• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2004.10a
• /
• pp.778-781
• /
• 2004

As the technique of high-speed end-milling is widely adopted to in machining field. The investigation for microscopic precision of workpiece is necessary for machinability evolution. In this study, cutting force, cutting temperature and microhardness were investigated to evaluate damaged layer in conventional machining and high-speed machining. Damaged layer was measured using optical microscope. The thickness of damaged layer depends on cutting process parameters, specially feed per tooth and radial depth. It is obtained that the characteristics of damaged layer is high-speed machining better than conventional machining.

• International Journal of Precision Engineering and Manufacturing
• /
• v.4 no.1
• /
• pp.49-55
• /
• 2003

This paper presents the experimental results to verify the environmental consciousness with economic balances due to cutting fluid behaviors and effectiveness in machining process. The cutting fluid improves the productivity through cooling, lubricating effects, however its environmental impact also increases according to the cutting fluid usage. The primary mechanism in this study is the spin-of motion of cutting fluids away from the rotating workpiece. In this study some machining parameters are adopted to analyze the productivity as well as environmental impact. This study provides the criteria for the resonable cutting fluid usage quantitatively to develop the environmentally conscious machining process.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1997.10a
• /
• pp.19-22
• /
• 1997

The objective of this research is to use an analytical and experimental approach to develop optimal tool geometry for high speed machining. The tool geometry parameters and cutting process have complex relationships. Until now, numerous cutting tests were needed to acquire optimal design of endmill for the purpose of high speed machining, dut to the insufficient knowledge about process in high speed machining. In order to improve the cutting ability of endmill, a model for optimal cutter shape was developed to minimize resultant cutting force by combing cutting force and wear test and surface roughness test from optimized and conventional cutter with the same cutting condition. Using various tools with different geometry, relationships between the tool geometry parameter, rake angle, clearance angle, lengh of cutter have been stuied.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2002.10a
• /
• pp.493-497
• /
• 2002

In the part industry, pipe has required high accuracy in surface roughness and size. Especially, when producing the high frequency welding pipe, cutting process is very important as the finishing process that remove the hot welding bead. The objective of this paper is to investigate the hot machining high frequency welded pipe by simulation and experimental tests. To test the cutting process as hot machining, all cutting environment is reproduced in turning with heating system, and the test is accomplished by comparing with room temperature machining and hot machining in consideration of cutting force, tool wear and cutting temperature.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.31 no.9
• /
• pp.924-933
• /
• 2007

An impeller is a important part of turbo-machinery. It has a set of twisted surfaces because it consists of many blades. Five-axis machining is required to produce a impeller because of interference between tool and workpiece. It can obtain good surface integrity and high productivity. This paper proposes finish cutting method for machining impeller with 5-axis machining center and optimization of cutting condition by response surface method. Firstly, cutting methods are selected by consideration of operation characteristics. Secondly, response factors are determined as cutting time and cutting error for prediction of productivity. Experiments are projected by central composite design with axis point. Thirdly, regression linear models are estimated as single surface in the leading edge and as dual surface in the hub surface cutting. Finally, cutting conditions are optimized.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1997.10a
• /
• pp.895-898
• /
• 1997

These days, most of new materials, which is in use widely as cutting process materials have a characteristic in common. That is hard cutting. So, it happens that hardness by cutting temperature. And hardness on cutting process has an effect on tool wear or life shortness of tools. To solve these problems hot-machining is proposed. When a material is heated, organization of material is soften. So cutting process becomes easy. When such a hot-machining method applies on drilling process and then heated material is processed, cutting force is less than usual drilling process cutting force. In this paper, when a material is heated, cutting force on drilling process is measured. It is decided that the best suitable temperature area. And it suggest that the better hot-machining condition as surface accuracy is measured.

• Journal of the Korean Society for Precision Engineering
• /
• v.16 no.5 s.98
• /
• pp.11-18
• /
• 1999

Recently high speed machining is being studied actively to reduce machining time and to improve machining precision. To perform efficient high speed machining, evaluation of high speed machinability must be studied preferentially and it can be identified by investigation of cutting force. To measure cutting forces in high speed machining, dynamometer which has high natural frequency was newly designed using 3-axes piezo force sensor. For newly designed dynamometer, calibration is conducted with sensitivity of force sensor modulated and proper preload and interference force are investigated experimently. Also, cutting force signals of newly designed dynamometer are compared with those of conventional one in high speed cutting experiment and its superiority is confirmed. Then using newly designed dynamometer, high speed machinability is evaluated about cutting force and tool wear in various cutting conditions.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.9 no.4
• /
• pp.440-451
• /
• 1985

This study is concerned with the analysis of cutting force system acting on ball-nose end mill in three-dimensional surface machining process. Conical tipped circular cutting edge element model and free surface machining process types are proposed to apply oblique cutting theory, and then derived equations are used for numerical approach of cutting force curves by matrix method. This approach has a good agreement with experimental results both in magnitude and shape within the range of 15 percent, which was conformed on 6061-T6 aluminum workpiece having twofold curvatured surface. From the cutting load variation to edge location, it is confirmed that circular cutting edge shapes has a better cutting ability than that of straight and both have a singularity near a tool point. It is also verified that what kind of machining condition is recommendable for three-dimensional machining process in connection with deflection of the cutter to workpiece and tool point wearing or system stability.

• Proceedings of the KSME Conference
• /
• 2007.05a
• /
• pp.1338-1343
• /
• 2007

High-efficient machining, which means cutting a part in the least amount of time, is the most effective tool to improve productivity. In this study, a new feed optimization method based on the cutting power regulation was proposed to realize the high-efficient machining in turning process. The cutting area was evaluated by using the Boolean intersection operation between the cutting tool and workpiece. And the cutting force and power were predicted from the cutting parameters such as feed, depth of cut, spindle speed, specific cutting force, and so on. Especially, the reliability of the proposed optimization method was validated by comparing the predicted and measured cutting forces. The simulation results showed that the proposed optimization method could effectively enhance the productivity in turning process.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2001.04a
• /
• pp.895-898
• /
• 2001

This paper presents an optimization cutting speed(OCS) program developed to improve the machining precision and tool life in high speed machining using ball end milling. This program optimized the cutting speed that is changing at any time in free surface machining of an automobile part like a connecting load die. The technique of optimization cutting speed makes the CAD/CAM-generated NC code go through a reverse post process, conducts cutting simulation, and obtain the effective tool diameter of the ball end milling. Then it changes the spindle revolution to within the range of critical cutting speed fit for the material of the workpieces depending upon the effective tool diameter. In this study, the machining precision and tool life were compared for the two connecting load dies processed using the general cutting method and the proposed optimization cutting speed technique, respectively.