• 한국생산제조학회지
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• 제19권6호
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• pp.739-745
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• 2010

The roller gear cam can control the rotational follower periodically by attaching several roller on the circumstance of follower shaft and it is widely used in non-backlash and precise actuating mechanism such as index table or ATC of machine tools. For machining the roller gear cam, 5 axis CNC machine tool is used and the geometric principle of CAM mechanism must be adopted to generate the NC-code and to develop the special CAD/CAM software because there is not commercial CAM system to machine the roller gear cam. The maker of the specially developed software in domestic user is generally from Japan or Taiwan. However these softwares do not reflect the post processing technique for finish machining in the module. Also, there is some limitation for further new application of itself and it needs higher costs for further application. In this study, the CAD/CAM software to overcome these problem was developed. And its reliability was verified by applying it in 5-axis CNC machining. Finally, the experimental result conducted in the 5-axis machining show good consistency in the movement of follower along the flute and in its Size.

• 한국정밀공학회지
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• 제22권7호
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• pp.122-129
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• 2005

Shoe with leather upper such as safety and golf shoe requires a roughing process where the upper is roughed fur helping outsole to be cemented well. It is an important and basic process for production of leather shoe but is not automated yet. Thus, there are problems that the defect rate is high and the quality of roughed surface is not uniform. In order to solve such problems, the interest in automation of roughing process is being increased and this paper introduces CAM system for 5-axis automatic roughing machine as one part of automation of roughing process. The CAM system developed interpolates a B-spline curve using points measured from the Roughing Path Measurement System. The B-spline curve is used to generate the tool path and orientation data fer a roughing tool which has not only stiffness but also flexibility to rough the inclined surface efficiently. For productivity, the upper of shoe is machined by side of the roughing tool and tool offset is applied to the roughing tool for machining of inclined surface. The generated NC code was applied to 5-axis polishing machine for the test. The upper of shoe was roughed well along the roughing path data from CAM and the roughed surface was proper fur cementing of the outsole.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2000년도 추계학술대회논문집 - 한국공작기계학회
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• pp.175-180
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• 2000

This paper describes the method and the process for impeller machining on 5-axis CNC machining center. Also, The CAD/CAM software for the impeller post processing is developed. The software can be interfaced with Solid-works software for confirmation of the impeller shapes. In this study, blades on impeller is described from Ruled-surfaces between two Ferguson curves. In this study, using 5-axis NC part program obtained from the developed software, a sample impeller was machined on 5-axis CNC machining center. The machined impeller was very agreeable to the designed impeller. Thus, theories proposed in this study can be very useful for the 5-axis machining of impeller blades with Ruled-surfaces.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2001년도 추계학술대회(한국공작기계학회)
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• pp.399-406
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• 2001

This study describes the geometric characteristic and the 5-axis machining method of end mill body with insert tip. The geometry of end mill body is consisted of the flute part and the insert tip part. Thus, this study defines the flute part as ruled surface with constant helix angle and the insert tip part as rectangular plane on general direction. The geometric algorithm and the 5-axis NC part program were calculated by our programmed software and a sampled end mill body was machined on 5-axis machining center equipped with two index tables. The machined end mill body with insert tip was very agreeable to the designed end mill body with insert tip. Thus, the method proposed in this study may be very useful for the machining of end mill body with insert tip.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1994년도 추계학술대회 논문집
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• pp.199-204
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• 1994

A method for determining the collision-free tool orientation for 5-axis milling is presented. In 5-axis milling, the proper tool orientation as well as the optimal CC-data has to be selected to machine the workpiece efficiently and accurately and accurately. Essentially, the tool orientation should be determined to avoid collisions between the tool and workpiece and to enable efficient machining. In this work, the tool orientation is determined at every CC-point which is assumed to be given. The procedure uses the potential energy method that assumes the tool and the part surfaces are charged with static electricity. This approach can detect can deteat both global and local collisions (gouging) irrespective of the tool shape. Further, in order to increase the machining efficiency, the material removal rate is maximized simultaneously.

• 한국CDE학회논문집
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• 제7권1호
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• pp.34-41
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• 2002

Five-axis NC machining, in general, is utilized in fabricating impellers, turbine blades, marine propellers that can be machined more effectively rather than three-axis machining. There have been many researches concerning tool interference avoidance, optimization of tool orientation. The C-space or Configuration-space was originated from the robotics area, which depicts interference-free joint-values in motion planning. In the paper we propose an optimizing scheme by which the maximum effective-radius of a face-milling cutter can be achieved for each CC(cutter-contact) point. Also the concept of a C-space for a CC point, the effective-radius map for 5-axis face-milling, and some illustrative examples of marine propeller machining, are presented.

• 한국기계가공학회지
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• 제16권4호
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• pp.127-134
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• 2017

A rotary table is a positioning device used in metalworking for the multiple axes of machine tools, and the utilization trend is increasing with machining efficiency. In the construction of a rotary table, the core technology is a power transfer unit that drives the table, typically a gear type and a roller gear cam type. As the rollers installed on the turret column have rolling movement on the contact surface of the roller gear cam, the roller gear cam type has the advantage of low wear, high load, and fast driving. Therefore, it is currently being replaced by a roller gear cam type. In this study, we researched a 5-axis machining method for the roller gear cam on a rotary table and a new method of applying double roller gear cam curve to reduce the noise and shock between the roller and the cam surface. We implemented the 5-axis machining process in this study using software to generate NC-code and machined the roller gear cams using a Mazak Integrex-200IV. We found that the roller gear cam and turret were able to identify mutual touch status and the noise from the operation of the roller gear cam was substantially reduced.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국내학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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• pp.1024-1030
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• 1993

In manufacturing press die with free surface, grinding operation is an important post process for surface finish and dimensional accuracy. With the advancement of NC technology. surface grinding operation is increasingly replaced by the gantry type manipulator. As the mechanics for grinding operation is different from machining operation, conventional CAM system for machining operation is hard to apply. In this. paper, we develop a five-axis CAM system by which an efficient gantry trajectory can be planned and verified. The developed system consists of four conceptual modules; namely CAD, PROCESS. CAM, and ANALYSIS. In the CAD module, the machined surface is represented by CL-data or surface modeler, and process parameters are specified by the PROCESS module. Then, the CAM module generates a series of grinding paths based on the grinding mechanics together with process databases for tool spaces and grinding conditions. The generated paths are verified via ANALYSIS module. Validation via real experiments is left for further study.

• 한국기계가공학회지
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• 제4권2호
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• pp.16-23
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• 2005

This study is intended to find out the reason of interference phenomenon of a machine tool when it operates for 5-axises working. The researcher made a Virtual Machine which has same figures of the 5 axises machine tool and Virtual Manufacturing System which has both Software factors - controller and NC code data to manipulate the movement characteristics of the machine - and Hardware factors - fixtures, workpiece, tools, holders and so on. With these virtual tools, this study is designed to find out the relation between the movement and the interference or collision, and also intended to verify the simulation and work-processing. In this study, the researcher found out, in case of the vertical 5 axises type, that it has more chances to have interference between the fixture, the workpiece and the main spindle including the tool holder due to the tilting kinetics of the main spindle. In case of the horizontal 5 axises type, on the other hand, the researcher found out that it has more possibility to have the interference between the main spindle and the rotary shaft.

• 한국강구조학회 논문집
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• 제26권5호
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• pp.385-396
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• 2014

1994년 미국 노스리지 지진 당시 상당 부분의 피해가 보 하부 플랜지에서 발생하였는데, 이의 원인으로 여러 가지가 거론되었지만 바닥슬래브와 합성작용에 의한 중립축 상승이 주요한 역학적 원인으로 인정되고 있다. 국내의 경우 지진에 저항하는 모멘트골조에 속하는 보(moment frame beam)의 경우에 순철골보로서 설계하고도 실제 시공시에는 보 상부 플랜지에 전단스터드를 필요 이상으로 과도하게 배치하는 오랜 관행이 존재하고 있어 내진성능 확보 차원에서 문제를 유발할 소지가 있다. 본 논문에서는 의도하지 않은 또는 과도한 합성작용이 내진성능에 미치는 부작용을 실물대 실험을 통해 재현하고 이의 개선방향을 모색하고자 하였다. 국내 관행에 따른 접합상세와 합성바닥구조를 갖는 실험체(PN700-C)의 경우, 합성도가 23% 정도임에도 불구하고, 상부플랜지 압축응력에 대해 중립축이 현저히 상승하였고 결국 3% 층간변위에서 콘크리트 압괴를 수반하면서 하부플랜지 취성파단이 발생하였다. 반면 합성바닥이 포함되어 있으나 합성작용이 최소화되도록 설계된 RBS접합부실험체(DB700-C)는 순철골(비합성) RBS접합부실험체(DB700-NC)와 유사한 이력거동을 보이면서 어떤 취성파괴도 없이 5% 수준의 뛰어난 층간변형 능력을 발휘하였다. 본 연구결과는 강구조접합부의 내진보강이나 신축에 있어 모멘트골조에 속한 철골보 및 접합부는 바닥구조와의 합성작용이 최소화되도록 설계 및 시공되어야 함을 시사한다.