• 한국정밀공학회지
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• 제15권10호
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• pp.172-179
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• 1998

To quickly determine the effect of the substitute component on the machine's performance is very important in the design and manufacturing processes. And minimizing machine cost and maximizing machine quality mandate predictability of machine accuracy. In this study, in order to evaluate the effects of the component's geometric errors and dimensions on the machining accuracy of gantry-type 5-axis machining centers, a geometric error analysis and virtual manufacturing system are developed based on the mathematical model for the shape generation motion of machine tool considering the component's geometric errors and dimensions, the solid modeling techniques and so on.

• 한국정밀공학회지
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• 제28권8호
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• pp.904-914
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• 2011

The volumetric errors of CNC machining centers are determined by 21 errors, including 3 linear errors, 6 straightness errors, 3 perpendicular errors, 9 angular errors and non-rigid body errors of the machine tool. It is very time consuming and hard to measure all of these errors in which laser interferometer and other parts are used directly. Hence, as many as 21 separate setups and measurements are needed for the linear, straightness, angular and perpendicular errors. In case of the 5-axis machining centers, two more rotary tables are used. It can make 35 error sources of the movement. Therefore, the measured errors of multi movements of the 5-axis tables are very complicated, even if the relative measured errors are measured. This paper describes the methods, those analyze the error sources of the machining centers. Those are based on shifted diagonal measurements method (SDM), R-test and Double ball bar. In case, the angular errors of machine are small enough comparing with others, twelve errors including three linear position errors, six straightness errors and three perpendicular errors can be calculated by using SDM. To confirm the proposed method, SDM was applied to measuring 3 axes of machine tools and compared with directly measurement of each errors. In addition, the methods for measuring relative errors of multi-axis analysis methods using R-test and Double Ball Bar are introduced in this paper.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1991년도 추계학술대회 논문집
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• pp.1-13
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• 1991

This paper describes two FMS, which were developed by SAEIL Heavy Industries. One is FMS for machining of circular parts, that are automobile's axle shafts. This system consists of 13 units, including 7 CNC machine tools. The other is FMS for machining of non-circular parts namely casted or steel block within size of 1.2 X 1.2 X 1.5m. This FMS consists of 8-machining centers, 1-automated warehouse, 2-unmanned Robo Trailers, and computer control room. All systems are functioning satisfactorily and so help greately towards automation of Korean industries.

• 한국정밀공학회지
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• 제8권4호
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• pp.7-22
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• 1991

This paper describes two FMS, which were developed by SAEIL Heavy Industries. One is FMS for machining of circular parts, that are automobile's axle shafts. This system consists of 13units, including 7CNC machine tools. The other is RMS for machining of non- circular parts namely casted or steel block within size of 1.2${\times}$1.2${\times}$1.5m. This FMS consists of 8-machining centers, 1-automated werehouse, 2,-unmanned Robo Trailers, and computer control room. All systems are functioning satisfactorily and so help greately towards automation of Korean industries.

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 1999년도 추계학술대회
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• pp.183-189
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• 1999

Nowadays advanced manufacturing companies are trying to find a way to check the performance of their production equipments and plants from remote sites. However, it is hard to monitor the status of machine or to check the performance of the processes because the regional limitation of distributed environment. This paper presents research results in the real time monitoring of machining processes and internet_based operation of machining centers via internet, which is implemented using VRML and JAVA.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2004년도 춘계학술대회 논문집
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• pp.354-358
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• 2004

There was not the evident analysis about the cutting process of CNC machining, and wouldn't be difficult to estimate the result of machining for the various cutting conditions. Therefore they were not founded the systemic technology about the optimum cutting conditions and selection of cutting tools. So this study have investigated the common facts for needs through the end-mill cutting machining by Machining-Centers or High-speed cutting machines, and developed the user-centered intelligent decision system to selection of the methodology about cutting conditions to improve the machining efficiency of end-mill cutting process.

• 산업공학
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• 제7권2호
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• pp.107-120
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• 1994

This study introduces a scheduling policy to achieve unmanned operations in machining shops representing the feature of both FMS and machining centers. The proposed policy considers the practical constraints in the machining shops such as lot sizes, multiple pallets, and jig/fixtures. In addition, rescheduling to cope with extraordinary events(eg., arrival of high-priority jobs and breakdown of machines) is included. Basically, the scheduling policy consists of four procedures; (1) selection of a job according to dispatching rule, (2) selection of a machine, (3) assignment of jobs to a multiple pallet for the unmanned operation during a certain shift, and (4) prevention of unexpected machine idle caused by constraints on jig/fixture.

• 한국생산제조학회지
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• 제22권3호
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• pp.349-355
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• 2013

Recently, there is an increasing need to produce more precise products with small deviations from defined target values. Machine capability is the ability of a machine tool to produce parts within a tolerance interval. Capability indices are a statistical way of describing how well a product is machined compared to defined target values and tolerances. Today, there is no standardized way to acquire a machine capability value. This paper describes a method for evaluating machine capability indices in machining centers. After the machining of specimens, the straightness, roundness, and positioning accuracy were measured by using CMM (coordinate measuring machine). These measured values and defined tolerances were used to evaluate the machine capability indices. It will be useful for the industry to have standardized ways to choose and calculate machine capability indices.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1995년도 추계학술대회 논문집
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• pp.830-835
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• 1995

To quickly determine the effect of the substitute component on the machine's performance is very important in the defign and the manufacturing processes. And minimizing machine cost and maximizing machine quality mandata predictability of machine accuracy. In the study, in order to evaluate the effects of the component's geometric errors and dimensions on the machining accuracy of gantry-type 5-axis machining centers, a geometric error analysis and virtual manufacturing system is developed based on the mathematical model for the shape generation motion of machine tool considering the component's geometric errors and dimensions, the solid modeling techniques and so on.

• 한국생산제조학회지
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• 제19권2호
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• pp.251-259
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• 2010

It is presented in this study a new efficient intelligent machining strategy, which can be used to remove the uncut volume at the boundary region of curved surfaces caused by cutter interference. The geometric form definitions and recognition of topological features of the surface triangulation mesh are used to generate cutter paths along successive and interconnected steepest pathways, that minimize the cusp height left after flat end milling. In order to machine the uncut volume gradually, the z-map cutter centers are adjusted to avoid cutter interference for the 6 kinds of avoidance types. And then, the generative subsequent paths are sequenced to determine the second step cutter paths for the next uncut volume. For the 2 kinds of test models with convex and concave surface region, the implemented software algorithm is evaluated by investigating the residual swelling of uncut volume for each machining step.