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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
Editor in Chief :
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
Trends in Virtual Machine Tool research
Jo, Dong-U ; Go, Jeong-Hun ; Jeong, Yeong-Hun ;
Journal of the Korean Society for Precision Engineering, volume 19, issue 6, 2002, Pages 9~14
Digital Manufacturing and Virtual Machine Tool
Ko, Tae-Jo ; Baek, Dae-Kyun ; Kim, Hee-Sool ;
Journal of the Korean Society for Precision Engineering, volume 19, issue 6, 2002, Pages 15~22
Development of Virtual CNC using a Software Based Open Architecture Controller
Yun, Won-Su ; Min, Byeong-Gwon ;
Journal of the Korean Society for Precision Engineering, volume 19, issue 6, 2002, Pages 23~28
A Study on Formation of Ejector-Pin Hollowness in Injection Molding
Hwang, Geum-Jong ; Lee, Hui-Gwan ; Yang, Gyun-Ui ;
Journal of the Korean Society for Precision Engineering, volume 19, issue 6, 2002, Pages 29~34
This paper presents formation of ejector-pin hollowness in injection molding. Injection molding process is widely used in production of plastic part for good dimensional accuracy and high productivity. However, the injection molding leaves ejector-pin hollowness on pal, which causes bad part surface and quality. Dimensions and profiles of ejector-pin hollowness are measured for formation or ejector-pin hollowness. The formation of ejector-pin hollowness is traced with dimensions and profiles of ejector-pin hollowness. The compression force and moment cause ejector-pin to form hollowness on part surface.
Verification of Tool Collision for 3-Axis Milling
Chung, Yun-Chan ; Park, Jung-Whan ;
Journal of the Korean Society for Precision Engineering, volume 19, issue 6, 2002, Pages 35~42
Verification of tool collision Is an important issue in die and mold machining. In this paper three functions of verification for 3-axis milling machining are schematically explained. Operators of geometric models are explained at first, which will be used in the functions of verification. The first verification function is getting a collision-free region when a tool assembly and a part surface model are given. The second function estimates the shortest length of cutter shank with that the tool cuts all of a region without collision The last one is cutting simulation considering all parts of tool assembly as well as cutter blade. Proposed approaches can be easily implemented by using several basic operators of geometric model. An example to calculate collision-free region is presented also.
Forces Prediction by Indirect Force Measurement and Pseudo-inverse Technique
Ahn, Byoung-Ha ; Shim, Jae-Sool ;
Journal of the Korean Society for Precision Engineering, volume 19, issue 6, 2002, Pages 43~50
In the design of structure, the forces acting on tai structure are key parameter fur noise and vibration control. However, in the complex structure, the forces at the injection point on the structure cannot be measured directly. So, it is necessary to find out Indirect force evaluation method. In this paper, forces have been measured with In-situ vibration responses and system information. And, three existing techniques of indirect force measurement, vita. direct inverse. principal component analysis and regularization have been compared. This paper shows that multi-vibration responses are essential for talc precise estimation of the forces. To check these conditions, rotary compressor is adopted as test sample, because it is very difficult to measure the injection forces from internal excitation to shell. It alas also been obtained that relatively higher force is transmitted through three welding paths to the compressor shell. It shows a good agreement between direct and indirect force evaluation with curvature shell and plate.
Position Tracking Control on the XY Ball-screw Drive System with the Nonlinear Dynamic Friction
Han, Seong-Ik ;
Journal of the Korean Society for Precision Engineering, volume 19, issue 6, 2002, Pages 51~61
A tracking control scheme on the XY ball-screw drive system in the presence of nonlinear dynamic friction is proposed. A nonlinear dynamic friction is regarded as the Lund-Grenoble friction model to compensate effects of friction. The conventional VSC method that often has been used as a non-model-based friction controller has poor tracking performance in high-precision position tracking application since it cannot compensate the friction effect below a certain precision level completely. Thus to improve the precise position tracking performance, we propose the integral type VSC method combined with the friction-model-based observer. Then this control scheme has the high precise tracking performance compared with the non-model-baked VSC method and the PID control method with a similar observer. This fact is shown through the experiment on the XY ball-screw drive system with the nonlinear dynamic friction.
Corrective Machining Algorithm for Improving the Motion Accuracy of Hydrostatic Table
Park, Chun-Hong ; Lee, Chan-Hong ; Lee, Hu-Sang ;
Journal of the Korean Society for Precision Engineering, volume 19, issue 6, 2002, Pages 62~69
For improving the motion accuracy of hydrostatic table, corrective machining algorithm is proposed in this paper. The algorithm consists of three main processes. reverse analysis is performed firstly to estimate rail profile from measured linear and angular motion error, in the algorithm. For the next step, corrective machining information is decided as referring to the estimating rail profile. Finally, motion errors on correctively machined rail are analized by using motion error analysis method proposed in the previous paper. These processes can be iterated until the analized motion errors are satisfied with target accuracy. In order to verify the validity of the algorithm theoretically, motion errors by the estimated rail, after corrective machining, are compared with motion errors by true rail assumed as the measured value. Estimated motion errors show good agreement with assumed values, and it is confirmed that the algorithm is effective to acquire the corrective machining information to improve the accuracy of hydrostatic table.
Experimental Verification on Corrective Machining Algorithm of Hydrostatic Table
Park, Chun-Hong ; Lee, Chan-Hong ; Lee, Hu-Sang ;
Journal of the Korean Society for Precision Engineering, volume 19, issue 6, 2002, Pages 70~76
Effectiveness of corrective machining algorithm is verified experimentally in this paper by performing corrective machina work practically to single side and double sides hydrostatic tables. Lapping is applied as machining method. Machining information is calculated from measured motion errors by applying the algorithm, without information on rail profile. It is possible to acquire 0.13
m of linear motion error, 1.40arcsec of angular motion error in the case of single side table, and 0.07
m of linear motion error, 1.42arcsec of angular motion error in the case of double sides table. The experiment is performed by an unskilled person after he experienced a little of preliminary machining training. Experimental results show that corrective machining algorithm is very effective, and anyone can improve the accuracy of hydrostatic table by using the algorithm.
Improvement of Motion Accuracy Using Transfer Function in Linear Motion Bearing Guide
Kim, Kyung-Ho ; Park, Chun-Hong ; Lee, Hu-Sang ; Kim, Seung-Woo ;
Journal of the Korean Society for Precision Engineering, volume 19, issue 6, 2002, Pages 77~85
An analysis method which calculates corrective machining information for improving the motion accuracy of linear motion guide Is proposed in this paper. The method is composed of two algorithms. One is the algorithm fur prediction of the motion errors from rail form error. The other is the algorithm for prediction of rail form error from the motion errors of table. Transfer function is utilized in each algorithm, which represents the ratio of bearing reaction force variation to unit magnitude of spatial frequencies of raid from error. As the corrective machining information is acquired from the measured motion errors of table, the method has a merit not to measure rail form error directly. Validity of the method is verified both theoretically and experimentally. By applying the method, linear motion error of test equipment is reduced from 5.97
m to 0.58
m, and reduced from 32.78arcsec to 6.21 arcsec in case of angular motion error. From the results, it is confirmed that the method is very effective to improve the motion accuracy of linear motion guide.
Process Design of Cold Forged Hub by Flow Control Forming Technique
Park, Jong-Nam ; Kim, Dong-Hwan ; Kim, Byung-Min ;
Journal of the Korean Society for Precision Engineering, volume 19, issue 6, 2002, Pages 86~95
This paper suggests the new technology to control metal flow in order to reduce the number of preforming and the machining for the cold forged product with complex geometry. This technology is the combined forming that consists of bulk and sheet forming with double action dies. To analyze the process, finite element simulation has been performed. The proposed technology is applied to hub model that is part of air conditioner clutch. The purpose of this study is to investigate the material now of hub through the relative-velocity control of punch and mandrel using the flow control forming technique.
Adjustment of Roll Gap for The Dimension Accuracy of Bar in Hot Bar Rolling Process
Kim, Dong-Hwan ; Kim, Byung-Min ; Lee, Young-Seog ;
Journal of the Korean Society for Precision Engineering, volume 19, issue 6, 2002, Pages 96~103
The objective of this study is to adjust the roll gap fur the dimension accuracy of bar in hot bar rolling process considering roll wear. In this study hot bar rolling processes fur round and oval passes have been investigated. In order to predict the roll wear, the wear model is reformulated as an incremental from and then wear depth of roll is calculated at each deformation step on contact area using the results of finite element analysis, such as relative sliding velocity and normal pressure at contact area. Archard's wear model was applied to predict the roll wear. To know the effects of thermal softening of DCI (Ductile Cast Iron) roll material according to operating conditions, high temperature micro hardness test is executed and a new wear model has been proposed by considering the thermal softening of DCI roll expressed in terms of the main tempering curve. The new technique developed in this study for adjusting roll gap can give more systematically and economically feasible means to improve the dimension accuracy of bar with full usefulness and generality.
Modal Analysis of Sandwich Plate Structure Considering Buckling
Han, Geun-Jo ; Ahn, Chan-Woo ; Ahn, Seong-Chan ; Hong, Do-Kwan ; Han, Dong-Seop ;
Journal of the Korean Society for Precision Engineering, volume 19, issue 6, 2002, Pages 104~108
Sandwich plate structure is widely used in various fields of industry due to its excellent strength and stiffness compared with weight. In this paper, the mechanical behavior of sandwich plate structure with honeycomb core considering buckling is investigated in detail. The focus of the analysis is to evaluate strength and stiffness of the plate structure with critical stress, natural frequency, and mode shapes. The results of this investigation are obtained from detailed finite element analysis for various parameters, such as length, height ratio, and thickness ratio of honeycomb core.
Active Control of Vibrational Intensity in a Compound Vibratory System
Kim, Gi-Man ;
Journal of the Korean Society for Precision Engineering, volume 19, issue 6, 2002, Pages 109~118
The vibrational intensity and the dynamic response of a compound vibratory system had been controlled actively by means of a feedforward control method. A compound vibratory system consists of a flexible beam and two discrete systems - a vibrating source and a dynamic absorber. By considering the interactive motions between discrete systems and a flexible beam, the equations of motion for a compound vibratory system were derived using a method of variation of parameters. To define the optimal conditions of a controller the cost function, which denotes a time averaged power flow, was evaluated numerically. The possibility of reductions of both of vibrational intensity and dynamic response at a control point located at a distance from a source were fecund to depend on the positions of a source, a control point and a controller. Especially the presence of a dynamic absorber gives the more reduction on the dynamic response but the less on the vibrational intensity than those without a dynamic absorber.
A Study on the Bandwidth of Gear Reduction Servo System according to Backlash and Motor Supplied Voltage
Baek, Joo-Hyun ; Hong, Sung-Min ; Yang, Tae-Suk ; Kim, Soo-Hyun ; Kwak, Yoon-Keun ;
Journal of the Korean Society for Precision Engineering, volume 19, issue 6, 2002, Pages 119~127
The paper presents the effect of the backlash magnitude and the supplied voltage of motor on the gear reduction servo system. The bandwidth of the system depends heavily on the supplied voltage of motor as well as the backlash magnitude. Specially, the bandwidth of the system increases as the supplied voltage of motor increases. 1t is shown that the system has the bandwidth of zero backlash in case of motor supplied voltage is infinite. It is also found that the magnitude of the supplied voltage of motor is very important in case of the analysis of the system bandwidth.
A Study of Deburring System Using The Image Processing Technique
Bae, Joon-Young ; Joo, Youn-Myoung ; Choi, Sang-Kyun ; Lee, Sang-Ryong ;
Journal of the Korean Society for Precision Engineering, volume 19, issue 6, 2002, Pages 128~135
Burr is a projected part of finished workpiece. It is unavoidable and undesirable by-product of most metal cutting or shearing process. Also, it must be removed to improve the fit of machined parts, safety of workers, and the effectiveness of finishing operation. But deburring process Is one of manufacturing processes that have not been successfully automated, so deburring automation is strongly needed. This paper focused on developing a basic algorithm to find edge of workpiece and match two different image data for deburring automation which includes automatic recognition of parts, generation of deburring tool paths and edge/comer finding ability by analyzing the DXF drawing file which contains information of part geometry. As an algorithm fur corner finding, SUSAN method was chosen. It makes good performance in finding edge and corner in suitable time. And this paper suggested a simple algorithm to find matching point between CCD image and drawing file.
Effects of Viscosity Control by Induction Heating on Micro Cell in Forming Process of Foamed Aluminum
Jeon, Yong-Pil ; Kang, Chung-Gil ;
Journal of the Korean Society for Precision Engineering, volume 19, issue 6, 2002, Pages 136~144
Melting method has long been considered difficult to realize because of problems such as the low foamability of molten metal, the varying size of cellular structures and solidification shrinkage. The parameters to solve the problem in electric furnace were stirring temperature, stirring velocity, heating velocity and foaming temperature It is important to consider the effects of induction heating, because it brings about the inner flow by the temperature gradient. Aspect ratio also depends on the induction heating. Mechanical properties are dependent on cell sizes and aspect rations. Therefore, this paper presents the effects of these parameters on the cell sizes. For the sake of this, combined stirring process was used to fabricate aluminum foam materials by the above mentioned parameters. Image analysis was performed to calculate the cell sizes, distributions, and aspect ratioes at the cross section of feared aluminum in the direction of height.
Silicon Wafering Process and Fine Grinding Process Induced Residual Mechanical Damage
O, Han-Seok ; Lee, Hong-Rim ;
Journal of the Korean Society for Precision Engineering, volume 19, issue 6, 2002, Pages 145~154
CMP (Chemical mechanical polishing) process was used to control the fine grinding process induced mechanical damage of Cz Silicon wafer. Characterization of mechanical damage was carried out using Nomarski microscope, magic mirror and also using angle lapping and lifetime scanner evaluation after heat treatment. Magic mirror and lifetime scanner were very useful for the residual damage pattern characterization and CMP process was effective on the reduction of fine grinding induced mechanical damage.
Development of Mosquito Trap with Effect of Air Cleaning by Using Theory of lnventive Problem Solving (TRIZ)
Lee, Kyeong-Won ;
Journal of the Korean Society for Precision Engineering, volume 19, issue 6, 2002, Pages 155~159
This paper describes the development process of mosquito trap with the effect of air cleaning by using the substance-field analysis and evolution pattern of systems in the theory of inventive problem solving (TRIZ). We g(It the concept of the mosquito trap with mosquito attractants instead of mosquito reluctants such as mosquito stick coil and skin medicine with bad and toxic smell. The number of mosquitos traped by one trap near cattle shed per one night in summer, was over 10 thousands with some effects of air cleaning
A Study on Digital Process of Injection Mold in Reverse Engineering
Lee, Hui-Gwan ; Kim, Hyeong-Chan ; Yang, Gyun-Ui ;
Journal of the Korean Society for Precision Engineering, volume 19, issue 6, 2002, Pages 160~165
A study on digital processes of injection mold in reverse engineering are presented. Reverse engineering is useful fur several cases, where user has no geometry information of object. Laser scanner is used to obtaining 3D coordinates of object. Sequences to process cloud data are described; sampling to reduce number of points, sorting to adjust the point order, and fitting to curve and surface, and so on. Split slide structure of mold is used fur undercut part and high viscosity material. Flow of injection molding are analysed to correct cooling channel and simulate molding conditions. NC tool paths are generated to carve core and cavity. The processes are performed in digital data for reduction of lead time and consecutive geometry data.
Low Cycle Fatigue Life Prediction of HSLA Steel Using Total Strain Energy Density
Kim, Jae-Hoon ; Kim, Duck-Hoi ;
Journal of the Korean Society for Precision Engineering, volume 19, issue 6, 2002, Pages 166~175
Low cycle fatigue tests are performed on the HSLA steel that be developed for a submarine material. The relation between strain energy density and numbers of cycles to failure is examined in order to predict the low cycle fatigue life of HSLA steel. The cyclic properties are determined by a least square fit techniques. The life predicted by the strain energy method is found to coincide with experimental data and results obtained from the Coffin-Manson method. Also the cyclic behavior of HSLA steel is characterized by cyclic softening with increasing number of cycle at room temperature. Especially, low cycle fatigue characteristics and microstructural changes of HSLA steel are investigated according to changing tempering temperatures. In the case of HSLA steel, the
-Cu is farmed in
of tempering temperature and enhances the low cycle fatigue properties.
A Study on Plasma Display Panel Barrier Rib Fabrication by Mold and Electromagnetic Wave
Son, Jae-Hyeok ; Im, Yong-Gwan ; Jeong, Yeong-Dae ; Jeong, Seong-Il ; Jeong, Hae-Do ;
Journal of the Korean Society for Precision Engineering, volume 19, issue 6, 2002, Pages 176~183
Plasma Display Panel(PDP) is a type of flat panel display utilizing the light emission produced by gas discharge. Barrier Ribs of PDP separating each sub-pixel prevents optical and electrical crosstalks from adjacent sub-pixels. The mold for forming the barrier ribs has been newly researched to overcome the disadvantages of conventional manufacturing processes such as screen printing, sand-blasting and photosensitive glass methods. The mold for PDP barrier ribs have stripes of micro grooves transferring glass-material wall. In this paper , Stripes of grooves of which width 48
m, depth 124
m , pitch 274
m was acquired by machining of single crystal silicon with dicing saw blade. Maximum roughness of the bottom of the grooves was 59.6 nm Ra in grooving Si. Barrier ribs were farmed with silicone rubber mold, which is transferred from grooved Si forming hard mold. Silicone rubber mold has the elasticity, which enable to accommodate the waviness of lower glass plate of PDP. The methods assisted by the microwave and UV was adopted for reducing the forming time of glass paste.
Optimization of the Thermal Behavior of Linear Motors with High Speed and Force [
Eun, In-Ung ;
Journal of the Korean Society for Precision Engineering, volume 19, issue 6, 2002, Pages 184~191
This paper presents the thermal behavior of a synchronous linear motor with high speed and force. Such a linear motor can successfully replace ball lead screw in machine tools because it has a high velocity, acceleration and good positioning accuracy. On the other hand, low efficiency and high heating up during operation are disadvantage of linear motors. For the application of linear motors to machine tools a water-cooling system is often used. In this research, structure of the linear motor and water cooler is changed to improve the thermal behavior of the linear motor. Some important effects of an integrated cooler, an U-cooler and a thermally symmetrical cooler are presented.
A Study on Design Criteria of Piping System in Petrochemical Plant
Min, Sun-Kuo ; Choi, Myung-Jin ;
Journal of the Korean Society for Precision Engineering, volume 19, issue 6, 2002, Pages 192~199
Largely, there are three kinds of the design criteria of piping system in petrochemical plant. The first is on the pipe thickness in accordance with the design pressure of piping system. The second is on the static state evaluation by thermal growth and the other is on the dynamic evaluation by piping vibration. According to the ASME B31.3 code, the internal pressure design thickness fur straight pipe shall be calculated as a code formula. And the static design by thermal displacement is defined 7000 cycles of fatigue life in operating the piping system with a design condition. However, the dynamic design evaluation in comparative with small displacements of high frequencies to the static condition has not established clearly the method, yet. So, this study purposes to present the trial of a proposal of dynamic design criterion on the basis of static design method.