CN106181596B - Multi-angle two-dimensional ultrasonic vibration assisted nano-fluid minimal quantity lubrication grinding device - Google Patents

Abstract

The invention discloses a multi-angle two-dimensional ultrasonic vibration assisted nano-fluid micro-lubrication grinding device, which includes a workpiece fixture for clamping a workpiece and a grinding wheel for grinding the workpiece. The workpiece fixture is connected with the two-dimensional ultrasonic vibration device. Maintain the sharpness of the cutting edge of the grinding wheel and cool the grinding temperature of the workpiece surface; one side of the grinding wheel is provided with an injection mechanism for injecting nano-fluid to the workpiece, forming a coupling between two-dimensional ultrasonic vibration and nano-fluid micro-lubrication grinding; the device The variable-angle two-dimensional ultrasonic vibration technology is applied to the grinding process. By adjusting the angles of the two ultrasonic vibrators, different combined vibration directions are generated to change the relative trajectory of the abrasive particles and the workpiece. Through the force measuring device and The temperature measuring device detects the grinding force and grinding temperature in real time, and at the same time cooperates with nano-fluid micro-lubrication to further improve the processing quality of the workpiece and avoid thermal damage to the workpiece.

Description

Multi-angle two-dimensional ultrasonic vibration assisted nanofluid minimal lubrication grinding device

technical field

The invention relates to the field of grinding processing, in particular to a multi-angle two-dimensional ultrasonic vibration-assisted nanofluid micro-lubrication grinding device.

Background technique

With the development of science and technology, the demand for hard and brittle materials, difficult-to-machine materials and new advanced materials is increasing, and higher requirements are put forward for the processing efficiency, processing quality and processing accuracy of key parts. Large grinding force and grinding heat are generated, causing a series of problems such as surface/subsurface damage of the workpiece and low life of the grinding wheel. Especially in the field of precision and ultra-precision machining, the existence of these machining defects seriously restricts the improvement of machining accuracy and machining efficiency of parts. Therefore, it is very necessary to reduce the grinding force and grinding heat and improve the grinding quality and efficiency during the grinding process.

Nano-fluid MQL grinding inherits all the advantages of MQL grinding and solves the heat transfer problem of MQL grinding. It is an environmentally friendly, efficient and low-consumption grinding technology. Based on the enhanced heat transfer theory that the heat transfer capacity of solid is greater than that of liquid, and the heat transfer capacity of liquid is greater than that of gas, a certain amount of nano-scale solid particles are added to degradable trace lubricating oil to generate nano-fluid, and the nano-fluid is atomized by high-pressure air , and sent into the grinding area in the form of a jet. The high-pressure air mainly plays the role of cooling, chip removal and conveying fluid; the micro-quantity lubricating oil mainly plays the role of lubrication; the nano-particles increase the heat transfer capacity of the fluid in the grinding area and play a cooling role. At the same time, the nano-particles have good wear resistance. The friction performance characteristics and high load-carrying capacity further improve the lubrication effect in the grinding area, significantly improve the surface quality and burn phenomenon of the workpiece, increase the service life of the grinding wheel, and improve the working environment.

Ultrasonic vibration is the conversion of 220V or 380V alternating current by an ultrasonic generator into an ultrasonic frequency electrical oscillation signal with a success rate of 300W and a frequency above 16kHz. The electrical signal is added to the transducer to generate mechanical vibration of the same frequency. This vibration is amplified by the amplitude modulator, and finally produces a sufficiently large mechanical vibration amplitude at the end of the tool. The ultrasonic generator is mainly composed of an oscillator, a voltage amplifier, a power amplifier and an output transformer. Among them, the oscillator is the core of the ultrasonic frequency generator. According to the needs of ultrasonic processing, the output waveform of the ultrasonic generator can be sine wave or non-sinusoidal wave, but sine wave is the most common. Ultrasonic transducers are energy conversion devices that convert alternating electrical signals into acoustic signals or convert acoustic signals in an external sound field into electrical signals within the ultrasonic frequency range. Commonly used transducers include hysteresis transducers and pressure transducers. Electric transducer. The ultrasonic amplitude modulator is an important component of the ultrasonic system. It is used to transfer the mechanical energy converted from electrical energy from the transducer to the workpiece to be processed. It is a mechanical amplification stage of the power ultrasonic amplitude to improve the efficiency of ultrasonic processing. In the grinding process, the process of plastic deformation of the workpiece material, the deformation of the machined surface and the degree of wear of the grinding wheel are all related to the conditions of the interaction between the abrasive grains and the contact surface of the workpiece during the grinding process, that is, the conditions in which they are located. time and space conditions. When ultrasonic vibration is added to the process system, the interaction conditions between the abrasive grains and the contact surfaces of the workpiece are very different from those of ordinary grinding. Although the high-frequency vibration with small amplitude will not have any effect on the size and shape of the workpiece surface, it will greatly change the friction and wear conditions of the abrasive grains, causing additional reciprocating motion between the abrasive grains and the contact surface of the workpiece, so that the abrasive grains The contact surface with the workpiece is periodically separated, and the grinding fluid can better enter the friction zone of the interface between the grinding wheel and the workpiece, reducing the generation of grinding force and grinding heat, and also reducing the resistance of the outflow of grinding debris, realizing Efficient cleaning of grinding debris in the grinding area. Moreover, the ultrasonic vibration promotes the intermittent cutting effect of the abrasive grains, and the impact load makes the workpiece material easier to convolute, and more microscopic cracks are generated in the cutting area to expand and reduce the grinding force and friction coefficient. The plastic deformation of the material in the grinding process mainly occurs in the stage of sliding and plowing. Since ultrasonic vibration grinding is a kind of pulsed intermittent grinding, the proportion of sliding and plowing is relatively reduced, so that it is better than grinding can be reduced, and the surface thermal damage is also significantly reduced.

In the prior art, the realization of the ultrasonic vibration grinding tool includes a connecting piece matched with the tool handle of the CNC machine tool or the drilling machine. Different connectors are made according to different handles, and this structure can be disassembled at any time to achieve a multi-purpose machine. A main shaft is installed on the connecting piece, a transducer is installed on the main shaft, the transducer is connected with the horn, the cutting tool is installed on the horn, and the transducer is also connected with the ultrasonic generator through the carbon brush. Ultrasonic vibration is applied to the spindle, which involves the transformation of the machine tool. It is difficult to implement, and the accuracy of ultrasonic vibration applied to the spindle of the machine tool is difficult to guarantee, and the loss of the spindle is also large, and further improvement and optimization are needed.

A grinding medium supply system coupled with low-temperature cooling and nano-particle jet micro-lubrication, the system includes at least one micro-quantity lubrication and low-temperature cooling nozzle combination unit, which is arranged on the side of the wheel cover of the grinding wheel and cooperates with the workpiece on the worktable ; The unit includes a micro-lubrication atomization micro-nozzle and a low-temperature cooling nozzle, the micro-lubrication atomization micro-nozzle is connected with a nanofluid pipeline and a compressed air pipeline, and the low-temperature cooling nozzle is connected with a low-temperature coolant pipeline; the nanometer of each unit The fluid pipeline, the compressed air pipeline and the low-temperature coolant pipeline are all connected to the nanofluid supply system, the low-temperature medium supply system and the compressed air supply system through control valves, and the nanofluid supply system, the low-temperature medium supply system and the compressed air supply system are connected to the Control unit connection. The invention combines low-temperature cooling with nano-particle jet microlubrication, which reduces grinding heat and achieves a good cooling effect, but does not achieve double optimization effects in terms of grinding force.

An ultrasonic vibration assisted grinding device, the device includes a disc-shaped rotary table lower base, a disc-shaped rotary table upper base, a horn clamping device lower base and a horn clamping device placed on a dynamometer The upper base, the ultrasonic generator connected to the horn and the workpiece support platform, the lower base of the disc-shaped rotary table and the upper base of the disc-shaped rotary table are concentrically positioned and rotatably connected, and the lower base of the horn clamping device The center of the base and the horn clamping device fit together in the middle of the base to clamp and fix the horn. Ultrasonic vibration in any direction is realized through the precise rotation of the upper and lower bases of the rotary table; at the same time, due to the use of the clamping method, it is convenient to adjust the level of the workpiece support platform; the dynamometer is only connected to the lower base of the rotary table, which can ensure the It can still measure the force in three directions of the grinding wheel when rotating at any angle. In this invention, the ultrasonic vibrator is supported by a bracket with a disc, and there is only one support point, which cannot guarantee the stability of the system. Moreover, one-dimensional ultrasonic vibration grinding has its limitations, and it needs to meet certain processing parameters to achieve the ideal processing effect.

To sum up, in the prior art, the relative trajectory of the abrasive grains of the grinding wheel and the workpiece is consistent. Long-term operation may easily cause excessive damage to the cutting edge, and the grinding wheel needs to be re-grinded, which delays the processing cycle of the workpiece; Cooling can easily cause thermal damage to the workpiece. In addition, the existing technology cannot realize real-time online detection of grinding force and grinding temperature.

Contents of the invention

In view of the above problems, in order to solve the deficiencies in the prior art, the object of the present invention is to provide a multi-angle two-dimensional ultrasonic vibration assisted nanofluid micro-lubrication grinding device, which applies the variable-angle two-dimensional ultrasonic vibration technology to the grinding process In this method, the angles of the two ultrasonic vibrators are adjusted to generate different combined vibration directions, so as to change the relative trajectory of the abrasive grains and the workpiece. The grinding force and grinding temperature are detected in real time by the force measuring device and the temperature measuring device. At the same time, it cooperates with nanofluid micro-lubrication to form a grinding mechanism at the interface between the grinding wheel and the workpiece, further improving the processing quality of the workpiece and avoiding thermal damage to the workpiece.

The scheme provided by the present invention is:

The multi-angle two-dimensional ultrasonic vibration assisted nanofluid minimal quantity lubrication grinding device, including the workpiece fixture for clamping the workpiece and the grinding wheel for grinding the workpiece, the workpiece fixture is connected with the two-dimensional ultrasonic vibration device to smooth the cutting edge of the grinding wheel The maintenance of the sharpness includes the workpiece fixture for clamping the workpiece and the grinding wheel for grinding the workpiece. The workpiece fixture is connected with the two-dimensional ultrasonic vibration device to maintain the sharpness of the cutting edge of the grinding wheel; in order to avoid heat to the workpiece In terms of damage, one side of the grinding wheel is provided with an injection mechanism for injecting nanofluid to the workpiece, and the two-dimensional ultrasonic vibration device and the nanofluid injected by the injection mechanism form a two-dimensional ultrasonic vibration on the workpiece to couple with nanofluid micro-lubrication grinding; nanofluid Through the oil-air two-phase flow nozzle, the atomization is sprayed to the grinding area, and the mechanism of grinding is formed by coupling with ultrasonic vibration; while improving the cooling and lubrication performance during the grinding process, the surface quality of the workpiece is further improved, and the grinding heat is effectively reduced. .

The two-dimensional ultrasonic vibration device includes a tangential ultrasonic vibration device and an axial ultrasonic vibration device, the tangential ultrasonic vibration device is arranged above or below the axial ultrasonic vibration device, and the tangential ultrasonic vibration device is parallel to the grinding direction of the grinding wheel;

The tangential ultrasonic vibrating device can be rotated relative to the axial ultrasonic vibrating device, and the angle can be adjusted from 40° to 180°. The angle can be adjusted so that the abrasive particles and the workpiece have different relative motion tracks, so as to realize different grinding The grinding effect makes the workpiece grinding surface form a denser texture and improves the surface quality of the workpiece.

The tangential ultrasonic vibrating device is arranged on the fixed plate, the fixed plate is arranged on the workbench, the axial ultrasonic vibrating device is arranged above the tangential ultrasonic vibrating device, the fixed plate is connected with the dynamometer, and the dynamometer is set as Connect with grinding force control system.

A temperature acquisition element is set on the workpiece fixture or on the workpiece, and the temperature acquisition element is connected to the temperature control system; wherein, a hole is drilled on the workpiece, and the temperature acquisition element such as a thermocouple wire is buried in the hole, and is drawn out from the bottom of the workpiece to be connected with the temperature control system. system connection.

The tangential ultrasonic vibration device is fixed on the fixed plate through a tangential bracket with an L-shaped longitudinal section, the top of the tangential bracket supports the tangential horn, and one end of the tangential horn is connected to the tangential transducer connection, the tangential transducer is connected with the ultrasonic generator, and the other end is fixed with the slide rail support seat through a universal joint, and the slide rail support seat supports the workpiece fixture; the universal joint is a spherical universal joint, and the spherical universal joint It consists of three parts: the ball core of the universal joint, the ball shell of the universal joint and the nut of the universal joint, and the contact areas of these three parts should be coated with petroleum jelly oil to reduce the energy loss during the transmission of ultrasonic vibration.

The axial ultrasonic vibration device includes an axial horn, one end of the axial horn is connected to the axial transducer, and the other end is connected to the axial support, and the axial support is arranged on the The lower surface of the slide rail support seat or the inner recess on the lower surface of the slide rail support seat; the axial transducer is connected to the ultrasonic generator;

An arc-shaped chute for limiting the movement track of the axial ultrasonic vibration device is arranged on the fixed plate, a slide bar is provided on the axially adjustable bracket, and the chute moves along the arc-shaped slide rail;

Further, the chute is a T-shaped chute, and the slide bar can be replaced by a positioning bolt.

At least one side of the T-shaped slider is provided with slider balls to avoid vibration damage to the slide rail support seat and the axial support;

Alternatively, a jack is provided at the bottom of the T-shaped slider, and jack balls are arranged on the contact surface between the jack and the T-shaped slider to reduce the energy consumed by the friction between the bottom surface of the T-shaped slider and the jack. The jack is an oil pressure jack, which includes a lifting sleeve , The lifting sleeve is set in the shell, and the bottom of the shell is equipped with a hydraulic oil inlet and outlet, and the hydraulic oil is pressed into the oil chamber through an external oil pressure device.

The ultrasonic generator is mainly composed of a voltage amplifier, a power amplifier, an oscillator and an output transformer, and the oscillator is its core. The ultrasonic generator has signal feedback function and can provide frequency tracking signal and output power feedback signal. In the case of unstable voltage, the output power of the ultrasonic generator will change, resulting in unstable mechanical vibration generated by the transducer. By adjusting the power amplifier through the power feedback signal, a signal with stable power can be output. The oscillator is adjusted by the frequency tracking signal so that the frequency of the output signal can track the resonance frequency point of the transducer. In addition, the ultrasonic generator has the functions of phase detection and phase adjustment, so that two ultrasonic vibrators in different directions can generate ultrasonic vibration signals with phase difference;

Both the tangential transducer and the axial transducer are piezoelectric transducers. Using the piezoelectric inverse effect of the piezoelectric transducer, the relative displacement of the positive and negative ions in the piezoelectric ceramic crystal under the action of the electric field force causes the crystal Internal stress is generated, which causes mechanical deformation of the crystal, thereby generating mechanical vibration with the same frequency as the ultrasonic electrical signal.

Both the tangential horn and the axial horn are used to increase the mechanical vibration generated by the transducer. The end surface of the amplitude horn in contact with the transducer is provided with a threaded hole, and the end surface in contact with the two is coated Vaseline oil to reduce the energy transmission loss between the transducer and the horn, where the horn is changed from a large end face to a small end face with a shoulder, so that it forms an interference fit with the bracket slot, used for The tangential ultrasonic vibrator and the axial ultrasonic vibrator are respectively fixed on the tangential support and the axial adjustable support, and the two horns are changed from the large end face to the small end face with a shaft shoulder, so that it forms an interference with the bracket slot The matching is used for fixing the tangential ultrasonic vibrator and the axial ultrasonic vibrator on the tangential support and the axial adjustable support respectively.

Further, the top of the tangential bracket is provided with a shoulder slot, and the circumference of the tangential horn is provided with a shoulder matching the shoulder slot, so that it forms an interference fit with the shoulder slot, and the tangential bracket cover Covering the shoulder and fixing it with the tangential support;

Wherein, a workpiece groove for fixing the workpiece is provided on the surface of the slide rail support seat, a workpiece positioning stopper capable of axial displacement is arranged in the workpiece groove, and a fixture bolt or screw capable of tangential displacement is arranged in the workpiece groove.

On the other side of the tangential support where the tangential support is fixed to the fixed plate, a protrusion is provided, and the axially adjustable support is rotatably fixed to the tangential support through the protrusion. Adjust the bracket for support;

Further, a dial is provided around the protrusion of the tangential support to indicate the rotation angle of the axially adjustable support relative to the tangential support;

Further, the longitudinal section of the axially adjustable bracket is L-shaped;

Further, the height of the axially adjustable support is lower than the height of the tangential support.

The injection mechanism includes a nozzle, the grinding wheel part is fixed in the grinding wheel cover, the nozzles are respectively fixed on one or both sides of the bottom of the grinding wheel, and the nozzles are separately connected to the nanofluid delivery pipe and the compressed air delivery pipe;

Further, the nanofluid delivery pipe and the compressed air delivery pipe are fixed on the side of the grinding wheel cover through a magnetic suction cup.

The beneficial effects of the present invention are:

The present invention provides a multi-angle two-dimensional ultrasonic vibration assisted nanofluid micro-lubrication grinding device and its measuring device for grinding force and grinding temperature, which can be directly installed on the magnetic workbench of the precision grinding machine without the need for precision grinding. The processing spindle is modified to ensure the processing accuracy of the machine tool and the effective transmission of ultrasonic vibration energy. Through the precise adjustment of the angle between the tangential support and the axially adjustable support, multi-angle two-dimensional ultrasonic vibration can be realized.

By changing the two-dimensional ultrasonic vibration angle, the relative motion trajectory between the abrasive grains of the grinding wheel and the workpiece is also changed, thereby changing the grinding force, grinding temperature and surface quality of the workpiece. Specifically: firstly, by adjusting the ultrasonic generator control The phase difference of the ultrasonic electrical signals in two directions, when the phase difference is π/2, the tangential ultrasonic vibration is coupled with the axial ultrasonic vibration, so that the abrasive grains of the grinding wheel and the workpiece form an elliptical relative motion trajectory, and the feed of the worktable direction, forming a motion trajectory imitating grinding. When the phase difference is 0 and π, the tangential ultrasonic vibration is coupled with the axial ultrasonic vibration, so that the abrasive grains of the grinding wheel and the workpiece form two sets of relative motion trajectories intersecting each other. The feed direction forms a motion track imitating honing; secondly, adjust the tangential support and the axial adjustable support to change the angle between the two directions of ultrasonic vibration, thereby further changing the shape of the elliptical motion track and the two groups intersecting each other The inclination angle of the straight line makes the grinding surface of the workpiece form a denser texture pattern and improves the surface quality of the workpiece; finally, the multi-angle two-dimensional ultrasonic vibration is coupled with the micro-quantity lubrication of the nanofluid. Abrasives are transported to the grinding area through the micro-lubrication system to cooperate with the grinding and honing motion trajectory formed by two-dimensional ultrasonic vibration to further improve the grinding quality.

The tangential bracket and the axially adjustable bracket of the present invention are connected to the dynamometer through the fixed plate, and the position of the lateral force instrument will not be affected when the angle of the axially adjustable bracket is adjusted, and the normal direction can still be measured conveniently and accurately. Grinding force, tangential grinding force and axial grinding force; Grinding temperature measuring device adopts artificial thermocouple temperature measurement method to monitor the grinding state in real time. The device realizes simultaneous on-line detection of grinding force and grinding temperature, which not only saves time, but also avoids processing errors caused by multiple assembly. Grinding force and grinding temperature are the key factors to evaluate the grinding effect. Through the accurate measurement of grinding force and grinding temperature and the analysis of experimental data, it can provide guidance for grinding process.

Description of drawings

Figure 1 is an axonometric view of a nanofluid micro-lubrication grinding device assisted by multi-angle two-dimensional ultrasonic vibration;

Fig. 2 is an axonometric view of the first part of the multi-angle two-dimensional ultrasonic vibration device of the first, second, and third embodiments;

Fig. 3 is the top view of the first, second and third embodiments;

Fig. 4 is the rotation sectional view of A-A in Fig. 3;

Fig. 5 is the top view of the fourth embodiment;

Fig. 6 is the top view of the fifth embodiment;

Fig. 7 is the axonometric view of the second part nanofluid minimal quantity lubrication grinding device;

Fig. 8 is the axonometric view of the grinding force and grinding temperature online measuring device of the third part;

Fig. 9 is a schematic diagram of clamping and positioning of the fixing plate and the force measuring instrument in five embodiments;

Figure 10 is a schematic diagram of the clamping and positioning of the tangential bracket and the fixing plate in five embodiments;

Fig. 11 is a schematic diagram of clamping and positioning of the axially adjustable bracket and the fixed plate in five embodiments;

Fig. 12 is a schematic diagram of the assembly of axially adjustable brackets and tangential brackets in five embodiments;

Fig. 13 is a schematic diagram of clamping and positioning of tangential ultrasonic vibrators and tangential brackets in five embodiments;

Fig. 14 is an assembly structure diagram of the slide rail support seat, the slider and the axial support of the five embodiments;

Figure 15 is a bottom view of Figure 14;

Fig. 16 is a structural schematic diagram of the workpiece positioning and clamping device;

Fig. 17 is the sectional view of the hydraulic jack of five kinds of embodiments;

Fig. 18 (a) is the sectional view of the ultrasonic transducer of five kinds of embodiments;

Figure 18(b) is a schematic diagram of the inverse piezoelectric effect in ultrasonic transducers of five embodiments;

Fig. 19 is a schematic diagram of the structure of the horn in five embodiments;

Fig. 20(a) is the relative movement track between the two-dimensional ultrasonic vibrating grinding wheel and the workpiece;

Fig. 20(b) is the relative movement trajectory of the two-dimensional ultrasonic vibrating grinding wheel abrasive grain grinding workpiece;

Fig. 20(c) is the relative motion trajectory of the two-dimensional ultrasonic vibrating grinding wheel abrasive grain honing workpiece;

Fig. 20(d) is a one-dimensional tangential ultrasonic vibration grinding wheel abrasive grain and workpiece relative motion trajectory;

Fig. 20(e) is a one-dimensional axial ultrasonic vibrating grinding wheel abrasive grain and workpiece relative motion trajectory;

Fig. 21 is the ultrasonic generator control chart of five kinds of embodiments;

Among them, Ⅰ-1-Axial negative copper sheet, Ⅰ-2-Axial transducer, Ⅰ-3-Axial horn, Ⅰ-4-Axial adjustable bracket cover screw, Ⅰ-5-Axial Adjustable bracket cover, Ⅰ-6-fixing plate, Ⅰ-7-axial support, Ⅰ-8-slide rail support seat, Ⅰ-9-workpiece fixture, Ⅰ-10-fixture screw, Ⅰ-11-workpiece cutting To the positioning screw, Ⅰ-12-workpiece, Ⅰ-13-workpiece positioning block, Ⅰ-14-workpiece axial positioning screw, Ⅰ-15-positioning screw, Ⅰ-16-hydraulic jack shell, Ⅰ-17- Universal joint ball core, Ⅰ-18-universal joint nut, Ⅰ-19-universal joint spherical shell, Ⅰ-20-jack positioning screw, Ⅰ-21-tangential bracket cover, Ⅰ-22-tangential bracket cover Screw, Ⅰ-23-dial, Ⅰ-24-tangential horn, Ⅰ-25-tangential transducer, Ⅰ-26-tangential positive copper sheet, Ⅰ-27-tangential negative copper sheet, Ⅰ -28-Tangential bracket, Ⅰ-29-Tangential bracket positioning screw, Ⅰ-30-Fixed plate positioning screw, Ⅰ-31-Axial adjustable bracket positioning nut, Ⅰ-32-Axial adjustable bracket positioning bolt , Ⅰ-33-Axial adjustable bracket, Ⅰ-34-Axial positive copper sheet, Ⅰ-35-Jack ball, Ⅰ-36-T-shaped slider, Ⅰ-37-Slider ball, Ⅰ-38-T Shaped chute, Ⅰ-39-shaft shoulder slot, Ⅰ-40-horn shoulder, Ⅰ-41-boss threaded hole, Ⅰ-42-tangential support boss, Ⅰ-43-jack ball set screw , Ⅰ-44-Lifting sleeve, Ⅰ-45-Inlet and outlet, Ⅰ-46-Piezoelectric ceramics, Ⅰ-47-Piezoelectric ceramic positioning screws, Ⅱ-1-Grinding wheel cover, Ⅱ-2-Magnetic chuck, Ⅱ -3-Grinding wheel, Ⅱ-4-Nano fluid delivery pipe, Ⅱ-5-Compressed air delivery pipe, Ⅱ-6-Nozzle, Ⅱ-7-Magnetic workbench, Ⅲ-1-Grinding force control system, Ⅲ-2 -Grinding force information collector, Ⅲ-3-amplifier, Ⅲ-4-dynamometer, Ⅲ-5-thermocouple, Ⅲ-6-grinding temperature information collector, Ⅲ-7-low-pass filter, Ⅲ -8-Grinding temperature control system, Ⅲ-9-ultrasonic generator, Ⅲ-10-negative wire, Ⅲ-11-positive wire.

Detailed ways

The present invention will be further described below in conjunction with the specific embodiments of the accompanying drawings:

The first embodiment of the present invention, as shown in Figures 1 to 4, Figures 7 to 19, Figures 20(a) to 20(c) and Figure 21, is about the tangential direction parallel to the grinding direction and the direction perpendicular to the grinding direction Axially coupled multi-angle two-dimensional ultrasonic vibration assisted nanofluid micro-lubrication grinding device and its grinding force and grinding temperature measurement device.

As shown in Figure 1, the multi-angle two-dimensional ultrasonic vibration-assisted nanofluid micro-lubrication grinding device and its grinding force and grinding temperature measurement device are composed of multi-angle two-dimensional ultrasonic vibration device I, nano-fluid micro-lubrication grinding device II and Grinding force and grinding temperature measuring device Ⅲ consists of three parts.

As shown in Fig. 2, the tangential bracket I-28 and the axially adjustable bracket I-33 respectively pass the tangential bracket positioning screw I-29, the axially adjustable bracket positioning bolt I-32 and the axially adjustable bracket positioning screw respectively. The cap Ⅰ-31 is positioned and clamped on the fixed plate Ⅰ-6; the tangential support boss Ⅰ-42 is used as the rotation center of the axially adjustable support Ⅰ-33. In order to achieve accurate positioning, the bottom of the axially adjustable support Ⅰ-33 There is a dial Ⅰ-23 on the matching part of the tangential support boss Ⅰ-42; there are three threaded holes arranged at an angle of 120° along the circumference on the tangential support boss Ⅰ-42, through three jack positioning screws Ⅰ- 20 Connect the hydraulic jack shell I-16 and the tangential bracket I-28 for positioning; the tangential horn I-24 and the axial horn I-3 pass through the tangential bracket cover I-21 and the axial horn respectively The adjustable bracket cover Ⅰ-5 is fixed on the tangential bracket Ⅰ-28 and the axially adjustable bracket Ⅰ-33; the tangential horn Ⅰ-24 is connected with the slide rail support seat Ⅰ-8 through a spherical universal joint, and Universal joint ball core Ⅰ-17 is connected with slide rail support seat Ⅰ-8 through thread, universal joint spherical shell Ⅰ-19 is connected with tangential horn Ⅰ-24 through thread, and universal joint spherical shell Ⅰ-19 outer The first layer is provided with threads and is connected with the universal joint ball core I-17 through the universal joint nut I-18; the workpiece fixture I-9 is fixed on the slide rail support base I-8 through three fixture screws arranged in an L shape.

As shown in Figure 3 and Figure 4, the installation method of the first embodiment can be seen more intuitively, the angle between the tangential ultrasonic vibrator clamped on the fixed plate I-6 and the axial ultrasonic vibrator is 90° , in order to improve the stability of the entire ultrasonic system, an oil hydraulic jack is installed under the slider Ⅰ-36, and the hydraulic jack contacts the bottom surface of the T-shaped slider Ⅰ-36 through the jack ball Ⅰ-35, which plays a supporting role and improves stability. At the same time, it can effectively reduce the energy consumed by the friction between the bottom surface of the T-shaped slider and the hydraulic jack; there is a chute I-38 on the fixed plate I-6, which is used to constrain the movement track of the axially adjustable bracket I-33 , the positioning bolt Ⅰ-32 of the axially adjustable bracket is installed in the chute, which is used to fix the axially adjustable bracket Ⅰ-33 on the fixed plate Ⅰ-6 while facilitating the adjustment of the axially adjustable bracket Ⅰ-33 ; The T-shaped slider Ⅰ-36 forms an interference fit with the slide rail support seat Ⅰ-8 through the slider ball Ⅰ-37 provided on the upper top surface and on both sides. Reduce the friction between the slide rail support seat Ⅰ-8 and the T-shaped slider Ⅰ-36, on the other hand, it can ensure the stability of the slide rail support seat Ⅰ-8. The interference fit is used to avoid local impact. Make the T-shaped slider Ⅰ-36 and the slide rail support seat Ⅰ-8 produce impact damage.

As shown in Figure 7, the nanofluid microlubrication grinding device includes a grinding wheel cover Ⅱ-1, a magnetic chuck Ⅱ-2, a grinding wheel Ⅱ-3, a nanofluid delivery tube Ⅱ-4, a compressed air delivery tube Ⅱ-5, and a nozzle Ⅱ -6. Magnetic workbench Ⅱ-7, in which there is a magnetic suction cup Ⅱ-2 on both sides of the grinding wheel cover Ⅱ-1, which is used to fix the nano fluid delivery tube Ⅱ-4 and the compressed air delivery tube Ⅱ-5; the nano fluid delivery tube Ⅱ-4 and compressed air delivery pipe Ⅱ-5 converge at the nozzle Ⅱ-6, so that the nanofluid and compressed air are fully mixed in the inner cavity of the nozzle Ⅱ-6 to form an aerosol sprayed to the interface between the grinding wheel Ⅱ-3 and the workpiece Ⅰ-12 Grinding plays the role of lubrication and cooling.

As shown in Figure 8, the dynamometer III-4 is connected to the multi-degree-of-freedom two-dimensional ultrasonic vibration device through the fixed plate I-6, and the dynamometer III-4 is fixed on the magnetic workbench II-7 by means of magnetic adsorption; The force measurement device includes grinding force control system Ⅲ-1, grinding force information acquisition instrument Ⅲ-2, amplifier Ⅲ-3, force measuring instrument Ⅲ-4, when the workpiece Ⅰ-12 is subjected to grinding force, the measurement signal is passed through the amplifier After Ⅲ-3 is amplified, it is transmitted to the grinding force information collector Ⅲ-2, and finally to the grinding force control system Ⅲ-1, which displays the magnitude of the grinding force; the grinding temperature measuring device includes thermocouple Ⅲ-5, grinding Cutting temperature information collection instrument Ⅲ-6, low-pass filter Ⅲ-7, grinding temperature control system Ⅲ-8, the measurement signal is transmitted to the grinding temperature information collection instrument Ⅲ-6 through the thermocouple Ⅲ-5, and then transmitted to the low Some interference signals are filtered through the filter III-7, and finally transmitted to the grinding temperature control system III-8, and the temperature at the working end of the thermocouple III-5 is displayed, which is the temperature of the workpiece I-12. Ultrasonic generator Ⅲ-9 provides ultrasonic frequency electrical signals for tangential transducer Ⅰ-25 and axial transducer Ⅰ-2 at the same time, and the ultrasonic frequency electrical signals are transmitted to the shaft through positive lead wire Ⅲ-11 and negative lead wire Ⅲ-10 Positive electrode copper sheet Ⅰ-34 and axial negative electrode copper sheet Ⅰ-1.

As shown in Figure 9, the dynamometer III-4 is connected to the fixed plate I-6 through four fixed plate positioning screws I-30, and the stability of the fixed plate I-6 will directly affect the stability of the entire two-dimensional ultrasonic vibration system Therefore, the span of the four fixing plate positioning screws I-30 is as large as possible, and in order not to hinder the rotation of the axially adjustable bracket I-33 and the installation of the tangential bracket I-28, the fixing plate positioning screw I-30 The top surface should be flush with the upper and lower surfaces of the fixed plate I-6.

As shown in Figure 10, the tangential bracket I-28 is fixed on the fixing plate I-6 by four tangential bracket positioning screws I-29; the chute I-38 does not extend to the bottom of the tangential bracket I-28, which It is because both the tangential bracket I-28 and the axially adjustable bracket I-33 have a certain width and a certain limit; and considering the rigidity of the fixed plate I-6 and the stability of the axially adjustable bracket I-33 The chute I-38 is not designed to be hollowed out.

As shown in Figure 11, the axially adjustable bracket Ⅰ-33 is positioned and clamped with the fixed plate Ⅰ-6 through two sets of axially adjustable bracket positioning bolts Ⅰ-32 and axially adjustable bracket positioning nuts Ⅰ-31; A group of axially adjustable bracket positioning bolts I-32 are embedded in the chute I-38, and move along the trajectory constrained by the chute I-38.

As shown in Figure 12, the axially adjustable bracket I-33 cooperates with it through the tangential bracket boss I-42 on the tangential bracket I-28; the scribe line on the tangential bracket boss I-42 can be accurately Indicate the angle of the dial I-23 on the axially adjustable bracket I-33, so as to complete the precise angle adjustment. At this time, it is the difference between the axially adjustable bracket I-33 and the tangential bracket I-28 in the first embodiment. The position relationship, the indication of the engraved line is 90°; the three boss threaded holes Ⅰ-41 at an angle of 120° on the tangential support boss Ⅰ-42 are matched with the threaded holes on the hydraulic jack shell Ⅰ-16, Secure with I-20-jack set screws.

As shown in Figure 13, the clamping method of the tangential ultrasonic vibrator and the tangential support I-28 is to fix the tangential ultrasonic vibrator on the tangential support I-28 through the tangential support cover I-21, and through two tangential Bracket cover screw Ⅰ-22 fixes tangential bracket cover Ⅰ-21 and tangential bracket Ⅰ-28; at the same time, tangential horn tangential bracket Ⅰ-24 is provided with shaft shoulder Ⅰ-40 and tangential bracket Ⅰ-28 The upper opening of the shoulder shoulder fits and fixes; the clamping method of the axial ultrasonic vibrator and the axial adjustable support tangential support I-33 is the same as that of the tangential ultrasonic vibrator and the tangential support I-28.

As shown in Figure 14, the support consists of three parts, namely: slide rail support seat Ⅰ-8, T-shaped slider Ⅰ-36 and axial support Ⅰ-7; for the convenience of axial support Ⅰ-7 The rotation is clamped and positioned by three positioning screws Ⅰ-15 at an angle of 120° and other T-shaped sliders Ⅰ-36; the T-shaped slider Ⅰ-36 is connected with the slide rail support seat Ⅰ-8 through the slider ball Ⅰ-37 Contact fit; in order to ensure the stability of the slide rail support seat Ⅰ-8, the clamping of the axial support Ⅰ-7 and the T-shaped slider Ⅰ-36 is very important, so when clamping these two parts, the positioning should be ensured Tighten screw I-15.

As shown in Figure 15, from the bottom view of the support, the positional relationship of the assembly of the three parts of the slide rail support seat I-8, the T-shaped slider I-36 and the axial support I-7 can be clearly seen, among which, Both sides of the T-shaped slider Ⅰ-36 have a row of slider balls Ⅰ-37 in contact with the two inner surfaces of the slide rail support seat Ⅰ-8 to reduce friction; and the T-shaped slider Ⅰ-36 and the slide rail support seat Ⅰ- There is a tangential displacement movement between 8, which is determined by the certain amplitude generated by the slide rail support seat Ⅰ-8, so there is a certain distance between the T-shaped slider Ⅰ-36 and the slide rail support seat Ⅰ-8 along the tangential direction. The gap provides displacement space for the slide rail support seat Ⅰ-8.

As shown in Figure 16, the workpiece fixture I-9 on the slide rail support base I-8 is positioned and clamped by three fixture screws I-10 arranged in an L shape; the axial direction of the workpiece I-12 passes through the workpiece positioning stopper I -13 and two axial positioning screws Ⅰ-14 to achieve positioning and clamping; tangentially through two tangential positioning screws Ⅰ-11 to achieve positioning and clamping; the use of workpiece positioning stopper Ⅰ-13 is because the size of the workpiece Ⅰ-12 is different First, it is difficult to keep the workpiece I-12 stable only by two axial positioning screws I-14, so the workpiece I-12 of different sizes can be stably clamped by the workpiece positioning stopper I-13.

As shown in Figure 17, the hydraulic jack includes the jack ball Ⅰ-35, the hydraulic jack shell Ⅰ-16, and the lifting sleeve Ⅰ-44; among them, the jack ball Ⅰ-35 passes through four jack ball positioning screws Ⅰ- 43 is fixed on the top of the lifting sleeve I-44; a sealing ring is provided in the contact area between the lifting sleeve I-44 and the inner cavity of the hydraulic jack shell I-16 to prevent hydraulic oil from leaking; The bottom of 16 is provided with oil inlet and outlet Ⅰ-45, and the hydraulic oil is pumped into the hydraulic jack shell Ⅰ-16 through the oil inlet and outlet Ⅰ-45 by peripheral pumping equipment, thereby realizing the lifting of the sleeve Ⅰ-44 up and down move.

As shown in Figure 18(a) and 18(b), four I-46 are arranged in the tangential transducer I-25, and they are connected to the tangential transducer I through the piezoelectric ceramic positioning screw I-47. -25 is connected and fixed; and four piezoelectric ceramic sheets I-46 are intersected with a tangential positive electrode copper sheet I-26 and a tangential negative electrode copper sheet I-27; the tangential transducer I-25 passes through piezoelectric ceramics The piezoelectric inverse effect of Ⅰ-46 converts the ultrasonic frequency electric signal generated by ultrasonic generator Ⅲ-9 into mechanical vibration. When a certain amount of charge is added to the crystal surface of piezoelectric ceramic Ⅰ-46, the crystal will deform, which is Piezoelectric inverse effect, the positive and negative ions in the crystal undergo relative displacement under the action of the electric field force, resulting in internal stress in the crystal and mechanical deformation of the crystal; the internal clamping method and working principle of the axial transducer Ⅰ-2 are the same as those The energy device Ⅰ-25 is the same.

As shown in Figure 19, the reason why the tangential horn I-25 can amplify the ultrasonic vibration amplitude is that the vibration energy passing through any section of it is constant, so the energy density is higher where the section is smaller. The energy density is proportional to the amplitude A ² , if the section is small, the energy density is high, and the amplitude is also large, that is, the amplitude of the section of the horn is amplified. The working principle of the axial horn I-3 is the same as that of the tangential horn I-25.

The formula for calculating the resonance length L is:

In the formula, L is the resonance length, the wavelength of the λ ultrasonic wave, which can be calculated by the following formula:

In the formula, c is the propagation velocity of ultrasonic waves in the medium, and f is the ultrasonic vibration frequency. Considering the economic cost and experimental conditions, 45 ^# steel is selected as the material of the horn, and the propagation speed of ultrasonic waves in 45 ^# steel is c=5170m/s , frequency f=20KHz, and the wavelength λ=258.5mm of the obtained ultrasonic waves through calculation, so as to obtain the resonance length L=129.25mm.

Calculate displacement node formula:

The displacement node x ₀ =64.625mm is obtained.

Amplification factor calculation formula:

M _P =N ² (4)

In the formula, Mp is the amplification factor, N is the area coefficient, S ₁ and 2 are the area of the input and output ends of the horn (mm2), and D _{1 and 2} in Figure 19 are the diameters of the input and output ends of the horn (mm). The diameters of the input and output ends are set according to the required amplification factor of the horn.

As shown in Figures 20(a) to 20(c), there are two relative motion trajectories between the abrasive particles and the workpiece along the two-dimensional ultrasonic vibration-assisted nanofluid micro-lubrication grinding wheel parallel to the grinding direction and perpendicular to the grinding direction. , are the imitation grinding motion trajectory and the imitation honing motion trajectory respectively; these two relative motion trajectories are generated by the phase adjustment link in the ultrasonic generator, when the phase difference is π/2, the coupling of tangential ultrasonic vibration and axial ultrasonic vibration , so that the abrasive grains of the grinding wheel and the workpiece form an elliptical relative motion trajectory, and the feed direction of the worktable is added to form a motion trajectory imitating grinding; when the phase difference is 0 and π, the tangential ultrasonic vibration is coupled with the axial ultrasonic vibration, so that The abrasive grains of the grinding wheel and the workpiece form two sets of relative motion trajectories of straight lines intersecting each other, and the feed direction of the worktable forms a motion trajectory imitating honing.

As shown in Figure 21, the 220V AC power supplies power to the oscillation stage, power stage and phase detection part of the ultrasonic generator III-9. The ultrasonic frequency signal generated by the oscillation stage is amplified by the amplifier stage, and the power of the ultrasonic signal is increased through the power stage. , and then passed to the transducer through impedance matching, the sampling signal feedback compares the output power of the ultrasonic generator Ⅲ-9 with the transducer power, if they are not equal, the signal is fed back to the oscillation stage and power stage to generate and convert The power equal to the transducer; the phase detection and phase adjustment part can detect and control the phase of ultrasonic vibration in two directions, so as to realize different phase differences and thus produce different motion trajectories.

Fig. 5, Fig. 7 to 19 and Fig. 21 are the second embodiment of the present invention, multi-angle two-dimensional ultrasonic vibration assisted nanofluid micro-lubrication grinding device, the second is the multi-angle two-dimensional ultrasonic vibration device I in the example , nanofluid micro-lubrication grinding device II and grinding force, grinding temperature measuring device III are the same as the first embodiment, the difference is that the axial ultrasonic vibrator is aligned with the cutting device by adjusting the axial adjustable bracket I-33 It forms an acute angle to the vibration direction of the ultrasonic vibrator, so as to further change the relative motion trajectory of the grinding wheel II-3 abrasive grains and the workpiece I-12, which can make the motion trajectory of imitation grinding and imitation honing more compact, so as to achieve the ideal grinding effect.

Fig. 6, Fig. 7 to 19 and Fig. 21 are the third kind of embodiment of the present invention, and the multi-angle two-dimensional ultrasonic vibrating device I in the third kind of example, nano fluid micro-lubrication grinding device II and grinding force, grinding The cutting temperature measuring device III is the same as the first embodiment, the difference is that by adjusting the axial adjustable bracket I-33, the vibration direction of the axial ultrasonic vibrator and the tangential ultrasonic vibrator form an obtuse angle, so as to further change the grinding wheel II. -3 The relative trajectory of abrasive grains and workpiece Ⅰ-12 can make the motion trajectory of imitation grinding and imitation honing more compact, so as to achieve the ideal grinding effect.

Fig. 1 to 4, Fig. 7 to 19, Fig. 20 (d) and Fig. 21 are the fourth embodiment of the present invention, tangential ultrasonic vibration assisted nanofluid micro-lubrication grinding device and its grinding force, grinding temperature measurement The device is the same as the multi-angle two-dimensional ultrasonic vibration device I, the nanofluid micro-lubrication grinding device II, and the grinding force and grinding temperature measurement device III of the first embodiment, which can be realized only by controlling the ultrasonic generator. Ultrasonic generator Ⅲ-9 only outputs tangential ultrasonic signals. Since the slide rail support seat Ⅰ-8 is connected to the axial support Ⅰ-7 through the T-shaped slider Ⅰ-38, when the tangential ultrasonic vibrator generates amplitude, the slide rail The supporting base I-8 can freely vibrate tangentially without being interfered by the axial bearing I-7, thereby producing the relative movement track of the abrasive grains of the grinding wheel II-3 and the workpiece I-12 shown in Fig. 20(d).

Figures 1 to 4, Figures 7 to 19, Figure 20(e) and Figure 21 are the fifth embodiment of the present invention, the axial ultrasonic vibration assisted nanofluid micro-lubrication grinding device and its grinding force and grinding temperature measurement The device is the same as the multi-angle two-dimensional ultrasonic vibration device I, the nanofluid micro-lubrication grinding device II, and the grinding force and grinding temperature measurement device III of the first embodiment, which can be realized only by controlling the ultrasonic generator. Ultrasonic generator Ⅲ-9 only outputs axial ultrasonic signals, and the axial ultrasonic vibrator drives the axial support to generate amplitude and transmits it to the slide rail support seat Ⅰ-8, because the slide rail support seat Ⅰ-8 connects with the tangential The ultrasonic vibrator is connected, so the axial vibration of the slide rail support seat I-8 will not be interfered, thereby producing the relative motion track of the abrasive grain of the grinding wheel II-3 and the workpiece I-12 as shown in Figure 20(e).

The specific working process of this program is as follows:

Taking the first embodiment as an example, the ultrasonic generator III-9 generates an ultrasonic frequency electric signal that matches the power of the axial transducer I-2 and the tangential transducer I-25, and passes through the negative lead wire III-10 and The positive wire III-11 is transmitted to the axial transducer I-2 or the tangential transducer I-25, and the axial transducer I-2 and the tangential transducer I-25 convert the ultrasonic frequency electric signal into ultrasonic The high-frequency mechanical vibration is transmitted to the axial horn Ⅰ-2 and the tangential horn Ⅰ-25, and the amplitude of the ultrasonic mechanical vibration is amplified by a certain multiple through the horn and then transmitted to the axial support Ⅰ-7 and The slide rail support seat Ⅰ-8, thereby driving the workpiece Ⅰ-12 and the abrasive grains of the grinding wheel to produce a relative motion trajectory, is connected with the slide rail and the slider by a spherical universal joint, so the slide rail support seat Ⅰ-8 is subjected to axial and and There is no internal force in the system when vibrating in the direction of vibration, which avoids the vibration and impact damage of the connecting parts in the ultrasonic vibration system. By controlling the phase adjustment link in the ultrasonic generator III-9 shown in Figure 21, the axial ultrasonic vibrator and the tangential ultrasonic vibrator generate ultrasonic vibration signals with different phase differences. When the phase difference is π/2, the tangential ultrasonic vibrator The ultrasonic vibration is coupled with the axial ultrasonic vibration, so that the abrasive grains of the grinding wheel and the workpiece form an elliptical relative motion trajectory, and the feed direction of the worktable is added to form the imitation grinding motion trajectory as shown in Figure 20(b); when the phase difference is When 0 and π, the tangential ultrasonic vibration is coupled with the axial ultrasonic vibration, so that the abrasive grains of the grinding wheel and the workpiece form two sets of relative motion trajectories intersecting each other, and the feed direction of the worktable is added, as shown in Figure 20(c). The trajectory of imitation honing. In the second and third embodiments, the angle of the axially adjustable bracket I-33 is adjusted to further change the shape of the relative motion track between the abrasive grains of the grinding wheel and the workpiece, so that the lines of the imitation grinding and imitation honing motion tracks are more precise. Dense, so as to obtain the ideal surface quality and grinding effect of the workpiece.

The grinding force produced by the grinding wheel II-3 grinding the workpiece I-12 is transmitted to the slide rail support seat I-8 through the workpiece fixture I-9, and the tangential grinding force, normal grinding force and axial grinding force respectively pass through Three different paths are delivered to the fixed plate I-6. Among them, the tangential grinding force is transmitted to the tangential horn I-24 through the spherical universal joint, and the tangential horn I-24 is rigidly connected with the tangential support I-28, so the tangential support I-28 is subjected to The tangential grinding force is then transmitted to the fixed plate Ⅰ-6; the normal grinding force is transmitted to the jack ball Ⅰ-35 through the T-shaped slider Ⅰ-36, and then transmitted to the tangential support boss Ⅰ-42, and finally transmitted to the fixed plate Ⅰ-6; the axial grinding force is transmitted to the axial support Ⅰ-7 through the T-shaped slider Ⅰ-36, and then transmitted to the axial horn Ⅰ-3, and the axial horn Ⅰ- 3 is rigidly connected with the axially adjustable bracket I-33, so the axially adjustable bracket I-33 receives the axial grinding force, and finally transmits it to the fixed plate I-6. The grinding force in three directions is transmitted to the dynamometer Ⅲ-4 through the fixed plate Ⅰ-6, and the measurement signal is amplified by the amplifier Ⅲ-3, then transmitted to the grinding force information acquisition instrument Ⅲ-2, and finally transmitted to the grinding force control System Ⅲ-1, and display the size of the grinding force.

The grinding temperature generated by the grinding wheel II-3 grinding the workpiece I-12 is transmitted to the grinding temperature information collector III-6 through the thermocouple III-5, and then transmitted to the low-pass filter III-7 to filter some interference signals, Finally, it is transmitted to the grinding temperature control system Ⅲ-8, and displays the temperature of the working end of the thermocouple Ⅲ-5, which is the temperature of the workpiece Ⅰ-12.

After the ultrasonic vibration device completes the experimental processing task, the magnetic workbench II-7 is demagnetized, and the dynamometer III-4 and the entire equipment can be unloaded.

Multi-angle two-dimensional ultrasonic vibration-assisted nanofluid minimal quantity lubrication grinding surface creation mechanism:

In the two-dimensional grinding process, a single abrasive particle is excited by two-dimensional ultrasonic vibration on the workpiece, making it perform spiral or linear staggered cutting in the grinding area. In one vibration cycle, the abrasive particle periodically changes the cutting direction. Make multiple grinding edges around the abrasive grains participate in the cutting, forming a "multi-edge cutting" process, which is conducive to the sharpness of the abrasive grain cutting edge and the cooling of the grinding temperature on the surface of the workpiece, which is different from the abrasive grains in the ordinary grinding process. The micro-arc cutting method has a longer cutting path than ordinary grinding, that is, the cutting action area of a single abrasive grain increases, and the cutting edge on each surface of a single abrasive grain periodically contacts and cuts the workpiece material. In the microscopic processing area, an intermittent processing state of sometimes cutting and sometimes separating is formed, which is a cutting process that is continuous on the macroscopic level and intermittent on the microscopic level. During the two-dimensional grinding process, the spiral cutting tracks formed by the many abrasive grains on the grinding wheel interfere with each other, forming interweaving cutting tracks on the grinding surface, thus forming the unique differential cutting effect of two-dimensional ultrasonic assisted grinding. The creation process of two-dimensional ultrasonic-assisted grinding surface is not limited to the cutting traces of abrasive grains without subsequent cutting edges, but the spiral or linear interlaced cutting trajectories of many abrasive grains. The interference trajectory to a certain extent can make a single grain The wider the abrasive grain cutting groove, the greater the axial ultrasonic amplitude, the wider the abrasive grain cutting groove, the volume of material removed per unit time increases, the material removal rate is improved, and the interference of many abrasive grains is increased at the same time. The width and height of the uncut marks are significantly reduced, which reduces the roughness of the grinding surface and greatly improves the quality of the grinding surface.

In the process of two-dimensional ultrasonic assisted vibration grinding, two-dimensional ultrasonic vibration parallel to the direction of the linear velocity of the grinding wheel (x direction) and perpendicular to the direction of the linear velocity of the grinding wheel (y direction) is applied to the workpiece. :

x＝A cos(2πft)+vt (6)

In the formula, A is the amplitude of tangential ultrasonic vibration, B is the amplitude of axial ultrasonic vibration, f is the frequency of ultrasonic vibration, v table feed speed, is the phase difference between tangential ultrasonic vibration and axial ultrasonic vibration.

When the worktable is stationary, the feed speed of the worktable v=0, the two equations of formula (6) and formula (7) are the parameter equations of the relative motion track of the grinding wheel and the workpiece expressed by the parameter t, and the parameter t After elimination, the Cartesian coordinate equation of the trajectory is obtained, the formula is:

This is the ellipse equation, which is the Cartesian coordinate equation of the relative motion trajectory of the abrasive grains of the grinding wheel and the workpiece. The shape of the ellipse is determined by the phase difference between the tangential ultrasonic vibration and the axial ultrasonic vibration decided, a few special cases are discussed below:

when , that is, the phase difference between the tangential ultrasonic vibration and the axial ultrasonic vibration is equal, at this time, it can be obtained by the formula (8):

Therefore, the relative trajectory of the abrasive grains of the grinding wheel and the workpiece is a straight line passing through the origin, and the slope is the ratio of the two amplitudes At time t, the displacement of the abrasive grains of the grinding wheel away from the equilibrium position:

Therefore, the frequency of the harmonic vibration of tangential ultrasonic vibration and axial ultrasonic vibration is equal to the original frequency, and the amplitude is equal to along a straight line vibration.

When , the phase of the tangential ultrasonic vibration is opposite to that of the axial ultrasonic vibration, that is, the abrasive grains of the grinding wheel are in another straight line Make harmonic vibrations with the same frequency and amplitude. Will and The synthesis of the relative motion trajectory of the abrasive grains of the grinding wheel and the workpiece is the motion trajectory of imitation honing shown in Fig. 20(c).

when , at this time it is obtained by formula (8):

That is, the relative movement track of the abrasive grains of the grinding wheel and the workpiece is an ellipse with the coordinate axis as the main axis, and the movement direction of the abrasive grains of the grinding wheel along the elliptical track is shown in Fig. 20(a). While the abrasive grains of the grinding wheel are moving in an elliptical manner, the relative motion trajectory obtained by making a uniform linear motion along the tangential direction with the feed speed v is shown in Fig. 20(b) as the simulated grinding trajectory.

On the basis of controlling the phase adjustment part of the ultrasonic generator so that the abrasive grains of the grinding wheel and the workpiece have different relative motion trajectories, by adjusting the angle of the axially adjustable bracket, the inclination angle of the spiral and linear interlaced motion trajectories is further changed, which is consistent with the The combination of nanofluid micro-lubrication and grinding conditions enables the abrasive grains of the grinding wheel to form denser texture lines on the surface of the workpiece, thereby obtaining higher surface quality and grinding effect of the workpiece.

The above is only a preferred embodiment of the present invention, not all embodiments of the present invention, and is not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention , should be included within the protection scope of the present invention.

Except for the technical features described in the description, the rest of the technical features are known to those skilled in the art. In order to highlight the innovative features of the present invention, the above technical features will not be repeated here.

Claims (9)

1. Multi-angle two-dimensional ultrasonic vibration assisted nanofluid micro-lubrication grinding device, which is characterized in that it includes a workpiece fixture for clamping the workpiece and a grinding wheel for grinding the workpiece, and the workpiece fixture is connected to the two-dimensional ultrasonic vibration device , to facilitate the maintenance of the sharpness of the cutting edge of the grinding wheel; one side of the grinding wheel is provided with a spraying mechanism for spraying nanofluid to the workpiece, and the two-dimensional ultrasonic vibration device and the nanofluid sprayed by the spraying mechanism form two-dimensional ultrasonic vibration and nanofluid on the workpiece. Fluid minimal lubrication grinding coupling; the two-dimensional ultrasonic vibration device includes a tangential ultrasonic vibration device and an axial ultrasonic vibration device, and the tangential ultrasonic vibration device is arranged above or below the axial ultrasonic vibration device; the tangential ultrasonic vibration device is relatively The axial ultrasonic vibration device can be rotatably installed; The injection mechanism includes a nozzle, the grinding wheel part is fixed in the grinding wheel cover, one side or both sides of the bottom of the grinding wheel are respectively fixed nozzles, and the nozzles are separately connected with the nano fluid delivery pipe and the compressed air delivery pipe; on the workpiece fixture or the workpiece A temperature acquisition element is arranged on the top, and the temperature acquisition element is connected with the temperature control system. 2. multi-angle two-dimensional ultrasonic vibration assisted nanofluid micro-lubrication grinding device according to claim 1, it is characterized in that, described tangential ultrasonic vibration device is arranged on fixed plate, and fixed plate is located on workbench, shaft The directional ultrasonic vibrating device is arranged above the tangential ultrasonic vibrating device, the fixed plate is connected with the dynamometer, and the dynamometer is set to be connected with the grinding force control system. 3. multi-angle two-dimensional ultrasonic vibration assisted nanofluid micro-lubrication grinding device according to claim 2, is characterized in that, described tangential ultrasonic vibration device is fixed on the described On the fixed plate, the top of the tangential bracket supports the tangential horn, one end of the tangential horn is connected to the tangential transducer, the tangential transducer is connected to the ultrasonic generator, and the other end is connected to the slide rail through a universal joint The support seat is fixed, and the slide rail support seat supports the workpiece fixture. 4. The multi-angle two-dimensional ultrasonic vibration-assisted nanofluid micro-lubrication grinding device according to claim 3 is characterized in that, the top of the tangential support is provided with a shoulder slot, and the circumference of the tangential horn is provided with a The shaft shoulder matched with the shaft shoulder card slot, the tangential support cover covers the shaft shoulder and is fixed with the tangential support. 5. The multi-angle two-dimensional ultrasonic vibration-assisted nanofluid micro-lubrication grinding device according to claim 4 is characterized in that, the surface of the slide rail support seat is provided with a workpiece groove for fixing the workpiece, and a shaft can be arranged in the workpiece groove. The stopper is positioned toward the displaced workpiece, and clamp bolts or screws capable of tangential displacement are arranged in the groove of the workpiece. 6. the multi-angle two-dimensional ultrasonic vibration assisted nanofluid micro-lubrication grinding device according to claim 4, is characterized in that, on the said tangential support, the other side where the tangential support is fixed with the fixed plate is provided with a protrusion , the axially adjustable bracket is rotatably fixed to the tangential bracket through the protrusion, and the axial ultrasonic vibration device is supported by the axially adjustable bracket; Further, a dial is provided around the protrusion of the tangential support to indicate the rotation angle of the axially adjustable support relative to the tangential support; Further, the longitudinal section of the axially adjustable bracket is L-shaped; Further, the height of the axially adjustable support is lower than the height of the tangential support. 7. The multi-angle two-dimensional ultrasonic vibration assisted nanofluid micro-lubrication grinding device according to claim 6, wherein the axial ultrasonic vibration device comprises an axial horn, and one end of the axial horn is connected to the shaft Connect to the transducer, the other end is connected to the axial support, and the axial support is arranged on the lower surface of the slide rail support seat through a T-shaped slider; the axial transducer is connected to the ultrasonic generator; An arc-shaped chute for limiting the movement track of the axial ultrasonic vibration device is arranged on the fixed plate, and a slide bar is provided on the axially adjustable support, and the slide bar moves along the arc-shaped chute; Further, the chute is a T-shaped chute, and the slide bar can be replaced by a positioning bolt. 8. The multi-angle two-dimensional ultrasonic vibration assisted nanofluid micro-lubrication grinding device according to claim 7, wherein at least one side of the T-shaped slider is provided with slider balls, so as to avoid the contact between the slide rail support seat and Vibration damage of axial support; Alternatively, a jack is provided at the bottom of the T-shaped slider, and jack balls are arranged on the contact surface between the jack and the T-shaped slider, so as to reduce the energy consumed by the friction between the bottom surface of the T-shaped slider and the jack. 9. The multi-angle two-dimensional ultrasonic vibration assisted nanofluid micro-lubrication grinding device according to claim 1, characterized in that the nanofluid delivery tube and the compressed air delivery tube are fixed to the side of the grinding wheel cover by a magnetic chuck.