scholarly journals Deep Hole Fabrication on Inside Wall of Another Hole by Means of Electrical Discharge Machining

2015 ◽  
Vol 81 (11) ◽  
pp. 995-999
Author(s):  
Tohru ISHIDA
Keyword(s):  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Deep Hole ◽  
Inside Wall

Fundamental Study on Hole Fabrication Inside a Hole by Means of Electrical Discharge Machining

2014 ◽  
Vol 8 (5) ◽  
pp. 773-782 ◽  
Author(s):  
Tohru Ishida ◽  
◽  
Yuichi Okahara ◽  
Masahiko Kita ◽  
Akira Mizobuchi ◽  
...  
Keyword(s):  
Electrical Discharge ◽  
Degrees Of Freedom ◽  
Electrical Discharge Machining ◽  
Simple Device ◽  
Fundamental Study ◽  
Hydraulic Equipment ◽  
Inside Wall

It is necessary to machine holes of complicated shapes for building pipelines of pneumatic or hydraulic equipment. However, the degrees of freedom of machinable hole shapes are limited, because holes are usually fabricated by drilling. To improve the degrees of freedom of these shapes, the authors have devised a method of fabricating a hole on the inside wall of another hole by means of electrical discharge machining. The method employs a very simple device. The results of the fundamental experiments indicate that this method has the ability to machine such a hole.

Elementary Study on the Creation of Cross Section's Changing Holes by Means of Electrical Discharge Machining

2009 ◽  
Vol 3 (5) ◽  
pp. 592-601 ◽  
Author(s):  
Tohru Ishida ◽  
◽  
Yuichi Mochizuki ◽  
Yoshimi Takeuchi ◽  
Keyword(s):  
Cross Sections ◽  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Electrical Discharge Machine ◽  
New Method ◽  
Mechanical Parts ◽  
Translational Movement ◽  
Discharge Machine ◽  
The Creation ◽  
Inside Wall

This study deals with the development of a new method to machine holes whose cross sections variously change along their axes. Machined holes have straight axes and constant circular cross sections, since holes are generally machined by drills. In other words, the shapes of machined holes do not have much variety. This study, however, develops a new, elementary device which can machine a certain shape on the inside wall of a straight hole by means of electrical discharge machining. This results in the creation of holes with variously changing cross sections. The aforementioned device consists of an electrode for electrical discharge machining and some mechanical parts, and is installed on a die-sinking electrical discharge machine (EDM). The device and EDM operate as a reciprocating block slider crank mechanism, so a translational movement of the main axis of the EDM can be converted into a rotational movement of the electrode. As a result, shapes which are identical to the envelope of the locus of the electrode movement can be machined. This leads to the creation of a semicircular space on the inside wall of a straight hole by starting the machining after setting the electrode in the hole. Experimental results show that, by changing the shape of the electrode, the device can produce variously shaped, semicircular spaces inside a straight hole. This proves that the new method of machining has the ability to create holes which have complicatedly changing cross sections.

scholarly journals Improving Machining Performance for Deep Hole Drilling in the Electrical Discharge Machining Process Using a Step Cylindrical Electrode

2021 ◽  
Vol 11 (5) ◽  
pp. 2084 ◽  
Author(s):  
Kamonpong Jamkamon ◽  
Pichai Janmanee
Keyword(s):  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Side Wall ◽  
Machining Process ◽  
Hole Drilling ◽  
Electrode Wear ◽  
Deep Hole ◽  
Cylindrical Electrode ◽  
Machining Performance ◽  
Deep Hole Drilling

The performance of electrical discharge machining for drilling holes decreases with machining depth because the conventional flushing and electrode cannot completely eliminate debris particles from the machining area. In this study, a modified electrode for self-flushing in the electrical discharge machining process with a step cylindrical shape was designed to improve machining performance for deep hole drilling. The experimental results of the step cylindrical electrode showed that the material removal rate increased by approximately 215.7%, 203.8%, and 130.4%, and the electrode wear ratio decreased by approximately 47.2%, 63.1%, and 37.3%, when compared with a conventional electrode for the diameters of 6, 9, and 12 mm, respectively. In addition, the gap clearance and concavity of the side wall of the drilled hole was reduced with the step cylindrical electrode. The limited high flank of the electrode led to an increase in the escape area of the debris that was partially removed from the machining area, and the limited secondary spark on the side wall of the electrode resulted in a reduction in machining time.

scholarly journals Using Response Surface Methodology of Deep Hole Electrical Discharge Machining Study of Nickel-Base Alloy Inconel-718

2021 ◽  
Author(s):  
Shao Hsien Chen ◽  
Kuo-Tai Huang
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Inconel 718 ◽  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Base Alloy ◽  
Deep Hole ◽  
Nickel Base Alloy ◽  
Machining Speed ◽  
Nickel Base

Abstract The blades in the high-pressure turbine section of engines of modern aerospace and defense industries need to be drilled for pressurization. The milling and drilling of nickel-base material Inconel-718 are likely to create tool wear and tear, so the drilling process of milling is replaced by deep hole electrical discharge machining (EDM) extensively. However, the EDM creates reaming or overcut phenomenon, so reducing overcut by parameter optimization is an important study. This study used will use response surface methodology to establish the influencing factors of machining parameters in the hole enlargement and machining speed. The experimental results show that the main influencing factor in the nickel-base alloy deep hole EDM is the discharge voltage (V), the secondary factor is the discharge current (I). The hole enlargement of processed hole without optimization is 60um~100um. The DOE is used for hole enlargement measurement and machining speed measurement to design important parameters, and to predict experiment data analysis. The half normal probability graph, Pareto chart and Analysis of variance (ANOVA) are used to learn about the significant factors of parameters and the influence of interaction. The outlet value of optimized parameters is relatively uniform, and the hole morphology is relatively free of residue stacking. Finally, the inlet and outlet results are improved by 17.9% compared with the original parameters. The optimization parameter value predicted by the fitted model is 0.0392mm, and the optimized upper and lower holes validation experiment machining error is 0.0380mm, and the values are quite close, proving that this prediction model is accurate. The model prediction of this DOE can enhance the applied technology of deep hole EDM for nickel-base alloy.

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