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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 17, Issue 12 - Dec 2000
Volume 17, Issue 11 - Nov 2000
Volume 17, Issue 10 - Oct 2000
Volume 17, Issue 9 - Sep 2000
Volume 17, Issue 8 - Aug 2000
Volume 17, Issue 7 - Jul 2000
Volume 17, Issue 6 - Jun 2000
Volume 17, Issue 5 - May 2000
Volume 17, Issue 4 - Apr 2000
Volume 17, Issue 3 - Mar 2000
Volume 17, Issue 2 - Feb 2000
Volume 17, Issue 1 - Jan 2000
Selecting the target year
Recent State of Rapid Prototyping Technique for Rapid Product Manufacturing
Yang, Dong-Yeol ; Son, Hyeon-Gi ;
Journal of the Korean Society for Precision Engineering, volume 17, issue 10, 2000, Pages 5~10
State of the Art in Rapid Tooling
Song, Yong-Ak ;
Journal of the Korean Society for Precision Engineering, volume 17, issue 10, 2000, Pages 11~16
Shape Reverse Engineering for Rapid Product Development
Choi, B.K ; Bae, S.H ; Yoo, S.K ; Jeong, Won-Hyeong ;
Journal of the Korean Society for Precision Engineering, volume 17, issue 10, 2000, Pages 17~25
Measurement Systems for Rapid Product Development
Lee, Kwan-H ; Son, Selkbae ; Park, Hyunpung ;
Journal of the Korean Society for Precision Engineering, volume 17, issue 10, 2000, Pages 26~34
Open Manufacturing System Using MMS Service and Object Oriented Manufacturing Devices(2nd Report)
Kim, Seon-Ho ; Kim, Dong-Hun ; Park, Gyeong-Taek ;
Journal of the Korean Society for Precision Engineering, volume 17, issue 10, 2000, Pages 41~48
Manufacturing devices must be integrated for constructing CIM environment, but integration of heterogeneous system meets several economical and technological difficulties. In this case, MMS(Manufacturing Message Specification) can be an effective method, but it has problems which MMS products are generally very expensive and majority of the existing manufacturing devices do not support MMS. This paper describes the development of a gateway for Non-MMS-Compatible CNC machine tools to serve MMS and the implementation of OSI(Open System Interconnection) upper layer on TCP/IP. The developed system is applied to construct cell controller with heterogeneous devices under CIM environment and to evaluate interoperability and portability.
A Study of Crack Growth Behavior of Al2024
Lee, Won-Seok ; Lee, Hyun-Woo ;
Journal of the Korean Society for Precision Engineering, volume 17, issue 10, 2000, Pages 49~55
This study describes the fatigue characteristics for Al2024 alloy, which is aircraft structure material. For this work, the plane-strain fracture toughness test, the plane-stress fracture toughness test and the crack growth rates test were conducted under the standard testing method. Test equipment is a computer-controlled closed-loop fatigue testing machine. The data of each test result is very important to aircraft structure reliability estimation, life prediction, design analysis, endurance analysis and damage tolerance analysis. In addition, the fatigue crack growth threshold(
) value decreased as the stress ratio increased. Also,
decreased as the thickness increased in LT, TL directions.
Solid Freeform Fabrication of Metal Prototype Using Direct Metal Shaping Process
Kim, Jae-Do ; Park, Jin-Yong ; Cho, Myeong-Woo ;
Journal of the Korean Society for Precision Engineering, volume 17, issue 10, 2000, Pages 56~62
A fast and precise technique to make 3-dimensional object which is called direct metal shaping process is processed. It is very useful technique in design and inspection. Using this developed system, a solid object is made. In experiment, test parts are built by varying three factors, laser power, scan path, scan speed. This process used device, which is different from the widely used in rapid prototyping in that powder feeding device is used. Spraying powder directly at the focused laser beam and then three dimensional object is made by the deposit of melted metal powder. The optimum scanning path is found to be zigzag path, which had little thermal affection on base metal. As a result of these experiments, it was found that optimum scanning speed is 15mm/sec laser power is 50W. This constructed 3-dimensional object could be used in mold manufacturing directly.
Automatic Inspection of Geometric Accuracy of Optical Fiber Single Ferrules
Kim, Gee-Hong ; Kim, Seung-Woo ; Lim, Ssang-Gun ;
Journal of the Korean Society for Precision Engineering, volume 17, issue 10, 2000, Pages 63~68
We present an automatic inspection system which been developed to evaluate the geometric tolerances of the optical fiber connectors with an dimensional accuracy of
. The main part of the inspection system comprises a series of machine vision and laser scanning probes to measure the internal and external circle diameters along with concentricity by making the most of advanced edge detection algorithms. Actual experimental results obtained through various repeatability tests demonstrate that the system well satisfies the required industrial demands for in-situ inspection of optical fiber connections in real manufacturing environment.
A Study on the Design of Valve Mode MR Damper using Permanent Magnet
Kim, Jung-Hoon ; Oh, Jun-Ho ;
Journal of the Korean Society for Precision Engineering, volume 17, issue 10, 2000, Pages 69~76
Lots of semi-active control devices have been developed in recent years because they have the best features of passive and active system. Especially, controllable magneto-rheological(MR) fluid devices have received significant attention in these area of research. The MR fluid is the material that reversibly changes from a free-flowing, linear viscous fluid to a semisolid with a controllable yield strength in milliseconds when exposed to a magnetic field. If the magnetic field is induced by moving a permanent magnet instead of applying current to a solenoid, it is possible to design a MR damper consuming low power because the power consumption is reduced at steady state. This paper proposes valve mode MR damper using permanent magnetic circuit that has wide range of operation with low power consumption, a design parameter is adopted. The magnetic circuit, material of choke and choke type are selected experimentally with the design parameter. The behaviors of the damper are examined and torque tracking control using PID feedback controller is performed for step, ramp and sinusoidal trajectiories.
Design of the Prestressed Cold Extrusion Die with Two Stress Rings
Heo, Gwan-Do ; Yeo, Hong-Tae ; Ye, Sang-Don ;
Journal of the Korean Society for Precision Engineering, volume 17, issue 10, 2000, Pages 77~82
The design of the prestressed cold extrusion die with two stress rings has been performed in this study. The cold extrusion has been simulated by the rigid-plastic FEM. The stress analysis of die has been performed for both after shrink fitting and during extrusion by using the elastic FEM and the Lame's equation. According to the variation of interferences and diameter ratios, the maximum effective stress has been evaluated. As results, interferences and diameters were determined by the minimization of the maximum effective stress of die insert. The comparison of the maximum effective stress between the proposed design and the conventional design has been discussed. It was found that the maximum effective stress in the die insert is considerably affected by the stiffness of the first stress ring.
Development of Beam Rotating Actuator Based on Voice Coil Motor Type for Mulit-beam Optical Disc System
Lee, Cheong-Hee ; Kim, Soo-Hyun ; Kwak, Yoon-Keun ;
Journal of the Korean Society for Precision Engineering, volume 17, issue 10, 2000, Pages 83~88
multi-beam optical drive is a method to improve the data transfer rate for the optical disc systems by parallel recording and reading on neighboring multi-tracks. In this paper, the beam rotating actuator, which is necessary for the multi-bean optical disc drive to from beam spots on multi-tracks simultaneously, has been developed. The Voice Coil Motor is used as a drive mechanism for high resolution and small size of the actuator. And rotating guide based on link structure is designed for frictionless and axisless rotation of rotating part including dove prism and for rotating in axis of geometric center of dove prism. The characteristics of the actuator are experimented by laser vibrometer, Polytec OFV1102 and a dynamic analyzer, HP35670A. It shows that the actuator has good linearity, rotating range
, minimum rotating angle
and natural frequency 113.9Hz. Therefore the actuator can be applied in a multi-beam optical disc system.
Development of Engineering Database for Injection Mold Design
Kim, Seong-Geun ; Heo, Yeong-Mu ; Byeon, Cheol-Ung ;
Journal of the Korean Society for Precision Engineering, volume 17, issue 10, 2000, Pages 89~94
Engineering database for CIM of injection mold production has been developed to manage design information and parameters of injection mold. The database has direct connection with product data management system and management database. Design specifications are generated in initial stage of mold design with integration of management information. Design parameters and bill of materials for mold base parts are generated during the CAD process and transferred to the manufacturing database and procurement system. Standard modules for parts and mold base are constructed using national standard and legacy data of industries. The engineering database provides important information route for CIM of injection mold design and production.
Development of the Effective Clamping Force Measuring System for Spring Clamp
O, Gi-Seok ; Jo, Myeong-U ; Seo, Tae-Il ;
Journal of the Korean Society for Precision Engineering, volume 17, issue 10, 2000, Pages 95~101
The purpose of this study is to develop an improved measuring system, which allows for effectively measure spring clamping forces. This system consists of eight or twelve measuring points in order to acquire the clamping force distribution of the whole range of spring clamp. Each measuring point consists of load cells equipped with 4 strain gauges. Using different bearings, we calibrate the roundness of the measuring points. For quality control and database construction, a software system is established. furthermore, uncertainty is calculated to validate the confidence of this system. Various experiments confirm the effectiveness of this measuring system.
The Effect of Gas Pressure on the Stiffness of Products Manufactured with Gas-Assisted Injection
Park, Gyun-Myeong ; Park, Bong-Hyeon ; Lee, Seong-Hui ; Kim, Cheong-Gyun ;
Journal of the Korean Society for Precision Engineering, volume 17, issue 10, 2000, Pages 102~109
In the present study, gas-assisted molding and structural vibration analysis of hollow long cylinder with the variation of gas injection pressure are performed. Though there are so many parameters such as delay time, injection pressure, and gas pressure on gas-assisted molding, the latter has the most dominant effect on this process. Therefore, the present paper deals with the effects of gas pressure on the dynamic stiffness of the model by means of vibration analysis and then suggests the fundamental materials which can be directly adapted to manufacturing lines.
Trajectory Tracking Control of a Pnuematic Cylinder with an Adaptive Controller
Lee, Su-Han ; Jo, Ho-Seong ; Jang, Chang-Hun ;
Journal of the Korean Society for Precision Engineering, volume 17, issue 10, 2000, Pages 110~118
An adaptive controller for trajectory tracking control of a pneumatic cylinder is proposed. The controller is directly derived by using Lyapunov function, and very simple and computationally efficient since it does not require the mathematical model or the parameter values of a pneumatic system. It is also shown that the system is bounded stable with the controller, and the size of tracking errors can be made arbitrarily small. The stability and the performance of the controller is also verified experimentally. The results of the experiments demonstrate that the proposed controller achieves more accurate trajectory tracking performance than a PD controller.
A Study on the Performance Improvement of a 3-D Shape Measuring System Using Adaptive Pattern Clustering of Line-Shaped Laser Light
Park, Seung-Gyu ; Baek, Seong-Hun ; Kim, Dae-Gyu ; Jang, Won-Seok ; Lee, Il-Geun ; Kim, Cheol-Jung ;
Journal of the Korean Society for Precision Engineering, volume 17, issue 10, 2000, Pages 119~124
One of the main problems in 3D shape measuring systems that use the triangulation of line-shaped laser light is precise center line detection of line-shaped laser stripe. The intensity of a line-shaped laser light stripe on the CCD image varies following to the reflection angles, colors and shapes of objects. In this paper, a new center line detection algorithm to compensate the local intensity variation on a line-shaped laser light stripe is proposed. The 3-D surface shape measuring system using the proposed center line detection algorithm can measure 3-D surface shape with enhanced measurement resolution by using the dynamic shape reconstruction with adaptive pattern clustering of the line-shaped laser light. This proposed 3-D shape measuring system can be easily applied to practical situations of measuring 3-D surface by virtue of high speed measurement and compact hardware compositions.
Modeling and Parameter Estimation of an Electrohydraulic Servo System by the Least Square Method
Roh, Hyoung-Woo ; Song, Chang-Sup ;
Journal of the Korean Society for Precision Engineering, volume 17, issue 10, 2000, Pages 125~131
By using the test of signal error, model structure of an electrohydraulic servo system is determined. For determining parameter of the electrohydraulic servo system, using time discrete model of parametric method, parameters in time discrete model are searched by the least square method. By bilinear transform, we have found the model of electrohydraulic servo system in s domain. Afterwards, we have compared experimental data with simulation data by MATLAB having the identified parameter. As the result, experimental data is agreed with simulation data very well.
Minimization of Burr Formation in Drilling with Step Drill
Ko, Sung-Lim ; Kim, Jin-Ho ;
Journal of the Korean Society for Precision Engineering, volume 17, issue 10, 2000, Pages 132~140
In conventional drilling, burr geometry can be changed according to the variation of drill geometry like point angle, rake angle. Step drilling is proposed to minimize the burr formation in drilling operation. The burr formed in first cutting can be removed in second cutting by the edge in step. The burr formed in second cutting by the edge in step can be minimized according to the change of geometry like, step angle and depth. The mechanism in step drilling is analyzed. Some step drills are applied to drilling the input shaft which is used for vehicle steering. To measure the burr formed in drilling, laser and height gage are used.
A Study on Vision Sensor-based Measurement of Die Location for Its Remodeling
Kim, Jitae ; Na, Suck-Joo ;
Journal of the Korean Society for Precision Engineering, volume 17, issue 10, 2000, Pages 141~146
We introduce the algorithms of 3-D position estimation using a laser sensor for automatic die remodeling. First, a vision sensor based on the optical triangulation was used to collect the range data of die surface. Second, line vector equations were constructed by the measured range data, and an analytic algorithm was proposed for recognizing the die location with these vector equations. This algorithm could make the transformation matrix without any specific corresponding points. To ascertain this algorithm, folded SUS plate was measured by the laser vision sensor attached to a 3-axis cartesian manipulator and the transformation matrix was calculated.
A New Error Compensation Method in Linear Encoder Using a Phase-Modulated Grating
Song, Ju-Ho ; Kim, Gyeong-Chan ; Kim, Su-Hyeon ; Gwak, Yun-Geun ;
Journal of the Korean Society for Precision Engineering, volume 17, issue 10, 2000, Pages 147~154
A new hardware compensation method reducing displacement measurement errors, caused by tilt of index scale in moire linear encoders, has been developed. In conventional moire linear encoders, the detectors are aligned perpendicular to the line of moire fringes this structure is very sensitive to an unwanted tilt of the gratings. In this paper, a newly designed grating, called a phase-modulated grating, is developed to compensate for non-orthogonal errors. By using the phase-modulated grating instead of a conventional index, it is possible to reduce non-orthogonal errors of moire linear encoders.
A Comparison of the Cooling Effects for the Compressed Cold Air and Coolant on the Cylindrical Grinding with WA Wheel
Lee, Seok-Woo ; Choi, Hon-Zong ; Jeong, Hae-Do ;
Journal of the Korean Society for Precision Engineering, volume 17, issue 10, 2000, Pages 155~161
Recently, environmental pollution has become a big problem in industry and many researches have been done in order to preserve the environment. In the grinding process, the coolant has great influence on environment. It contains several chemicals(sulfur, phosphorus and chlorine) to improve the grinding efficiency. If these additives go into the workplace atmosphere, it is harmful for workers. It can also cause the environment pollution. Because of these reasons many studies have been done to minimize the amount of coolant. However the small amount of coolant can cause the thermal defect on the ground surface layer. This study forced the effects of the compressed cold air when the spindle shaft materials(SCM4 & SCM21) were cylindrical ground with WA wheel. The compressed cold air was used as the coolant and grinding performance was compared with that of the conventional grinding fluids(emulsion). Many experiments were carried out with these two cooling materials. The surface roughness, residual stress, and roundness were measured for the cylindrical grinding. The test results showed that the compressed cold air was very useful as the cooling materials for grinding process. It was also efficient to minimize the thermal defects of workpiece and could also play a role in solving environmental pollution.
Current Equation Loop Design of Muti-channel Direct Drive Valve Actuation
Nam, Yoonsu ;
Journal of the Korean Society for Precision Engineering, volume 17, issue 10, 2000, Pages 162~169
A Direct Drive Valve(DDV) hydraulic actuation system which is commonly used as an aircraft's control surface driving actuator has multi-loop control structure to ensure its safety operation. However, because of not perfect matching of one self channel characteristics with the others, the servo valve driving current of each channel can be widely different. Therefore, the long-time use of DDV actuator without any correction of these channel current offsets will cause the problem of performance or life expectancy degradation due to unwanted heats in the linear motor. A current equalization loop structure which can minimizes current offsets between channels is introduced and designed. The performance of the current equalization loop is investigated and verified through the analytic and experimental ways.
Development of a Module to Predict Burr Formation Using the Finite Element Method
Go, Dae-Cheol ; Go, Seong-Rim ;
Journal of the Korean Society for Precision Engineering, volume 17, issue 10, 2000, Pages 170~179
The objective of this study is to develop an analytical module for the prediction of burr formation during cutting process using the finite element method. This module is based on the rigid-plastic finite element method, ductile fracture criterion, fracture propagation technique and node separation criterion. The sequence of burr formation from burr initiation through end of burr formation is simulated and investigated by this module. The effect of material properties, such as AL6061-T6, AL2024-T4 and Copper, and cutting condition, such as rake angle and cutting depth, on burr formation is also discussed in this study. To validate this module the analysis results are compared with experimental ones.
Precise Forging Simulation by a Local Remeshing Technique
Ryu, Chan-Ho ; Park, Jae-Min ; Joun, Man-Soo ;
Journal of the Korean Society for Precision Engineering, volume 17, issue 10, 2000, Pages 180~185
In this paper, a local remeshing technique assisted by flexible user-interface capabilities is presented for precise forging simulation. The rigid-plastic finite element formulation is introduced and the detailed approach to the new local remeshing technique is given. A piercing process in cold forging is simulated by the presented technique and the simulated results are compared with those obtained by the technique and the simulated results are compared with those obtained by the conventional approach and experiments. A typical application example is also given, which emphasizes the capability of the local remeshing technique in forging simulation.
A Change of Foaming Magnitude as Thickness of Mold System
Hwang, Yun-Dong ; Cha, Seong-Un ; Yun, Jae-Dong ; Kim, Ji-Hyeon ;
Journal of the Korean Society for Precision Engineering, volume 17, issue 10, 2000, Pages 186~191
We use so many plastic products in everyday. Because polymer materials have a lot of merits including low cost and easiness of forming, they are widely using at many manufacturing industries. Microcellular foaming process appeared at MIT in 1980's to save a quantity of material and increase mechanical properties. The information about the thickness of cavity plays an important role in appling microcellular foaming process to the conventional injection molding process. It is essential to make an effective foam. The goal of this research is to measure the relation between the change of cavity's thickness and foaming magnitude made after inserting a gas. R/t is a conception that indicate proportion between radius and thickness of cavity in mold system. By means of SEM observation of side surface of cavity sample, foaming magnitude of cavity is mold system. By means of SEM observation of side surface of cavity sample, foaming magnitude of polymer in microcellular foaming process is decreasing gradually as the value of R/t is increasing. The proposed foaming magnitude changes data of polymer in relation to mold system can be applied in more extensive injection molding process, such as optimum design of mold for microcellular foaming process.
Development of a Design System for Multi-Stage Gear Drives (2nd Report: Development of a Generalized New Design Algorithm)
Chong, Tae-Hyong ; Bae, In-Ho ; Park, Gyung-Jin ;
Journal of the Korean Society for Precision Engineering, volume 17, issue 10, 2000, Pages 192~199
The design of multi-stage gear drives is a time-consuming process because it includes more complicated problems, which are not considered in the design of single-stage gear drives. The designer has no determine the number of reduction stages and the gear ratios of each reduction stage. In addition, the design problems include not only dimensional design but also configuration design of gear drive elements. There is no definite rule or principle for these types of design problems. Thus the design practices largely depend on the sense and the experiences of the designer, and consequently result in undesirable design solution. A new and generalized design algorithm has been proposed to support the designer at the preliminary phase of the design of multi-stage gear drives. The proposed design algorithm automates the design process by integrating the dimensional design and the configuration design process. The algorithm consists of four steps. In the first step, the user determines the number of reduction stages. In the second step, gear ratios of every stage are chosen using the random search method. The values of the basic design parameters of a gear are chose in the third step by using the generate and test method. Then the values of the dimensions, such as pitch diameter, outer diameter and face width, are calculated for the configuration design in the next step. The strength and durability of each gear is guaranteed by the bending strength and the pitting resistance rating practices by using AGMA rating formulas. In the final step, the configuration design is carried out using simulated annealing algorithm. The positions of gears and shafts are determined to minimize the geometrical volume (size) of a gearbox while avoiding interferences between them. These steps are carried out iteratively until a desirable solution is acquired. The proposed design algorithm is applied to the preliminary design of four-stage gear drives in order to validate the availability. The design solution has considerably good results in both aspects of the dimensional and the configuration design.
A Study on Vibration Characteristic of Thin Plate in Crack Propagation by Laser Holography Method
Kim, In-Gwon ; Kim, Koung-Suk ; Yoon, Sung-Un ; Kang, Ki-Soo ;
Journal of the Korean Society for Precision Engineering, volume 17, issue 10, 2000, Pages 200~205
This paper presents the vibration characteristics of a rectangular plate with 45
oblique crack and a smooth plate subjected to a uniaxial tension. The experiment is adopted by the time-average holography method. The natural frequency and mode shape are considered accurate according to the increasement of tensile load in the study. When tensile load is zero, the vibration modes are almost agreed with the smooth and the 45
obliquely cracked plate. But since then, according to the increasement of load, it is shown that vibration modes are extremely varied. The effects of the crack length in the vibration characteristic are discussed in detail. It is indicated that the increase of the crack length makes the variation of the frequencies and modes complicate in the range of even a small load.