• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.6
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• pp.1243-1248
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• 2018

Metal Powder Metallurgy is a manufacturing technology that makes unique model parts or a certain type of product by using a hardening phenomenon when a powder of metal or metal oxide is put it into a mold and compression-molded by a press and then heated and sintered at a high temperature. Powder metallurgical press equipment is mainly used to make the parts of automobile, electronic parts and so on, and most of them are manufactured using precise servo motor. The intelligent precision servo control powder molding press system which is designed and implemented in this paper has advantages of lowering the price and maintaining the precision by using the mechanical camshaft for the upper ram part and precisely controlling the lower ram part using the high precision servo system. In addition, OPC-based monitoring and process data collection systems are designed and implemented to provide scalability that can be applied to smart manufacturing management systems that utilize Big Data in the future.

• Design & Manufacturing
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• v.12 no.3
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• pp.25-30
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• 2018

Recently The automotive industry is trying to increase the energy efficiency by reducing the weight of the car body and engine components as a way to achieve high energy efficiency. In particular, the reduction of the weight of the vehicle through the weight reduction of the vehicle body has the advantage that the fuel consumption and the output can be improved. But at the same time, there is the disadvantage that the strength becomes weak due to the reduction of the material thickness. Therefore, in order to overcome these disadvantages, materials with high strength according to the unit thickness have been actively developed, and researches for applying them have also been increasing. In this study, we will investigate the application of cold rolled steel sheet, which is a lightweight material, to a horn bracket that secures a installed in an automobile engine room. The horn bracket secures the horn on the car engine and is bolted to the outer wall of the engine. The momentum is acted on the bracket due to the distance between the bolt fastening part and the car horn installed on the bracket end side. Therefore, the body part of the bracket is more likely to be destroyed by the influence of the continuous stress. In this paper, design optimization for weight reduction and strength enhancement was performed to solve this problem, and possibility of applying the rolled steel sheet material as lightweight material by tensile test and fabrication was confirmed.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.28 no.4
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• pp.393-405
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• 2018

Objective: This study examines the types of hazardous factors in the working environment and the time-trend for their exposure levels over 10 years (2007 to 2016). Study Design and Method: The types of hazardous factors and exposure levels were drawn from the 19 measurement reports on the working environment over 10 years at a shock absorber manufacturing facility. Risk assessment of the types of factors and time-trend of exposure levels were evaluated using the factors and exposure levels. Results: A total of 34 hazardous factors were evaluated. The types were noise, 15 organic compounds, seven kinds of acid sand alkalis, eight kinds of heavy metals, and three other compounds. Special management materials used were nickel, hexavalent chrome, and sulfuric acid. Human carcinogens (1A) used were trichloroethylene, nickel, and sulfuric acid. There were six types of substances belonging to the IARC's 2B (body carcinogens) classification or higher, including, methyl isobutyl ketone, ethyl benzene, and trichloroethylene. No detection was found for 627 out of the 2065 total measurements in 19 exposure survey reports, representing 30.4%. Organic solvents, acid and alkali products, and heavy metals showed continuous low exposure concentrations. Noise, welding fumes, and the evaluation of mixed solvents show a gradual decrease in geometric mean and maximum over the time-trend of 10 years. Conclusions: In the case of a shock absorber manufacturing facility, the hazardous factors of noise and the evaluation of mixed solvents still indicate high concentrations exceeding the exposure limits and necessitate reduction studies. These two factors and welding fumes showed a continuous decrease in their ten-year tendency. Organic compounds, acids/alkalis, and heavy metals were managed smoothly in a work environment of continuous low concentrations.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.221-223
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• 2016

Currently in the automobile market, models with many convenient functions combined with IT have been released. This change has a strength that there could be many convenient and useful functions related to driving while flaws of vehicles caused by malfunctions of these electronic equipments could trigger serious incidents. Among them, the sudden unintended acceleration considered as the most serious is a serious flaw that could threaten driver's life. However, the causes for sudden acceleration incidents have not been clearly investigated with no coping measures. As manufacturers shift the responsibility to drivers' carelessness, drivers' burden is continuously increasing. Thus, this paper designed the system to cope with sudden acceleration incidents by changing conditions of controlling parts like accelerator and brake, and internal image of the driver's seat into data through the integrated module.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.6
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• pp.98-105
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• 2019

In order to improve the fuel economy and dynamic behavior of automobiles, the weight reduction tendency of automobile parts is obvious. Also, in order to maximize assembly and maintenance convenience, various parts are integrated and modularized. Multi-piece methods require many manufacturing processes and become a factor of lowering the strength of parts. It is advantageous to overcome the disadvantages by integrally manufacturing to reduce the processing steps and ensure the strength of the parts. However, when it is necessary to process in a narrow space inside the part, it is impossible to process with the existing spindle. The angle head spindle is only a component of a machine tool, but it is a core part that requires high technology and is highly utilizable in products requiring high precision machining. Therefore, various and continuous studies needs for angle head spindles in areas such as vibration absorption, operational safety, excellent dimensional stability, and strength. In this paper, we propose an optimal design for angle head spindle by performing structural analysis and shape optimization for angle head spindle gear and case.

• Journal of Convergence for Information Technology
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• v.9 no.5
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• pp.27-33
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• 2019

Various technical and societal approaches are being made to realize the auto driving (AD) and cooperative driving (CD) including communication network and extended advanced driver support system is under development. In CD, it is important to share the roles of the driver and the system and to secure the stability of the driving, so a efficient interface scheme between the driver and the vehicle is required. This study proposes a research model including driver, system and driving environment considering the role and function of driver and system in CD. An efficient interface between the driver and the vehicle to cope with various driving situations on the CD using the analysis of the driving environment and the research model is also proposed. Through this study, it is expected that the proposed research model and interface scheme could contribute to CD system design, cockpit module development and interface device development.

• Journal of the Korea Convergence Society
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• v.12 no.2
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• pp.201-213
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• 2021

Recently, personal mobility has been spreading and using increasing, but the pedestrian environment is getting worse and accidents are also rapidly increasing. Therefore, this study conducts a status survey related to the elements of pedestrian disturbances in personal mobility and identifies the problems. The following measures are presented to improve the pedestrian environment for the mobility handicapped through expert opinion surveys. The movement of individual mobility means in the walking space is prohibited, and the speed limit shall be stipulated to enable the mobility handicapped to walk safely and conveniently. Parking spaces will have to create obstacle zones in the parking area next to the roadway or at the border of sidewalks and roads, and regulations are needed to collect illegally parked vehicles. It is necessary to switch from the existing automobile-oriented road to the road structure considering the use of low and medium-speed vehicles.

• Journal of Environmental Analysis, Health and Toxicology
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• v.21 no.4
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• pp.209-219
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• 2018

In the areas of RoHS, WEEE, ELV and REACH, reinforcement of environmental regulations against harmful substances is a global trend not only in EC but also in all over the world. In the fields of Korea's major export products such as material parts, electrical and electronic products and automobile parts, we are responding to these regulations consistently. To develop reference material for analyzing lead and cadmium in paints, the candidate materials were produced through the screening process which separated shapes and sizes. To secure the traceability of the candidate materials produced, the characteristics and uncertainties are estimated by ICP-AES analysis using the primary reference material. The short-term and long-term stabilities also are evaluated in parallel. In order to calculate the final certification value of the candidate material, the verification were carried out by the performance evaluation through the comparison among the KOLAS (Korea Laboratory Accreditation Scheme) laboratories, and the CRM was produced in accordance with ISO Guide 35. The certified values and uncertainties of Pb and Cd of the final paint standard, determined according to the joint analysis among laboratories, are Pb [($191.4{\pm}3.1$) mg/kg, ($944.1{\pm}5.6$) mg/kg] and Cd [($45.0{\pm}2.6$) mg/kg, ($225.5{\pm}3.5$) mg/kg]. These standard materials were developed to enhance the reliability of measurement analysis, including the validity and traceability of measurement results. Also it is expected that the CRM will be used as QCM (quality control material) for the product design and the process monitoring, so that regulation and management of hazardous heavy metals can be systematically implemented.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.1
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• pp.402-408
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• 2021

Vehicle engineering analysis in the event of an accident caused by a car built on mechanical design has not been investigated in-depth but relies on the subjective experience knowledge of the investigator. This study analyzed the correlation between the speed, progress, steering, and braking before impact, which is consistent with the final stop position, by drawing a site situation chart using the CAD (CAD) program and repeating 250 crashes using the PC-Crash program. The following situations were investigated: lower impact velocity; greater impact speed of the vehicle, which is not affected significantly by the departure angle; higher vehicle speed, such as the effective impact velocity, after the impact; higher vehicle speed; and lower vehicle speed. (Ed note: I am unsure what you are saying here. It appears contradictory and not a complete sentence. Please check the changes.)The simulation results of this study identified the process of returning to the magnetic progression lane after recognizing the opposite porter while Mighty was carried out on the uphill left-curve section in a position that crossed the center line, and the collision of the porter's front left side, pushing the porter in the right diagonal direction and making the front stop towards approximately 11 o'clock.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.5
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• pp.677-684
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• 2021

This paper presents a time-to-digital converter for measuring absolute time differences. The time-to-digital converter was designed and fabricated in 0.18-um CMOS technology and it can be applied to Light Detection and Ranging system which requires long time-cover range and 50ps time resolution. Since designed time-to-digital converter adopted the reference clock of 625MHz generated by phase locked loop, it could have absolute time resolution of 50ps after automatic calibration and its cover range was over than 800ns. The time-to-digital converter adopted a counter and chain delay lines for time measurement. The counter is used for coarse time measurement and chain delay lines are used for fine time measurement. From many times experiments, fabricated time-to-digital converter has 50 ps time resolution with maximum INL of 0.8 LSB and its power consumption is about 70 mW.