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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of the Korean Society for Precision Engineering
Journal Basic Information
Journal DOI :
Korean Society of Precision Engineering
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Volume & Issues
Volume 29, Issue 12 - Dec 2012
Volume 29, Issue 11 - Nov 2012
Volume 29, Issue 10 - Oct 2012
Volume 29, Issue 9 - Sep 2012
Volume 29, Issue 8 - Aug 2012
Volume 29, Issue 7 - Jul 2012
Volume 29, Issue 6 - Jun 2012
Volume 29, Issue 5 - May 2012
Volume 29, Issue 4 - Apr 2012
Volume 29, Issue 3 - Mar 2012
Volume 29, Issue 2 - Feb 2012
Volume 29, Issue 1 - Jan 2012
Selecting the target year
Development of Core Technologies of Multi-tasking Machine Tools for Machining Highly Precision Large Parts
Jang, Sung-Hyun ; Choi, Young-Hyu ; Kim, Soo-Tae ; An, Ho-Sang ; Choi, Hag-Bong ; Hong, Jong-Seung ;
Journal of the Korean Society for Precision Engineering, volume 29, issue 2, 2012, Pages 129~138
DOI : 10.7736/KSPE.2012.29.2.129
In this study, three types of large scale multi-tasking machine tools together with core technologies involved have been developed and introduced; a multi-tasking machine tool for large scale marine engine crankshafts, a multi-tasking vertical lathe for windmill parts, and a large scale 5-axis machine tool of gantry type. Several special purpose devices has been necessarily developed for the purpose of handling and machining big and heavy workpieces accurately, such as PTD (Pin Turning Device) with revolving ring spindle for machining eccentric crankshaft pins, hydrostatic rotary table and steady rest for supporting and resting heavy workpieces, and 2-axis automatic swiveling head for high-quality free surface machining. Core technologies have been also developed and adopted on their detail design stage; 1) structural design optimization with FEM structural analysis, 2) theoretical hydrostatic analysis for the PTD and rotary table bearings, 3) box-in-box type cross-rail and octagonal ram design to secure machine rigidity and accuracy, 4) constant spindle rpm control against gravitational torque due to unbalanced workpiece.
Development of a Multi-Tasking Machine Tool for Machining Large Scale Marine Engine Crankshafts and Its Design Technologies
An, Ho-Sang ; Cho, Yong-Joo ; Choi, Young-Hyu ; Lee, Deug-Woo ;
Journal of the Korean Society for Precision Engineering, volume 29, issue 2, 2012, Pages 139~146
DOI : 10.7736/KSPE.2012.29.2.139
A multi-tasking machine tool for large scale marine engine crankshafts has been developed together with design technologies for its special devices. Since work pieces, that is, crankshafts to be machined are big and heavy; weight of over 100 tons, length of 10 m long, and diameter of over 3.5 m, several special purpose core devices are necessarily developed such as PTD (Pin Turning Device) for machining eccentric pin parts, face place and steady rest for chucking and resting heavy work pieces. PTD is a unique special purpose device of open-and-close ring typed structure equipped with revolving ring spindle for machining eccentric pins apart from journal. In order to achieve high rigidity of the machine tool, structural design optimization using TMSA (Taguch Method based Sequential Algorithm) has been completed with FEM structural analysis, and a hydrostatic bearing system for the PTD has been developed with theoretical hydrostatic analysis.
Optimization of Multi-tasking Vertical Lathe For Windmill Parts
Choi, Hag-Bong ; Lee, Jong-Hoon ; Park, Woo-Sang ; Sin, Heung-Chul ; Oh, Jong-Suk ; Park, Chun-Hong ; Lee, Dong-Yun ;
Journal of the Korean Society for Precision Engineering, volume 29, issue 2, 2012, Pages 147~155
DOI : 10.7736/KSPE.2012.29.2.147
Wind power, which is one of the promising renewable energies, has shown the high growth rate of 35 % of the annual average in the recent 5 years and also windmill related equipment market has been fast-growing. Yaw & Pitch bearing are the key parts of windmill and are machined by huge vertical lathe which is monopolized by the advanced countries. The purpose of this study is to develop the multi-tasking vertical lathe for 5 MW grade windmill bearings, which might be mass produced 3 or 5 years later. In this study, the structure of the crossrail and rotary table, which are the key units of the huge multi-tasking vertical lathe, were optimized through the finite element analysis. Also the basic performance of the rotary table has been evaluated.
Analysis for the Cross Rail Design and the Zig-Zag Motional Error in Gantry Type Machine
Lee, Eung-Suk ; Lee, Min-Ki ; Park, Jong-Bum ; Kim, Nam-Sung ; Ham, Jun-Sung ; Hong, Jong-Seung ; Kim, Tae-Sung ;
Journal of the Korean Society for Precision Engineering, volume 29, issue 2, 2012, Pages 156~160
DOI : 10.7736/KSPE.2012.29.2.156
Recently, the demands of the large scale machine tools gradually increase to machine the large parts, such as large scale crankshaft, yaw and pitch bearings for the wind power generator and the vehicle or aircraft components. But the high technology is necessary in order to develop the huge machine tools. Furthermore, the global market of it has been monopolized by a few companies. So, we need to develop the large scale machine tools and study its core technology to rush into the increasing market. In this study, we carried out the researches for the important core technology of a multi-tasking, machine tool; a large scale 5-axis machine tool of gantry type for multi-task machining. This study is focused on the design of large size gantry type multi-axis machine. In the case of large size of machine the cross rail deflection in the X-axis is significant. To reduce the deflection due to the eccentric spindle head, a special hollow type design in the cross rail with outside ram is adapted in this study. Also, the Zig-Zag motion in the Y-axis is inevitable with the gantry geometry, which is by the un-balancing, different motion at the left and the right columns moving. We tried to reduce the influence of Zig-Zag motion using FEM with different loading conditions at the left and the right side column.
A Study on Surface Fabrication of Super Hydrophobic using Pico Second Laser
Cho, Il-Hwan ; Lee, Jae-Hoon ; Noh, Ji-Whan ; Lee, Seoung-Won ;
Journal of the Korean Society for Precision Engineering, volume 29, issue 2, 2012, Pages 161~169
DOI : 10.7736/KSPE.2012.29.2.161
Recently, a study for the functional surface production of super hydrophobic of natural and biomimetic artificial has attracted much attention. To make process methods of super hydrophobic surface has a variety of ways such as lithography, etching, and laser ablation. However, we were used ultra-shot pulse laser ablation process which has the virtue of more environmental friendliness and simple process. In this paper, we were fabricated a multiplicity of super hydrophobic patterns on mold surface(NAK80) using by optimizing the laser processing conditions and it was transferred on PDMS. Also, we measured contact angle super hydrophobic patterns on PDMS. The result showed there is no patterns on PDMS were measured 94 degrees, by contrast, optimized super hydrophobic patterns on PDMS was 157 degrees. Therefore we fabricated super hydrophobic surface on mold. Based on these experimental results, it is possible to mass production using ultra shot pulse laser ablation of super hydrophobic pattern and to be applied for a variety of industries.
Development of Multi-Degree of Freedom Carbon Fiber Plate Force/Torque Sensor
Lee, Dong-Hyeok ; Kim, Min-Gyu ; Cho, Nahm-Gyoo ;
Journal of the Korean Society for Precision Engineering, volume 29, issue 2, 2012, Pages 170~177
DOI : 10.7736/KSPE.2012.29.2.170
A force/torque sensor using carbon fiber plate was designed and developed to make the sensor be able to measure a wide range of multi degree of force and torque. Using carbon fiber plate of 0.3 mm thickness, the sensor was designed and developed, which has a
level order of resolution and about 0.01 N ~ 390 N of wide measurement range. The elastic deformation part has a tripod plate structure and strain gauges are attached on the part to detect the force/torque. The coefficient of determination for the sensor is over 0.955 by the calibration experiment so that the linearity of the sensor is confirmed to be good. Also, experiments on applying 0.005 ~ 40 kg (0.05 ~ 390 N) to each axis were implemented and the sensor is proved to be safe under a high load. Finally, to verify the function calculating the direction of load vector, the directions of various load vectors which have the same magnitude but different directions and the directions of the calculated load vectors are compared and analyzed to accord well.
Design of a Transformable Track Mechanism for Wall Climbing Robots
Lee, Gi-Uk ; Seo, Kun-Chan ; Kim, Hwang ; Kim, Sun-Ho ; Jeon, Dong-Su ; Kim, Hong-Seok ; Kim, Jong-Won ;
Journal of the Korean Society for Precision Engineering, volume 29, issue 2, 2012, Pages 178~184
DOI : 10.7736/KSPE.2012.29.2.178
This paper presents a transformable track mechanism for wall climbing robots. The proposed mechanism allows a wall climbing robot to go over obstacles by transforming the track shape, and also increases contact area between track and wall surface for safe attachment. The track mechanism is realized using a timing belt track with one driving actuator. The inner frame of the track consists of serially connected 5R-joints and 1P-joint, and all joints of the inner frame are passively operated by springs, so the mechanism does not require any actuators and complex control algorithms to change its shape. Static analysis is carried out to determine design parameters which enable
wall-to-wall transition and driving over projected obstacles on wall surfaces. A Prototype is manufactured using the transformable track on which polymer magnets are installed for adhesion force. The size of the prototype is
) and weight is 4kgf. Experiments are performed to verify its climbing capability focusing on
wall to wall transition and driving over projected obstacle.
Development of a Cooling Circuit Design System for Injection Molding Die of Vehicular Lamp
Cho, Hyeon-Uk ; Park, Jung-Whan ; Park, Soo-Jung ; Shin, Dong-Jin ; Lee, Seok-Jung ;
Journal of the Korean Society for Precision Engineering, volume 29, issue 2, 2012, Pages 185~192
DOI : 10.7736/KSPE.2012.29.2.185
The paper presents the development of a cooling circuit design system that automatically creates 3D cooling circuit on a given section plane conforming to design specifications, generates 3D solid model of cooling line segments defined on a 2D sketch plane, and verifies interference of 3D cooling channel with the molding die surface. The system was developed mainly for designing plastic injection molding die of vehicular lamp, which helps the mold designer to rapidly construct cooling circuits but also reduce designer's unintended mistakes by conforming to the dimensional design specifications. It is used by an injection molding die manufacturing company in Korea, and reported approximately 20% reduction of cooling channel design time.
A Study on the Optimal Shape Design of Front Axle of Wheel Loader using the Design of Experiments
Yoo, Dae-Won ; Lee, Jai-Hak ;
Journal of the Korean Society for Precision Engineering, volume 29, issue 2, 2012, Pages 193~200
DOI : 10.7736/KSPE.2012.29.2.193
Wheel loader is one of the construction machinery capable of variety of tasks and the demand on functional diversity and structural reliability is growing. As a study on the optimal shape design of front axle for wheel loader through the design of experiments, this paper assessed the design parameters affecting the maximum stress. As a result, a value of 126.77 MPa of minimum stress was obtained, and optimal factors showed the values of w = 100.0 mm,
and R = 118 mm. It showed an accuracy of 98.7% compared with the structural analysis.
Analysis of the Phase Noise and Vibration Sensitivity in OCXO
Kim, Dong-Sik ; Kim, Jong-Pil ; Kim, Se-Young ; Sung, Jin-Bong ;
Journal of the Korean Society for Precision Engineering, volume 29, issue 2, 2012, Pages 201~207
DOI : 10.7736/KSPE.2012.29.2.201
In this paper, We studied the effects of vibration on the phase noise characteristics of radar mounted on UAV(Unmanned Aerial Vehicle) for analyzing vibration sensitivity. The phase noise performance of OCXO is degraded due to airborne vibration, which results in deterioration of radar performance. Desired phase noise level as well as vibration sensitivity which meet the overall system requirements have been obtained after analyzing the vibration sensitivity under the consideration of OCXO itself. The shock mount is placed below OCXO to stabilize undesired vibration caused by external vibration. As a result, improved phase noise performances as well as better vibration sensitivity have been achieved.
Characterization of V-Insert Clamp Joint Applied to Automobile Exhaust Pipes
Hwang, Young-Eun ; Yoon, Sung-Ho ;
Journal of the Korean Society for Precision Engineering, volume 29, issue 2, 2012, Pages 208~213
DOI : 10.7736/KSPE.2012.29.2.208
In this study, the mechanical joint performance of the V-Insert clamp applied to automobile exhaust pipes was evaluated through the experimental investigation of its axial load capacity. The axial load of the V-Insert clamp was also determined by using theoretical equations presented by Shoghi and compared with the experimental results. As results of the theoretical prediction, the axial load of the V-Insert clamp tended to increase along with smaller angle of the V-Insert segment and the lower friction coefficient between the V-Insert segment and exhaust pipes. The experimental results under tightening effects were similar to the theoretical results and the axial load of the V-Insert clamp presented maximum values in the range of all torques at distance of 2mm between each exhaust pipes. The experimental results under loading effects were similar to the theoretical results in the range of lower torques but deviated from the theoretical results in the range of higher torques. These results would be beneficial to improve the joint and sealing performance of the V-Insert clamp.
Fabrication and Performance Evaluation of the HVM Micromixer using Horizontal and Vertical Multi-mixing (HVM) Flow Motion
Yoo, Won-Sul ; Kim, Seong-Jin ; Kang, Seok-Hoon ; Lee, Dong-Kyu ; Go, Jung-Sang ; Park, Sang-Hu ;
Journal of the Korean Society for Precision Engineering, volume 29, issue 2, 2012, Pages 214~221
DOI : 10.7736/KSPE.2012.29.2.214
Recently, the biochip which is a prime representation of NT, IT, BT, as an example of convergence technology, has been frequently mentioned. With the recent rapid advance in biotechnology, these compact devices, such as lab-on-a-chip or u-TAS, have been developed, and more research is needed. These compact devices typically use the micro-channel in order to shed or detach and mix a variety of materials. Specially, in micro-fluidic systems, a mixer is necessary to produce a mixture because only laminar flow occurs at a low-Reynolds number. To solve this problem, HVM a micromixer that induces a horizontal and vertical multi-mixing flow motion, is proposed. The mixing performance was analyzed and verified by optimizing the shape through the CFD analysis and evaluating the structural analysis and the soundness with material properties that are obtained through the basic experiment.
Needle Insertion Force of Biological Soft Tissue for Haptic based Intravenous Injection Simulator
Ahn, Bum-Mo ; Jung, Eun-Young ; Lee, Young-Ho ; Lim, Yong-Soo ; Park, Rae-Woong ; Kim, Jung ; Park, Dong-Kyun ;
Journal of the Korean Society for Precision Engineering, volume 29, issue 2, 2012, Pages 222~228
DOI : 10.7736/KSPE.2012.29.2.222
Haptics and virtual reality are rapidly growing technologies in medical fields. Physicians and nurses can benefit from medical simulation via training and acquire surgical and clinical techniques. In this paper, the research on needle insertion force of biological tissue for haptic based intravenous injection simulator was carried out. We built the setup for needle insertion (intravenous injection) experiments and performed the experiments on live pigs. The force responses against needle insertion were measured using the experimental setup. In addition, the modeling of needle insertion force was carried out with the experimental results and numerical models via nonlinear least-squares method. The results presented in this paper indicate that the developed models can be applied not only to estimate the force feedback during intravenous injection procedure but also to improve the overall training quality of the medical simulator.
Effect on Improvement of Muscle Strength for Loading Pattern using Electric Exercise Instrument
Kang, Seung-Rok ; Kim, Kyung ; Jeong, Gu-Young ; Seo, Young-Bum ; Jeong, Jang-Sik ; Kim, Jung-Ja ; Kwon, Tae-Kyu ;
Journal of the Korean Society for Precision Engineering, volume 29, issue 2, 2012, Pages 229~238
DOI : 10.7736/KSPE.2012.29.2.229
This study is to compare muscle strength between isotonic exercise and isotonic & isokinetic exercise. Participants are 12-man and 10-woman whom they are healthy without medical history in shoulder, elbow and lumbar joint. We performed experiment total 4-weeks that exercise 3-days a week each exercise pattern. We measured shoulder, elbow and lumbar joint torque with BIODEX and circumference of muscle in upper arms once a week. The result showed that isotonic & isokinetic exercise pattern significantly more improved joint torque in shoulder, elbow, lumbar than isotonic exercise pattern. Because that isotonic & isokinetic exercise pattern supplied muscle strengthen and caused muscle contraction. This exercise pattern can be used new exercise training method for major athlete and normal people. Also this pattern can be used rehabilitation treatment.
Biomechanical Effect on Knee Adduction Moment by Lateral Wedge Insole in Transfemoral Amputee
Chang, Yun-Hee ; Lee, Wan-Hee ;
Journal of the Korean Society for Precision Engineering, volume 29, issue 2, 2012, Pages 239~244
DOI : 10.7736/KSPE.2012.29.2.239
The prevalence of knee osteoarthritis was higher people with lower limb amputation. This was identified that transfemoral amputees have a greater external knee adduction moment than ablebodied subjects by biomechanical studies. Therefore, they need rehabilitative intervention for prevention and reduction of knee osteoarthritis. The purpose of this study was to determine the effect of lateral wedge insole used in the treatment of knee osteoarthritis. This study was participated in fourteen unilateral transfemoral amputees and we were analyzed the difference gait variables between without lateral wedge insole and with
lateral wedge insole during gait. Our results showed that step length ratio was more symmetrical and, hip adduction and ankle inversion angle were more close to normal value, and knee adduction moment was decreased as the wedge angle increases. We proposed that these data would be utilized conservative treatment of knee osteoarthritis in lower limb amputees.