• 한국생산제조학회지
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• 제7권4호
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• pp.56-63
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• 1998

The purpose of this is to analyze experimentally how the change of cutting speed have effects on hole over size of cutting hole, surface roughness of workpiece and roundness during the deep hole machining of SM55C with solid BTA drill using BTA drilling system. Conclusion reached is as follows. (1) The diameter was expanded for 25$\mu$m at the first section and then was reduced 0$\mu$m and 15$\mu$m respectively at the 10m and 20m section comparing to the diameter of tool with respect to the variation of cutting length at 70m/min of cutting speed. 0.15mm/rev of feed. (2) It was proved that roughness was below 8.67$\mu$m for the whole section of cutting length. (3) The roundness has been below 12$\mu$m. Regarding the polygon phenomenon, it has been proved that not only uneven best at 70m/min of cutting speed. 0.15mm/rev of feed.

• 한국생산제조학회지
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• 제25권6호
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• pp.401-409
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• 2016

The formation of micro-burrs in micro-milling processes causes several problems related to productivity and surface integrity. It should be minimized and suppressed by effective monitoring of the cutting conditions. This paper presents the correlation between the micro-burr length and cutting signals in the micro-milling process of an Al alloy (Al6061-T6). The acoustic emission (AE) signals and cutting force signals are acquired during the experiments. The characteristics of the cutting signals are obtained by analyzing the AE root mean square value and resultant cutting force. In addition, the micro-burr length is measured according to the cutting conditions by analyzing a scanning electron microscopy image of the machined surface. The results of this study can be used to enhance the surface quality of micro parts.

• 한국정밀공학회지
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• 제10권4호
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• pp.206-215
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• 1993

The finite element method is applied to analyze the mechanism of metal cutting, especially micro metal cutting. This paper introduces some effects, such as constitutive deformation laws of workpiece material, friction of tool-chip contact interfaces, tool rake angle and also simulate the cutting process, chip formation and geometry, tool-chip contact, reaction force of tool. Under the usual plane strain assumption, quasi-static analysis were performed with variation of tool-chip interface friction coefficients and tool rake angles. In this analysis, cutting speed, cutting depth set to 8m/sec, 0.02mm, respectively. Some cutting parameters are affected to cutting force, plastic deformation of chip, shear plane angle, chip thickness and tool-chip contact length and reaction forces on tool. Several aspects of the metal cutting process predicted by the finite element analysis provide information about tool shape design and optimal cutting conditions.

• 생물환경조절학회지
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• 제19권3호
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• pp.153-158
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• 2010

고구마 만기재배를 위하여 '진홍미'를 공시하여 생육 및 수량에 미치는 삽수크기 및 삽식깊이의 영향을 조사하였다. 삽수크기에 따라 삽식 30일 후 줄기신장, 마디수 및 생체중 등은 유의한 차이를 보였으나, 120일 후에는 10cm와 30cm 삽수 간에서만 차이를 보였다. 삽식깊이에 따라 삽식 30일 후 초기 생육은 2마디 깊이 삽식에서 가장 양호하였고, 4마디 깊이 삽식에서 오히려 늦어지는 경향을 보였다. 그러나 120일 후 지상부 생육은 유의한 차이를 보이지 않았다. 삽수 크기가 클수록 주당 총저수와 주당 총저중, 상저비율이 증가하였으며, 식물체당 괴근수 및 괴근중, 10a당 수량 등은 10cm 삽수에서 20~30cm 삽수보다 유의하게 감소하였다. 또한 삽식깊이가 깊을수록 식물체당 괴근수는 증가한 반면, 평균 괴근중은 감소하였고, 10a당 수량은 3마디 삽식에서 기장 높았다. 띠라서 고구마 만기재배에서 생육 및 수량을 증대시키기 위해서는 삽수크기는 20cm 이상, 삽식깊이는 2~3마디로 재배하는 것이 좋을 것으로 생각된다.

• 유공압시스템학회:학술대회논문집
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• 유공압시스템학회 2010년도 춘계학술대회
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• pp.66-69
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• 2010

A punched pipe in a muffler for an automobile has many important variables, like location of holes in the pipe and length of the pipe related to noise reduction of a diffuser. This pipe is cut depending on length of product and this process, generally workers cut pipes by hands. In this process, there are many errors and it relies on the skill of workers, so it can happen that cycle time for complete product gets long and productivity gets low. Therefore, we need a vision system to distinguish holes in the punched pipe and a transfer system to set the cutting position automatically by moving the pipe depending on forward and backward part of the holes. This paper explains the development of an automatic transfer device which will cause the beating pipe to be cut correctly, exactly the same length as the product.

• 대한기계학회논문집
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• 제12권2호
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• pp.252-261
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• 1988

본 연구에서는 강의 2차원 적삭실험을 행하고 칩의 두께측정으로부터 구한 전단각 해에 의한 전단각 값의 비교를 통하여 이들 전단각 해의 한계성을 고찰하였으며,Zorev에 의한 제한된 전단과정과 마찰과정의 상호 의존성에 입각한 정역학적인 평형조건 과 공구경사면에 작용하는 응력분포의 가정하에서 전단각.PHI.의 새로운 해를 유도하고 이의 실현성을 검토하였다.

• 한국정밀공학회지
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• 제33권6호
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• pp.447-452
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• 2016

The simulation of Carbon fiber reinforced polymer (CFRP) machining facilitates the selection of optimal cutting parameter for high machining efficiency and better surface quality. In this study, This paper proposes a dual-dexel model to represent the fiber laminate with computational geometry method to calculate the fiber length removed per revolution and fiber cutting angles. A flat end milling simulation software is developed in C# to simulate and display the CFRP milling process. During simulation, fiber lengths, fiber cutting angle and engaged cutting angle can be displayed in real-time. A CFRP plate with different angles in different layer is used to compare the simulation results.

• 한국환경복원기술학회지
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• 제5권5호
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• pp.22-29
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• 2002

This study was conducted to suggest develop revegetation methods and to classification of cutting-rock slopes revegetation type. The data was collected from pre-experienced data, reports and journal. Also research result was reflected from field research for the conditions of construction, vegetation types and field conditions. As the result of analyze, the factors affecting the plant coverage rates of cutting-rock slopes were period of construction, revegetation methods, slope gradient and slope length. Classification of cutting-rock slopes revegetation type was fourth from material of revegetation measures and spray type. It is recommended to adjust the proposed factor as environment, field condition and characteristic related with revegetation measures on slopes for the presentation of revegetation standard.

• 대한기계학회논문집B
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• 제25권6호
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• pp.837-844
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• 2001

Jet cutting technology currently makes use of a generic supersonic gas jet to improve the cutting speed and performance. In order to get a better understanding of the flow characteristics involved in the supersonic jet cutting technology, the axisymmetric Navier-Stokes equations have been solved using a fully implicit finite volume method. Computations have been conducted to investigate some major characteristics of supersonic coaxial turbulent jets. An assistant gas jet has been imposed on the primary gas jet to simulate realistic jet cutting circumstance. The pressure and the temperature ratios of the primary and assistant gas jets are altered to investigate the major characteristics of the coaxial jets. The total pressure and Mach number distributions, shock wave systems, and the jet core length which characterize the coaxial jet flows are strongly affected by the pressure ratio, but not significantly dependent on the total temperature ratio. The assistant gas jet greatly affects the basic flow characteristics of the shock system and the core length of under and over-expanded jets.

• 한국표면공학회지
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• 제34권4호
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• pp.337-341
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• 2001

TiN coating of high speed end mill is recently generalized. The study of coating layer using ion plating is mainly about the coating method and the why of the longer life of coated tools. In CNC machning process, metal cutting isn't carry out until the tools including the end-mill and so on are fractured. Namely, it is difficult precision processing when the cutting force of the cutting tool is near the limit the fracture cutting force. So, the estimate of the life by wear and fracture is important. Therefore, this study is about the method to estimate the capacity of the coating layer in relation to the tendency of cutting force and the influence of the cutting capacity of coated end-mill by the condition N2, Ar, temperature. The cutting length is in inverse proportion to the cutting force ratio. So, the life of the TiN coated end mill can be predicated by the ratio of the increase of the cutting force.