A very high frequency self-oscillating pulse source for micro-energy electrical machining

Abstract

The invention discloses a very high frequency (VHF) natural vibration type micro energy electromachining impulse source. At the connected moment of a direct current power supply E of the electromachining impulse source, weak electric current saltation and noise can be generated in a circuit, the part of energy is amplified by a resonance oscillation unit, certain proportion of energy is inputted into the grid electrode of a field effect transistor through a feedback unit to keep continuous self-oscillation, and after reaching certain degree, the voltage amplitude and frequency are tend to be stable to form dynamic equilibrium. The other part of energy is stored by a capacitor C4 and passes through a current-limiting resistor R3 to reach a tool electrode and a workpiece, so that the workpiece is machined. The very high frequency (VHF) natural vibration type micro energy electromachining impulse source is suitable for micro electromachining, the generated voltage pulse width can reach 5ns, the discharge frequency can reach 100 MHz, and the peak-to-peak value gap voltage can reach 400 V or above, so that the machining quality of the workpiece surface can be improved, and conventionaldefects including thermal damage, recasting layer and heat affected zone generated during the workpiece machining process can be reduced to realize the effect similar to cold machining.

Description

Technical field [0001] The invention belongs to the technical field of micro electrical processing, and specifically relates to a very high frequency self-vibrating micro-energy electrical processing pulse source. Background technique [0002] The micro-EDM technology is a typical special processing technology. Its material removal energy comes from a high-frequency, high-heat flux pulse heat source, and the instantaneous high temperature and high pressure generated by pulse discharge are used to achieve processing. Because micro-EDM has a series of advantages such as simple equipment, good controllability, no cutting force, and strong applicability, it has obvious advantages compared with traditional machining, and has great application potential in the processing of micro devices. Considered to be one of the most promising microfabrication methods. Micro EDM is generally considered to be a single pulse discharge with an energy of 10 -6 ~10 -8 J, EDM with pulse width within 10μ...

AI Technical Summary

Problems solved by technology

There is no maintenance voltage, and the power supply voltage can also be used for discharge machining at a low voltage of 0.1V, but reducing the power supply voltage will reduce the discharge gap and make it difficult to perform continuous processing; in order to reduce the discharge energy, usually no capacitor is connected in the circuit. Only distributed capacitance is used for EDM, but even if a non-metallic bed and a shielded cable as short as possible are used, it is difficult to reduce the distributed capacitance to less than 100pF. It can be considered that the distributed capacitance determines the limit of the minimum discharge energy of the RC pulse power supply

For an independent pulse power supply, there is a gap to maintain the voltage during processing, generally 20~30V, and the discharge energy of a single pulse can be reduced by compressing the pulse width. Due to the limitations of traditional switching components, it is difficult to compress the pulse width to Very small, the discharge energy of a single pulse is difficult to further reduce

Images