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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of the Korean Society for Precision Engineering
Journal Basic Information
Journal DOI :
Korean Society of Precision Engineering
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Volume & Issues
Volume 19, Issue 12 - Dec 2002
Volume 19, Issue 11 - Nov 2002
Volume 19, Issue 10 - Oct 2002
Volume 19, Issue 9 - Sep 2002
Volume 19, Issue 8 - Aug 2002
Volume 19, Issue 7 - Jul 2002
Volume 19, Issue 6 - Jun 2002
Volume 19, Issue 5 - May 2002
Volume 19, Issue 4 - Apr 2002
Volume 19, Issue 3 - Mar 2002
Volume 19, Issue 2 - Feb 2002
Volume 19, Issue 1 - Jan 2002
Selecting the target year
Research Trends on the Development of Micro Force Sensor and Its Application
Kim, Jong-Ho ; Park, Yon-Kyu ; Kang, Dae-Im ;
Journal of the Korean Society for Precision Engineering, volume 19, issue 3, 2002, Pages 7~12
Measurement of Weak Forces in Atomic Force Microscopy
Koo, Ja-Yong ; Kim, Dal-Hyun ;
Journal of the Korean Society for Precision Engineering, volume 19, issue 3, 2002, Pages 13~18
Principal and Applications of Nanoindentation Test
Han, Jun-Hui ; Lee, Gwang-Ryeol ; Kim, Gwang-Seok ; Lee, Sang-Yul ;
Journal of the Korean Society for Precision Engineering, volume 19, issue 3, 2002, Pages 19~26
The State of Art in Nano-Force Standards and Measurement
Park, Yon-Kyu ; Kang, Dae-Im ; Kim, Jong-Ho ;
Journal of the Korean Society for Precision Engineering, volume 19, issue 3, 2002, Pages 27~32
Precision in situ Measurement using Non-Contacting Capacitive Sensor with 4-Electrodes
Kim, Jae-Yeol ; Lee, Lae-Duck ; Park, Ki-Hyung ; Ma, Sang-Dong ; Yang, Dong-Jo ;
Journal of the Korean Society for Precision Engineering, volume 19, issue 3, 2002, Pages 33~38
To establish the national standard of capacitance, four main electrodes of the cross capacitor which were evaluated to linearity and roundness less the
respectively have to be adjusted symmetrically in an inner cylinder. Four LM shafts with diameter of 5 mm were installed between main electrodes of the cross capacitor, and the electrodes were adjusted, as the first step, by means of the measured capacitance. In the second step, the symmetrical adjustment up to
was performed by using a ball sensor, ball-type movable sensor, non-contacting capacitive sensor and upper guard sensor which were developed in this project.
A Newly Designed Contact Profiler for Microstructure
Choi, Dong-Jun ; Choi, Jai-Seong ; Choi, In-Mook ; Kim, Soo-Hyun ;
Journal of the Korean Society for Precision Engineering, volume 19, issue 3, 2002, Pages 39~45
A simple and low cost stylus profiler made of ferrite cores is developed. The devised profiler consists of a contact probe, a measuring transducer, a signal processing unit, and a motorized stage. The contact probe attached to 4-bar spring maintains sufficient stiffness to protect disturbances. An overlap-area type inductive position sensing system is selected as a measuring transducer, which has high sensitivity, repeatability and linearity. The transducer is composed of coil bundles and ferrite cores which have good electromagnetic characteristics in spite of low cost. The repeatability of the profiler with the proposed inductive sensing system is better than 50nm. Experimental results are shown that the proposed profiler can measure the line or 3D profile of an object with sub-micron features.
Structural Design of a Coil Cover for High Capacity Alternator
Kim, Dae-Won ; Kim, Jong-Soo ;
Journal of the Korean Society for Precision Engineering, volume 19, issue 3, 2002, Pages 46~51
Recently, High capacity alternator are used fur some special equipments in industry. But, several serious problem are occured, especially, broken coil of rotor, caused by crash with stator on rotating the rotor. Although added coil cover thor protect coil of rotor, coil cover is broken. In this study purpose 2 step for corrected that problems. First, three dimensional finite element method far investigate what is most important point. For that purpose, performed stress analysis of coil and coil cover that modeling and finite analysis by ANSYS software. Second, Apply prestress when winding the coil on stator to modify direction of net force. Vector analysis is used for determine corrected prestress. Result of the analysis and prestress are reviewed.
Rejection Scheme of Nearest Neighbor Classifier for Diagnosis of Rotating Machine Fault
Choe, Yeong-Il ; Park, Gwang-Ho ; Gi, Chang-Du ;
Journal of the Korean Society for Precision Engineering, volume 19, issue 3, 2002, Pages 52~58
The purpose of condition monitoring and fault diagnosis is to detect faults occurring in machinery in order to improve the level of safety in plants and reduce operational and maintenance costs. The recognition performance is important not only to gain a high recognition rate bur a1so to minimize the diagnosis failures error rate by using off effective rejection module. We examined the problem of performance evaluation for the rejection scheme considering the accuracy of individual c1asses in order to increase the recognition performance. We use the Smith's method among the previous studies related to rejection method. Nearest neighbor classifier is used for classifying the machine conditions from the vibration signals. The experiment results for the performance evaluation of rejection show the modified optimum rejection method is superior to others.
Variation of Grinding Force and Wheel Life in Surface Grinding
Choi, Soung-Sam ; Koo, Yang ; Kwak, Jae-Seob ; Ha, Man-Kyong ; Park, No-Kwang ;
Journal of the Korean Society for Precision Engineering, volume 19, issue 3, 2002, Pages 59~65
In the grinding process, the degree of the sharpness in wheel grain affects the surface roughness and the dimensional accuracy. If a wheel with dull grains is used, te grinding force will be increased and the surface roughness deteriorated. To produce a precision component, the magnitude of parameters related to the wear amount of a grinding wheel has to be limited. In this study, a variation of the grinding force and the surface roughness were measured to seek the machining characteristics of the WA and CBN wheels. From the wear amount of the grinding wheel and the removal rate of workpiece, the grinding ratio was calculated. And also the wheel life was determined at a rapid decreasing point of the grinding ratio. The difference between the surface of wheel-workpiece before grinding and after wheel life was clearly verified with a microscopic photo.
Measurement of Out-of-plane Displacement in a Spot Welded Canti-levered Plate using Laser Speckle Interferometry with 4-step Phase Shifting Technique
Baek, Tae-Hyun ; Kim, Myung-Soo ; Na, Eui-Gyun ; Koh, Seung-Ki ;
Journal of the Korean Society for Precision Engineering, volume 19, issue 3, 2002, Pages 66~72
Electronic Speckle Pattern Interferometry (ESPI) has been recently developed and widely used because it has advantage to be able to measure surface deformations of engineering components and materials in industrial areas with non-contact. The speckle patterns to be formed with interference and scattering phenomena can measure not only out-of-plane but also in-plane deformations, together with the use of digital image equipment to process the informations included in the speckle patterns and to display consequent interferogram on a computer monitor. In this study, the experimental results of a canti-levered plate using ESPI were compared with those obtained from the simple beam theory. The ESPI results of the canti-levered plate analyzed by 4-step phase shifting method are close to the theoretical expectation. Also, out-of-plane displacements of a spot welded cacti-levered plate were measured by ESPI with 4-step phase shifting technique. The phase map of the spot welded cacti-levered plate is quite different from that of the canti-levered plate without spot welding.
A Study on the Environmentally Conscious Machining Technology Cutting Fluid Atomization and Environmental Impact through Spin-Off Mechanism in fuming Operation(1)
Hwang, Joon ; Chung, Eui-Sik ;
Journal of the Korean Society for Precision Engineering, volume 19, issue 3, 2002, Pages 73~79
This paper presents the experimental results to verify the environmental consciousness with economic balances due to cutting fluid behaviors, effectiveness in machining process. Even though cutting fluid improves the Productivity through the cooling, lubricating effects, its environmental impact is also increased according to the cutting fluid usage. The primary mechanism considered in this study is the spin-off motion of fluids away from rotating workpiece. In this study some parameters arc adopted to analyze the productivity(tool wear), environmental impact(mist diffusion rate). The results present talc criteria for the resonable cutting fluid usage quantitative1y to develop the environmentally conscious machining process.
Fabrication of Tungsten Carbide Microshaft Using Electrochemical Machining
Kang, Myung-Ju ; Oh, Young-Tak ; Chu, chong-Nam ;
Journal of the Korean Society for Precision Engineering, volume 19, issue 3, 2002, Pages 80~87
Tungsten carbide microshaft is used as micro-punch, electrode of MEDM (micro-electro-discharge machining), and micro-tool because it has high hardness and high rigidity. In this study, the tungsten carbide microshaft was fabricated using electrochemical machining. Concentration of material removal at the sharp edge and metal corrosion layer affect the shape of the microshaft. Control of microshaft shape was possib1e through conditioning the machining voltage and electrolyte concentration. By applying periodic voltage, material removal rate increased and surface roughness improved. The fabricated microshaft in
electrolyte maintained sharper end edge and better surface finish than those fabricated by other electrolytes.
Development of Automatic Filling Process using Low-Melting Point Metal for Rapid Manufacturing with Machining Process
Shin, Bo-Seong ; Yang, Dong-Yeol ; Choi, Du-Seon ; Kim, Ki-Don ; Lee, Eung-Suk ; Je, Tae-Jin ; Hwang, Kyeong-Hyeon ;
Journal of the Korean Society for Precision Engineering, volume 19, issue 3, 2002, Pages 88~94
Recently, the life cycle and the lead-time of a product are to be shortened in order to satisfy consumer's demand. It is thus important to reduce the time and cost in manufacturing trial products. Several technique have been developed and successfully commercialized in the market of RPM(Rapid Prototyping and Manufacturing). However, most commercial systems currently use resins or waxes as the raw materials. So, the limited mechanical strength for functional testing is regarded as an obstacle towards broader application of rapid prototyping techniques. To overcome these problems, high-speed machining technology is being investigated worldwide for rapid manufacturing and even for direct rapid tooling application. In this paper, some fundamental experiments and analyses are carried out to obtain the filling time, materials, method, and process parameters for HisRP(High-Speed RP) process. HisRP is a new RP process that is combined high-speed machining with automatic filling. In filling process, Bi58-Sn alloy is chosen as filling material because of the properties of low-melting point, low coefficient of thermal expansion and no harm to environment. Also the use of filling wire it if advantage since it needs simple and flexible mechanism. Then the rapid product, for example a skull, is manufactured for aluminum material by HisRP process with an automatic set-up device thor 4-faces machining.
Vibration Analysis of a BEBTS(Built-in Eccentric Bearing-Torsional Spring) Type ABTU(Automatic Belt Tension Unit)
Choe, Yeong-Hyu ; An, Yeong-Deok ; Jeong, Won-Ji ;
Journal of the Korean Society for Precision Engineering, volume 19, issue 3, 2002, Pages 95~100
Built-in Eccentric Bearing-Torsional Spring (BEBTS) type Automatic Belt Tension Unit (ABTU) is one of typical belt tension units. The BEBTS type ABTU system frequently experiences torsional vibration about its pivot due to the variation of belt tension. However, it is very difficult to analyze the rotational (or torsional) vibration of the ABTU because the exciting moment varies according to the change of belt tension. To get over this difficulty, in this paper. the ABTU was simplified as 1-DOF translational motion model in the tangential direction. Its equation of motion was derived and solved. The time history and frequency responses were computed and examined for three of BEBTS type ABTUs which are made by different manufacturers but the tame kind.
Improvement of Machinability for QRO90 High Hardened Core Part by High Speed Machining
Gang, Myeong-Chang ; Kim, Jeong-Seok ; Lee, Deuk-U ; Im, Yu-Eop ;
Journal of the Korean Society for Precision Engineering, volume 19, issue 3, 2002, Pages 101~106
This paper presents an experimental investigation of high speed machining of dies and molds. Several critical issues involved with the high speed machining of QRO90 tool steel of hardness up to HRc62, have been studied and explained from a detail analysis of experimental observations. The experiments were performed using ball end mills. The effect of different process parameters on tool life and surface finish produced was also investigated. The cutting parameters involved were; cutting speeds in the range of 100 to 40 / m/min, axial depth of cut from 0.1 to 0.5mm, pick feed of 0.1 to 0.5mm. Run out and acceleration signals were observed during the experiment to investigate cutting slates. Compressed air and flood coolant were used and the effect of coolant on tool life was also determined.
Development of Straightness Measurement System thor Flat Workpieces
Kim, Hyeon-Su ; Jang, Mun-Ju ; Hong, Seong-Uk ; Park, Cheon-Hong ;
Journal of the Korean Society for Precision Engineering, volume 19, issue 3, 2002, Pages 107~113
This paper presents a straightness measurement system for flat and long workpieces. The measurement system consists of a laser, a CCD camera and processing system, a carrier system with a stylus, and some optical units. The carrier system accompanies the stylus, which displaces and retroreflector along the surface profile. The optical unit is used to optically amplify displacement of the stylus unit. The developed system is applied to a ground surface and a LM guide unit. The experimental results show that the developed system can measure the straightness of flat surface and moving systems.
The Study on the Improvement of Friction Properties of Graphite/Nylon Composite by oil-Impregnation
Gang, Seok-Chun ; Jeong, Dae-Won ;
Journal of the Korean Society for Precision Engineering, volume 19, issue 3, 2002, Pages 114~122
Electric conductivities, mechanical properties and friction properties were investigated far graphite-nylon composites impregnated with oil. Specific resistivity of composites containing oil from 2% to 6% were in the range of
cm, which were applicable for anti-static purpose of composites improved by the impregnation of graphite with 2%. Improvement in the impact strength and friction properties of graphite/nylon composites was achieved by the impregnation of oil. The coefficient of friction of the composites containing graphite from 2% to 4% and oil with 2 - 4% showed much loller than that of virgin nylon. Also the abrasive wear of the oil impregnated graphite composites were decreased about 1/3 - 1/10.
Improvement of the Thermal Characteristics of Synchronous Linear Motors Through Insulation
Eun, In-Ung ;
Journal of the Korean Society for Precision Engineering, volume 19, issue 3, 2002, Pages 123~130
Linear motors can drive a linear motion without intermediate gears, screws or crank shafts. Linear motors can successfully replace ball lead screw in machine tools because they have a high velocity, acceleration and good positioning accuracy. On the other hand, linear motors emit large amounts of heat and have low efficiency. In this paper, heat sources of a synchronous linear motor with high velocity and force measured and analyzed. To improve the thermal characteristics of the linear motor, an insulation layer with low thermal conductivity is inserted between cooler and machine table. Some effects of the insulation layer are presented.
A Design System of Dies for Hot Extrusion of Structural Shapes from Aluminum Alloys
Cho, Hae-Yong ; Kim, Kwan-Woo ; Choi, Jae-Chan ;
Journal of the Korean Society for Precision Engineering, volume 19, issue 3, 2002, Pages 131~136
A design system of dies for hot extrusion of structural shapes such as Z's, L's, T's, U's and H's from aluminium alloys was developed in this study. The developed design system of dies is based of estimated die design rule system. The design rules for die design are obtained from the handbooks, plasticity theories and relevant references. The environment of the system is AutoCAD and AutoLISP, the graphic programming language was used for the configuration of the system. This system includes five major modules such as section shape design module, die opening number module, die opening layout module, die correction module and die bearing design module that are used to determine design variables. This system would be used to design of dies for hot extrusion from aluminum alloys and widely used in manufacturing course.
A Study on the Cutter Runout In-Process Compensation Using Repetitive Loaming Control
Hwang, Joon ; Chung, Eui-Sik ; Hwang, Duk-Chul ;
Journal of the Korean Society for Precision Engineering, volume 19, issue 3, 2002, Pages 137~143
This paper presents the In-process compensation to control cutter runout and improve the machined surface quality. Cutter runout compensation system consists of the micro-positioning servo system with piezoelectric actuator which is embeded in the sliding table to manipulate radial depth of cut in real-time. Cutting force feedback control was proposed in the angle domain based upon repetitive learning control strategy to eliminate chip load variation in end milling process. Micro-positioning control due to adaptive actuation force response improves the machined surface quality by compensation runout effect induced cutting force variation. This result will provide lots of information to build-up the preciswion machining technology.
Noise Source Identification and Countermeasure for the Noise of LPG Injector
Kim, Won-Jin ; Park, Chong-Hyun ; Kim, Sung-Dae ; Lee, Byung-Ho ;
Journal of the Korean Society for Precision Engineering, volume 19, issue 3, 2002, Pages 144~151
This work focuses on finding out the noise source and the method of reducing the noise level of LPG(liquefied petroleum gas) fuel injector. The noise of LPG injector in operating condition is due to the impact between valve and valve seat. This study shows that if the revolution of engine is increased, the noise of LPG injector will be more serious but it is not nearly affected by the increment of fuel pressure. The source and transmission paths of noise are identified through the analysis of noise generation mechanism and noise spectrum. The sound absorbing material is tested to verify its efficiency of sound absorption thor the LPG injector. The effect of noise reduction of absorbing material is remarkable when the engine speed is high. Consequently two methods of reducing the noise level are suggested from the identified results. The one is to equip the absorbing material on the outer side of injector and the other is to coat with a soft material or equip a soft ring on the surface of impact.
Forming Error and Compensation in RP Using SLA
Park, Sang-Ryang ; Park, Dong-Sam ;
Journal of the Korean Society for Precision Engineering, volume 19, issue 3, 2002, Pages 152~159
SLA (Stereolithography Apparatus) it a process used to rapidly produce polymer components directly from a computer representation of the part. Though SLA is being recognized as an innovative technology, it still cannot be used to fully practical application since it lacks of dimensional accuracy compared to conventional process. If the shrinkage were perfectly uniform and no distortion took place, excellent part accuracy could still be achieved through and appropriate scaling factor when generating the build file. However, in certain geometries involving intersecting thick and thin sections, nonuniform retrain shrinkage becomes the engine of part distortion. In order to improve the part accuracy of SLA, this paper evaluates how largely each parameter of SLA contributes to the part accuracy and estimates the optimal set of parameter which minimizes the dimension error of the test part, "Slab (100mm
2mm)"and "scale bar"part. Three control parameters such as critical exposure, generation depth and fill cure depth are used.