• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.6
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• pp.783-790
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• 2013

Circular path generation for ball bar measurement using the simultaneous movement of two axes with at least one rotary axis requires the execution of CAM software. However, a change in the machine type or measurement condition requires a new execution of the CAM software, which is cumbersome. This paper presents a circular path generation technique that does not require CAM software and is applicable to different types of driving axes with an arbitrary structural configuration of machine tools and any ball bar setup condition. Mathematical equations are derived for three cases using the proposed technique. In addition, to inspect the measurement feasibility for avoiding physical interference among the ball bar parts, a tilting angle calculation is proposed. The validity of the proposed technique was verified by performing a ball bar experiment with A and C as the simultaneous axes of a five-axis machine tool.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.6
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• pp.1157-1163
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• 2009

In order to improve in quality and productivity using the CNC machine tools, it has been endeavored to elevate production process by adding supplementary axes(2 axes) to 2,3 axial CNC machine tools. It is because the movement between the progress of work in processed goods is remarkably decreased more than that of general CNC machine tools that productivity improvement with precision maintenance can be improved. VBScript in CAD/CAM is applied to utilize CNC machine tools added supplementary axes so that Multi-axial &Multi-process manufacturin g program can be conveniently drawn up. However, there is generally much skilful work and operation by the manual program of CAD(2.5D) and CNC machine tools in the filed. As a result of conducting an experiment by COM-filing VBScript at the spot of Insert Tip for milling Face Cutter in CAD/CAM Software(2.5D), it was not only timesaving to draw up program but also more convenient than complicated Multi CAD/CAM Software to approach and possible to program various products instantaneously.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.11a
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• pp.636-642
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• 1996

본 연구는 4축 또는 5축 NC 공작기계에 사용되는 Rotary Table의 오차를 측정하고 이를 보정하기 위한 연구이다. 먼저 일반적인 Rotary Table에 대한 오차모델이 설정되었으며, Rotary Table에서 존재하는 6가지의 오차를 각각 측정하였다. 측정방법은 3개의 길이오차는 1 개의 정밀볼(Master ball)과 3개의 LVDT, 3개의 각도 오차는 6각 폴리곤과 Autocollimator를 사용하여 측정하였다. 측정된 오차 성분들은 오차모델을 이용하여 보상치를 계산하였으며, 이 값은 추후 원래의 측정오차와 비교하는 방법으로 모델의 정확성을 검증할 것이다. NC 공작기계상에서 Rotary Table의 실제 보상 실험을 위하여 30$^{\circ}$간격으로 정밀한 볼이 장착된 볼-테이블을 설계하였다.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.6
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• pp.19-25
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• 2019

We have developed a tool that uses finite element analysis (FEA) to rapidly evaluate a shaft-bearing system of machine tools. We extracted commercial data on suitable clamping units and defined the inner profile of the shaft to avoid needing direct user input to define the profile. We use a splitting algorithm to convert the shaft into beam elements with two diameters and length. To validate the tool, we used it to design and evaluate a shaft-bearing system and found that our tool automated the construction of an FE system model in a commercial FEA package as well as the static stiffness evaluation; both tasks were completed in seconds, demonstrating a significant reduction from the minutes normally required to complete these tasks manually.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.16 no.5
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• pp.47-54
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• 2017

This study examines the implementation of a kinematic machining tool to evaluate the interference and collision phenomenon of 5-axis machining of wing ribs from airplanes, particularly for a large-size model airplane. We develop a machine simulation model of a parallel kinematic machining tool that can operate in a virtual space, which is equivalent to the authentic conditions in the field. The investigation of the simulation function elements indicates the necessity to generate the 6-axis machining, which attaches an angle head to the main axis of the machine. Using an NC program for the wing ribs, we attempt to verify the correspondence and conformity between the machine simulation model and the actual equipment.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1997.10a
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• pp.243-247
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• 1997

기존의 복합 Turning Center 보다 비구심상태에서의 가공, 3축밀링가공 및 3축/4축 동시 Milling가공 등의 특징을 갖고 복잡한 형상과 기능을 갖도 있는 부품 생산용 각형 FMS/C의 기본기계가 될 다기능 복합가공기[최대가공경 310mm *최대가공길이600mm, 6축제어(4축동시가공), ATC Magazine 20개, 주축18.5KW, 제2주축 15KW 회전수36-1,600RPM의 강력, 고속, 정밀 다기능 복합가공기]를 제2차 선도기술개발사업을 통해 개발을 추진하고 있다.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.04a
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• pp.284-289
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• 2002

In this paper, we develop a six-axes machining center tool(MCT) and CAD/CAM system based RAD Tool Program. The MCT consists of two mechanical parts, i.e., a X-Y-Z Cartesian coordinate typed MCT and a parallel-typed tilting table. Kinematics and singularity are accomplished to design the parallel-typed tilting table, and RAD Tool Program Is developed for the six-axes MCT, which requires the commands of position as well as orientation for machining of complex shape. In RAD Tool, the CAD/CAM system has a tool path generator, NC code generator and a graphic simulator. This paper designs the parallel-typed tilting table to meet the desired specification and presents the results of CAD/CAM system based RAD Tool Program.

• Journal of Aerospace System Engineering
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• v.12 no.4
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• pp.18-25
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• 2018

The head frame structure of a machine tool for aircraft parts, which requires machining precision and machining of difficult-to-cut materials is required to be light-weighted for precision high-speed machining and to minimize possible deformation by cutting force. To achieve high stiffness and for light-weight structure optimization design, a preliminary model was designed based on finite element analysis. The topology optimization design of light-weight, high stiffness, and low vibration frame structure were performed by minimizing compliance. As a result, the frame weight decreased by 17.3%, the maximum deflection was less than 0.007 mm, and the natural frequency increased by 30.6%. The static stiffness was increased in each axis direction and the dynamic stiffness exhibited contrary results according to the axis. Optimized structure with the high stiffness of low vibration in topology optimization design was confirmed.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.2 no.4
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• pp.33-39
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• 2003

The stiffness of multi-articulated industrial robots is very weak, because their structure is an articulated type with some links and joints. Thus it is known that cutting processes for metals are not accepted in machine shop well, but they have a lot of merits for cutting processes, for example, drilling, tapping, and engraving etc, because of the characteristics of their high degree of freedom. The temptation of cutting aluminium was carried out to investigate the feasibility and the limitations or constraints for cutting metals on them. First the mode shapes of 6 degree of freedom welding robot were taken and analysed, and next the cutting processes were practically carried out on it. The results of study were found out to show the feasibility of cutting processes at drilling under 6mm of tool diameter, as well as to have some limitations and constraints, for examples, feed rate, depth of cut and cutting force etc.

• Journal of the Korean Society for Precision Engineering
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• v.6 no.4
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• pp.21-31
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• 1989

역사적으로 CNC기술이 생산성향상에 기여한바는 매우 크다. 최근에는 고도의 생산성을 추구하는 CNC공작기계는 수요자들의 요구에 부응하여 관련업계는 CNC 기술의 발전을 더욱 가속화 시키고 있다. 오늘날의 CNC는 더욱 향상된 Computer Architecture에 적합한 Software System과 고속, 고집적의 소자기술을 결합한 것이라 볼 수 있으며, 그 결과는 생산을 자동화 하고 전체를 하나의 system화 하려는 요구에 부응하고 유연(Flexible)하며, 사용하기에 편리하고(User-friend- ly), 신뢰성과 높은 생산성을 갖추고 있다. 새로운 CNC 기술이 요구되는 응용분야는 고도로 자동 화 되고 결합 된 FMS에서 부터 단축제어용에 이르기까지 매우 광범위하다. 3축의 Milling, 6축 Machining Center, 전용기 등 Stand-alone 기계들을 위주로한 중소형기계 공장에 적합한 CNC 기술이 개발되고 있는 동시에 CELL LEVEL, 좀더 큰 규모의 FMS 또는 그 이상으로 자동화된 system을 구성하 기 위하여 많은 새로운 기능이 요구되고 종래의 CNC와는 다른 역할의 변화가 필요하다. 실제로는 많은 경우에 이러한 두가지의 응용이 공존하고 있으며, CNC의 기능이나 성능을 희생하지 않고 동일한 Hardware로 여러가지의 응용을 만족시켜야 한다. 생산공정과 생산기술의 변화가 반영되어야 하며, Control 기술도 변화하고 있다. 유연하고 확장가능한 Software, Hardware 구조의 CNC가 실제적으로 가장 Cost-effective한 해결책이다.