Development of

Small-sized and Simplified Sinker Electrical Discharge Machining (EDM)

Machine

Hiroyuki KidoTsukuba University of Technology Course of Design/Process Systems Department of Industrial Information 　Division of Industrial Technology

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Electrical Discharge Machining (EDM)

Electrically isolated

Arc

Vaporization

Removed MaterialPressur

e

EDM is a non-contact type method of thermal machining using electricity, and thus EDM can work irrespective of the hardness of workpiece. EDM is regarded as one of special machining methods.

Figure 1 Machining Process

Objectives

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•Develop and operate a machine using an unique machining method of EDM.

•Understand the mechanism and principle of EDM

•Apply the research results to actual manufacturing.

Assembly of Small-sized and Simplified EDM (SSEDM)

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1Clean damper

2Stepping motor

3Displacement gauge

4Coupling

5Threaded shaft

6Shank holder

7Motor bracket

8Slide

9Stage

10Vise

Figure 2 Assembly Drawing of SSEDM 　

Overview of SSEDM

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EDM Machine

Control Panel

Ion Exchange Unit ＊

Figure 3 Overview of SSEDM＊ Reference ：Manufacture of de-ionized water circulation system ： Wataru Nozoe ： System Technology Special Research ： 2010

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Main Control Items

Figure 4 Control Panel

Drive FrequencyBase VoltageMotor Connection

Power Connection

Pow

er

Stop

Up

Down

Acceleration

Base Voltage Check

Drive Frequency Check Contact Detection

Servo Control

Semi-auto Control

Drive Signal

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Figure 6 Contact Detection

Stop

Figure 5 Servo Control

To slide the electrode up and down to keep the machining voltage equal to the base voltage.

Figure 7 Semi-auto Control

Main Control Items

To see how many mm the electrode was consumed by.

(1)Servo Control

(2) Contact Detection

(3) Semi-auto Control

Machining Mechanism

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Workpiece

Figure 8 Machining Mechanism 　

Electrode

Mirror

Trial Machining

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Figure 10 Machining Result

Figure 9 Machining Situation

Machining Eccentricity

・ Workpiece ： Stainless Steel Pipe with a diameter of 1.5 mm・ Electrode ： Lead for Mechanical Pencil・ Machining Time ： 51sec.

Crushing

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Summary

•A small-sized EDM machine (SSEDM) was developed.

•SSEDM performed machining with small dimension.