• 한국생산제조학회지
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• 제9권3호
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• pp.90-95
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• 2000

Today fiber composite materials are routinely used in such wide applications as ships automobiles aircraft space vehi-cles containers sporting goods and appliances. The current knowledge of machining glass fiber reinforced polyester com-posites unfortunately is inadequate for its optimum utilization in many applications. Therefore This paper deals with drilling characteristic of glass fiber reinforced polyester composites. In the drilling of glass fiber reinforced polyester the quality of the cut surfaces is strongly dependent on the drilling parameters. drilling tests were carried out on glass fiber reinforced polyester using standard HSS tools. The material containing random chopped strand fibers and woven roving was fabricated by hand lay-up The entrance and exit surface of the holes was examined. The cutting force was also mea-sured to analyze the drilling characteristics,.

• 한국레이저가공학회지
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• 제2권3호
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• pp.32-41
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• 1999

This study is about Jig used in wiring when we make Probecard and Large Scale Intergrated Electronic Circuit. The most universal wiring method is molding with Bond. Polymer film is punched down and adhesives is applied after wiring. Due to shrinkage and modification many problems still have happened in the process of molding. To solve these problems, ceramic plate was introduced in the study. Using Laser, an experiment of microhole treatment on ceramic plate was proceeded. Laser energy, assistance gas, and special features by purity degree were analyzed with the 35W low capacity YAG-Laser. In the condition of energy 0.08J, frequency 20Hz and interval time 200$mutextrm{s}$, about 70${\mu}{\textrm}{m}$ microhole was adequate for the Probecard Jig. In the purity experiment of ceramic materials, high purity ceramic met with good result for microhole. But the price is too high. The shape and size of holes machined combustion gas $O_2$ were better than those in $N_2$ and Ar, the inert gas.

• 한국정밀공학회지
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• 제19권4호
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• pp.147-153
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• 2002

In the preceding research, the active balancing device, which is an electro-magnetic type, has been developed and active balancing method using influence coefficient method is also proposed. The stability of active balancing control is studied in this paper. A stable condition for active balancing control is derived by estimating errors of influence coefficients. A gain scheduling control using influence coefficients of the reference model is proposed when dynamic characteristic of rotor system is changed. The stability of the balancing method is verified by experiments.

• 산업기술연구
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• 제26권A호
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• pp.69-73
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• 2006

Mach peening treatment is one of the various kinds of techniques to improve the fatigue properties. The mach peening process gives high-level work hardening and compressive residual stress near the surface layer, improving the fatigue strength. In addition, this treatment reduces slip bands that initiate the fatigue cracks near the surface. During impingement, a plastic indentation surrounded by a plastic zone is formed. Mach peening treatment characteristic is less energy consumption and is an environmental friendly processing methods that is not accompanied by pollution. It is machining process that can prevent fatigue fracture beforehand in structure using already as well as process of production. The test results showed that fatigue crack propagation delay appeared by drilling type 43%, mach peening type 110%.

• 대한기계학회논문집A
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• 제33권3호
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• pp.224-230
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• 2009

FIB has been commonly used as a very powerful tool in the semiconductor industry. It is mainly used for mask repair, device correction, failure analysis and IC error correction, etc. Currently, FIB is not being applied to the fabrication of the micro and nano-structured mold, because of low productivity. And also sputtering rate has been required to fabricate 3D shape. In the paper, we studied the FIB-Sputtering rate according to mold materials. And surface roughness characteristics had been analysed for micro or nano mold fabrication. Si wafer, Glassy Carbon, STAVAX and DLC that have been normally considered as good micro or nano mold materials were used in the study.

• 한국생산제조학회지
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• 제19권6호
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• pp.746-752
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• 2010

Rib structure has been used to bed and column of machine tool to heighten weight stiffness ratio, cost performance and weight saving. In this paper the bed rib structure was estimated with thermal characteristics. Using superposition principle, machine tool designer can describe every complicated heat generation in the machine tool thermal source. As thermal characteristics, thermal deformation of guide rail and column and Maximum-minimum temperature variation were selected. The size, configuration and direction against the thermal loading surface operated to the thermal characteristics. The DB chart was made following rib structure estimating thermal characteristics. With superposition principle and DB chart, machine tool designer can prognosticate the thermal characteristics without FEM analysis to every bed rib structure.

• 한국기계가공학회지
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• 제16권4호
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• pp.1-8
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• 2017

This paper concerns the possibility of 3D printing reverse idle gears for tractor transmission. For the purposes of this experiment, idle gears were manufactured using a SLA 3D printer, FDM 3D printer, and through machining. The accuracy of the idle gears produced in these three different ways were evaluated by the properties of their outer diameter, inner diameter, roundness, concentricity, parallelism, span, backlash, and gear grade. The tooth characteristics of the idle gears were evaluated by their profile, lead, and the pitch of the gears. The results of this experiment determined that the surface conditions created by the finishing process had a significant impact on the dimensional accuracy of the gears and the characteristics of their teeth.

• 한국기계가공학회지
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• 제16권4호
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• pp.62-68
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• 2017

Since the aircraft parts industry is a high-value-added industry, mass production order production, and the hundreds of thousands. Therefore, parts produced However, since these parts require high reliability and stability, a high degree of precision is required. In Korea, there on the roughness of the machined surface in cutting process. However, research on the surface roughness characteristic obtained by which is widely used for aircraft parts is still insufficient in Korea. The purpose of this study is to investigate the effect of turning tool rotation speed and X axis feed rate on the surface roughness of cutting tools in CNC lathes during cutting of aluminum alloy 7075.

• 한국정밀공학회지
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• 제14권11호
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• pp.93-101
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• 1997

Ever since the nonlinearity of machine tool dynamics was established, researchers attempted to make use of this fact to devise better monitoring, diagnostics and control system, which were hitherto based on linear models. Theory of chaos which explains many nonlinear phenomena comes handy for furthering the analysis using nonlinear model. In this study, measuring system will be constructed using multi-sensor (Tool Dynamometer, Acoustic Emission) in end milling process. Then, it will be verified that cutting force is low-dimensional chaos by calculating Lyapunov exponents. Fractal dimension, embedding dimension. And it will be investigated that the relation between characteristic parameter calculated from sensor signal and tool wear.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2000년도 추계학술대회논문집 - 한국공작기계학회
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• pp.188-192
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• 2000

In multi-purpose lathe, the design of tilting turret slide system has an important and critical role to enhance accuracy of the machining process. Tilting turret unit is traveled by 3-axis slide systems. There is a need to design this part very carefully. In this research, 3-axis sliding system with tilting turret is modeled by considering the element dividing, material properties, and boundary conditions using MSC/PATRAN. Mode and frequency analysis of each structures such as saddle, careg, and turret are simulated by MSC/NASTRAN, for the purpose of developing the effective design. The results of mode analysis and frequency analysis are visualized with PATRAN, and the mothod which can solve the resornance problem by eigenvalues and eigenvectors of each axe is developed as well.