Apparatus for electric discharge micromachining

An electro discharge machining apparatus, comprising:

• a first holder for holding a workpiece to be subjected to electro discharge machining;
• an electrode provided opposing the workpiece held by the first holder;
• a capacitor for supplying electric charge to the electrode and the workpiece so as to generate pulse electro discharge between the workpiece and the electrode;
• a power source for applying a voltage to the capacitor;
• a switching element provided between the capacitor, and at least one of the electrode, the workpiece and the power source;
• and
• a switch controller for controlling on and off of the switching element,
• wherein the switching element alternately is turned on and off so that duration of the pulse electro discharge is less than or equal to a predetermined time.

An electro discharge machining apparatus, comprising:

• a first holder for holding a workpiece to be subjected to electro discharge machining;
• an electrode provided opposing the workpiece held by the first holder;
• a capacitor for supplying electric charge to the electrode and the workpiece so as to generate pulse electro discharge between the workpiece and the electrode;
• a power source for applying a voltage to the capacitor;
• a current detecting element for detecting a current flowing between the workpiece and the electrode;
• a control unit for, based on the current detected by the current detecting element, judging whether or not a period of the pulse electro discharge is less than or equal to a predetermined period;
• and
• an adjuster for, when it is judged that the period of the pulse electro discharge is less than or equal to the predetermined period, adjusting an electric resistance value between the power source and the capacitor so that the period of the pulse electro discharge is greater than the predetermined period.

An electro discharge machining apparatus, comprising:

• a first holder for holding a workpiece to be subjected to electro discharge machining;
• an electrode provided opposing the workpiece held by the first holder;
• a capacitor for supplying electric charge to the electrode and the workpiece so as to generate pulse electro discharge between the workpiece and the electrode;
• a power source for applying a voltage to the capacitor;
• a current detecting element for detecting a current flowing between the workpiece and the electrode;
• a control unit for, based on the current detected by the current detecting element, judging whether or not a short circuit has occurred for a predetermined time between the workpiece and the electrode;
• and
• an adjuster for, when it is judged that a short circuit has occurred for the predetermined time between the workpiece and the electrode, adjusting an electric resistance value between the power source and the capacitor so that a period of the pulse electro discharge is elongated.