• Design & Manufacturing
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• v.17 no.1
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• pp.7-12
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• 2023

Recently, with the emergence of the 4th industrial revolution, the demand for smart factories and factory automation is increasing. In this study, a tool life prediction program was developed to select optimal machining conditions using CNC milling equipment, which is widely used in flexible production and automation. The equipment used in the experiment was Hwacheon Machine Tool's 5-axis machining equipment, and the tool used was a 17F2R tool. For the machining path, the down-milling cutting method was selected and long-term machining was performed. The analysis standard for side wear on the tool was set at 0.1 to 0.2 mm, and tool life data and wear data were obtained in the cutting experiment. The program was created through the data obtained from the experiment, and a prediction rate of over 90% was secured when comparing the experimental data and the predicted data.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.13 no.5
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• pp.57-63
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• 2014

At present, a high-speed swivel tool head of a small size is required to improve the productivity of CNC automatic lathes. Hence, there is growing interest in shorter machining times with higher cutting speeds. However, an increase in the rotation speed of a swivel tool head also has adverse effects, such as vibration and noise caused by the swivel tool head system. In this work, the fatigue life and contact pressure of a swivel tool head bearing system driven by gears were calculated. Based on the calculated results, a prototype swivel tool head was manufactured and its static and dynamic characteristics, i.e., the vibration, noise and precision, were measured using a reliability testing device which allows the application of cutting force to the end of the swivel tool head.

• Archives of design research
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• v.18 no.1 s.59
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• pp.223-232
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• 2005

By supply of high performance computer becomes all industries automation and convenient of our life. Can speak that is pursuit of swiftness and variety that is prior most development of information society and production system in competitive industrial design product development process. Specially, students who consumer personality studies design according to variableness must present idea in a short time. Therefore, find a new tool that can show quick modeling result for present of new idea or fast design specifications examination and production at college or corporation now. According to such environment change did request by cost time and cost-cutting until reach in production from product design because competition is gone vigorously. University arrived to think RP induction by result presentation and so on for third dimension model by various design process. This research purpose is going to compare difference methods(Manual processing, CNC machine) with students' design result manufacture process on RP appliance that is using in college. Consequently, think that this study is helpful in the college of which is making use of RP appliance or planning installation. By result of this research, model of big curved line is profitable in hand process, by CNC Is profitable when model is going to manufacture finely, RP work could know that size of product is profitable small thing as is complicated.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1993.04b
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• pp.108-113
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• 1993

The material for the machine tool structure should have high static stiffiness and damping in its property to improve both the static and dynamic performances. The static stiffness of a machine tool can be inceased by using either higher modulus material in the structure of a machine tool. However, the machine tool structrue with high stiffness but low damping is vulnerable to vibration at the resonance frequencies of the structure . For the high precision and highsped machine tool structure, therefore, the high damping capacity is most important in order to suppress vibration. The damping of a machine tool can not be increased by increasing the static stiffness. The best way to increase the damping capacity of the machine tool structure is to use a composite material which is composed of on material with high stiffness with low damping and another material with low stiffness with high damping. Therefore, in this paper, the bed of the ultra high precision grinding machine for mirror surface machining of brittle materials such as ceramics and composite materials was designed and manufactured with the epoxy concrete material. The epoxy concrete material was prepared by mixing epoxy resin with different size sands and gravels. The modulus, compressive strength, coefficient of thermal expansion, specific heat, and damping factor were measured by varying the compaction ratio, sizes and contents of the ingredients to assess the effect of the processing parameters on the mechanical properties of the material. Based of the measured properties, the prototype epoxy resin concrete bed for the mirror surface CNC grinding machine was designed and manufactured.

• Journal of the Korean Wood Science and Technology
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• v.16 no.4
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• pp.54-60
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• 1988

Machinabilities means inherent properties of pinus densiflora at Chunyang district to be CNC machined easily or not, and processing abilities of the tool and machine together. This explanation signifies that machinabilities have two phases of signification, depended on considering and stress either materials or tools preferentially. This paper discuss machinabilities, the following items are usually employed as the indices of stress distribution at the cutting tool rake face. The stress distributions on the chip - tool contact surface at the early stage of the chip forming and under the stage of fringe pattern in wood cutting were analyzed the photoelastic method. The tool used in the present experiment was the special cutting tool H.S.S. one made in laboratory. And isochromatic fringe pattern and isolinic line of work piece by chip-behavior during the cutting operation were photographed with the feed camera continuously. The effects on the stress, distribution on the rake face of the epoxy tool and the strain distribution in the work piece of wood plate by chip behavior are cleared in pre cent experiment.

• Journal of Welding and Joining
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• v.29 no.2
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• pp.80-87
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• 2011

In this study, the friction stir spot welding (FSSW) of Mg alloy sheets has been tried using an apparatus devised with a CNC milling machine to give the precise control of joining condition including tool speed. The probe tool used is made of hard metal and composed of cylindrical shoulder and pin parts. The variation of morphologies formed after the friction stir spot welding depending on the plunge speed of the tool were investigated at each rpm of tool. The history of the temperature distribution and the vertical load induced during the spot welding with friction time were measured by using an Infrared Thermal Imager (THERMA CAMTM SC2000) and a loadcell located below the specimen fixture, respectively. Tensile-shear tests were also performed to evaluate the fracture load of welded specimens. In order to characterize the friction stir spot welding of Mg alloy sheets, the variation of the fracture load was discussed on micrographic observations, temperature distribution during the FSSW according to the plunge speeds of tool.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.04a
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• pp.528-535
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• 2002

In order to achieve high precision machine tools, the research for performance enhancement of feed drive systems is required. Development of the high speed feed drive system has been a major issue for the past few decades in machine tool industries. The reduction of the tool change time as well as rapid travel time can enhance the productivity. However, the high speed feed drive system generates more heat in nature, which leads thermal expansion that has adverse effects on the accuracy of machined parts. Stick-slip friction has a great influence on the contouring accuracy of CNC machine tools. In this paper table levitation system has been developed for the stick-slip in a feed drive systems. And also, the driving position is set near the center of the main slideway. From the results, it is confirmed that yaw error and straightness can be improved.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1997.10a
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• pp.59-64
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• 1997

This paper investigates the relationship between cutting conditions and Acoustic Emission(AE) signals; AEavg, AErms, AEmode, as the base working to monitor the tool wear with in-process. For this purpose, cutting tests were conducted on a CNC lathe with comprehensive cutting conditions.. It is known that AEavg and AErms are proportionaly increased as the increasing of cutting velocity and depth of cut respectively. It is also known that AEmode among three kinds of AE signals may be applied for in-process monitoring to make the self diagnosis system because of its stability to the variation of cutting condition.

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

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.7 no.6
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• pp.64-71
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• 1998

This paper investigates the relationship between cutting conditions and Acoustic Emission(AE) signals; $AE_{avg}$, $AE_{rms}$, $AE_{mode}$$AE_{avg}$ and $AE_{rms}$ are increased as the increasing of cutting velocity and depth of cut respectively. The new parameters, derived from $AE_{avg}$ and $AE_{rms}$, which may be used for the in-process detection of tool wear is discussed. It is also known that $AE_{mode}$