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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 20, Issue 6 - Dec 2011
Volume 20, Issue 5 - Oct 2011
Volume 20, Issue 4 - Aug 2011
Volume 20, Issue 3 - Jun 2011
Volume 20, Issue 2 - Apr 2011
Volume 20, Issue 1 - Feb 2011
Selecting the target year
A Study on the Sheet Separation Reduction of Stainless Steel using Hollow Spot Electrode Tip for Resistance Spot Welding
Huh, Dong-Woon ; Rhee, Se-Hun ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 20, issue 6, 2011, Pages 679~684
Recently, STS 301L joints of side panels to frames for stainless steel rolling stock have been made out by using existing welding methods including Resistance Spot Welding, Laser Welding and Arc Welding. Most of the processes were jointed by spot welding because it is faster at welding and comparatively less expensive for investment in welding facilities than other methods. During spot welding, however, indentation of the metal surface was made due to pressure and melting property of welding. Moreover, since the melting metal was forced to periphery of the plate as indentation was made, sheet separation, which cracked apart between jointed sheets, was carried out. A slight deformation which resulted from sheet separation deteriorated the emotional quality of railway vehicles. This paper suggests that by processing conventional spot electrode tip appropriately, melting metal is able to push up around the processed part (Hollow Spot Electrode Tip) and prevent from being dislodged from first place to periphery. Consequently, sheet separation is remarkably decreased. Also, the emotional quality of appearance of stainless steel rolling stock is enhanced considerably.
Feeding Characteristics of Ball Guide in High Speed Spindle's Bearing Preload Units
Lee, Chan-Hong ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 20, issue 6, 2011, Pages 685~691
The Bearing preload units are used for stable rotational movements of high speed spindles. The feeding mechanism of the preload unit is important to prevent overheat of bearings and to keep constant bearing load under thermal deformation of spindle unit. In this study, ball slide guide and ball bush as feeding mechanism of preload unit are selected. The maximum static friction force, radial stiffness and damping ratio of ball slide guide with ball load, ball number and ball size are widely investigated. In conclusion, the surface of ball slide guide must be heat treated to reduce static friction force. The number and size of ball are increased to control sensitive bearing preload force.
Development of Contact Point Estimation Algorithm of Dry type Clutch with Considering the friction pad wear
Kim, Sung-Mo ; Kim, Mo-Seong ; Shin, Chang-Woo ; Lim, Won-Sik ; Cha, Suk-Won ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 20, issue 6, 2011, Pages 692~696
A clutch is a very important component when engine starts and gear shifting is needed. The clutch the most commonly used is the dry clutch. This type of clutch has pads, and they are worn after disengagement of clutch little by little. The characteristics of the clutch changes as these pads wear, so wear needs to be measured, and the clutch should be controlled for proper operation. In this study, the clutch contact point estimation algorithm has been developed. From this algorithm, clutch force map changes depending on wear, and the clutch operates properly. We also see the shifting transient of a vehicle for drivability with throttle valve position control and synchronizer movement.
Stability of an Elastic Pendulum System due to Random Excitations
Lee, Sin-Young ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 20, issue 6, 2011, Pages 697~702
Responses of multi degree of freedom systems under random excitations can be estimated by using Monte Carlo simulation. The equations of motion of an elastic pendulum system include nonlinear terms and show irregular characteristics under random excitation. While the magnitude of random excitation is small the response of an elastic pendulum shows borderlines. As the magnitudes of excitation increase, the responses show divergence with very large amplitudes of motion and the tendency is diverse dependent on the magnitude and type of random excitations and the ratio of natural frequencies.
Displacement Error Estimation of a High-Precision Large-Surface Micro-Grooving Machine Based on Experimental Design Method and Finite Element Analysis
Lee, Hee-Bum ; Lee, Won-Jae ; Kim, Seok-Il ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 20, issue 6, 2011, Pages 703~713
In this study, to minimize trial and error in the design and manufacturing processes of a high-precision large-surface micro-grooving machine which is able to fabricate the molds for 42 inch LCD light guide panels, the effects of the structural deformation of the micro-grooving machine according to the positions of the X-axis, Y-axis and Z-axis feed systems were examined on the tool tip displacement errors associated with the machining accuracy. The virtual prototype (finite element model) of the micro-grooving machine was constructed to include the joint stiffnesses of the hydrostatic bearings, hydrostatic guideways and linear motors, and then the tool tip displacement errors were measured from the virtual prototype. Especially, to establish the prediction model of the tool tip displacement errors, which was constructed using the positions of the X-axis, Y-axis and Z-axis feed systems as independent variables, the response surface method based on the central composite design was introduced. The reliability of the prediction model was verified by the fact that the tool tip displacement errors obtained from the prediction model coincided well those measured from the virtual prototype. And the causes of the tool tip displacement errors were identified through the analysis of interactions between the positions of the X-axis, Y-axis and Z-axis feed systems.
The effect of Surface Roughness on Wire-cut Electric Discharge Machining of Discharge Energy in Aluminium Alloy 2024
Ryu, Cheong-Won ; Choi, Seong-Dae ; Lee, Soon-Kwan ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 20, issue 6, 2011, Pages 714~719
The surface roughness depending on the machining method is very important because is produce a finished product through riveting, sealing, bonding, and special paint in order to curb the turbulence and air resistance which occur between the sheets. Aluminum alloy 2024 which is widely used for interior and exterior material of aircraft are tested. Jin-young JW-60C wire cutting machine was used in this experiment. In this paper, the experimental investigation has been performed to find out the influence of the surface roughness and surface shape characteristics on the wire-cut EDM of discharge energy in aluminium alloy 2024. The selected experimental parameters are peak current, no-load voltage, off time and feed rate. The experimental results give the guideline for selecting reasonable machining parameters. The high discharge energy on the idle time, almost no change in surface roughness can be seen.
Multi-thin plate welding characteristics of Low Carbon Steel for Ni-MH battery of using Continuous Wave Nd:YAG laser
Yang, Yun-Seok ; Hwang, Chan-youn ; Yoo, Young-Tae ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 20, issue 6, 2011, Pages 720~728
Lap joint welding conducts low carbon steel plates using a 2.0kW continuous wave Nd:YAG laser beam. The specimen is composed of thin plate of 20 sheets. Process Variables contain two controlled parameters of the laser power and the welding speed. In order to quantitatively examine the characteristics of the lap welding, the welding quality of the cut section, stain-stress behavior, and the hardness of the welded part are investigated. The weld width difference between the top and the bottom because the welding speed is increased. The reason, cooling rate is decreased because of fast welding speed. When the heat input is higher, larger volume of the base metal will melt and the welding heat has longer time to conduct into the bottom from the top. The microstructure and tensile properties of the joints are investigated in order to analyze the effects of heat input on the quality of laser welded specimen. From the results of the investigation, We observe that welding quality is good for the laser power of 1800W, and laser welding speed from 1.8m/min to 2.2m/min.
Observation of the Shrinkage Characteristics of the Machined Zirconia Abutment by the full sintering process
Lee, Ho-Cheol ; Park, Seong-Jun ; Kim, Jae-Duk ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 20, issue 6, 2011, Pages 729~734
The full sintering process of zirconia has some extent of shrinkage and the custom abutment design should consider the pre-compensation volume of the shape. In this paper, we concentrated to reveal the asymmetric sintering characteristics. The circular profile of all six samples were measured using the three dimensional coordinate machine. After the full sintering process, the profiles were measured again. The roundness were compared to those of the original shapes and the percent of shrinkage were calculated. On the other hand, surface roughness was also investigated after the full sintering process. The final average surface roughness was improved by the sintering of the machined zirconia surface.
Shape Optimal Design for the Leg Parts of Chair
Kang, Sung-Soo ; Jeong, Young-Soo ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 20, issue 6, 2011, Pages 735~739
In this study, a chair with 5 or 6 legs was designed using the commercial program CATIA V5 in order to efficiently design considering the load conditions. In addition, the stress analysis and shape optimization were carried out using ANSYS Workbench for the chair consisting of stainless steel, aluminum alloys, magnesium alloys and structural steel. As a result, a chair with five legs showed the maximum equivalent stress at the end of the edge of the wheel parts and on the other hand, a chair with six legs showed the maximum equivalent stress at the corner of the connecting parts of the pillar and leg. In addition, the material and the weight was reduced by shape optimization for the chair model with 5 legs and maximum equivalent stress for stainless steel was found that greatly relaxed, compared with that of before shape optimization model.
The Vibration Characteristic of Carbon-Carbon Composite Material due to Tensile Loading
Oh, Seung-Gyu ; Kwac, Lee-Ku ; Kim, Hong-Gun ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 20, issue 6, 2011, Pages 740~744
Carbon-carbon composite material is the reinforced carbon fiber. Because of its high strength, elasticity and the excellent heat-resisting property in high temperature, carbon-carbon composite material has been used in many fields such as aerospace and automotive industries, etc. Especially, aircraft brake discs used at aerospace can be cracked due to its fatigue and vibration under various loading condition. This research is focused on the influence of the vibration of carbon-carbon composite material by using accelerometer with impact hammer excitation. And the change of vibration mode will be known by applying tensile loading test.
A Study on Clamping Characteristics of Jaw-wedge for Automatic Jig Vise
Jung, Si-Kyo ; Maeng, Hee-Young ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 20, issue 6, 2011, Pages 745~750
A jig vise is a device to clamp workpiece precisely, which is widely used for various machine tools and manufacturing purpose. A new elastic structured jaw-wedge of jig vise is developed, in this paper, so as to satisfy the clamping requirement and the suppression effect of upright movement of workpiece. The advanced design parameters of jaw-wedge are derived step by step considering the stress distribution and the displacement profiles of ANSYS analysis, and it could find the optimum model which shows the uniform displacement profiles and exhibits the non-concentrated stress distribution of jaw neck. As a result, it is ascertained that an jaw-wedge developed in this study is the simple elastic structure which is effective for automatic multiple clamping purpose without the danger of shear crack or bucking of jaw.
Performance Analysis of Electronic Parking Brake
Kim, Sung-Mo ; Jeong, Jong-Yeol ; Shin, Chang-Woo ; Lim, Won-Sik ; Cha, Suk-Won ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 20, issue 6, 2011, Pages 751~755
Electric Parking Brake(EPB) is the system operated by electric control actuator. It differs from the mechanical parking brake system which is operated by lever and pedal in need of human power. The EPB system is composed of DC motor, helical and differential epicyclic gear, screw, cables, and sensor. This paper describes about the EPB system mathematically and constructs a modeling of the EPB system using MATLAB/SIMULINK. Especially, SimMechanics library in SIMULINK is used to make each parts of system a module. By made modeling of the friction torque between bolt and nut. Cable tension can be maintained after the motor operating stops.
A Piezo-driven Ultra-precision Stage for Alignment Process of a Contact-type Lithography
Choi, Kee-Bong ; Lee, Jae-Jong ; Kim, Gee-Hong ; Lim, Hyung-Jun ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 20, issue 6, 2011, Pages 756~760
This paper proposed an alignment stage driven by piezo actuators for alignment process of a contact-type lithography. Among contact-type lithography processes, an UV-curable nanoimprint process is an unique process to be able to align patterns on upper and lower layers. An alignment stage of the UV-curable nanoimprint process requires nano-level resolution as well as high stiffness to overcome friction force due to contact moving. In this paper, the alignment stage consists of a compliant mechanism using flexure hinges, piezo actuators for high force generation, and capacitive sensors for high-resolution measurement. The compliant mechanism is implemented by four prismatic-prismatic compliant chains for two degree-of-freedom translations. The compliant mechanism is composed of flexure hinges with high stiffness, and it is directly actuated by the piezo actuators which increases the stiffness of the mechanism, also. The performance of the ultra-precision stage is demonstrated by experiments.
Optimization Design on the Sealing Surface Profiles of Contacting Seal Units
Kim, Chung-Kyun ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 20, issue 6, 2011, Pages 761~766
In this study, the optimized design profiles between a seal ring and a seal seat of contacting seal units has been proposed based on the FEM computed results. The maximum temperatures, the thermal distortions in axial and radial directions, and maximum contact normal stresses between a seal ring and a seal seat have been analyzed for various contact sealing profiles. The FEM computed results present that the contact area between seal rings and seal seats is very important for a good tribological performance such as low friction heating, low wear, high contact normal stress in a primary sealing components. The seal surface model III in which has a small sealing contact area shows low dilatation of primary sealing components, and high contact stress between a seal ring and a seal seat. This model with small contact surface of a seal ring produces high friction heating and contact stress. But the model III produces very small deformations of contacting sealing surface because of high convection heat transfer by cooling water circulation around the seal ring surface. Thus, the analysis results recommend a short width of a primary sealing unit rather than a big width of contact surfaces of contacting seal units for reducing a leakage and axial deformation of primary seal components.
A Study on Select Bearing Position of High Speed Spindle Considering the Thermo Behavior
Park, Su-Seong ; Chung, Won-Jee ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 20, issue 6, 2011, Pages 767~772
The thermal deformation of machine tool spindle influences the performance of the manufacturing systems for precision products. According to previous studies, major factors that will affect the stiffness of the spindle include spindle diameter, elasticity of the material, bearing stiffness and bearing span. It is difficult to change spindle diameter or elasticity of the material. but change of bearing position is easy in the given range compared to other factors. In this paper, we will find a solution to minimize thermal deformation through Change the span of the bearing.
One-Sided Nondestructive Evaluation of Back-Side Wedge By Using Ultrasonic Sound
Jeong, Jong-An ; Hsu, David K. ; Im, Kwang-Hee ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 20, issue 6, 2011, Pages 773~777
Conventional ultrasonic thickness measurement is to be considered as the assumption that the ultrasonic velocity is known. In actual applications the velocity is often not well known and access is often limited to one side. This paper aims at determining the ultrasonic velocity and thickness of plates with parallel or wedged surfaces using contact measurements made on one surface only. For wedged plates the thickness at one point and the wedge angle are determined. Equations are used for determining the ultrasonic velocity, thickness and wedge angle of the plate based on the times-of-flight measured by two contact transducers coupled to one surface. The time-of-flight of the obliquely reflected longitudinal wave echo was measured as a function of the separation between the two transducers. In addition, a simulation was made for comparing the experimental data and a FEM image. Experiments and simulations were performed on flat and wedged plates of aluminium materials; the calculated results for the unknown quantities are generally agreed with them to some degree.
A Study on Orientations Interpolation of 6-Axis Articulated Robot using Quaternion
Ahn, Jin-Su ; Chung, Won-Jee ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 20, issue 6, 2011, Pages 778~784
This paper presents the study on orientations interpolation of 6-axis articulated robot using quaternion. In this paper, we propose a control algorithm between given two orientations of 6-axis articulated robot by using a quaternion with spherical linear interpolation. In order to study the quaternion interpolation, We created Inverse kinematics program and Interpolation program using LabVIE
. The rotation angle of each axis were calculated using both euler orientations interpolation program and quaternion orientations interpolation program. The proposed control algorithm is shown to be effective in terms of motor angles and torques when compared to a conventional Euler angle interpolation, by using both LabVIEW
An Experimental Study for Mechanical Properties of Al-Mg-Mn-Si Alloy by ECA pressing
Kook, Jong-Han ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 20, issue 6, 2011, Pages 785~792
Equal channel angular(ECA) pressing is the established processing technique in which a polycrystalline metal is pressed through the die to achieve a very high plastic strain. Therefore, the capability to produce an ultra-fine grain size in the materials is provided. To investigate that mechanical properties at elevated temperature have the ultrafine grain ECA pressing, experiments were conducted on an Al-4.8% Mg-0.07% Mn-O.06% Si alloy. After having been solution treated at 773K for 2hrs, the billet for ECA pressing was inserted into the die. And it was pressed through two channel of equal to cross section intersecting at a 90 degree angle. The billet can be extrude repeatedly because of 1:1 extrusion ratio. Since the billet is passed through the cannel for 2 times, a large strain is accumulated in the alloy. The tensile tests on elevated temperature were carried out with initial strain rate of
at eight temperature distributed from 293K to 673K.
A Study on Design of High Pressure Injection Nozzle for Avoiding Chip Curling
Yi, Chung-Seob ; Yun, Ji-Hun ; Jeong, In-Guk ; Song, Chul-Ki ; Suh, Jeong-Se ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 20, issue 6, 2011, Pages 793~798
In this study, it was grasped to the flow characteristics of cutting fluid injected by nozzle installed in high pressure holder for avoiding chip curling occurred during machining process. And for avoiding chip curling, the possibility of elimination under various chip conditions was checked. Consequently, the highest discharging pressure and velocity was shown in 150 of nozzle inflow angle. Also as nozzle outlet diameter is small, the pressure and velocity of injected flow are high. Moreover, It could be confirmed that width and thickness of chip have no direct effect on chip elimination and it is achieved by torque generated by injected cutting fluid.
A study on the machinability of Carbon Fiber Reinforced Plastics on tool shape
Shin, Bong-Cheul ; Kim, Kyu-Bok ; Ha, Seok-Jae ; Cho, Myeong-W ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 20, issue 6, 2011, Pages 799~804
CFRP(Carbon Fiber Reinforced Plastics) has been used many industries aerospace, automobile, medical device and building material industries, etc. Because it is lighter than other metals and has good properties, such as rigidity, strength and wear. CFRP may be cured integrity. However, it needs postprocessing similar to drilling or endmilling for shape cutting and combination of various material. In this paper, tool dynamometer and accelerometer used to signal analysis for machining properties under various cutting conditions and tool shape changes. In addition, microscope used to verify the machined CFRP surface. As the results, it was found that the cutting force and the vibration were decreased in the increasing of cutting edge (2-flute < 4-flute < composite tool), and the good machined surface can be obtained in this experiments.
A Study on the Flow and Power Characteristics of Rotor in the APU
Yi, Chung-Seob ; Jeong, In-Guk ; Yun, Ji-Hun ; Suh, Jeong-Se ; Lee, Tae-Eui ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 20, issue 6, 2011, Pages 805~810
Recently, Use of Auxiliary power unit(APU) is increasing by growing demand for improvement of insufficient electric power and installation of emergency generation devices in military tracked vehicles and civil markets. And the trend is that the units are demanded for smaller size, lighter weight and higher output power, etc to suit consumer demands. To achieve these, it is essential to develop high performance system. Therefore, in this study, it was conducted in numerical analysis to investigate flow characteristics of rotor in APU generator. Also output performance of APU applied on the rotor is analyzed by experimental method. As the result, higher rotating speed of rotor caused high air flow rate at suction and it leads to linear increase of discharging flow rate. The maximum theoretical power was achieved at 12
/min of flow rate and, at that time, output power of generator was about 7.825 kW. Also, it can be confirmed the stabilization of output performance is achieved in about 2 seconds by experiment.
Ultra-precision High Numerical Aperture Plastic Objective Lens for Blu-ray Disc Pick-up
Kim, Boo-Tae ; Hyun, Dong-Hoon ; Yoo, Kyung-Sun ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 20, issue 6, 2011, Pages 811~816
We develop a plastic object lens for blu-ray disc playing pick-up module as morethan 0.85 numerical aperture in this research. We design plastic object lens for blu-ray disc playing pick-up module's each factor's in balanced and made our designed lens by injection molding. Furthermore, by correction designing in mold-core, we optimization our lens efficiency as world grade; wave front aberration
. RMS, light axis differential 0.3967arcmin. We can manufacture localized blu-ray disc's pick-up lens's component and by this fact we obtain international competitiveness. The result of this research will be very helpful to develop a single objective lens for 3 different wavelength of laser diodes in playing and recording pick-up module.
Temperature and Property Control of High Strength Steel in Hot Strip Mills
Park, Cheol-Jae ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 20, issue 6, 2011, Pages 817~823
This paper proposes a cooling stop temperature control(CST) and a phase transformation control(PTR) which aim at obtaining the uniform temperature and quality along the longitudinal direction of the high strength steel on the run-out table(ROT) process. The problems of the temperature control are analyzed for the conventional steel and the new control concepts are derived from a time-temperature transformation(TTT) diagram. The proposed control technologies are verified from the simulation results under the temperature prediction model by the heat transfer governing equation, and the temperature estimation simulator. It is shown through the field test of the hot strip mills that the phase transformation ratio of the high strength steel is considerably improved by the proposed temperature controls.
A Study on the Improvement of Productivity and Surface Roughness in Mold Machining using the Optimization of Cutting Force
Jeon, Eon-Chan ; Lee, Su-Yong ; Lee, Woo-Hyun ; KIm, Dong-Hoo ; Chun, Jung-Do ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 20, issue 6, 2011, Pages 824~829
The mold is widely used for mass production in present industry. Also, product cycle time is faster, for this request, high productivity improvement in mold machining is required. And, In case of mold manufacturing company, the delivery shortening is required to quickly manufacture new product. Therefore, we aim for the delivery shortening though the method of machining time shortening in mold machining. On this paper, first, we made the NC-code of Insert die-casting as the object model using PowerMill. And then, analyzed cutting force by Toolpath in Insert mold machining using Production Module of Advantedge which is cutting force analysis program. After that, we came up with the optimum conditions of productivity improvement throughout the analysis result of before and after optimization of cutting force, machining time variation, and surface roughness by changing min tangential force to 80, 85, 90% of max tangential force.
Analysis of Load Distribution and Sharing on the Planetary Reducer for Wind Turbines
Park, Young-Jun ; Lee, Geun-Ho ; Kim, Jeong-Kil ; Song, Jin-Seop ; Park, Sung-Ha ;
Journal of The Korean Society of Manufacturing Technology Engineers, volume 20, issue 6, 2011, Pages 830~836
Most of pitch/yaw reducers consist of several planetary geartrains. Planetary geartrains make gearboxes to be small and light, low noise and good efficiency. Most important thing in the planetary geartrain is load distribution on the gear tooth flank. In this study, the effect of output shaft bearings on the load distribution of gear tooth flank has been investigated. The commercial software was employed to compare the load distribution of two models depending on the bearing type. The spherical roller bearing(SRB) and the cylindrical roller bearing(CRB) were used as output shaft bearings in the
model, and two taper roller bearings(TRB) were used in the
model. As a result, it was found that the
model. showed better performances on the load distribution of gear tooth flank, this results stated that the output shaft bearing system could be important consideration when designing reducers for wind turbine systems.