the condensation portion (15) and the evaporation portion (17) respectively, a plurality of miniature ultrasonic transducers (4) are provided on the same side of the stepped hollow shaft (3), miniature ultrasonic transducer leads (10) connected to the miniature ultrasonic transducers (4) pass through the stepped hollow shaft (3) and are connected to an external power supply, and a directional device is also provided at the bottom end of the stepped hollow shaft (3).

2. The targeted ultrasonic focused dispersion nanofluid heat pipe grinding wheel according to claim 1, characterized in that: The orientation device comprises a strong magnetic needle (6), a nut (7) is provided at the bottom of the strong magnetic needle (6), the nut (7) is threadedly connected to the stepped hollow shaft (3), and an indicating concave point (8) is provided on the stepped hollow shaft (3) outside the heat pipe cavity, and the indicating concave point (8) and the miniature ultrasonic transducer (4) are in the same direction.

3. The targeted ultrasonic focused dispersion nanofluid heat pipe grinding wheel according to claim 2, characterized in that: The top and bottom of the stepped hollow shaft (3) are rotatably connected to the evaporation portion (17) and the evaporation portion (17) respectively through rolling bearings (2). An oil retaining ring (11) is provided above the rolling bearing (2) at the bottom, and a bearing end cover (12) is provided below. A trapezoidal felt ring (14) is also provided below the bearing end cover (12).

4. The targeted ultrasonic focused dispersion nanofluid heat pipe grinding wheel according to claim 1, characterized in that: A sealing ring (13) is provided at the connection between the micro ultrasonic transducer (4) and the stepped hollow shaft (3).

5. The targeted ultrasonic focused dispersion nanofluid heat pipe grinding wheel according to claim 1, characterized in that: The cross-sectional diameter of the heat pipe cavity in the evaporation portion (17) is larger than the cross-sectional diameters of the heat pipe cavity in the condensation portion (15) and the insulation portion (16).

6. The targeted ultrasonic focused dispersion nanofluid heat pipe grinding wheel according to claim 1, characterized in that: The side wall of the evaporation portion (17) is provided with an arc structure, and the position where the miniature ultrasonic transducer (4) is mounted on the stepped hollow shaft (3) is also provided with an arc structure corresponding to the arc structure.

7. The targeted ultrasonic focused dispersion nanofluid heat pipe grinding wheel according to claim 1, characterized in that: The condensation portion (15) is evenly distributed with heat dissipation fins on its periphery.

8. The targeted ultrasonic focused dispersion nanofluid heat pipe grinding wheel according to claim 1, characterized in that: The insulating portion (16) is composed of an upper and a lower part, which are fixedly connected by bolts (9).

9. The method for using a targeted ultrasonic focused dispersion nanofluid heat pipe grinding wheel according to claim 2, characterized in that: The following steps are involved: The tool holder (1) is mounted on the main spindle of the machine tool, and the step hollow shaft (3) is rotated so that the indicating concave point (8) on the step hollow shaft (3) points to the area where the outer wall of the evaporation part (17) and the workpiece are ground, so that the micro ultrasonic transducer (4) is aligned with the area where the outer wall of the evaporation part (17) and the workpiece are ground. After the strong magnetic needle (6) at the end reaches the equilibrium position, the nut (7) is tightened to fix the positional relationship between the strong magnetic needle (6) and the step hollow shaft (3). Then, the external power supply of the micro ultrasonic transducer (4) is turned on, and the machine tool is started to drive the tool holder (1) to rotate. The strong magnetic needle (6) always maintains the same direction under the action of the earth's magnetic field, so that the step hollow shaft (3) remains stationary, so that the micro ultrasonic transducer (4) on the step hollow shaft (3) is always focused on the grinding arc area corresponding to the heat pipe cavity, thereby realizing the targeted dispersion of the nanofluid in the local area of ​​the grinding arc area and accelerating the heat exchange cycle.

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