• 한국생산제조학회지
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• 제7권6호
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• pp.49-56
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• 1998

Super precision working technique and machine tool have been continually developed thanks to advanced electronic field. To obtain good result. it is necessary to investigate surface in grinding with $mu extrm{m}$ level. There were quite many researches to satisfy these demands by using non-contact methods through the computer vision. In this study, the texture of working surface was analyzed. co-occurrence matrices was obtained from the surface roughness. Texture parameter was obtained using position operator composed of $ heta$, d according to variation of angle direction and distance. As a result, it was found that surface texture was more affected by direction($\theta$) than distance(d).

• 한국정밀공학회지
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• 제26권5호
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• pp.64-71
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• 2009

Cylindrical lens core for optical transceiver was designed and machined. With the lens design data, WC asymmetric core surface data were generated for non-revolutional ultra-precision grinding. Grinding process for optimum machining conditions of target surface was studied in terms of surface roughness and form profile. We used experimental results to optimize turbine speed, feed-rate and depth of cut with durable grinding wheel wear. Ground WC cores were measured contact type profilers and verified.

• 한국정밀공학회지
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• 제21권8호
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• pp.27-33
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• 2004

The ultra-precision cutting is a key technique for the manufacture of optical components such as aluminium mirrors, electroless nickel mirror, plastic mirror in a variety of advanced science and technology applications. The paper presents experimental results of ultra-precision diamond fuming of electroless nickel materials. In general, the cutting condition such as feed rate and depth of rut, have effect on the surface roughness in ultra-precision diamond turning. To obtain an optimal cutting condition, we studied the effect of the cutting speed. the tool length, the tool nose radius, the feed rate and depth of cut on the surface roughness. So, the relationship of the surface roughness and cutting condition has been clarified. From the experimental results, the machined surface roughnesses were obtained less than 1nm rms.

• 한국공작기계학회논문집
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• 제11권2호
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• pp.95-102
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• 2002

Due to the development of the CNC machine tool and CAM software, sculptured surface machining can be broadly used in die and mold industries and ball end milling process is often used for the sculptured surface machining. It is found out how feedrate affects the precision of the machining and also tried to study the most suitable feedrate in specific cutting condition. Two eddy current sensors were used far measuring tool deflections of X, Y axis, dynamometer for cutting force and roundness tester for roundness. It was found that the tool deflection is getting better as tool path is going to further from the center of convex surface. The reason is that the cutting force is increased as the tool approaches to the center. Examining the roundness, cutting force and tool deflection characteristics, it was found that the most suitable feedrate is 90mm/min in convex surface and 120mm/min in concave surface.

• 한국생산제조학회지
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• 제9권4호
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• pp.75-84
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• 2000

The main goal of our research is to compensate the milled surface errors induced by the tool deflection effects, which occur during the milling process. First, we predict cutting forces and tool deflection amount. Based on predicted deflection effects, we model milled surface shapes. We present a compensation methodology , which can generate a new tool trajectory, which is determined so as to compensate the milled surface errors. By considering manufacturing tolerance, tool path compensation is generalized. To validate the approaches proposed in this paper, we treat an illustrative example of profile milling process by using flat end mill. Simulation and experimental results are shown.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 춘계학술대회 논문집
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• pp.827-831
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• 1997

Conductive veramic matrix composite(CMC) workpiece of TiC 33%/Al /sab 2/O /sab 3/ 66% Y /sab 2/ O /sab 3/ was machined by die sinking electrical discharge machining(EDM) according to different pulse duration and suty factor for reverse polarity of electrode. Material removal rate(MRR) was examined by process under various operating conditions. The surface morphology was evaluated by surface roughness values and scanning electron microscopy(SEM) research. The more MRR was obtained according to increase pulse duration and duty factor. Also the maximum surface roughness(Rmax) of EDMed surface was slightly changed with increased pulse duration and duty factor. The SEM photographs of EDMed surface showed wide recast wide recast distribution region of melting materials in purse duration 0.130(ms) than 0.048(ms).

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 춘계학술대회
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• pp.845-850
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• 2003

The scattered light pattern from a machined surface generally contains much information concerning the surface roughness. The light pattern can be acquired by optical system and analyzed by statistical method. This kind of surface roughness measurement system can be easily adopted on the machine measurement. But the fully assembled system is too complex to implement on small systems using micro-controller. This study proposes the idea of reducing the number of optical components by removing screen and examines image processing of a light pattern to minimize the negative result of incomplete optical system. And the Gaussian blur filtering is concluded to be the best method of proposed measurement system. Furthermore light intensity variation of image pattern can be treated as a signal, therefore FIR filtering gives the similar result of Gaussian blur effect.

• 한국기계가공학회지
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• 제2권3호
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• pp.90-95
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• 2003

The W-EDM is very important In precision machining of die, punch and small parts of precision products, so this machining method is widely used in various fields of industry. In this study, machining characteristics of Hand Drum Form and surface roughness are investigated experimentally. As Hand drum form has great effect on straightness of cut-surface of workpiece, its evaluation is very important in precision cutting. As experimental material, the mold material, STD11 is used and machined by CNC wire-EDM using the 025mm wire in diameter with repeated cutting up to 6 times. The thickness of workpiece is vaned in 20, 40, 60, 80, 100mm Hand drum form and surface roughness are measured after each cutting. Experimental results show that four times-cutting is optimum in the point of hand drum form and surface roughness.

• 한국공작기계학회논문집
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• 제16권1호
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• pp.53-59
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• 2007

The cutting tests of wood patterns are carried out using CNC milling machine. The cutting forces are monitored to analyse the cutting process. The surface characteristics of machined surface are investigated at various cutting conditions such as cutting speed, feed speed, cutting direction of wood pattern and wood material. In the CNC end-milling, the surface roughness increases as feed speed increases and decreases as cutting speed increases. However, the cutting force and surface roughness are different along the cutting direction and material of wood pattern.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 춘계학술대회 논문집
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• pp.788-793
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• 1997

The surface,generated by end milling operation, is deteriorated by tool runout,vibration,friction,tool deflection, etc. In many source,deflection of tool affects to surfave accuracy. To develop a surface accracy model,method for the prediction of the topography of machined surfaces has been developed based on models of machine tool kinematics and cutting tool geometry. This model accounts for not only the ideal geometrical surface, but also the deflection of tool resulted in cutting force. For the more accurate prediction of cutting force,flexible end mill model is used to simulate cutting process. Compute simu;ation have shown the feasibility of the surface generation system.