• Transactions of the Korean Society of Machine Tool Engineers
• /
• v.12 no.3
• /
• pp.25-30
• /
• 2003

In metal cutting chatter is the unstable cutting phenomenon which caused by the interaction between the dynamics of the chip removal process and the structural dynamics of machine tool. When the vibration and chatter on, it reduces tool life and results in poor surface roughness and low productivity of the machining process. In order to observe the effect of chatter on the turned surface, the surface simulation model based on the surface-shaping system are developed under the ideal condition and the occurrence of the regenerative chatter, and it is compared with experiment of profile. In this study, the experiments were conducted in a CNC lathe without cutting fluid to investigate the phenomenon of the chatter.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2001.10a
• /
• pp.19-25
• /
• 2001

In metal cutting, chatter is an unstable cutting phenomenon which is due to the interaction of the dynamics of the chip removal process and the structural dynamics of machine tool. When chatter occurs, it reduces tool life and results in poor surface roughness and low productivity of the machining process. In this study, the experiments have been conducted to investigate phenomenon of the chatter in CNC lathe without cutting fluid. In the experiments, two accelerometers were attached at the tail stock and tool holder and the signals were caught. In order to observe the effect of chatter on the surface roughness profiles, surface roughness profiles were generated under the ideal condition and the occurrence of the chatter based on the surface simulation model using surface-shaping system. Finally, the result of experiment and simulation have been compared.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.18 no.7
• /
• pp.1643-1653
• /
• 1994

To facilitate the manufacturing of dull using CNC grinding machine, the simulation of helical groove machining with given wheel profile and setting condition is necessary. Considering the wheel as a collection of thin disks, the flute configuration is predicted in a cross section perpendicular to the axis and the grinding wheel profile is also predicted to machine the desired helical groove with given setting conditions. Two programs for these processes are developed. Using programs interactively, the helical groove machining process can be predicted more accurately. By clarifying the geometrical relation between the shape of cutting edge and the flute configuration in the cross section which is perpendicular to drill axis, it becomes possible to predict the necessary cross sectional shape of wheel for desired drill cutting edge shape. Some factors for the software are considered concerning prediction of accuracy and computing time.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2000.10a
• /
• pp.8-13
• /
• 2000

In this paper, a new adaptive cross-coupling control (CCC) method with an improved contour error model is proposed to maintain contouring precision in high-speed nonlinear contour machining. The proposed method utilizes variable controller gains based on the instantaneous curvature of a contour and the feedrate command. In addition, a real-time federate adaptation scheme is included in the proposed CCC to regulate cutting force. The proposed method is evaluated and compared with the conventional CCC for nonlinear contouring motion through computer simulations. The simulation results show that the proposed CCC improves the contouring accuracy and regulates cutting force more effectively than the existing method.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2002.10a
• /
• pp.174-179
• /
• 2002

In metal cutting, Chatter is an unstable cutting phenomenon which is due to the interaction of the dynamics of the chip removal process and the structural dynamics of machine tool. when vibration and chatter occurs, it reduces tool life, results in poor surface roughness and low productivity of the machining process. In this study, the experiments were conducted in CNC lathe without cutting fluid to investigated phenomenon of the chatter, In the experiments, accelerometers were set up at the tail stock and tool holder and the signals were picked up. In order to observe the effect of chatter on the surface roughness profiles, in this paper, surface roughness profiles will be generated under the ideal condition and the occurrence of the chatter based on the surface simulation model.

• Journal of the Korean Professional Engineers Association
• /
• v.21 no.4
• /
• pp.6-11
• /
• 1988

The study on the progress of automatic machining system has been active centering at the CNC machine tools recently to lead the applied production technology like unmaned machining to the practical level, and to make these application more efficient, they require detective method for tool wear and breakage while machining. In this study chiefly on turning, first derive cutting force about the tool surface by the cutting resistant sensor and with which change into electric signal and compare with the standards to make the tool life detection system to let know the tool life and study its application; the cutting resistance detected by the cutting resistant sensor has increased to the level of standards, the measuring system which can decide whether we change tools on the basis of comperative circuit is shown to be very reliable model for cutting tool life detection system.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2001.10a
• /
• pp.85-90
• /
• 2001

Recent general Press brake has many problems in cutting high accurate products in the progress of industry. Previous hand-operated press brake needs many pre-processing works to adjust bending ang1e and marking-off works to calculate bending length. Also, the hand-operating work makes many geometric errors and has difficulty for variety-mass production. To solve these problems, this paper proposes Computer Numerical Control (CNC) general press brake and development of servo-control system based on database for reduction of geometric errors and pre-processing work time and high accuracy bending work.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 1997.10a
• /
• pp.207-212
• /
• 1997

The purpose of this study is the development of CAM system which can cut and measure any shape by machining center and coordinate measuring machine. The overall goal of the CAM system is to achieve the CNC machining, from digitizing through to final cutting. The hardware of the system comprises PC and machining center, CMM. There are three steps in the CNC machining, (1) workpiece measuring on the CMM, (2) geometric modeling by the CAD system, (3) NC commands generation by the tool path compensated for tool nose radius. It is developed a software package, with which can conduct a micro CAM system in the PC without economical burden.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1994.10a
• /
• pp.9-14
• /
• 1994

The modern CNC machine require increasingly an exact monitoring and control of cutting process. They are to make final taret which construct full automation factories as unmanned system. In this study, we decided that we develop new techique to monitor and detect tool breakage on the machining operation using face milling machine with multi-point throwaway tips. The technology in which the tool is illuminated by an beam of Laser is used by image of tool fracture through CCD camera.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.13 no.2
• /
• pp.471-477
• /
• 2012

SCM420 steel tempered after performing gear hove PACVD carbide coating on the surface after the cutting surface hardness was high. Difficult-to-cut, without coating is classified as mild as large, including materials like mild, high strength that improves tool life and productivity have limited availability. Drive to improve it in the TiCN-coated carbide call for war to the finish coating on cutting a hob skiving good workability, tool wear less, 2.5-fold increase in tool life results were obtained. Experiments using CNC Skiving hobbing machine with wet cutting conditions, cutting speed and feed rate to apply a variety of the tool wear and surface roughness data were obtained. Results from condition 2 (V = 200m/min F = 0.7mm/rev) cutting speed feed mark the cutting surface microstructure and surface roughness Rmax $4.7{\mu}m$(Ra $1.19{\mu}m$) of the data was obtained.