간행물

한국기계기술학회지 KCI 등재 Journal of the Korean Society of Mechanical Technology 韓國機械技術學會誌

권호리스트/논문검색
이 간행물 논문 검색

권호

제20권 제4호 (2018년 8월) 25

학술연구

1.
2018.08 구독 인증기관 무료, 개인회원 유료
The objective of this study was to develop formability evaluation techniques in order to apply aluminum sandwich panel for automotive body parts. For this purpose, formability evaluation by using FLD (forming limit diagram) was carried out in order to secure the fundamental data for the measurement of sheet metal forming and the establishment of optimum forming conditions of the aluminum sandwich panel. From the results of these formability evaluation, the formability of aluminum alloy sheet which was the skin component for the sandwich panel was higher than that of sandwich panel. In addition, the formability of sandwich sheet which was made by present study was same as that of sandwich panel made by foreign country. Also, it was found that sandwich panel made in present study could have the excellent deep draw-ability when it was compared to the foreign made sandwich panel.
4,000원
2.
2018.08 구독 인증기관 무료, 개인회원 유료
The error between the speed display of the speedometer and the speed display of the navigation occurs in the process of driving the vehicle which makes most of the driver confused and also experience anxiety hence in this paper, by the car management law number 73 (2), tests were conducted with following procedures measured by standard speed tester to analyze the error clearly. The experiment was carried out by installing a car on a speed tester with a speed difference of 10km/h from 30 to 80km/h according to the manufacturer and the vehicle. The result was obtained by measuring differences of the speed display error between the speedometer and navigation when driving the car on the road at the same speed. With the standard speed gauge at 40km/h, error percentage of the speed tester and Morning was 15.9% (5.5km/h) and Sonata was 6.4% (2.4km/h). The error percentage between different car company models was 9.5%. With the standard speed gauge at 40km/h, the error percentage of speed displayed by navigation and Morning was 14.2% (5km/h) and Sonata was 5.3% (2.4m/h). The error percentage between different car company models was 9.6%(3km/h). It was shown that according to the standard safety and rules of the speedometer, the cars were manufactured considering the safety. The speed difference between the speed tester and the navigation was 1.7% (0.5km/h) for Morning, 0.6% (0.2km/h) and 1.1% (0.3km/h) for Trax.
4,000원
3.
2018.08 구독 인증기관 무료, 개인회원 유료
Prior to the experimental and production stages of the center pillar, a structural analysis must be carried out at the design stage. The commercial software for the structural analysis at the design stage provides benefits such as cost-effective and time economy. In this study, the structural analysis was performed to investigate the stress and displacement characteristics of the center pillar for five types of the applied loads using SolidWorks. The equivalent stress was relatively larger on the outside plate than the inside plate. The maximum equivalent stress according to the change of the applied loads increased linearly in the range of 47~181%. The deformation was larger at the upper end of the center pillar, and the maximum displacement was linearly increased in the range of 35~187%. The analysis results of the center pillar according to the applied loads show that the location and distribution of the maximum stress and displacement of the center pillar can be predicted.
4,000원
4.
2018.08 구독 인증기관 무료, 개인회원 유료
Coupling is commonly used as a mechanical fastener to connect the turbine housing and the bearing housing in a turbocharger assembly. The finite element analysis was used to predict the structural behaviors of the coupling system, which could be caused by the bolt clamping force in the assembly process and the thermal deformation during turbocharger operation. The back plate is used to prevent gas leakage from the turbine housing to the bearing housing while the fixed pin is inserted to set the reference position between the two parts. Thus, in order to predict the mechanical behaviors of the coupling system numerically, the temperature distributions were calculated by heat transfer analysis based on the rated speed of the diesel engine. As a result of analyzing the structural characteristics of the turbocharger, the contact pressure of the back plate was influenced by thermal deformations whereas the bending deformation of the fixed pin was affected by the thermal deformation and the pin position.
4,000원
5.
2018.08 구독 인증기관 무료, 개인회원 유료
It is known that the cooling performance can be improved about 5~12% and the COP (Coefficient of Performance) can be improved about 10~15% when the IHX (Internal Heat Exchanger) was applied in a vehicle. Thus, the aim of this study was to observe the influence of the fins shape on the turbulence flow and turbulence kinetic energy gradient in IHX. All the applied parameters of the fin such as rotation angle, spacing ratio, height ratio and mass flow rate are changed. The governing equations for the flow motion simulation were applied to continuity equation and Navier-Stokes equation, and the turbulence model was applied by the Shear Stress Transport(SST) model, which has the advantage of turbulence simulation. As the rotation angles of the front and back fins were increased, the difference in the maximum turbulent kinetic energy gradient between fins was reduced. As the inlet flow mass increased, the turbulent kinetic energy difference between front and back fins were increased. The turbulence area tended to increase with increasing fin height ratio.
4,000원
6.
2018.08 구독 인증기관 무료, 개인회원 유료
As product diversity increases and product life cycle gets shorter, lead time reduction and manufacturing cost saving of die & mold are getting important in machinery, automotive, and electronics industries. To develop a novel free-machining die & mold steel, we try to modify the chemical compositions of AISI P20 mold steel by adding boron, nitride, and sulfur. After making three types of mold steels which are base metal of AISI P20 mod., boron and nitrogen added, and boron, nitrogen, and sulfur added to the base metal. Milling tests are carried out using TiN, TiCN, and TiAlN coated WC end-mills under various cutting conditions. Boron and nitrogen added steel machined by TiN coated tool shows the most excellent tool wear and surface roughness characteristics. The results might come from BN inclusions in base metal acting as a stress concentration source and lowering strain resistance during cutting process. The relationship between tool wear and surface roughness are also discussed including feed rate effects.
4,000원
7.
2018.08 구독 인증기관 무료, 개인회원 유료
As the demand for high-speed and high-precision machining increases, the need for cooling and filtering of cutting oil is high. A new concept of coolant heat exchange filter is developed by installing cooling coil through which refrigerant(R410-a) passes through the coolant filtering device. For structural safety evaluation of the heat exchanger filter for cutting oil suppling device of machine tool, thermal stress and vibration analysis were performed using ANSYS program. The results of structural and thermal stress analyses have led to the conclusion that the cooling system has structural stability. From modal analysis, first natural frequency is 12.37 hz and deformation is 22.041 mm. Sixth natural frequency is 26.887 hz and deformation is 25.563 mm.
4,000원
8.
2018.08 구독 인증기관 무료, 개인회원 유료
The hydro-forming design process of the sub-frame side members was studied using a high strength steel of 440 MPa in tensile strength. In the part design stage of the side member, the cross section analysis and the overall process design of the part shape were done. In the detailed simulation results, the maximum thickness reduction rate due to hydro-forming was predicted to be 13% and this was predicted to be a safe level without cracking. The end curvature was reduced to increase the stiffness of the part to design more secure parts and two types of grooves were added to the cross section and compared. The thickness reduction rates of the narrow and wide were improved by 18.6% and 15.6%, respectively when the narrow and wide grooves were added.
4,000원
9.
2018.08 구독 인증기관 무료, 개인회원 유료
Currently, the cutting oil supply device is not equipped to cool the cutting oil. Therefore, additional cooling device should be connected to cool the cutting oil. This has the disadvantage of increasing the size of the device and reducing its cooling capability. To overcome these shortcomings, cooling coils are applied to the outside of the cutting oil filtering device to develop a heat exchanger filter for simultaneous coolant filtering and cooling to improve the compactness of the cutting oil supply device and cooling capability of the cutting oil. For the development of heat exchanger filter, flow and heat transfer analysis were performed. Due to the small heat transfer area of 10 cooling coils, less heat exchange occurred. In the 20 cooling coils, the coolant cooling coils prevented smooth flow of the cooling oil in the heat exchanger filter. The cooling efficiency of the 15 cooling coils were best, and the cooling temperature decreased non-linearly as the supply flow rate of the cutting oil increased.
4,000원
10.
2018.08 구독 인증기관 무료, 개인회원 유료
To improve life time of machine components, higher alloy grade materials are used by adding more metal alloy components and content. Also production processes are further complicated and subdivided such as the forging, preliminary heat treatment, quality heat treatment, rough machining and finished machining process. Those reasons become major cause of large stress in the materials, and the residual stress generated during the manufacturing process causes fatal defects, such as crack, surface tear, warping and deformation of the products. It is necessary to evaluate the residual stress on the entire processes, from forging process to final finished machining process. Also in order to avoid those problems caused by residual stresses, it is necessary to know in advance what process is important to be controlled and what parameters affect residual stress. By the hole drilling method, residual stress was measured in each manufacturing process step. In this study, the hardness of the surface, the cutting force test and the metal analysis were performed to clarify the influence of manufacturing process parameters.
4,000원
11.
2018.08 구독 인증기관 무료, 개인회원 유료
The cooling operating characteristics of the 3 room air conditioner are experimentally investigated for the number of the indoor units (A, B, C) and the operating conditions (standard, overload) under the cooling operation. The cooling capacity and COP were calculated using a multi-type calorimeter. Also, EEV opening, compressor frequency, and superheat degree were obtained when the compressor started. From the experimental results, we can see that the performance and operation characteristics of the air conditioner depend on the indoor unit operation method. In case of simultaneous and single operation, the cooling overload performance was measured lower than the standard condition. Also, in the overload operation, the power consumption of the compressor was greatly increased and the COP was also decreased.
4,000원
12.
2018.08 구독 인증기관 무료, 개인회원 유료
This paper proposes a fusion controller combing an anti-windup PID controller and BELBIC (Brain Emotional Learning Based Intelligent Controller) for controlling the position and vibration of a robot system having a single flexible manipulator. A finite element model of the flexible manipulator is developed. The reliability of it is verified by comparing the natural frequencies computed using the finite-element method with the experimentally measured ones. An MSC.ADAMS computational model of the robot system is interfaced with the proposed controller in MATLAB/Simulink, for carrying out a simulation. The simulation is performed with various references inputs and endpoint masses. The effectiveness and robustness of the proposed controller for control of the position and vibration of the flexible manipulator is shown through the simulation.
4,000원
13.
2018.08 구독 인증기관 무료, 개인회원 유료
Prior to the design and production stages of the center pillar, the structural analysis must be carried out at the concept stage. Commercial softwares for the structural analysis provide benefits such as performance prediction and deformation. In this study, the structural analysis using SolidWorks was performed to investigate the stress and displacement characteristics of the center pillar for two types of collision positions and velocities. As the impact velocity increased, the maximum equivalent stress and displacement of the center pillar were larger. In the case of passenger cars, the equivalent stress and displacement according to the velocity change increased by about 133% and 116% at 16.5m/s , based on 5.5m/s . Also, the equivalent stress and displacement in the SUV car increased by about 119% and 378%, respectively
4,000원
14.
2018.08 구독 인증기관 무료, 개인회원 유료
In this study, the applicability of biodiesel fuel was investigated as an hopeful alternative fuel for a compression ignition engine. The exhausted smoke emission of biodiesel fuel was reduced remarkably in comparison with commercial diesel fuel, that is, it was reduced approximately 64% at 2500 rpm, full load condition. And, torque, power and brake specific energy consumption rate did not showed significant differences. But, NOx emission of biodiesel fuel was slightly increased in comparison with the commercial diesel fuel. Generation of CO2 is considerably reduced by photosynthetic action in the course of growing biomass series plants, the material for biodiesel fuel.
4,000원
15.
2018.08 구독 인증기관 무료, 개인회원 유료
In this paper, we investigated the change of sectional shape according to the tension when the reed wire was rolled. When rolling is performed, the tension acting on the reed wire acts in the opposite direction of the rolling progress and prevents twisting or bending phenomenon. The shape of the cross section was changed according to the tension acting on the reed wire, and the reed wire was rolled by continuously rolling the flat rolled wire and the tension was applied to the reed wire to control the simulation. As a result of the experiment, it was confirmed that the dimensions of the thickness and width after rolling can be adjusted through the tension acting on the lead wire. It was also confirmed that as the tension increased, the length of the lead wire increased and the residual stress increased.
4,000원
16.
2018.08 구독 인증기관 무료, 개인회원 유료
Fluid motion within the internal combustion engine cylinder plays a major role in controlling the fuel/air mixing and combustion processes in spark-ignition engines, and the combustion processes in compressionignition engines. In-cylinder flow is quite unstable and varies from one cycle to another. Various methods of in-cylinder flow measurement and fuel/air mixing characterization have been developed during the past few decades. In particular, laser based flow diagnostic techniques have been utilized for this purpose. This study will focus on the quantification of spark-ignition engine in-cylinder flow using the laser based flow diagnostic techniques. The measurement methods, including high speed flow visualization and laser Doppler velocimetry (LDV), will be discussed.
4,000원
17.
2018.08 구독 인증기관 무료, 개인회원 유료
In this study, We studied design method to reduce scattering reflection by adding a three - dimensional structure to light guide plate of LED backlight widely used in small and portable devices. In order to improve the efficiency of the light-incident part, a three-dimensional structure is used in which a repetitive structure of a prism shape and a semi-cylindrical shape is repeatedly added to the light-entering face in light-guide plate. As a result of the study, it was found that uniform luminance values were obtained in the light-incident portion and the backlight when a repetitive pattern of a semi-cylindrical shape was added as compared with a case in which a prism shape was added. Particularly, when a rectangular lens with a semi-cylindrical shape is added, the average value of the total luminance is increased by about 15% from 7278 lm to 8324 lm as compared with a general light guide plate.
4,000원
18.
2018.08 구독 인증기관 무료, 개인회원 유료
An interference fit is a fastening between two parts which is achieved by friction after the parts are pushed together, rather than by any other means of fastening. A fit is depending on which part has its size controlled to determine the fit. To select an amount of interference see KS standard tables for class from light to heavy drive fits. The aim of this paper is to find the optimal gap under the interference fit with lowest contact pressure to the two cylinders. To accurately determine the amount of interference clearance, must consider the fluctuation of the response parameters such as contact pressure, displacements and stresses. The response of the cylinder system is modelled with the probabilistic finite element method using the Monte Carlo simulation. The probabilistic design is carried out using ANSYS probabilistic design software. And then the optimal design of the interference gap is sequentially solved to find the solution. The practical optimal design is proposed for the design of the interference fit system. The numerical results are obtained where the displacements and stresses treated as constraints.
4,000원
19.
2018.08 구독 인증기관 무료, 개인회원 유료
A micromixer is a component of a lab-on-a-chip or microfluidic device that mixes two or more chemicals together. The purpose of this study is to assess the performance of passive micromixer of various shapes. Six shapes of micromixers compared mixing performance. Three dimensional modeling was carried out to have the same hydraulic diameter. The commercial code, ANSYS Fluent, was used to simulate the internal mixing flow. A numerical analysis method is described in detail in this paper. The performance of the micromixer was compared with the mixing index and pressure drop. Consequently, the CDM-8T shape showed reasonable mixing performance and relatively low pressure drop.
4,000원

생산기술

20.
2018.08 구독 인증기관 무료, 개인회원 유료
Since the so-called diesel gates of German automobiles, interest in environmentally-friendly vehicles has been rising, among other alternatives, hydrogen-fueled electric vehicles with 0% vehicle emissions are expected to replace a significant portion of passenger cars. Here, we analyze trends of US, Europe, PCT (WO) 3-patent offices application of hydrogen-fueled electric vehicles and analyze the patent application trends of national and individual companies, the patent application trend of detailed technology through clustering analysis, technology competitiveness. The global market for hydrogen-fueled electric vehicles, which is currently only 0.01% of other alternatives, is expected to grow to several percent in 2020. Major automobile makers such as Japan, United States of America, Germany, and Korea continue to fiercely compete for eco-friendly vehicles.
4,000원
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