Study on high-spindle-speed EDM with non-contact electrical feeding using resonance of discharge circuit

2016 Fiscal Year Final Research Report

• Project/Area Number: 15K13843
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Production engineering/Processing studies
• Research Institution: The University of Tokyo
• Principal Investigator: Kunieda Masanori 東京大学, 大学院工学系研究科(工学部), 教授 (90178012)
• Project Period (FY): 2015-04-01 – 2017-03-31
• Keywords: 放電加工 / 微細加工 / 非接触給電 / 静電誘導給電 / 高速工具回転 / 共振 / 放電回路

Outline of Final Research Achievements

In EDM, the tool electrode is rotated to flush the debris in the gap and to cool the electrode surface. In RC circuit however, a brush is used to connect the power supply to the tool electrode. Thus, it is difficult to rotate the tool at high speed. With the electrostatic induction feeding method, since a pulse voltage is coupled to the discharge gap by a capacitance existing between the feeding electrode and the rotating spindle, non-contact electrical feeding can be realized. However, since the capacitance is extremely small, the discharge energy per pulse is insufficient to conduct rough machining. To overcome the problem, controlled pulse train method was introduced. High frequency discharge is allowed to continue within a controlled pulse train duration. By utilizing resonance in the circuit, the amplitude of the gap voltage can be amplified higher than the AC power supply. As a result, high-spindle-speed machining became possible under finishing to rough machining conditions.

Free Research Field

特殊加工