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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of The Korean Society of Manufacturing Technology Engineers
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Journal DOI :
The Korean Society of Manufacturing Technology Engineers
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Volume & Issues
Volume 22, Issue 6 - Dec 2013
Volume 22, Issue 5 - Oct 2013
Volume 22, Issue 4 - Aug 2013
Volume 22, Issue 3 - Jun 2013
Volume 22, Issue 3_1spc - Jun 2013
Volume 22, Issue 2 - Apr 2013
Volume 22, Issue 1 - Feb 2013
Selecting the target year
Key Technology Analysis for Machining Process Optimization and Automation
Kim, Dong-Hoon ; Song, Jun-Yeob ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 22, issue 2, 2013, Pages 179~184
DOI : 10.7735/ksmte.2013.22.2.179
In this article, we introduce the study case of technology that can automatically compensate the errors of these factors of a machine during processing on the machine tool`s CNC(Computerized Numerical Controller) in real time. The biggest factors that lower the machining accuracy are thermal deformation and chatter vibration. This study is related to the detection and compensation of thermal deformation and chatter vibration that can compensate for faster and produce processed goods with more precision by autonomous compensation. In addition, this study is related to the active control of vibration during machining, monitoring of cutting force and auto recognition of machining axes origin. Thus, we attempt to introduce the related contents of the development we have made in this article.
Dynamics Analysis of a 2-DOF Planar Translational Parallel Manipulator
Pham, Van Bach Ngoc ; Kim, Han Sung ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 22, issue 2, 2013, Pages 185~191
DOI : 10.7735/ksmte.2013.22.2.185
In this paper, the dynamics of a novel 2-DOF planar Translational Parallel Manipulator (TPM) is analyzed. The suggested TPM is made up of two PPa (Prismatic-planar Parallelogram) legs. Since all the linear actuators are mounted on the base, the proposed TPM can be applied for high speed positioning applications. The Lagrangian equations of the first type is employed to derive the inverse dynamic equations. It is shown that the analytical inverse dynamics equations match very well with ADAMS simulations. These analytical inverse dynamics equations will be used for the real-time computed torque control in the further work.
Study of 3D Simulator for Human Hand Writing
Kang, Tae-Won ; Lee, Kee Sung ; Choi, WonSik ; Kim, Tae-Woo ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 22, issue 2, 2013, Pages 192~198
DOI : 10.7735/ksmte.2013.22.2.192
A light-weight enough to be portable yet functionally complete hand-writing machine was designed with hardware assembled and software implemented. The machine simulating human hand-writing not only allows identical massive scriptings on papers in human`s proxy, but also offers emotional appearance as if the script was directly hand-written in ink. The features of human writing were independently put together to complete the action of scripting. The writing style could be altered in order to mimic a person`s own specific writing style. The present work demonstrates that the assembled hand-writing machine was able to duplicate writing of scripts in almost parallel lines in consistent manner. The machine can be used in the emotional marketing area where seasonal greetings or thank-you cards are to be sent in massive manner. The pen-holding machine can also find an emotional application such as writing a short greeting note on a plastic lid on a disposable coffee cup in coffee-selling stores.
Structural Analysis on Durability of Forklift due to Opening and Closing Between Forks
Cho, Jaeung ; Han, Moonsik ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 22, issue 2, 2013, Pages 199~205
DOI : 10.7735/ksmte.2013.22.2.199
Stress and deformation on forklift happened at loading, unloading or moving freight are studied by structural and fatigue analysis in this study. As model 1 as closing type between forks has lower stress and stain than model 2 at opening type, model 1 has more durability than model 2. Among the cases of nonuniform fatigue loads, `SAE bracket history` with the severest change of load becomes most unstable but `Sample history` becomes most stable. In case of `SAE bracket history` with the severest change of load at model 1 and 2, maximum life is shown with Cycle. Minimum damage with 854 at model 2 becomes much higher than model 1. As the gap between forks becomes open, the damage probability becomes higher. The structural result of this study can be effectively utilized with the safe and stable design of forklift by investigating prevention and durability against its damage.
A Study on Synchronization Control Technique of Dual-Servo Press System
Na, Sang-Gun ; Kwon, O-Shin ; Kang, Jae-Hoon ; Heo, Hoon ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 22, issue 2, 2013, Pages 206~215
DOI : 10.7735/ksmte.2013.22.2.206
In this paper, a synchronization control technique of dual-servo motor driven press system is proposed. An independent cascade PID control technique has been applied to the conventional press system for advancement of control stability. However, it is not easy to reduce synchronous error using the independent cascade PID control technique when some different load disturbances are involved in each motor. The eccentric error of the slide caused by the problem degrade the control performance of the BDC(Bottom Dead Center). In order to achieve reduction of the synchronous error between two servo motors and accurate position control simultaneously, a new control scheme comprised with cascade PID control loop and cross-coupling loop is proposed. In simulation using Matlab SIMULINK, the AC servo system is designed. The control performance of proposed technique is compared with conventional control technique to the model of AC servo system. Also, the sub-scale model of dual-servo motor driven press system which can replicate the slide motion is constructed for experimental verification for the performance of the proposed control technique. The cross-coupling control technique reveals more precise and stable performances in the position and synchronization controls.
Stability Analysis on Solar Tracker Due to Wind
Kim, Yong-Woo ; Lee, Seoung Yeal ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 22, issue 2, 2013, Pages 216~222
DOI : 10.7735/ksmte.2013.22.2.216
A solar power generator is usually installed outdoors and it is exposed to extreme environments such as heavy fall of snow and high speed wind. Therefore, the solar tracker structure should be designed to have sufficient static and dynamic stiffness against such environmental conditions. In this paper, eigenvalue analysis of the solar tracker is carried out by varying the pose of the solar panel and unsteady flow analysis around a single tracker or multi-trackers arranged in a line is performed by varying the parameters such as wind directions, wind speeds and the pose of the solar panel to evaluate whether there exists an instability of resonance due to vortex shedding. Finite element eigenvalue analysis shows that natural frequencies and modes are almost not influenced by the pose of the solar panel and the finite element flow analysis shows that there does not exist periodic vortex shedding due to the flow around single tracker or multiple solar trackers in a line.
Fundamental Design of Cyclone Collector for Oil Mist
Jang, Sung-Cheol ; Ahn, Hwi-Woong ; Lee, Chan-Kyu ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 22, issue 2, 2013, Pages 223~227
DOI : 10.7735/ksmte.2013.22.2.223
Dust collecting performance of cyclone collector for oil mist was alalyzed in the study. The purposes of using cutting fluid during cutting have been colling, lubricating, chip washing and anti-corroding. However, the present manufactaring industry restricts the use of cutting fluid because cutting fluid confains poisonous substances which are harmful to the human body. Also, the optimum design oil-mist collector. The new oil mist collector was designed. In the near future, this device must be tested in the real machining center and CNC machine. Cutting using oil-mist showed better cutting characteristics than dry, air and fluid cutting with respect to by cutting force, tool wear and surface roughness. The model(A, B Type cyclone) of the set of fixture and alveolus are made by using a CAE software. Finally, we have obtained a model A Type solution by using orthogonal array. Therefore, it could be confirmed that as the model-A was increased and model-B was decreased, cut diameter was decreased.
Evaluation of Thermal Characteristics of a Direct-Connection Spindle Using Finite Element Co-Analysis
Kim, Tae-Won ; Choi, Jin-Woo ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 22, issue 2, 2013, Pages 228~234
DOI : 10.7735/ksmte.2013.22.2.228
This study focuses on development of a finite element model for analysis of thermal characteristics of a direct-connection spindle of a machining center by joint simulation of heat transfer and thermal deformation. Two finite element analyses were carried out procedurally for heat transfer, first, to identify temperature distribution of components of the spindle and then for thermal deformation to identify their structural behavior based on the temperature distribution. It was assumed that the heat transfer between a component revolving and the surrounding air is identical to that between a flat plate and the running air on it and the heat transfer is based on a uniform surface heat flux for turbulent flow. The results from the analyses were compared with those from experiments to validate the finite element model.
Disposable Microfluidic Infusion Pump using Elastomeric Blister Actuator
Jang, Woong Ki ; Kim, Hyung Jin ; Kim, Byeong Hee ; Seo, Young Ho ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 22, issue 2, 2013, Pages 235~240
DOI : 10.7735/ksmte.2013.22.2.235
This paper presents a disposable microfluidic infusion pump using the restoring force of elastomeric membrane of Polydimethylsiloxane. Microfluidic infusion pump consists of hydraulic resistance control part, elastomeric blister actuator part, drug inlet and outlet. Expanded elastomeric blister actuator continuously pushes liquid in the chamber to outlet. At same time, microchannel diameter near the outlet was controlled by thin elastomeric membrane in hydraulic resistance control part. Eventually flow rate of infused liquid is controlled by air pressure. In experimental study, the amount of the filled liquid in the blister is precisely controlled by the height of the blister. Flow rate of infused liquid could be controlled, that is, controlled release of the drug over time was possible by adjusting hydraulic resistance and restoring pressure with the blister actuator.
Approximate Modeling of Doctor Blade Contact Pressure for Realization of Uniform Image Quality
Choi, Ha-Young ; Park, Seung Chan ; Lee, Jongsoo ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 22, issue 2, 2013, Pages 241~247
DOI : 10.7735/ksmte.2013.22.2.241
The doctor blade is equipped in a toner cartridge and is a device to maintain the uniform thickness of a toner by controlling the pressure on the developing roller. The contact pressure between the developing roller and the doctor blade is one of the significant factors for image quality and durability of toner cartridge. The purpose of this study is to develop approximation model in order to minimize the time and cost which are needed much required in making optimal design of the doctor blade. Central composite design was used for the design of experiment and response surface design was used for approximation. The data for contact pressure were acquired through finite element analysis and data of image density and toner weight were acquired through experiment. The approximation model developed in this study has presented very high fitness.
Interaction Factors and Response Surface Analysis on the Factors Influencing the Flow Front Temperature at Metal Injection Mold
Kim, Myoung-Ho ; Yoon, Hi-Seak ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 22, issue 2, 2013, Pages 248~255
DOI : 10.7735/ksmte.2013.22.2.248
The objective of this study is to optimize the Metal Injection Molding(MIM) process with design of experiments(DOE) and numerical analysis. To derive the optimal process condition, experiment or numerical analysis was performed under various process conditions. To analyze the interaction among influential factors contributing to the temperature at flow front and response surface in MIM, both central point and axial point were added to the full factorial design with 2 levels and 5 factors and then their impacts on response variable in 43 experimental conditions were analyzed and the significance was evaluated. As a result, sprue, runner, and gate were completely filled in about 0.247 seconds after injection, the front part of the green body was filled in about 0.3344 seconds, the green body except gate, etc changed to almost solid state in about 3.29 seconds, the Packinging pressure was completed in about 6.29 seconds, and the green body inside and outside and sprue, etc became solid in 13.2 seconds. The impact of individual or reciprocal action of factors on the temperature at flow front was analyzed through regular probability, test statistics, main effect, and interaction effect. As a result, of a total of 31 combinations of factors, 9 unit factors and reciprocal actions were significant, and the screening was also possible. A proper regression equation was drawn with regression analysis and response surface design on the response variable of temperature at flow front, and the applicability could be verified.
Path Control for NeuroMate Robot in a Skull Drilling System
Chung, Yun-Chan ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 22, issue 2, 2013, Pages 256~262
DOI : 10.7735/ksmte.2013.22.2.256
This paper presents a linear path control algorithm for NeuroMate robot in a skull drilling system. For the path control inverse kinematics of the robot is analyzed and a linear interpolation algorithm is presented. A geometric approach is used for solving inverse kinematic equations for the robot. Four feasible solutions are found through the approach. The approach gives geometric insights for selecting the best solution from the feasible solutions. The presented linear interpolation algorithm computes a next position considering current velocity and remaining distance to the target position. Presented algorithm is implemented and tested in a skull drilling system.
Experimental evaluation of machining limit in machining V-shaped microgrooves on electroless nickel plated die materials
Kim, Hyun Chul ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 22, issue 2, 2013, Pages 263~267
DOI : 10.7735/ksmte.2013.22.2.263
The continuing demand for increasingly slimmer and brighter liquid crystal display (LCD) panels has led to an increased focus on the role of light guide panels (LGPs) or optical films that are used to obtain diffuse, uniform light from the backlight unit (BLU). The most basic process in the production of such BLU components is the micromachining of V-shaped grooves. Thus, given the current trend, micromachining of V-shaped grooves is expected to play increasingly important roles in today`s manufacturing technology. LCD BLUs comprise various optical elements such as a LGP, diffuser sheet, prism sheet, and protector sheet with V-shaped grooves. High-aspect-ratio patterns are required to reduce the number of sheets and enhance light efficiency, but there is a limit to the aspect ratio achievable for a given material and cutting tool. Therefore, this study comprised a series of experimental evaluations conducted to determine the machining limit in microcutting V-shaped grooves on electroless nickel plated die materials when using single-crystal diamond tools with point angles of
. Cutting performance was evaluated at various cutting speeds and depths of cut using different machining methods and machine tools. The experimental results are that V-shaped patterns with angles of
or up can be realized regardless of the machining conditions and equipment. Moreover, the feed rate has little effect on machinability, and it is thought that the fly-cut method is more efficient for shallow patterns.
Real-Time Prediction of Electrode Wear for the Small Hole Pass-Through by EDM-drill
Choi, Yong-Chan ; Huh, Eun-Young ; Kim, Jong-Min ; Lee, Cheol-Soo ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 22, issue 2, 2013, Pages 268~274
DOI : 10.7735/ksmte.2013.22.2.268
Electric discharge machining drill (EDM-drill) is an efficient process for the fabrication of micro-diameter deep metal hole. As there is non-physical contact between tool (electrode) and workpiece, EDM-drill is widely used to machine the hard machining materials such as high strength steel, cemented carbide, titanium alloys. The electro-thermal energy forces the electrode to wear out together with the workpiece to be machined. The electrode wear occurs inside of a machining hole. and It causes hard to monitor the machining state, which leads the productivity and the quality to decrease. Thus, this study presents a methodology to estimated the electrode wear amount while two coefficients (scale factor and shape factor) of the logarithmic regression model are evaluated from the experiment result. To increase the accuracy of estimation model, the linear transformation method is adopted using the differences of initial electrode wear differences. The estimation model is verified through experiment. The experimental result shows that within minute error, the estimation model is able to predict accurately.
Comparative Study of the Manufacturing Cost and Productivity of Spiral and Straight Bevel Gear
Park, Chang-Seop ; Yang, Yan-Seok ; Kim, Su-Jin ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 22, issue 2, 2013, Pages 275~280
DOI : 10.7735/ksmte.2013.22.2.275
The tractor front axle has the lower standard for noise and vibration relatively and it increase the possibility to develop of the alternative straight bevel gear of the expensive spiral bevel gear. The purpose of this paper is to compare of the spiral vs. the straight bevel gear manufacturing process. The manufacturing cost and productivity are compared after the spiral bevel gear of the tractor front axle is replaced of to the straight bevel gear. If spiral bevel gear is replaced to straight bevel gear, the cost is reduce 4.6% and productivity is increase 18%.
Process Management Systems for Integrated Real-Time Shop Operations in Heterogeneous Multi-Cell Based Flexible Manufacturing Environment
Yoon, Joo-Sung ; Nam, Sung-Ho ; Baek, Jae-Yong ; Kwon, Ki-Eok ; Lee, Dong-Ho ; Lee, Seok-Woo ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 22, issue 2, 2013, Pages 281~286
DOI : 10.7735/ksmte.2013.22.2.281
As the product lifecycle is getting shorter and various models should be released to respond to the needs of customers and markets, automation-based flexible production line has been recognized as the core competitiveness. According to these trends, system vendors supply cell-level systems such as FMC(Flexible Manufacturing Cell) that is integration of core functions of FMS(Flexible Manufacturing System) and RMC(Reconfigurable Manufacturing Cell) that can easily extend components of FMC. In the cell-based environment, flexible management for shop floor composed of existing job shop, FMCs and RMCs from various system vendors has emerged as an important issue. However, there could be some problems on integrated operation between heterogeneous cells to use vendor-specific cell controllers and on seamless information flow with high level systems such as ERP(Enterprise Resource Planning). In this context, this paper proposes process management systems supporting integrated shop operation of heterogeneous multi-cell based flexible manufacturing environment: First of all, (1) Integrated Shop Operation System to apply the process management system is introduced, and (2) Multi-Layer BOP(Bill-Of-Process) model, a backbone of the process management system, is derived with its data structure. Finally, application of the proposed model is illustrated through system implementation results.
A Study On The Embedded Fault Diagnosis System Implementation
Kim, Han-Gyu ; Jang, Ju-Su ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 22, issue 2, 2013, Pages 287~291
DOI : 10.7735/ksmte.2013.22.2.287
Fault Diagnosis is a process of detecting and isolating faults in a system. On demanding for safety and high reliability systems make it important for some reasons such as economical and environmental incentives. Especially embedded technology and IT technology combined with precise sensing techniques has been doing well developed and applied to fault diagnosis and prognosis in industrial systems like as automotive, ship, heavy industry and aerospace as well. This paper, as an empirical application of diesel engine, presents a method how to get raw data from physical systems, what to consider for successful implementation and which theoretic mathematical models should be applied. In a sense of system level Adaptive Filtering (we call Modified Kalman Filter) and a unit of part level Hidden Markov Process was developed and applied.
A Concept of Self-Optimizing Forming System
Park, Hong-Seok ; Hoang, Van-Vinh ; Song, Jun-Yeob ; Kim, Dong-Hoon ; Le, Ngoc-Tran ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 22, issue 2, 2013, Pages 292~297
DOI : 10.7735/ksmte.2013.22.2.292
Nowadays, a strategy of the self-optimizing machining process is an imperative approach to improve the product quality and increase productivity of manufacturing systems. This paper presents a concept of self-optimizing forming system that allows the forming system automatically to adjust the forming parameters online for guarantee the product quality and avoiding the machine stop. An intelligent monitoring system that has the functions of observation, evaluation and diagnostic is developed to evaluate the pully quality during forming process. Any abnormal variation of forming machining parameters could be detected and adjusted by an intelligent control system aiming to maintain the machining stability and the desired product quality. This approach is being practiced on the pully forming machine for evaluating the efficiency of the proposed strategy.
A Study on the Optimization of Deburring Process for the Micro Channel using EP-MAP Hybrid Process
Lee, Sung-Ho ; Kwak, Jae-Seob ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 22, issue 2, 2013, Pages 298~303
DOI : 10.7735/ksmte.2013.22.2.298
Magnetic abrasive polishing is one of the most promising finishing methods applicable to complex surfaces. Nevertheless this process has a low efficiency when applied to very hardened materials. For this reason, EP-MAP hybrid process was developed. EP-MAP process is expected to machine complex and hardened materials. In this research, deburring process using EP-MAP hybrid process was proposed. EP-MAP deburring process is applied to micro channel, thereby it can obtain both deburring process and polishing process. EP-MAP deburring process on the micro channel was performed. Through design of experiment method, error of height in this process according to process parameter is analyzed. When the level 1 parameter A(magnetic flux density) and level 2 parameter B(electric potential), C(working gap) and level 3 parameter D(feed rate) are applied in the deburring process using EP-MAP hybrid process, it provides optimum result of EP-MAP hybrid deburring process.
Development of an Automatic Face Velocity Controller for a Fume Hood System
Kim, Hogeol ; Jeong, Kyuwon ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 22, issue 2, 2013, Pages 304~309
DOI : 10.7735/ksmte.2013.22.2.304
In chemical, medical or biology laboratories Fume Hoods are basic facilities which can protect researchers from dangerous gas as blowing the contaminated air outside. After the air inside the laboratory room is sucked into the hume hood, then, it is blew out by a fan rotated by an AC induction motor. In addition, a damper controls the inside opening of a duct, which the air flows through. The face velocity, air velocity through the front door, have to be kept constant as the set value even though the opening of the door is varied. However, conventional fume hood used to be operated by operator`s manual switches. So that, in this paper an automatic control system is developed which controls the face velocity by adjusting the rotating speed of the blow motor and the opening of the damper. Experiments show that this developed system can be used at such laboratories.
Analysis of Contact Pressure for a 300mm Wafer Polishing Table with Air-Bag Head
Ro, Seung-Kook ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 22, issue 2, 2013, Pages 310~317
DOI : 10.7735/ksmte.2013.22.2.310
In this paper, the contact pressure of the wafer and polishing pad for final polishing process for 300 mm-wafer were investigated through numerical analysis using FEM tool, ANSYS. The distribution of the contact pressure is one of main parameters which affects on the flatness and surface roughness of polished wafers. Two types of polishing head, a hard type head with ceramic disk and a soft type head with air bag were considered. The effects of the deformation and initial shape of table on the contact pressure were also examined. Both heads and tables were modeled as 3D finite element model from solid model, and the material properties of polishing pads and rubber plate for the air-bag head were obtained from tensile tests. The contact pressure deviation on wafer surface was smaller with air bag head than hard type head even when the table had form errors such as convex or concave. From this 3D analysis, it could be concluded that the air-bag head has better uniformity of the contact pressure on wafer. Also, the effects of inner diameter of air bag and radial clearance between wafer and retainer were investigated as view point of contact pressure concentration on the edge of wafer.
Implementation of LabVIEW
-based Joint-Linear Motion Blending on a Lab-manufactured 6-Axis Articulated Robot (RS2)
Lee, D.S. ; Chung, W.J. ; Jang, J.H. ; Kim, M.S. ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 22, issue 2, 2013, Pages 318~323
DOI : 10.7735/ksmte.2013.22.2.318
For fast and accurate motion of 6-axis articulated robot, more noble motion control strategy is needed. In general, the movement strategy of industrial robots can be divided into two kinds, PTP (Point to Point) and CP (Continuous Path). Recently, industrial robots which should be co-worked with machine tools are increasingly needed for performing various jobs, as well as simple handling or welding. Therefore, in order to cope with high-speed handling of the cooperation of industrial robots with machine tools or other devices, CP should be implemented so as to reduce vibration and noise, as well as decreasing operation time. This paper will realize CP motion (especially joint-linear) blending in 3-dimensional space for a 6-axis articulated (lab-manufactured) robot (called as "RS2") by using LabVIEW
(6) programming, based on a parametric interpolation. Another small contribution of this paper is the proposal of motion blending simulation technique based on Recurdyn
V7 and Solidworks
, in order to figure out whether the joint-linear blending motion can generate the stable motion of robot in the sense of velocity magnitude at the end-effector of robot or not. In order to evaluate the performance of joint-linear motion blending, simple PTP (i.e., linear-linear) is also physically implemented on RS2. The implementation results of joint-linear motion blending and PTP are compared in terms of vibration magnitude and travel time by using the vibration testing equipment of Medallion of Zonic
. It can be confirmed verified that the vibration peak of joint-linear motion blending has been reduced to 1/10, compared to that of PTP.
Experimental Study on the Reduction of Noise Dispersion for HEV Relay
Kim, Wonjin ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 22, issue 2, 2013, Pages 324~330
DOI : 10.7735/ksmte.2013.22.2.324
The dispersion of acoustic noise during the turn-on and turn-off switching of HEV(hybrid electric vehicle) relay was experimentally analyzed to identify the reason for the dispersion of noise level. An effective method was proposed to reduce the dispersion of noise level. First, a method to wrap the side of moving core with a tape was adopted to reduce the transverse vibration. It enabled the moving core to make a consistent motion and reduce the dispersion of noise level from switching operation of relay. Second, the dispersion of noise level from vibration transmission of parts such as the outer frame and yoke caulking part of relay were tested to find out main sources. From this result, it was identified that the yoke caulking part made inconsistent transient vibration and noise dispersion.
A Study on the Control Characteristics of FHA by Using PLC
Jang, Sung-Cheol ; Hong, Soon-Nam ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 22, issue 2, 2013, Pages 331~336
DOI : 10.7735/ksmte.2013.22.2.331
The purpose of this study is to visualize the characteristics of ER fluids as preceding step of developing 3 port ER valves. As the strength of the electric field increases, more clusters in flow are made and these clusters are thought to be the reasons of the load flow rate being increased and the outlet flow rate being decreased. The ER Valves and load and outlet flow rate check method are considered to be applied to the fluid power control system. Using the manufactured pressure control valve, a one-link manipulator with FHA in robot system is driven. As a result, it is experimentally confirmed that the pressure control valve using ER fluids is applicable to use in driving actuator. If it applies characteristics of the ER fluids, it will be able to apply in the control system for the ER Valve which occurs from industrial controller(PLC).
Crack Propagation at Boundary Face of Composite Compact Tension Specimen
Cho, Jae-Ung ; Han, Moon-Sik ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 22, issue 2, 2013, Pages 337~341
DOI : 10.7735/ksmte.2013.22.2.337
In this study, fatigue crack propagation in composite material under fatigue is investigated by simulation result. When another material on the specimen exists vertically to the crack line, the phenomena that crack may go straight or propagate along the boundary face according to the elastic modulus ratio of another material to matrix are investigated with compact tension specimen by compliance method. Crack propagation direction is evaluated by compliance method. By arranging this study result systematically about the crack propagation behavior due to the stiffness of inhomogeneous material, high-tech material (automobile, aircraft and steel industry) can be improved. The estimation of safety design and life (construction & nuclear power station, etc.) will be of great value industrially.