Електроерозійний дрото-вирізний верстат Mitsubishi SG-S series

The Mitsubishi SG-S is a series of CNC die-sinking EDM machines for mould and die making, aerospace components and medical technology. The series comprises three models — SG8S, SG12S and SG28S — which differ in axis travel, table size and maximum workpiece weight. The machines are designed for machining steel, cemented carbide, titanium and other electrically conductive materials.

Standard equipment includes the GV80 generator, an integrated C-axis with a zero-point clamping system, and a fire extinguishing system.

Design and accuracy

Positioning accuracy is ensured by:

• a rigid machine structure;
• high-precision ball screws and linear guides;
• an integrated C-axis.

The main structural components are cast. The compact layout is achieved by concentrating the structural material along the axis travel paths. The rigid head design provides high Z-axis dynamics.

Z-axis drive

The Z-axis drive provides acceleration of up to 1.6 g and traverse speed of up to 20 m/min. Fast electrode retraction and plunging improve flushing of the working gap and reduce machining time. All axes feature collision protection.

The CNC, generator electronics, axis amplifiers, inverter and motors are all manufactured in-house by Mitsubishi Electric.

GV80 generator

The core of the SG-S series is the GV80 generator with a maximum output current of 80 A. The generator is optimised for graphite electrodes: it provides low electrode wear, which makes it possible to reduce the number of electrodes required per part. The generator is also suitable for machining cemented carbide.

The generator controls the energy of each discharge pulse. This produces sharper edges and reduces micro-cracking in the surface layer, including when machining cemented carbide, which has a positive effect on the service life of machined forming tools. The actual quality of the surface layer depends on the machining conditions, the workpiece and electrode materials, and the number of finishing passes.

According to the manufacturer, the achievable surface roughness on steel is Ra 0.1 µm. The value depends on the machining conditions, electrode material and machining area.

Option — GV120 generator. On the SG12S and SG28S, the standard generator can be replaced with a 120 A generator when a higher material removal rate is required for large cavities.

IDPM — machining deep cavities

The IDPM (Power Master) function optimises Z-axis motion when machining deep cavities and ribs:

• fast electrode retraction and plunging;
• controlled sinking on contact surfaces;
• intensive flushing in deep ribs.

The function aims to reduce machining time while keeping electrode wear to a minimum.

Maisart — artificial intelligence in the control system

D-CUBES generation controls use Maisart, the artificial intelligence technology developed by Mitsubishi Electric. It provides:

• predictive machine operating strategies;
• self-learning process optimisation;
• continuous adjustment of machining parameters.

The goal is higher productivity and lower electrode wear.

Programming and operation

Programming is carried out in a dialogue-based mode:

• a clear dialogue in plain language;
• simple selection of the machining technology;
• automatic assignment of the machining strategy;
• external programming software is included in the scope of supply.

A graphical interface for workpiece and electrode setup simplifies job preparation. Online help is available on the control panel.

3D check function. The EDM program can be verified on the machine control panel against an imported 3D model in Parasolid format.

Job scheduling and data analysis

Integrated job scheduling makes it possible to:

• assign job priorities;
• insert urgent programs into the queue;
• connect an external programming system.

This provides the basis for automating machine operation.

The SG-S control system includes data analysis tools:

• advance calculation of erosion time;
• analysis of operating data, including the actual cost of each job;
• data export for external processing.

Working area

The three-sided drop-down tank provides easy access to the working area for workpiece setup. The ground worktable is positioned at an ergonomic height and has T-slots. The top cover opens for crane loading.

Options and clamping systems

Automatic electrode changer with 10 or 20 positions.

Clamping systems. The C-axis interface is compatible with EROWA, System 3R and Hirschmann clamping systems.

Glass linear scales on all axes are available as an option to increase positioning accuracy.

The machine configuration is selected to suit the production requirements: workpiece size and weight, material, electrode type, and accuracy and surface finish requirements.

Maintenance

The machine is designed for long service life, provided that scheduled maintenance is carried out in accordance with the manufacturer's instructions, including filter and dielectric replacement and inspection of the fire extinguishing system.