Three-dimensional fine electric spark servo scanning rough and finish machining combined process

Abstract

A three-dimensional fine electric spark servo scanning rough and finish machining combined process belongs to the technical field of special micro machining. The process which is adaptive to machining of micro three-dimensional cavities with millimeter-sized and utilizes a servo control discharge clearance to realize real-time on-line compensation of axial consumption of an electrode includes removing a large quantity of cavity materials rapidly when in rough machining, applying a maximum method of servo feed depth of an tool electrode of each scanning point to avoid and reduce lack of machining and over-cutting machining and guarantee consistency of processed depths of different layers when in finish machining, further, feeding back processed depth of each layer by combing with tool electrode low-voltage electric contact in a closed loop form, then applying a variable velocity servo scanning method to compensate depth error, and finally completing molding process with high surface precision and high size precision by adopting low discharge energy and thin dividing thickness. The combined process resolves the problem of precision limitation of processed depth of three-dimensional servo scanning, eliminates contradiction between high precision and high efficiency, and can be applied to high-precision and high-efficiency machining of micro three-dimensional cavities made of metal alloy and conductive silica-based materials.

Description

technical field [0001] The invention belongs to the technical field of micro-special processing, and in particular relates to a three-dimensional micro-electric spark servo scanning rough-finish combination process for metal alloys and conductive silicon-based materials within a millimeter size. Background technique [0002] Micro-3D cavities have broad application prospects in micro-electromechanical systems (MEMS) and related fields of micro-nano technology. Based on the principle of non-contact discharge, the three-dimensional micro-EDM technology that uses simple-shaped tool electrodes to scan (mill) layer by layer has the advantages of low cost, large design freedom, easy chip removal, and low cost of tool electrode preparation. [0003] However, the energy distribution between electrodes in the discharge process determines the inevitability of electrode loss, and the real-time compensation technology for electrode loss is the key to ensure the effective progress of the...

AI Technical Summary

Problems solved by technology

Compared with the three-dimensional micro-cavity to be processed, the discharge area at the end of the micro-electrode is small, resulting in a long processing time for the micro-three-dimensional cavity

Measures such as increasing the discharge energy, improving the effective discharge rate, and increasing the diameter of the tool electrode can improve the processing efficiency, but at the same time, the scanning depth (layer thickness) of each layer is increased, resulting in the step shape error of the three-dimensional surface.

Moreover, increasing the discharge energy will make the surface precision of the processed microstructure worse; increasing the electrode diameter will introduce the adverse effects of loss and deformation at the end of the electrode, and it will not be possible to process finer structures such as inner corners and narrow grooves.

In fact, most of the material removal in the micro three-dimensional cavity has nothing to do with the molding accuracy. If you want to process the micro cavity with high precision, you will sacrifice a lot of unnecessary processing time, and if the time is too long, the processing stability will deteriorate, and even the processing process will fail.

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