CN-122007995-A - Closed alternating pressure polishing control method and system for microstructure parts

CN122007995ACN 122007995 ACN122007995 ACN 122007995ACN-122007995-A

Abstract

The invention discloses a closed alternating pressure polishing control method and system for a microstructure part, wherein the method comprises the steps of placing the part to be processed in a processing cavity to construct a closed loop, filling polishing liquid to form a constant-volume and pressure-maintaining processing environment, driving the polishing liquid to circularly flow in the closed loop, applying alternating pressure, rigidifying the polishing liquid at a high-pressure phase of the alternating pressure, selectively removing materials on microscopic peaks, maintaining the polishing liquid in a flexible fluid state to realize chip removal when the polishing liquid flows through microscopic valleys at a low-pressure phase, acquiring current temperature data of the polishing liquid and current output resistance moment data of a power source for driving the polishing liquid to circulate in real time, and generating a compensation instruction to adjust the switching frequency of the alternating pressure or increase the amplitude of the alternating pressure if the falling slope of the current output resistance moment data reaches a preset threshold value. The invention realizes accurate targeted polishing and maintains the consistency of the removal rate in long-period processing.

Inventors

HUANG RUI
SUN XUKE
LUO JINLONG
LI XIAOJIAN
GUO JIANG
ZHANG ZHENING
HU SHAOWEI
SUN ZHONGHUI

Assignees

宁波锦辉光学科技股份有限公司

Dates

Publication Date: 20260512
Application Date: 20260410

Claims (8)

1. The closed alternating pressure polishing control method for the microstructure part is characterized by comprising the following steps of: S1, placing a part to be processed in a processing cavity, controlling the processing cavity to be communicated with a polishing solution circulation unit to construct a closed loop, and filling the closed loop with polishing solution with a shear thickening characteristic so as to enable the closed loop to form a constant-volume and pressure-maintaining processing environment; S2, driving the polishing liquid to circularly flow in the closed loop and continuously flow through microscopic peaks and microscopic valleys on the surface of the part to be processed, and simultaneously applying periodically-changing alternating pressure to the polishing liquid, wherein based on the space throttling difference of the microscopic peaks and the microscopic valleys on the polishing liquid, the control parameters of the alternating pressure are configured to enable the local instantaneous shear rate of the polishing liquid to reach a critical shear rate when the polishing liquid flows through the microscopic peaks in a high-pressure phase of the alternating pressure so as to trigger a shear thickening effect to rigidify the local polishing liquid and selectively remove materials on the microscopic peaks, and enable the polishing liquid to maintain a flexible fluid state when the polishing liquid flows through the microscopic valleys in a low-pressure phase of the alternating pressure or because the local instantaneous shear rate of the polishing liquid is lower than the critical shear rate so as to realize chip removal and avoid morphology damage on the microscopic valleys; S3, acquiring current temperature data of the polishing solution in the closed loop and current output resistance moment data of a power source for driving the polishing solution to circulate in real time; And S4, judging whether the descending slope of the current output resistance moment data reaches a preset threshold value, and if so, generating a compensation instruction according to a viscosity compensation relation corresponding to the current temperature data so as to automatically increase the switching frequency of the alternating pressure or increase the amplitude of the alternating pressure, so as to compensate the attenuation of the shearing thickening effect caused by the temperature rise of the polishing liquid in real time, thereby maintaining the consistency of the removal rate of the microscopic peaks by the polishing liquid.
2. The polishing control method according to claim 1, wherein in the step S2, the instantaneous pressure value P (t) of the alternating pressure satisfies the following formula: ; Wherein, the To form the base static pressure of the processing environment, For the amplitude of the alternating pressure, Is the switching frequency of the alternating pressure.
3. The polishing control method according to claim 1, wherein in the step S4, the compensation instruction follows a priority policy as follows: preferentially increasing the switching frequency of the alternating pressure to improve the local instantaneous shear rate of the polishing solution when flowing through the microscopic peaks; If the switching frequency reaches the upper limit of system execution and the current output resistance moment data is not restored to the target value, the amplitude of the alternating pressure is further increased, so that the removal rate is compensated by increasing the normal impact kinetic energy of the polishing liquid on the microscopic peaks.
4. The polishing control method according to claim 2, wherein in step S1, the value of the base static pressure is configured to maintain the bulk modulus of the polishing liquid in the closed circuit at a preset stable interval to eliminate the attenuation effect of trace residual bubbles in the polishing liquid on the alternating pressure transmission process.
5. The polishing control method as recited in claim 1, further comprising: and monitoring the concentration of the cuttings impurity in the polishing solution in real time, and dynamically adjusting the circulating flow rate of the polishing solution according to the concentration of the cuttings impurity so as to maintain the stability of the distribution of the flow field in the processing cavity.
6. A closed alternating pressure polishing system for microstructured parts, characterized by performing the polishing control method according to any one of claims 1 to 5, comprising: -a machining chamber (10) configured to house the part (60) to be machined; A polishing liquid circulation unit (20) which is communicated with the processing cavity (10) to construct the closed loop and is configured to drive the polishing liquid to circulate; A pressure regulating module (30), in communication with the closed circuit, configured to apply the alternating pressure to the polishing liquid; A sensing module (40) configured to acquire the current temperature data and the current output drag torque data, and And the controller (50) is respectively in communication connection with the polishing solution circulating unit (20), the pressure regulating module (30) and the sensing module (40), and is configured to generate the compensation instruction according to the current temperature data and the current output resistance moment data.
7. The polishing system according to claim 6, wherein the pressure adjustment module (30) comprises: a servo proportional relief valve (31) for receiving a high-frequency pulse width modulation signal from the controller (50) to perform a pressure regulating action on the polishing liquid, and And an accumulator (32) for absorbing pressure pulsation generated by the polishing liquid circulation unit (20) to maintain the processing environment.
8. The polishing system according to claim 6, wherein the sensing module (40) comprises: A temperature sensor (41) arranged at the position of a liquid return port of the processing cavity (10), and And the dynamic torque sensor (42) is integrated on an output shaft of the driving motor of the polishing solution circulating unit (20) and is used for acquiring the current output resistance moment data in real time.

Description

Closed alternating pressure polishing control method and system for microstructure parts Technical Field The invention relates to the technical field of ultra-precise machining, in particular to a closed alternating pressure polishing control method and system for a microstructure part. Background With the development of precision manufacturing technology, the application of micro-structural parts in the fields of aerospace, medical instruments, precision optics and the like is increasingly wide. The surfaces of such parts usually have complex microscopic peaks and microscopic valleys, which place extremely high demands on their surface quality and topography accuracy. Currently, fluid polishing techniques are often used to treat complex fine profiles, where processing using the non-newtonian fluid characteristics of a shear thickening polishing solution is a research hotspot in the art. However, the existing fluid polishing methods still have a number of limitations in practical applications. On the one hand, conventional fluid polishing generally adopts constant pressure to drive the polishing liquid to flow, and this processing mode cannot fully utilize the physical difference of the surface morphology of the micro parts, so that the polishing liquid is kept in a high-shear state in the processing area continuously. The method is not only extremely easy to cause unexpected overscut damage to microscopic valleys to be protected and difficult to realize the truly selective targeted polishing, but also the continuous rigidifying state makes the waste chips of the cut materials difficult to be effectively discharged along with the fluid and easily causes blockage of the microstructure. On the other hand, the rheological effect of the shear thickening fluid is greatly affected by temperature, and under the continuous mechanical friction and fluid shearing action, the temperature of the processing environment is inevitably increased, so that the basic viscosity and the shear thickening performance of the polishing solution are physically attenuated. The existing polishing system often lacks a deep self-adaptive compensation mechanism aiming at the thermal attenuation phenomenon, and the material removal rate can obviously drop and fluctuate along with the extension of the processing time, so that the consistency of the polishing process of the microstructure parts and the stability of mass production are seriously restricted. Disclosure of Invention The invention provides a closed alternating pressure polishing control method and system for a microstructure part, and aims to solve the technical problems that the conventional fluid polishing technology is easy to cause over-cutting damage to microscopic valleys during microstructure processing, and cannot effectively overcome the attenuation of a shearing thickening effect caused by the temperature rise of polishing liquid, so that the removal rate of microscopic peaks is inconsistent. The invention provides a closed alternating pressure polishing control method of a microstructure part, which comprises the following steps: S1, placing a part to be processed in a processing cavity, controlling the processing cavity to be communicated with a polishing solution circulation unit to construct a closed loop, and filling the closed loop with polishing solution with a shear thickening characteristic so as to enable the closed loop to form a constant-volume and pressure-maintaining processing environment; S2, driving the polishing liquid to circularly flow in the closed loop and continuously flow through microscopic peaks and microscopic valleys on the surface of the part to be processed, and simultaneously applying periodically-changing alternating pressure to the polishing liquid, wherein based on the space throttling difference of the microscopic peaks and the microscopic valleys on the polishing liquid, the control parameters of the alternating pressure are configured to enable the local instantaneous shear rate of the polishing liquid to reach a critical shear rate when the polishing liquid flows through the microscopic peaks in a high-pressure phase of the alternating pressure so as to trigger a shear thickening effect to rigidify the local polishing liquid and selectively remove materials on the microscopic peaks, and enable the polishing liquid to maintain a flexible fluid state when the polishing liquid flows through the microscopic valleys in a low-pressure phase of the alternating pressure or because the local instantaneous shear rate of the polishing liquid is lower than the critical shear rate so as to realize chip removal and avoid morphology damage on the microscopic valleys; S3, acquiring current temperature data of the polishing solution in the closed loop and current output resistance moment data of a power source for driving the polishing solution to circulate in real time; And S4, judging whether the descending slope of the current output resistance