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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Journal of the Korean Society for Precision Engineering
Journal Basic Information
Journal DOI :
Korean Society of Precision Engineering
Editor in Chief :
Volume & Issues
Volume 8, Issue 4 - Dec 1991
Volume 8, Issue 3 - Sep 1991
Volume 8, Issue 2 - Jun 1991
Volume 8, Issue 1 - Mar 1991
Selecting the target year
Development of Flexible Manufacturing Systems(FMS)
Gang, Cheol-Hwi ;
Journal of the Korean Society for Precision Engineering, volume 8, issue 4, 1991, Pages 7~22
This paper describes two FMS, which were developed by SAEIL Heavy Industries. One is FMS for machining of circular parts, that are automobile's axle shafts. This system consists of 13units, including 7CNC machine tools. The other is RMS for machining of non- circular parts namely casted or steel block within size of 1.2
1.5m. This FMS consists of 8-machining centers, 1-automated werehouse, 2,-unmanned Robo Trailers, and computer control room. All systems are functioning satisfactorily and so help greately towards automation of Korean industries.
Calculation of Turbulent Offset Jet
Lee, Woo-Jung ; Kim, Kwang-Yong ; Cho, Yong-Chul ;
Journal of the Korean Society for Precision Engineering, volume 8, issue 4, 1991, Pages 23~32
The paper discusses the problem of the flow over the backward facing step and the offset jet, which are calculated numerically. Standard k- .epsilon. model and its LPS modification are used as turbulence models. Hybrid central/upwind scheme and skew- upwind scheme are used as numerical schemes. The numerical scheme has a strong influence on the offset jet rather than the flow over backward facing step. The skew-upwind scheme gives good results in both cases. However, the k- .epsilon. model with LPS modification yields no remarkable improvements in the predictions of both flows. The skew-upwind scheme improves the prediction of reattachment length in the offset jet.
A Study on Work Roll Wear and Surface Roughness of Steel Strip in the Cold Rolling
Jeon, Eon-Chan ; Kim, Sun-Kyung ;
Journal of the Korean Society for Precision Engineering, volume 8, issue 4, 1991, Pages 33~40
The decrease in surface roughness of work roll and steel strip in cold rolling of low carbon steel strip has been investigated by working distance, materials, total separating force and total reduction ratio. The main results are as follows; For the same lubricating conditions. 1) The changing of surface roughness of steel strip were similar to work roll. The transcription ratio is in inverse proportion to the carbon content of steel strip. 2) The surface roughness of steel strip is hardly change according to changing of total separating force and total reduction ration. 3) The wear of work rolls surface is more rapid in that case of continuous casted steel strip than ingot casted steel strip. The aluminium content dull powder adhere on the rolls surface, and so. It makes the mirror surface of work roll accelerate.
A Study of Automated Analysis of In-Plane Strain and Stress of Center Cracked Plate by Laser Speckle Photography Method
Kim, Gyeong-Seok ; Na, Gi-Dae ; Jung, Nak-Gyu ; Cha, Yong-Hun ; Jung, Un-Gwa ;
Journal of the Korean Society for Precision Engineering, volume 8, issue 4, 1991, Pages 41~54
Laser speckle photography-one of the Laser speckle measurement methods which, recently, are used widely in various science, and engineering applications are succesfully used in the non-contact measurement of In-plaane displacement. In this study, automated measurement and analysis are tried in the laser speckle photo- graphy method using a video camera, computer control and processing, and a X-Y positioning table driven by computer controlled stepping motor. The experiment was compared with the theorecial strain and stress data from finite element method. The result showed that displacement, strain and stress can be measured more accurately and conveniently by using this approach.
Automated Process Planning System based on Knowledge Base for Injection Mold
Cho, Kyu-Kap ; Lim, Ju-Taek ; Lee, Ga-Sang ; Kim, Pil-Seong ; Kim, Byeong-Hyeon ;
Journal of the Korean Society for Precision Engineering, volume 8, issue 4, 1991, Pages 55~63
This paper deals with development of a Computer Aided Process Planning System based on knowledge base in addition to database for injection mold as a part of Computer Integrated Manufacturing System for injection mold manufacture. The prposed system consists of four modules such as manufacturing feature code generation module machine tool selection and sequencing module, operation and cutting tool selection mudule and standard time estimation module. The system is programmed by using Turbo Pascal on the IBM-PC/AT. The performance of the system is evaluated by using real problems and the test results indicate that the proposed system is a practical and efficient system.
A Study on Surface Integrity in Ground Layers
Kim, Gyung-Nyun ; Cheong, Chae-Cheon ; Cha, Il-Nam ;
Journal of the Korean Society for Precision Engineering, volume 8, issue 4, 1991, Pages 64~75
The design of structures of modern industry has developed to satisfy stringent service, realiability and safety. Up to now, geometric profile which means surface foughness and dimension accuracy is mainly treated in manufacturing process of work surface. But it is inevitable to evaluate changes of surface geometry as well as the nature of alterations in surface layers because surface of workpiece changes as a result of phase transformation, chemical changes, plastic deformation and stress changes. This paper is to present principal data for safety design by verifying the effect of grinding conditions and method in grinding layers and to explain the method of measuring surface integrity. In this paper, structural steel(SM20C) is used as a workpiece. Of integrity, surface roughness in view of surface texture is analyzed by frequency domain and residual stress, structures and defect of ground layers in view of surface metallurgy are investigated.
Estimation Of System Parameters With Arma Model
Hwang, Won-Geol ;
Journal of the Korean Society for Precision Engineering, volume 8, issue 4, 1991, Pages 76~83
Development of off-line Robot Task Programming System for Polishing Process of Sculptured Surfaces
Chung, Seong-Chong ; Kuk, Keum-Hwan ; Choi, Gi-Bong ;
Journal of the Korean Society for Precision Engineering, volume 8, issue 4, 1991, Pages 84~94
In order to achieve high accuracy of teaching and increase productivity using industrial robots in polishing process of dies, an off-line task programming system was developed on IBM-PC/386 under WINDOWS 3.0 operating system. The internal structure and the machematical basis of CAMPoli are described. Surface modeling technique of polishing dies with sculptured surfaces is introduced by poing data interpolation methodology through the use of CL-data transmitted from conventional CAM system. Tool selection, polishing speed, polishing pressure and kinds of tool motions can be determined and selected by user specified polishing variables. Task creation and verification of polishing path via computer graphics simulation of polishing tool can be done by the menu- driven function of CAMPoli system. Post-processing module is attached to generate robot language. Some simulation results are provided as verification means of the system.
Computational Study on Swirling Turbulent Flow in a Stationary Pipe
Park, Bong-Kyu ; Kim, Kwang-Yong ; Cho, Yong-Chul ;
Journal of the Korean Society for Precision Engineering, volume 8, issue 4, 1991, Pages 95~106
A numerical computation of turbulent wirling flow in a stationary pipe is presented in this work. Major concerns of this study are: 1) To approve similarity laws which were verified experimentally. 2) To investigate the effects of curvature modification for the K- .epsilon. model. To account for effects of swirl, Rodi's curvature correction and Kim & Chung's are applied. The governing differential equations for eliptic flow are discretized by control volume formulation method, and the discretized equations are calculated ay line by line TDMA and SIMPLE algorithm. The computational results also satisfy similarity laws which are based on swirl angle as in experiments. And the curvature modification of Rodi improves compuational accuacy than the standard K- .epsilon. model. But such lower order closure models are not adequate for the prediction of this complex flow.
A Study on the Dynamic Stability of a Flexible Missile with Mass Variation
Ryu, Bong-Jo ;
Journal of the Korean Society for Precision Engineering, volume 8, issue 4, 1991, Pages 107~117
The dynamic stability problem of nonconservative system is one of the important problems. In this study, flexible missile with mass variation is regarded as a free Timoshenko beam subjected to a controlled follower force. The stability was studied numerically through the finite element method. Through the study, the obtained results are as follows:  Without force direction control (1) In the case of no mass reduction, the existence of concentrated mass increases critical follower force. (2) Mass reduction rate of the beam slightly effects on the change of critical follower force.  With force direction control (1) Shear deformation parameter S contributes insignificantly to the force at instability when
. (2) With mass variation, increase of concentrated mass increases critical follower force at instbility. (3) The type of promary instability is determined by the sensor location.
Measurement of Defects with Scanning Acoustic Microscope and Acoustic Emission
Choi, Man-Yong ; Park, Ik-Gun ; Han, Eung-Kyo ;
Journal of the Korean Society for Precision Engineering, volume 8, issue 4, 1991, Pages 118~125
Acoustic microscopy has attracted much interest recently as potential nondestructive evaluation technique for detecting and sizing defects of surface and sub-surface. Also acoustic emission testing method has been developed for detecting microcracks which is more than 30
in length quantitatively on ceramics. In the present paper, acoustic emission during the four point bending test in hot-pressed sintered
specimen which was stressed by thermal shock, has been measured by high sensitive sensing system. The surface and sub-surface cracks were detected by scanning acoustic micrscope of 800 MHz and conventional ultrasonic testing in C-scope image. The purpose was to investigate the location and size of cracks by SAM and AE technique, whose experimental data demonstrate good for detecting microcracks.
Stduy on the Dynamic Gripping Force of a 3-Jaw Chuck
Park, Tae-Won ; M. Tsutsumi ; I. Tokasiki ;
Journal of the Korean Society for Precision Engineering, volume 8, issue 4, 1991, Pages 126~136
In order to reduce the possibilities of personnel injuries and damages to machines and to obtaim higher efficiency and machining accuracy in the manufacturing system, the chucking technology has recentry become important. The chucking technology of work greatly affects both the grometrical accuracy and fonctional performance of the workpiece. In this study, the dynamic gripping force of a 3-jaw power chuck is investigated on the factors of the shape of jaw and the shape of workpiece. From this investigation, the following observations are obtained. 1) The higher stiffness of workpiece is, the higher decrease of dynamic gripping force is. 2) The nearer to the root of jaw is, the higher decrease of dynamic gripping force is. 3) The centrifugal force of affectting the decrease of dynamic gripping force has to be considered in the centrifugal force of affecting jaw.1
A Study on Design of a Damper for Reducing Torsional Vibrations of a Driveline with Universal Joints
Park, Bo-Yong ; Song, Chang-Seop ; Kang Hyo-Sik ;
Journal of the Korean Society for Precision Engineering, volume 8, issue 4, 1991, Pages 137~145
A universal joint is a connecting device of two hinges which can transmit torque from one shaft to another at fixed or at varying angles of intersection. It has been used properly not only as rotational but also as intermittent motion. For the particular kinematics condition of a universal joint, torsional and bending vibrations are produced excessively in an elastic driveline. In this paper only the torsional vibration behavior of a driveline with universal joints is analyzed numerically with the discrete model and a design method of the dynamic vibration damper is proposed, in order to reduce torsional vibrations especially in resonance region as a result of parametric variation.