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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 21, Issue 6 - Dec 2012
Volume 21, Issue 5 - Oct 2012
Volume 21, Issue 4 - Aug 2012
Volume 21, Issue 3 - Jun 2012
Volume 21, Issue 2 - Apr 2012
Volume 21, Issue 1 - Feb 2012
Selecting the target year
A Safety Study on the Stress Characteristics of a Composite Pressure Cylinder for a Use of 70MPa Hydrogen Gas Vehicle
Kim, Chung-Kyun ; Kim, Do-Hyun ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 21, issue 1, 2012, Pages 1~6
DOI : 10.7735/ksmte.2012.21.1.001
This paper presents a stress safety of a composite pressure cylinder for a hydrogen gas vehicle. The composite pressure cylinder in which is composed of an aluminum liner and carbon fiber wound layers contains 104 liter hydrogen gas, and is compressed by a filling pressure of 70 MPa. The FEM computed results are analyzed based on the US DOT-CFFC basic requirement for a hydrogen gas cylinder and KS B ISO specification. The FEM results indicate that the stress, 255.2 MPa of an aluminum liner is sufficiently low compared with that of 272 MPa, which is 95% level of a yield stress for aluminum. Also, the composite layers in which are wound on the surface of an aluminum cylinder are safe because the stress ratios from 3.46 to 3.57 in hoop and helical directions are above 2.4 for a minimum safety level. The proposed composite pressure cylinder wound by carbon fibers is useful for 70 MPa hydrogen gas vehicles.
Strength Evaluation of CFRP Hat-shaped Sectional Members Due to Variation of Collapse Conditions Under Hygrothermal Environment
Yang, Yong-Jun ; Yang, In-Young ; Sim, Jae-Ki ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 21, issue 1, 2012, Pages 7~14
DOI : 10.7735/ksmte.2012.21.1.007
CFRP composite material has the superior specific strength and rigidity compared to metallic materials, and is widely adopted in the various fields. However, CFRP composite material has the weakness in hygrothermal and crash environment. Especially, moisture ingress into composite material under hygrothermal environment can change molecule arrangement and chemical properties. In addition, interface characteristics and material component properties can be degraded. A collapse experiment has been made to research the differences of absorbed energy and deformation mode between absorbed specimens of moisture and non-moisture. As a result of this study, the effect of moisture absorption and impact loads of about 30~50% reduction in strength are shown.
A Study about the Discrimination of Counterfeit \50,000 won bills Using Optical Fiber Sensor
Kang, Dae-Hwa ; Hong, Jun-Hee ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 21, issue 1, 2012, Pages 15~20
DOI : 10.7735/ksmte.2012.21.1.015
The authenticity of bank note is threatened by increasing a counterfeit note with development of the information industry, recently. The importance of counterfeit discrimination is stressed, but there is a limits to popularization. Because usually, the existing counterfeit discriminator uses invisible ray zone like UV, IR, etc. The purpose of this paper is the construction of counterfeit discrimination system for \50,000 won bills. This system is used optical fiber sensor with excellent confidence as well as easy way of using in wave length of a visible ray zone. The light was altered by lightening optical fiber sensor to particular part of bank notes in order displacing response of optical fiber sensor. The experiment was processed with data of 100 bank notes on manufacture optical fiber, probe, jig. As a result, the discrimination conuterfeit was verified when the experiment was processing with hologram or CSI on the bank notes with three kinds of color printer.
Structural Safety Analysis According to the Shape of Door Impact Bar
Han, Moon-Sik ; Cho, Jae-Ung ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 21, issue 1, 2012, Pages 21~25
DOI : 10.7735/ksmte.2012.21.1.021
In this study, the safest model can be selected by the simulation result of structural safety analysis according to the shape of impact bar affected at side door of automobile. The open sectional model of semicircle type has the lowest deformation and stress among 4 kinds of models. As the weight of this model has 30% in comparison with other models, it becomes most economical and stable. As the open sectional model of cap type the highest deformation and stress among 4 kinds of models, it becomes weakest. The closed models with circular and rectangular types has the stress far lower than cap type. The maximum deformation is shown at the center part of impact bar but the maximum stress occurs at the joint part between impact bar and frame.
Improvement of Filling Characteristics of Micro-Bumps in the Stencil Printing Process
Seo, W.S. ; Min, B.W. ; Park, K. ; Lee, H.J. ; Kim, J.B. ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 21, issue 1, 2012, Pages 26~32
DOI : 10.7735/ksmte.2012.21.1.026
In the present study, the stencil printing process using solder paste are numerically analyzed. The key design parameters in the stencil printing process are the printing conditions, stencil design, and solder paste properties. Among these parameters, the effects of printing conditions including the squeegee angle and squeegee pressure are investigated through finite element (FE) analysis. However, the FE analysis for the stencil printing process requires tremendous computational loads and time because this process carries micro-filling through thousands of micro-apertures in stencil. To overcome this difficulty in simulation, the present study proposes a two-step approach to sequentially perform the global domain analysis and the local domain analysis. That is, the pressure development under the squeegee are firstly calculated in the full analysis domain through the global analysis. The filling stage of the solder paste into a micro-aperture is then analyzed in the local analysis domain based on the results of the preceding global analysis.
A Study on the Tool Wear and Surface Roughness in Cutting Processes for a Neural-Network-Based Remote Monitoring system
Kwon, Jung-Hee ; Jang, U-Il ; Jeong, Seong-Hyun ; Kim, Do-Un ; Hong, Dae-Sun ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 21, issue 1, 2012, Pages 33~39
DOI : 10.7735/ksmte.2012.21.1.033
The tool wear and failure in automatic production system directly influences the quality and productivity of a product, thus it is essential to monitor the tool state in real time. For such purpose, an ART2-based remote monitoring system has been developed to predict the appropriate tool change time in accordance with the tool wear, and this study aims to experimently find the relationship between the tool wear and the monitoring signals in cutting processes. Also, the roughness of workpiece according to the wool wear is examined. Here, the tool wear is indirectly monitored by signals from a vibration senor attached to a machining center. and the wear dimension is measured by a microscope at the start, midways and the end of a cutting process. A series of experiments are carried out with various feedrates and spindle speeds, and the results show that the sensor signal properly represents the degree of wear of a tool being used, and the roughnesses measured has direct relation with the tool wear dimension. Thus, it is concluded that the monitoring signals from the vibration sensor can be used as a useful measure for the tool wear monitoring.
Determination on the Optimal Sealing Conditions of the Vacuum Glass Edge Parts using Design of Experiments Technique
Lee, Jong-Gon ; Jeon, Euy-Sik ; Kim, Young-Shin ; Park, Ho ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 21, issue 1, 2012, Pages 40~45
DOI : 10.7735/ksmte.2012.21.1.040
The glass edge sealing is one of the vacuum glazing core manufacturing process and it needs the high reliability for the vacuum keeping. Conventionally, the glass edge sealing had been being researched by the method that pasted the flit on the glass edge part and bonded two sheets of glass. But this way has the defect that can`t make tempered glass. In order to remedy it`s faults, in this paper, the glass edge was sealed by using the hydrogen mixture gas torch within the furnace. The parameter having an effect on the glass edge sealing through the basic test was set. And the correlation of the thickness of the glass edge and parameter were analyzed through the design of experiment. By using the Taguchi method, the optimal process condition for the glass edge sealing was drawn and the validity was verified.
Heat Radiation of Multichip 10W LED Light Using Thermoelectric Module(TEM)
Cho, Young-Tae ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 21, issue 1, 2012, Pages 46~50
DOI : 10.7735/ksmte.2012.21.1.046
This paper amis at improving the heat radiation performance of thermoelectric module (TEM) for a commercialization of high-powered LED light with using a multichip LED module. In addition, a 10W multichip LED light was prepared for the heat performance on radiating of which LED light was made for a use of testing by the driving of the thermoelectric module. So, it was found that about 30% in the effect of temperature reduction was confirmed if compared with the radiation heat by heat sink only.
Structural and Fatigue Analysis on Bicycle Pedal
Han, Moon-Sik ; Cho, Jae-Ung ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 21, issue 1, 2012, Pages 51~57
DOI : 10.7735/ksmte.2012.21.1.051
This study investigates structural and fatigue analyses at bicycle pedal. Maximum deformation at model 1 is 2 times as much as model 2 at static analysis. Models 1 and 2 have the possibility of the weakest strength at the part of contact with chain gear. Among the cases of nonuniform fatigue loads at Models 1 and 2, `SAE bracket history` with the severest change of load becomes most unstable but `Sample history` becomes most stable. In case of `Sample history` with the average stress of 0 to
MPa and the amplitude stress of 0 to
MPa, the possibility of maximum damage becomes 4%. This stress state can be shown with 5 to 7 times more than the damage possibility of `SAE bracket history` or `SAE transmission`. The analysis result of this study can be effectively utilized with the safe design of pedal.
Surface Encoding Method Based on the Superposed Pattern
Jung, Kwang-Suk ; Park, Sung-Jun ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 21, issue 1, 2012, Pages 58~64
DOI : 10.7735/ksmte.2012.21.1.058
Instead of the surface pattern arranged repeatedly in two axial direction on a plane, we propose double patterns superposing two one-axial linear patterns as a reference target for surface encoding. A upper layer of the superposed pattern is the transparent glass with grooves cut in it at a fixed pitch. The position is sensed by detecting a shift of beam due to difference of a refractive index. And a lower layer is the aluminum with color-coated grooves. The amount of beam reflected on the layer varies according to its targeting position and is detected for encoding. For the above reference pattern, we can detect two-axial positions using only the single beam. Furthermore, the pattern size can be expanded with a size of the detector kept constant, meaning that the measured range can be expanded easily. In this paper, we review the existing optical encoding methods for grid pattern, and discuss the hardware implementation of the suggested surface encoding method.
Weight Reduction for Compressor Brackets
Kwon, Soon-Ki ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 21, issue 1, 2012, Pages 65~69
DOI : 10.7735/ksmte.2012.21.1.065
According to the developments of automobile industry, a technology has been studied in a point of view of environment, which is to increase fuel consumption rate. Especially it is well known that a weight reduction is one of the main technologies to increase the fuel consumption rate and, also to decrease the cost of manufacturing. This paper presents the method for reducing weight of bracket, which connects air conditioner compressor to engine, based on dynamic stress analysis and engineer`s intuition for optimal design.
One-wavelength Ultrasonic Horn Design for Ultrasonic Machining of Mobile Phone Battery Terminal Welding
Seo, Jeong-Seok ; Jang, Sung-Min ; Beck, Si-Young ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 21, issue 1, 2012, Pages 70~75
DOI : 10.7735/ksmte.2012.21.1.070
The technique with ultrasonic vibration refers to the many industries. Especially Ultrasonic Connection Method is widely used for mobile battery, secondary battery, automobile components and also they recently started using it for terminal connecting of solar community battery. In this study, ultrasonic welding horn is analysed and designed with FEM, then manufactured based on it. Resonance frequency and amplitude of horn would be measured and compared with the designing result to judge the suitability. Al/Al specimen is welded by the manufactured horn and verify its performance via the weldability evaluation.
Parameter Calibration of Laser Scan Camera for Measuring the Impact Point of Arrow
Baek, Gyeong-Dong ; Cheon, Seong-Pyo ; Lee, In-Seong ; Kim, Sung-Shin ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 21, issue 1, 2012, Pages 76~84
DOI : 10.7735/ksmte.2012.21.1.076
This paper presents the measurement system of arrow`s point of impact using laser scan camera and describes the image calibration method. The calibration process of distorted image is primarily divided into explicit and implicit method. Explicit method focuses on direct optical property using physical camera and its parameter adjustment functionality, while implicit method relies on a calibration plate which assumed relations between image pixels and target positions. To find the relations of image and target position in implicit method, we proposed the performance criteria based polynomial theorem model that overcome some limitations of conventional image calibration model such as over-fitting problem. The proposed method can be verified with 2D position of arrow that were taken by SICK Ranger-D50 laser scan camera.
Dutile Regime Parallel Grinding of BK7
Lee, Hyeon-Sung ; Kim, Min-Jae ; Koo, Hal-Bon ; Hwang, Yeon ; Kim, Hye-Jeong ; Kim, Jeong-Ho ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 21, issue 1, 2012, Pages 85~89
DOI : 10.7735/ksmte.2012.21.1.085
Conventional grinding of BK7 glass will normally result in brittle fracture at the surface, generating severe sub-surface damage and poor surface finish. The precision grinding of BK7 glass in parallel grinding modes has been investigated. Grinding process, maximum chip thickness, ductile/brittle regime, surface roughness and sub-surface damage have been addressed. Special attention has been given to the condition for generating a ductile mode response on the ground surface. Experiments reveal that the level of surface roughness and depth of sub-surface damage vary differently for different condition. This study gives an indication of the strategy to follow to achieve high quality ground surfaces on brittle materials.
Quality Evaluation of Hard Anodizing Zone for Lightness of the EV Brake Disks
Park, C.S. ; Sung, B.S. ; Cha, Y.H. ; Kim, J.Y. ; Lee, J.H. ; Park, Y.S. ; Kang, D.J. ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 21, issue 1, 2012, Pages 90~94
DOI : 10.7735/ksmte.2012.21.1.090
This study evaluates the strength of surface treatment parts using the hard anodizing method to the aluminum alloy brake disks. In order to achieve weight reduction of vehicles, Eco-friendly cars parts of the high-quality and competitive price is to equip. Especially while pursuing parts of weight reduction, it has to maintain the strength of the surface of the brake by nature. To enhance surface strength of aluminum alloy, we use hard anodizing technology in the surface treatment. This study is resulted of 3 times greater the hardness value of the hard anodized specimen than the aluminum alloy specimen for the lightweight parts of EV brake disk
Contact Fatigue Life for RRG System
Nam, Hyoung-Chul ; Kim, Chang-Hyun ; Kwon, Soon-Man ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 21, issue 1, 2012, Pages 95~101
DOI : 10.7735/ksmte.2012.21.1.095
An internal type roller ring gear(RRG) system composed of either a pin or a roller ring gear and its conjugated cam pinion can improve the gear endurance from that of a conventional gear system by reducing the sliding contact, while increasing the rolling motion. In this paper, we first proposed the exact cam gear profile and the self-intersection conditions obtained when the profile shift coefficient is introduced. Then, we investigated contact stresses and surface pitting life to fmd characteristics for surface fatigue by varying the shape design parameters. The results show that the pitting life can be extended significantly by increasing the profile shift coefficient.
Nondestructive Evaluation of the Turbine Blade of Wind Energy By Using T-Ray
Im, Kwang-Hee ; Jeong, Jong-An ; Hsu, David K. ; Lee, Kil-Sung ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 21, issue 1, 2012, Pages 102~108
DOI : 10.7735/ksmte.2012.21.1.102
A study of terahertz waves (T-ray) was made for the nondestructive evaluation of FRP (Fiber reinforced plastics) composite materials. The to-be-used systems were time domain spectroscopy (TDS) and continuous wave (CW). The composite materials investigated include both turbine blades of wind energy (non-conducting polymeric composites) and conducting carbon fiber composites. Terahertz signals in the TDS mode resembles that of ultrasound; however, unlike ultrasound, a terahertz pulse was not able to detect a material with conductivity. This was demonstrated in CFRP (Carbon fiber reinforced plastics) laminates. Refractive index (n) was defined as one of mechanical properties; so a method was solved in order solve the "n" in the material with the cut parts of the turbine blades of wind energy. The defects and anomalies investigated by terahertz radiation were foreign material inclusions and simulated disband. Especially, it is found that the T-ray went through the turbine blade with greater thickness (about 90mm).
A Study on the Sway Suppression Control of Container Cranes
Baek, Woon-Bo ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 21, issue 1, 2012, Pages 109~115
DOI : 10.7735/ksmte.2012.21.1.109
In this paper, we consider the sway suppression control problem for container cranes with load hoisting. The proposed control law improves the positioning accuracy but also the sway suppression through fast stabilization of the under-actuated sway dynamics, which is based on a class of feedback linearizing control incorporated with an additional control including the sway angle and its rate as well as positioning errors and their rates. For the design of the additional control, a variable structure control with the proper sway damping and simple switching action is employed, thus preventing excessive overshoots of the trolley travelljng and effectively suppressing the residual sway of container arrived at the target position. Simulation results are provided to show effectiveness of the proposed controller in the presence of such uncertainties as winds and the variation of payload weights.
Development of Three Dimensions Laser Direct Patterning System
Paik, Byoung-Man ; Lee, Jae-Hoon ; Shin, Dong-Sig ; Lee, Kun-Sang ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 21, issue 1, 2012, Pages 116~122
DOI : 10.7735/ksmte.2012.21.1.116
The purpose of this study is on the development of 3-D conductive pattern fabrication system using laser. For development 3-D direct patterning system, we used the dynamic focusing, the laser power stabilizer and the auto aligning techniques. These technologies are already used commercially. However operation and control integrated system for 3-D direct patterning are not yet developed. The objective of this paper is to introduce laser direct structuring and develop the operating and integration system. Also we implemented new application of laser direct structuring.
Optimal Mechanism Design of In-pipe Cleaning Robot
Jung, C.D. ; Chung, W.J. ; Ahn, J.S. ; Shin, G.S. ; Kwon, S.J. ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 21, issue 1, 2012, Pages 123~129
DOI : 10.7735/ksmte.2012.21.1.123
Recently, interests on cleaning robots workable in pipes (termed as in-pipe cleaning robot) are increasing because Garbage Automatic Collection Facilities (i.e, GACF) are widely being installed in Seoul metropolitan area of Korea. So far research on in-pipe robot has been focused on inspection rather than cleaning. In GACF, when garbage is moving, the impurities which are stuck to the inner face of the pipe are removed (diameter: 300 mm or 400 mm). Thus, in this paper, by using TRIZ (Inventive Theory of Problem Solving in Russian abbreviation), an in-pipe cleaning robot of GACF with the 6-link sliding mechanism will be proposed, which can be adjusted to fit into the inner face of pipe using pneumatic pressure(not spring). The proposed in-pipe cleaning robot for GACF can have forward/backward movement itself as well as rotation of brush in cleaning. The robot body should have the limited size suitable for the smaller pipe with diameter of 300 mm. In addition, for the pipe with diameter of 400 mm, the links of robot should stretch to fit into the diameter of the pipe by using the sliding mechanism. Based on the conceptual design using TRIZ, we will set up the initial design of the robot in collaboration with a field engineer of Robot Valley, Inc. in Korea. For the optimal design of in-pipe cleaning robot, the maximum impulsive force of collision between the robot and the inner face of pipe is simulated by using RecurDyn(R) when the link of sliding mechanism is stretched to fit into the 400 mm diameter of the pipe. The stresses exerted on the 6 links of sliding mechanism by the maximum impulsive force will be simulated by using ANSYS
Workbench based on the Design Of Experiment(in short DOE). Finally the optimal dimensions including thicknesses of 4 links will be decided in order to have the best safety factor as 2 in this paper as well as having the minimum mass of 4 links. It will be verified that the optimal design of 4 links has the best safety factor close to 2 as well as having the minimum mass of 4 links, compared with the initial design performed by the expert of Robot Valley, Inc. In addition, the prototype of in-pipe cleaning robot will be stated with further research.
Development of Gear Stiffness Module for Multi-Body Dynamic Analysis on Gears
Song, Jin-Seop ; Lee, Geun-Ho ; Park, Young-Jun ; Bae, Dae-Sung ; Lee, Chul-Ho ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 21, issue 1, 2012, Pages 130~136
DOI : 10.7735/ksmte.2012.21.1.130
Dynamic as well as static and geometric design parameters such as inertia, tooth profile, backlash and clearance can be directly considered via multi-body dynamic analysis along with contact analysis. However, it is time consuming to use finite elements for the consideration of the tooth flexibility in the multi-body dynamic analysis of gears. A computationally efficient procedure, so called, Gear Stiffness Module, is suggested to resolve this calculation time issue. The characteristics of gear tooth compliance are discussed and rotational stiffness element concept for the Gear Stiffness Module is presented. Transmission error analyses for a spur gear system are carried out to validate the reliability and efficiency of the module. Compared with the finite element model, the Gear Stiffness Module yields considerably similar results and takes only 3% of calculation time.
A Study on Development of Vane Damper for Industry Flow Control Fan
Yi, Chung-Seob ; Jeong, In-Guk ; Yun, Ji-Hun ; Suh, Jeong-Se ; Jang, Sung-Cheol ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 21, issue 1, 2012, Pages 137~143
DOI : 10.7735/ksmte.2012.21.1.137
In this study, it was conducted to design each components of vane damper for industrial flow control fan and the flow rates were analysed by experimental and numerical method. Through environmental test, it could be confirmed that the designed vane damper was appropriate. Also, almost identical results with test could be drawn from numerical method. Finally, flow rates of electric and pneumatic actuator were measured by test. As the results, difference of flow rate according to opening ratio was smaller in pneumatic actuator than that in electric actuator.
A Research on the Change of Cutting Characteristics in Hardened A17075-T6 Depending on Turning Conditions
Lee, Hee-Deok ; Kim, Jeong-Suk ; Jeong, Ji-Hoon ; Im, Hak-Jin ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 21, issue 1, 2012, Pages 144~149
DOI : 10.7735/ksmte.2012.21.1.144
The cutting characteristics of hardened aluminum alloy A17075-T6 were investigated during turning processing. Under variation conditions of cutting speed, depth of cut, and feed rate, the characteristics of cutting force, surface roughness, and machined texture were investigated. Surface roughness became worse in proportion to the increase of the feed rate. The thickness of material alteration layer which is derived from the effect of cutting force was the biggest when feed rate 0.148mm/rev. This research confirmed that the deformed layer is dominantly dependent on the variation of feed rate.
A Numerical Analysis on Flow Characteristic of 200HP Grade Water Jet for Small Ship
Yi, Chung-Seob ; Jeong, Jae-Hoon ; Lee, Jong-Su ; Yun, Ji-Hun ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 21, issue 1, 2012, Pages 150~155
DOI : 10.7735/ksmte.2012.21.1.150
Water jet propulsion system has low efficiency than screw propeller at low speed, but has been applied in high speed ship due to its better cavitation performance and high rotation capacity. In this study, a numerical analysis was conduct to understand the flow in the propulsion system of 200HP grade water jet for small ship. As the result, it could be confirmed that total pressure and force of the flow was increased through the impeller and the straight-ability of discharging flow to outlet was improved by guide vane. Also, the reliability of numerical analysis was secured by comparing peripheral velocity calculated by design values with that calculated by numerical analysis.
Design of Tilting Unit for Mobile Radio Communication Repeater
Lee, Jung-Hyun ; Park, Jae-Won ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 21, issue 1, 2012, Pages 156~160
DOI : 10.7735/ksmte.2012.21.1.156
Recently WCDMA signal transmission technology by large output microwave antenna have showed reduction of human resources and operating expense. But the existing antenna brackets cost is very expensive also its structure and functions are complicated. Unit brackets, suspending some sensors, subjected to acceleration loads, often fail due to self-vibration. To prevent such failures, it is necessary to understand the fatigue failure mode and to evaluate the fatigue life using tests or analysis techniques. The objective of this study is to develop the component test specifications, which are applicable to predict fatigue life at initial product design step, for unit brackets using vibration fatigue technique. So its application is limited to installation and management. In this project, we studied about more convenient bracket for microwave antennas through improvement on the existing antenna bracket`s shortcoming and could develop an improved universal antenna bracket system for simple installation and application.
Automatic Flow Control and Network Monitoring of IV Injection
Kim, Jin-Nam ; Kwon, Won-Tae ; Lee, Kang-Hee ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 21, issue 1, 2012, Pages 161~166
DOI : 10.7735/ksmte.2012.21.1.161
Intravenous (IV) injection is widely used to supply Ringer solution directly into a vein in hospital. Generally, a passive injection method has been used, which causes the inconsistent flow rate of fluid and inappropriate control of injection time by a patient. It leads to an unnecessary nurse`s overwork and decrement of IV injection`s effect. To solve these problems, flow control infusion pumps have been developed. But because of relatively heavy weight and high price, its usage has been limited. In the present study, a new automatic IV injection system is developed. It is installed with a small pressing mechanism driven by a small electric motor to regulate the flow rate by pressing tube. Proportional integral derivative (PID) feedback control algorithm is applied to control the electric motor. The system is smaller in size and uses lower power than the existing commercial product. The newly developed system is also installed with networking capability, which enables monitoring the status of several automatic IV injection system at the same time.
A Study on the Development of Progressive Die and Forming Process for Asymmetric Automotive Door Striker
Youn, Jae-Woong ; Kim, Hong-Seok ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 21, issue 1, 2012, Pages 167~174
DOI : 10.7735/ksmte.2012.21.1.167
For high production rate of parts requiring multiple operations such as punching, blanking, or other operations are generally done with progressive dies. However, progressive die is generally limited to use for sheet metal forming due to the technical difficulties in rod or bulk material. This study proposes a new technique of progressive die and forming process for asymmetric automotive door striker, which is conventionally manufactured with separate tandem processes using solid rod. In order to design forming process and die, FEM simulation was performed to divide proper intermediate processes and analyze its formability. As a result, Forming processes were divided into 3 stages with upper and side punches and also, workpiece feeding and location mechanism was designed and manufactured in this study. Finally, forming tryouts were carried out by using the manufactured progressive die to verify the forming quality and productivity.
Development of Dynamic Vibration Absorber to Reduce Unbalance Response in Flexible Rotor-Bearing System
Yu, Tae-Gyu ; Bae, Gyu-Hyun ; Kim, Kil-Hwan ; Hong, Seong-Wook ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 21, issue 1, 2012, Pages 175~181
DOI : 10.7735/ksmte.2012.21.1.175
This paper presents a novel dynamic vibration absorber (DVA) to suppress the unbalance response of flexible rotor-bearing systems. The DVA unit consists of two DVAs, an adapter to place the DVAs and an adapter frame to locate the adapter. The essential feature of the proposed DVA unit is to place itself on any desirable location of the shaft without disassembling the rotor-bearing system under consideration. A simulation with a 3D element based commercial rotor dynamic software is made to test the possibility of the proposed DVA on the suppression of unbalance response in rotor-bearing systems. Experiments are performed to validate the proposed DVA unit. The simulation and experiments show that the proposed DVA unit is very effective to suppress the unbalance response in rotor-bearing system at designated rotational speeds of interest.
Dynamic Design of a Mass-Spring Type Translational Wave Energy Converter
Choi, Young-Hyu ; Lee, Chang-Jo ; Hong, Dae-Sun ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 21, issue 1, 2012, Pages 182~189
DOI : 10.7735/ksmte.2012.21.1.182
This study suggests a dynamic design process for deciding properly design parameters of a mass-spring type Wave Energy Converter (WEC) to achieve sufficient energy conversion from wave to power generator. The WEC mechanism, in this research, consists of a rigid sprung body, a platform, suspension springs and dampers. The rigid sprung body is supported on the platform via springs and dampers and vibrates translationally in the heave direction under wave excitation. At last the resulting heave motion of the sprung body is transmitted to rotating motion of the electric generator by rack and pinion, and transmission gears. For the purpose of vibration analysis, the WEC mechanism has been simply modelled as a mass-spring-damper system under harmonic base excitation. Its maximum displacement transmissibility and steady state response can be determined by using elementary vibration theory if the harmonic ocean wave data were provided. With the vibration analysis results, the suggested dynamic design process of WEC can determine all the design parameters of the WEC mechanism, such as sprung body mass, suspension spring constant, and damping coefficient that can give sufficient relative displacement transmissibility and the associated inertia moment to drive the electric generator and transmission gears.