• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2001년도 춘계학술대회 논문집
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• pp.71-73
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• 2001

The requirements for higher productivity call for high speed of the machine tool axes. Iron core type linear DC motor is growly accepted for a viable candidate of the high speed machine tool feed unit. LDM, however, has inherent disturbance force components: cogging and force ripple. These disturbance force directly affects the carrage tracking accuracy and must be eliminated or reduced. Reducing motor ripple, this paper adapted the feed forward compensation method. Experiments carried out on the linear motor test setup show that this compensation method is usable in order to reduce the motor ripple.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2002년도 추계학술대회 논문집
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• pp.365-369
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• 2002

This paper introduces that the machine tools's feed system optimizes by modeling for simulation and adjusting drive control parameter. The first method is frequency response of speed loop with design parameter by use of MATLAB application, in order that other axis can do equal to bandwidth. The second meted uses various sensor for analyzing machine tools's structure and adjustes jirk limitter.

• 한국공작기계학회논문집
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• 제16권6호
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• pp.125-132
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• 2007

Inherent dynamic interaction between flexible disk and workpiece creates partially non-flat surface profile. A flat zone was defined using minimum depth of engagement. Several key parameters were defined to explain the characteristics of the zone. Process conditions including disk rotation speed, initial depth of cut and feed speed were varied to produce product profile database. Correlation between key factors was examined to find the characteristic dependencies. Trends of key parameters were displayed and explained. Higher flat zone ratio was observed for lower depth of cut and higher disk rotation speed. Ratio of minimum depth of cut against target depth of cut increased for higher feed speed and disk rotation speed but was insensitive to the depth of cut variation. The process transition was visualized by continuously displaying instantaneous orientation of the deflected disk and the location of key parameters were clearly marked for comparison.

• 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.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 1999년도 제30회 추계학술대회
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• pp.208-212
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• 1999

In the use of glass fiber reinforced plastics(GFRP), cutting is often necessary. But the most of past studies have been interested in the effect of fiber orientation on tool wear. In this study, the effects of fiber contents on tool wear were investigated experimentally. By proper selection of cutting tool, the variables are cutting speed and fiber contents of 10, 20, 30wt% with fixed feed rate and depth of cut.

• 한국정밀공학회지
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• 제14권8호
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• pp.21-28
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• 1997

This paper presents the influence of the process parameters on the change in dynamic behavior of a lathe turning system. With variation of feed rate, depth of cut, direction of tool motion, cutting speed and tool location along the workpiece, the dynamic characteristics of stable cutting, chatter transition and fully developed chatter regions are demonstrated. The workpiece vibration during machining is continuously measured at different tool locations along the workpiece and quantitatively analyzed. Complex linear behavior due to change of process parameter values as well as fundamental wystem nonlinearity due to change of process configuration indicated by a tool path dependence of the locations of chatter onset and disappearance are described. Finally, the structural characteristics of the turning system which can have large and nonlinear effects on system behavior are presented.

• 열처리공학회지
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• 제5권3호
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• pp.165-170
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• 1992

The chip controls are investigated experimentally for the purpose of estimating cutting ability of hardened steel. In this experiment, hardened STD11 steel ($HR_c$ 60) is turned with carbide tool M20 under various cutting conditions and with several tool shapes. The main results obtained are as follows : 1) Cutting conditions of cutting speed 45m/min. feed 0.09-0.13 rev. depth of cut 0.4-0.6 are recommended for the chip excluding. 2) In case that the feed becomes larger and a lead angle of cutting tool becomes smaller, the chip excluding becomes easier. 3) It is confirmed that frank wear and crator wear on the cutting tool appear severely from about 10 min. after cutting start and chip excluding get worse.

• 한국정밀공학회지
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• 제10권1호
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• pp.34-41
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• 1993

SUS304 is wellknown as difficult-to-machine materials. It is easy to appear workhardened, and workhardening is one of the causes of groove wear on the tool. In this paper, the author would like to compare the width of flank wear with that of groove wear, and to find whether the groove wear can be used as a criterion of a tool life. The design of the twelve tests provides three levels for each variable (speed: 200m/min, 118m/min, 70m/min; feed: 0.3mm/rev, 0.17mm/rev, 0.1mm/rev; depth of cut: 0.4mm, 0.28mm, 0.2mm). The study of tool-life testing by statistical technique follows usual most scientific sequence. So the tool-life predicting equation is calculated by the method of least squares. The overall adequacy of the model can be verified by the analysis of variance. The results obtained are as follows : 1) When SUS304 is cut in 200(m/min), the width of flank wear is much larger than that of groove wear. 2) In cutting speed 118m/min, flank wear is a little larger than groove wear and in the cutting speed 70m/min, the latter is a little larger so that it is reasonable to determine the tool life according the crierion by groove wear in the low cutting speed (less than 70m/min). 3) Owing to the burr the depth of engagement along the cutting edge is extended toward the shank.

• 한국정밀공학회지
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• 제13권5호
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• pp.122-130
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• 1996

In this study, machinability of some aluminum-magnesium alloy are experimentally investigated using polycrystalline diamond tool with turning, and evaluated some independent cutting variables affected micrometal cutting characteristics as cutting force, specific cutting resistance, shear angles. To know the effect of cutting parameters of single point diamond machining, experiments were performed to measure cutting forces for high speed turning of aluminum alloy 6061-T6, SM45C and FC20 with poly- crystalline diamond and coated cemented carbide tool. Independent cutting variables were changed to a variety of cutting speed, feed rate, rake angles, material properties of workpiece and tool. Futhermore. Some useful informations are obtained in this study can guide micro metal cutting of aluminum alloy with diamond tool.

• 대한기계학회논문집A
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• 제21권9호
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• pp.1520-1530
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• 1997

Machining pressed compacts of ceramic and WC-Co materials can be the most cost effective way of forming the bodies prior to sintering when the required number of pieces is small. In this study, in order to clarify the machinability for turning, the $Si_3N_4$ and the WC-Co green compacts unsintered were machined under different cutting conditions with various tools. Absorbing chips by vacuum hose decreases tool wear. The tool wear becomes larger in the order of the ceramic, CBN and cemented carbide tools in machining the $Si_3N_4$ green compacts. In machining the WC-Co green compacts, the tool wear becomes larger in the order of the ceramic, cemented carbide and CBN tools. The land of cutting edge does not affect tool wear. When machining with cemented carbide tool, the tool wear i equal cutting length is nearly identical in spite of the increase of cutting spee, and the roughness of machined surface was the best in the cutting speed of 90 m/min. The tool wear decreases with the increase of rake angle and relief angle and with the decrease of nose radius. The machined surfaces become worse with the increase of feed rate and depth of cut, and with the decrease of rake angle and relief angle. The tool wear is not affected by the feed and depth of cut.