• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2000년도 춘계학술대회논문집 - 한국공작기계학회
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• pp.52-57
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• 2000

STD11 is one of difficult-to-cut materials and its cutting characteristic data is not built enough. A bad cutting condition of it leads to low productivity of die and mould, so it is necessary to evaluate the machining characteristics of STD11. In this paper, the relations of the geometry of ball-end mill and mechanics of machining with it are studied. The helix angle of ball-end mill varies according to a location of elemental cutting edge in the cutting process are difficult to calculate accurately. To calculate instantaneous cutting forces, it is supposed that the tangential, radial and axial cutting force coefficients are functions of elemental cutting edge location. Elemental cutting forces in the x,y and z direction are calculated by coordinate transformation. The total cutting forces are calculated by integrating the elemental cutting forces of engaged cutting edge elements. This model is verified by slot and side cutting experiments of STD11 workpiece which was heat-treated to HRC45.

• 한국정밀공학회지
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• 제15권6호
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• pp.40-47
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• 1998

Drilling is an indispensable process in manufacturing of the die and mould and the other mechanical parts which needs high dimensional and surface accuracy. In this paper, a new type of drilling method was proposed in order to improve both processing efficiency and accuracy. Specifically, the helical motion using ball end mill tools, instead of normal drilling method, was applied to perform an effective hole machining. In this paper, an theoretical background of the new type of drilling method was established, and the feasibility of the proposed theory was proved by experiments, where proposed drilling process in the paper gave a different machining specification than general method did.

• 한국공작기계학회논문집
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• 제16권5호
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• pp.191-197
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• 2007

Inclined surface milling in the mould and die industries is one of the most commonly needed cutting process. For the variety and complexity of cutting characteristics in various cutting condition, it is difficult to select a optimal tool path orientation. Especially, when the cutting process becomes unstable, it induces self-exited vibrations, a frequent cause of poor tool life, rough surface finish, damage to the workpiece and the machine tool itself, and excessive down time. The comparative results through FFT analysis in this study provide a guideline for the selection tool path orientation.

• Journal of Welding and Joining
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• 제23권3호
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• pp.40-46
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• 2005

Air gun has been one of the good tools to press two sheet metals. However, it is not easy to control the acting force precisely. A Servo-gun is a good tool to control the acting force on the workpiece comparing with the air gun. Servo-gun has a higher tensile shear strength and lower indentation depth as well as smaller spatter. Dynamic resistance was obtained according to the acting force and welding current. As the acting force was changed during welding, the welding quality was increased.

• 열처리공학회지
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• 제11권2호
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• pp.131-139
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• 1998

The object of this research is to estimate the hardenability of quenched carbon steels AISI 1050. The equation of transient heat conduction was analyzed to derive cooling curve by finite element method. The effects of temperature on physical properties, metallic structures and the latent heat by phase transformation were considered. A good agreement was found between analytical and experimental results to show that the proposed numerical procedure was reliable. This procedure could be used as the detabase for optimal condition of heat treatment cycle.

• 열처리공학회지
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• 제8권1호
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• pp.12-23
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• 1995

In this a set of constitutive equation relevant to the analysis of thermo-elasto-plastic materials with phase transformation during quenching process was presented on the basis of continuum thermo-dynamic. In calculating the transient thermal stresses, temperature between coolant and specimen(SM45C) surface was determined from the heat transfer coefficient. A calculation was made for specimen with 40mm in diameter quenched in coolant from $820^{\circ}C$ and the results are as follow. Stresses at starting point of transformation always show the maximum tensile value. Reverse of stresses takes place after completion of transformation of inner part at specimen.

• 대한안전경영과학회지
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• 제13권4호
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• pp.101-108
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• 2011

In this paper deals with strength of glass fiber reinforced plastics produced by shouting machine was investigated by universal testing instrument. We can obtain following results by performing the strength evaluation of polymer composite material according as varied environment temperature. The effect of environmental temperature on Strength properties was more sensitive in the weld specimen than parent. When changed environmental temperature, variation of strength in the parent was much bigger than it of weld specimen, that is, matrix in the parent, orientation in the specimen ware more sensitive to environmental strength. Tensile strength of polycarbonate matrix was similar regardless of mold temperature.

• 한국안전학회지
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• 제20권3호
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• pp.14-18
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• 2005

The ultrasonic handy scanner to be developed in this research is a nondestructive inspection equipment with various facility. The ultrasonic inspection is the technique area which apply range is increasing greatly with IT. The purpose of this research is development of a ultrasonic handy scan inspection device with the utility in a work spot. The ultrasonic handy scanner to be developed with portability in this research is able to carry out the spot inspection. It can contribute to the quality improvement, cost reduction and safety design.

• 한국재료학회지
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• 제9권10호
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• pp.1037-1040
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• 1999

열간압축 및 다이업셋한 Mischmetal-FeB-(C0,Ti,Al) 영구자석의 자기적 특성과 미세조직을 시료진동형 자력계, 투과전자 현미경, 주사전자 현미경, X-선 회절기를 이용하여 조사하였다. $\textrm{(MM)}_{12.5}\textrm{Fe}_{71.9}\textrm{Co}_{5.0}\textrm{Al}_{2.0}\textrm{B}_{8.6}$조성의 열간압축 자석은 $\textrm{H}_{c}$=4.27 kOe, $\textrm{B}_{r}$=4.75 kG, $\textrm{(BH)}_{max}$=3.82 MGOe의 특성을 보였다. 다이업셋 자석은 $\textrm{H}_{c}$=3.10 kOe, $\textrm{B}_{r}$=5.58 kG, $\textrm{(BH)}_{max}$=5.34 MGOe의 특성을 나타냈다. $\textrm{(MM)}_{12.5}\textrm{Fe}_{77.9}\textrm{Ti}_{1.0}\textrm{B}_{8.6}$ 조성의 경우, 열간압축 자석은 $\textrm{H}_{c}$=3.75 kOe, $\textrm{B}_{r}$=4.64 kG, $\textrm{(BH)}_{max}$=2.78 MGOe, 다이업셋 자석은 $\textrm{H}_{c}$=3.29 kOe, $\textrm{B}_{r}$=5.01 kG, $\textrm{(BH)}_{max}$=3.54 MGOe의 특성을 보였다. X-선 회절 및 투과전자 현미경 조사결과에 의하면, 다이업셋 자석에서 c축이 다이업셋 방향으로 놓이는 결정이방성이 나타나며, 이는 다이어셋 자석의 에너지적의 증가와 관련이 있는 것으로 보인다. Co의 Fe에 대한 일부 치환은 열간압축자석의 자기이방성을 증가시키는 것으로 나타났다.

• Design & Manufacturing
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• 제11권1호
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• pp.45-49
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• 2017

Currently, a lot of efforts to make increases the manufacturing efficiency have tried and there is growing the interest to implementing the machining operation through CAM automation and optimization. This kind of movement has shown gradually in 5X milling as well as 3X milling task. By the way, in case of 5X milling, it is difficult to hire the CAM experts who is an experience for 5X machining and also it has too big trouble to use them due to high cost. For this reason, you can see the manufacturer who is concern the CAM S/W to provide the NC automation program that beginners can generate easily the 5X milling in short term and the existing 5X milling process can be improved. These requirements need to make a NC automation process including the practical machining strategies same as the generation by NC expert. In order to support this, it is necessary to directly apply the 3D machining part based on NC template which includes the machining procedures, standard cutter library, auto machine area selection, analyze tool for part shape, machining condition setting considering the material stiffness to be provided by CimatronE and it should be created the 5axis machining data by a minimized operation. With user-friendly, CimatronE's NC machining automation tools improve the 5-axis machining process and speed up the process, maximizing work efficiency and improving product productivity compared to existing machining tasks.