Characteristics Of EDM Drilling Machines

Electrical Discharge Drilling Machine, also known as EDM drilling machine, micro-EDM drill, or fine-hole electrical discharge machine, operates on the principle of using a continuously vertically moving thin copper tube (called the electrode wire) as the electrode to remove metal through pulsed spark discharge, thereby shaping the workpiece.

Unlike EDM wire-cutting machines and die-sinking EDM machines, the EDM drilling machine employs a hollow copper rod as the electrode for electrical pulses. Dielectric fluid passes through the fine hole in the center of the copper rod to cool and remove debris.

The EDM drilling machine achieves perforation by generating high-temperature corrosion through discharges between the electrode and the metal. It is used to drill fine holes in ultra-hard steels, hard alloys, copper, aluminum, and any other conductive materials.

The EDM drilling machine can drill holes as small as 0.015 mm and can also create tapered holes. As a result, it is widely used in precision mold processing. It is generally employed as auxiliary equipment for EDM wire-cutting machines, serving purposes such as creating threading holes for wire-cutting, spinning holes for chemical fiber spinnerets, group holes for filter plates and sieve plates, heat dissipation holes in engine blades and cylinders, and oil or gas passage holes in hydraulic and pneumatic valves.

Based on the dielectric medium used, EDM drilling machines can be broadly categorized into two types: liquid-based and gas-based. Liquid-based EDM drilling machines use liquid as the dielectric medium. However, since the liquid must pass through the small hole in the copper rod, clogging may occur. Thus, the smallest hole achievable is 0.15 mm, with a maximum depth of 350 mm. Gas-based EDM drilling machines, on the other hand, use gas as the dielectric medium passing through the copper rod, which is less prone to clogging and allows for the drilling of more precise small holes.

Below are the key features of EDM drilling machines:

1.Suitable for processing various conductive materials such as stainless steel, hardened steel, hard alloys, copper, and aluminum.

2.Capable of drilling holes with diameters ranging from ∅0.3 mm to ∅3.0 mm, with a maximum aspect ratio of 200:1 or higher.

3.Maximum drilling speed of 20-60 mm per minute.

4.Can directly drill into inclined or curved surfaces using tap water as the working fluid.

5.Equipped with digital display devices for the X, Y, and Z axes of the worktable.

6.Features automatic electrode trimming functionality.

7.Provides rapid upward and downward movement for the spindle.

8.Offers adjustable machining voltage.

9.Includes edge positioning capability.