• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.05a
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• pp.1027-1031
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• 2000

In this paper, multiphase dynamic optimization of machine structure is presented. The final goal is to obtain ( i ) light weight, and ( ii ) rigidity statically and dynamically. The entire optimization process is carried out in two steps. In the first step, multiple optimization problem with two objective functions is treated using Pareto genetic algorithm. Two objective functions are weight of the structure, and static compliance. In the second step, maximum receptance is minimized using genetic algorithm. The method is applied to a simplified milling machine.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.12 no.3
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• pp.45-51
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• 2003

Milling process has beer used in aircraft, auto-component and mold industries widely. They need more accurate and precise parts to improve the performance and quality of their products. So, the geometrical form accuracy of the workpiece surface generated by this process is getting more and more important. Generally, the form accuracy is affected by machine conditions, cutting conditions, tool geometry, tool deflection by cutting force and tool path md so on. Even though they are controlled as perfect conditions, it is easily found that there is a line along the axis of a cylindrically milled part. It is presumed that the tool approaching causes this error on milled surface. Thus, the study for investigating the effect of the tool approaching path on the cylindrical surface geometry of the end-milled part is carried out.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.3 s.168
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• pp.52-60
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• 2005

This paper deals with the position control fur a feed drive system in CNC milling machine, which utilizes a modified error signal for the elimination of steady-state error. A linear time-invariant (LTI) system has consistent properties in response to standard test signal inputs. Those also appear in an error curve acquired from the response. From such properties, constructed is an error model for the position control of the feed drive. And then added is the output of the error model to the current error signal. Consequently the resulting proportional control system brings performance improvement in view of the steady-state error. The effectiveness of the proposed scheme is confirmed through simulations and experiments.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.16 no.2
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• pp.84-91
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• 2007

The radial error motion of a machine tool cutter/spindle system is critical to the dimensional accuracy of the parts to be machined. This paper presents an investigation into spindle run-out effects on cutting mark and surface roughness. We experimented the effects of spindle run-out on surface roughness in flat-end milling by cutting AL 7075 workpiece in various cutting conditions. In order to analyze the effects of run-out on the surface roughness, the spindle's radial error motions was measured by mounting a sphere target onto the spindle as a reference. From the experimental results, it was found that spindle un-out makes a directive effects on surface roughness in flat-end milling.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.2 no.2
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• pp.39-43
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• 2001

This paper aims to manufacturing of connecting rod die using CAD/CAM systems. CAD/CAM systems are consist of CAD(MDT4.0), CAM(Z-MASTER) software and CNC milling machine. CAM software is purpose to G-code generation for CNC programming. Then CAM software and CNC milling machine are connect to RS-232-C cable for data network.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1992.04b
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• pp.299-308
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• 1992

Determining tool-approach directions is an important issue when an effort is made to transfer CAD data into manufacturing automatically. An algorithm is developed to determine whether a given part can be machined on a three-axis milling machine. lf a set of feasible tool-approach directions exists for a sculptured surface, the NC tool path and G-codes for machining the surface on a three-axis milling machine can be generated automatically by an NC tool path generation algorithm. The algorithm can be used for orientation and fixturing of the workpiece for interference free machining. The algorithm can also be applied to checking the translational separability of polyhedral parts in automatic assembly.

• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.3
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• pp.713-723
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• 1995

In intelligent machine tools, a computer based control system, which can adapt the machining parameters in an optimal fashion based on sensor measurements of the machining process, should be incorporated. In this paper, the technology for adaptively optimizing the cutting conditions to maximize the material removal rate in face milling operations is proposed using the exterior penalty function method combined with multilayered neural networks. Two neural networks are introduced ; one for estimating tool were length, the other for mapping input and output relations from experimental data. Then, the optimization of cutting conditions is adaptively implemented using tool were information and predicted process output. The results are demonstrated with respect to each level of machining such as rough, fine and finish cutting.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2002.05a
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• pp.153-160
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• 2002

This paper shows the possibility of performing Lap joint using the friction stir welding and the determination of tool's dimensions for FSW in Milling machine. This research also is reported on obtaining the tensile-shear strength, 9.319 ( kgf/mm$^{2}$) and the energy absorption, 2,682 (kgf-mm) under this experiment. The optimal tool's dimensions and method for Lap joint in 2tmm aluminum alloy plate using FSW is as follows; The diameter of shoulder and pin are 9 $\phi$mm and 3$\phi$mm, the length of pin is 3.6mm. The conditions of shoulder of tool is not pressed into original base metal.

• Journal of the Korean Society for Precision Engineering
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• v.32 no.5
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• pp.441-446
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• 2015

Chattering during the milling process causes severe problems on both the workpiece and cutting tools. However, chatter vibration is the inevitable phenomenon that operators require the prediction before the process or monitoring system to avoid the chatter in real-time. To predict the chatter vibration with the stability lobe diagram, the dynamic parameters of machine tool are extracted by considering cutting conditions and adapting the material properties. In this study, experimental verifications were taken for various aluminum types with different feed rates to observe the effect of the key parameters. The comparison between experimental results and the predictions was also performed.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.16 no.5
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• pp.191-197
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• 2007

Inclined surface milling in the mould and die industries is one of the most commonly needed cutting process. For the variety and complexity of cutting characteristics in various cutting condition, it is difficult to select a optimal tool path orientation. Especially, when the cutting process becomes unstable, it induces self-exited vibrations, a frequent cause of poor tool life, rough surface finish, damage to the workpiece and the machine tool itself, and excessive down time. The comparative results through FFT analysis in this study provide a guideline for the selection tool path orientation.