• International Journal of Precision Engineering and Manufacturing
• /
• v.8 no.4
• /
• pp.10-15
• /
• 2007

Taguchi methods have been used for a long time to improve the product quality and process performance of a manufacturing system, Few researchers have applied this methodology in laser beam cutting (LBC) of sheet metals and found the considerable improvement in cut qualities. In all experimental investigations of LBC so far, the objective was to optimize the single quality characteristic at a time. In this paper the simultaneous optimization of multiple quality characteristics such as Kerf width and material removal rate (MRR) during pulsed Nd:YAG LBC of thin sheet of magnetic material (high Silicon-steel) has been presented using Taguchi's quality loss function. The results show the considerable improvement in multiple S/N ratio as compared to initial cutting condition. Also, the comparison of results from single and multi-objective optimization have been presented and it was found that the loss in quality is always possible shifting from single quality to multiple quality optimization.

• Journal of Fashion Business
• /
• v.11 no.1
• /
• pp.26-37
• /
• 2007

Madeleine Vionnet(1876$\sim$1975, France),the most prominent figure of the 20th century draping, started her apprentice in France in 1888 and expressed feminity of adult products through her various works until she closed the house in 1940. The feminine designs of the adult style appeared in 1930s, whose characteristics were silhouette and details that emphasize the body, and bias designs. Not only Vionnet, but also Chanel and Schiaparelli were the representative female designers at that time. The preliminary researches of Vionnet designs were mostly focused on her cutting methods. This paper purports to examine Vionnet's bias cutting method, to compare Vionnet with female designers of Chanel and Schiaparelli who led the mode of 1930s with feminine designs for the adult products in that period, and then to attempt creative designs by use of bias cutting.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.4 no.4
• /
• pp.14-20
• /
• 2005

This paper deals with the study of feasibility of rotary carbide tools in the machining of aluminium alloy. A rotary tool holder was designed and manufactured for this work. Experiments were performed using Taguchi methods and regression analysis to analyse the influence of various factors and their interactions on the cutting characteristics of rotary carbide tools during machining. The cutting force is influenced the most greatly at the inclination angle. The surface roughness is influenced distinctly at depth of cut. It deduced an equation to predict cutting force and surface roughness. Hence, it could be concluded here that the proposed model agrees with the experimental data satisfactorily.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.23 no.59
• /
• pp.119-127
• /
• 2000

This paper describes the database for wire cutting electrodischarge conditions and variable taper wire-cut Machining. Electodischarge wire-cut machining is applicable to all materials that are fairly good electrical conductors, including metals, alloys, and most carbides. Thus it provides a relatively simple method for making holes of any desired cross section in materials that are too hard or brittle to be machined by most other methods. In conventional wire cutting CAM systems usually generate the NC code omitting electrodischarge conditions, so operator edits the NC code manually. But it is very inefficient. Therefore in this paper we propose a wire cutting CAM system including database for electrodischarge conditions. Proposed system consists of three steps: 1) Development of database for electrodischarge conditions 2) Development of CAM functions, Including 2D CAD modeling tools, file I/O functions, wire path genera tion functions and postprocessor. 3) Development of variable taper wire-cut machining module. The proposed system has been tested in the JinYoung precision Machine Co.,LTD. and found to be working satisfactorily.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.19 no.3
• /
• pp.71-76
• /
• 2020

Various machining methods are being studied to improve the processing quality of the spherical R shape in press die. In this paper, we confirmed that changes in machining quality were associated with changes in cutting direction, path, and cutting angle, which are commonly used in the machining of molds. We obtained a surface roughness graph with each condition change in one specimen using an instrument that measured geometry and surface roughness simultaneously. The results of the study showed that the best surface roughness in the finish cut of the spherical surface was obtained using upward pick feed machining.

• Journal of the Korean Society for Precision Engineering
• /
• v.19 no.9
• /
• pp.90-97
• /
• 2002

Ceramics are being increasingly used in industry due to their outstanding physical and chemical properties. But these materials are difficult to machine by traditional machining processes, because they are hard and brittle. Recently, as one of various alternative processes, laser-beam machining is widely used in the cutting of ceramics. Although the use of lasers presents a number of advantages over other methods, one of the problems associated with this process is the uncertain formation of cracks that result from the thermal stresses. This paper presents a Bayesian probabilistic modeling of crack formation over thin alumina plates during laser cutting.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2002.10a
• /
• pp.181-184
• /
• 2002

In these day, fabrication technologies for micro parts become more important with the increase of interest on microsystem and developed through the various approaches in the whole world. Among these technologies; micro mechanical machining is one of the most effective methods for the fabrication of micro parts. In this study, we fabricated micro shafts using micro endmill and micromachining system and measured the cutting force at the process. Also, Based on the data, we simulated the deformation of micro shafts due to the cutting force. Through the simulation results, it was verified that the cutting force at the process is enough to cause dimensional error at the micro shafts.

• Proceedings of the KSR Conference
• /
• 2008.06a
• /
• pp.806-812
• /
• 2008

Many kinds of rolling-stocks that have various control methods are being operated by Seoulmetro which is a history of a city railroad rolling-stock. Seoulmetro is being faced with a wheel management comparing of other lines with a perpendicular wear of wheel and a side damage, and so on, by operating several cars at a loop line. This is causing maintenance expenses increase and deteriorating a fusibility of rolling-stock, for it has an effect on a rolling-stock using. A cutting pattern of wheel and a wear form affect the expected span of a wheel. A wheel cutting cause is classifed into cutting for reprofiling of a flange wear of wheel and for removing every kind defect which originates from wheel wear. In this study, Seoulmetro exhibit a stable rolling-stock use method and a reasonable management method of wheel, analysing wheel exchange condition and cutting management of wheel.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.9 no.6
• /
• pp.158-163
• /
• 2000

High speed machining of difficult-to-cut materials generates the concentrated thermal/frictional damage at the cutting edge of the tool and rapidly decreases the tool life. In this paper, the cutting environments, such as dry, fluid coolant, and compressed chilly air coolant, were investigated to improve the tool life. For this study, the compressed chilly air system was manufactured. The experiments were performed for various difficult-to-cut materials and various coated tools. The effectiveness of the developed methods on the basis of tool life was estimated. The results show that the cutting environment using compressed chilly air coolant provided better tool life than using the fluid coolant or using the dry.

• Journal of the Korean Society for Precision Engineering
• /
• v.16 no.9
• /
• pp.68-74
• /
• 1999

The influence of surface preparation methods after plasma cutting on the quality of weld zone was investigated. For comparison, three types of welded specimens were prepared by machining (WM), plasma cutting with light regrinding (WPG) and without regrinding (WP), by using three kinds of materials, carbon steel (SM45C), stainless steel (STS304) and aluminum alloy (A6061-T6). Nondestructive examination, hardness test, microstructure examination, and fracture toughness test were performed. The results showed that there was no appreciable reduction in hardness or fracture toughness in WP specimens. But a little difference in heat affected zone size was observed.