Method of and apparatus for electrical discharge machining a small and deep hole into or through a workpiece
AssigneeInoue-Japax Research Incorporated
InventorKiyoshi Inoue
Life of this patent
Estimating the term…
Abstract
An improved method of and apparatus for the electrical discharge machining of a small and deep hole of a diameter of 1 mm or less and a depth-to-diameter ratio of at least 5 into or through a workpiece wherein a water machining fluid medium is used having a specific resistivity of at least 10.sup.4 ohm-cm and is pumped through a tubular elongated electrode into the machining gap at a pressure of at least 20 kg/cm.sup.2, preferably 40 kg/cm.sup.2. An ultrasonic vibration is imparted to the elongated tubular electrode longitudinally thereof or transversely thereto.
Claims33
A method of electrical discharge machining a small and deep hole having a diameter of 1 mm or less and a depth to diameter ratio of at least 5 into or through a workpiece, the method comprising the steps of:
- juxtaposing a thin and elongated tubular electrode with the workpiece across a machining gap;
- supplying a water machining fluid through the tubular electrode into the machining gap at a pressure of at least 20 kg/cm.sup.2 ;
- applying a series of electrical machining pulses between the tubular electrode and the workpiece to cause time-spaced electrical discharges through the machining gap thereby removing material from the workpiece;
- and advancing the tubular electrode in its longitudinal direction relatively into the workpiece.
An apparatus for electrical discharge machining a small and deep hole of a diameter of 1 mm or less and a depth to diameter ratio of at least 5 into or through a workpiece, the apparatus comprising:
- a thin and elongated tubular electrode of at most a diameter of 0.5 mm juxtaposable with said workpiece to form a machining gap therebetween;
- fluid supply and pumping means for supplying a water machining fluid through said tubular electrode into said machining gap at a pressure of at least 20 kg/cm.sup.2 ;
- power supply means for applying a series of electrical machining pulses between said electrode and said workpiece to produce a succession of electrical discharges through said machining gap thereby removing material from said workpiece;
- and drive means for relatively displacing said tubular electrode and said workpiece to advance said elongated electrode longitudinally into said workpiece.
Dependencies are inferred from the claim text.