경사면 구멍가공의 진위치도 향상에 관한 연구

정종윤 ( Jong Yun Jung ),박철순 ( Chul Soon Park ),김지관 ( Jie Kwan Kim ),이동포 ( Dong Po Lee ) 대한설비관리학회 2012 대한설비관리학회지 Vol.17 No.1

Precision machining produces metallic parts with tight tolerances. However, precision components are sometimes produced with rough tolerances since parts have complex geometries. Because this may cause backlash or lower dimensional accuracy of parts, high tolerance should be fulfilled. This research finds errors from true position of holes made on a sloped surface of precision component. When holes are being produced, load requirements on a sloped surface are compared with ones on a normal plane. Statistical analyses are made through the analyzing data collected from the experiments. Applying the decision made this paper suggests how the machining conditions should be selected to low positional errors.

Structural Safety of Nozzle Plate using Simulation

Jong Yun Jung(정종윤),Heesung Park(박희성),Joon-Seob Kim(김준섭) 한국산업경영시스템학회 2018 한국산업경영시스템학회지 Vol.41 No.3

Modern manufacturing industries is to produce both precise and robust mechanical parts without failure while they are in service. In order to prevent a part failure for its lifetime, a mechanical design for a part should be examined on a basis of mechanical simulation. A nozzle plate, being a key part in steam engines, changes flow directions of steam in a turbine used in power plant. This paper is to the design and test for part safety and durability. Currently, nozzle plates are fabricated by welding nozzles to their plates. Welding causes some defects on the used materials while they are being manufactured. Another major defect is un-even pitches between welded nozzles. Welding causes phase changes because of high melting temperature of metal. This leads to decay on the welding spots, which weakens their structural strength and then, may lead to early damages on mechanical structures. This research proposes assembly-typed nozzle plate without welding. From the beginning, nozzle and plate are designed for insertion-typed assembly. Nozzle head and foot are designed in accordance with the grooves on outer ring and inner ring of a plate to make mating surfaces. Then the nozzle plate should be proved for structural and fatigue safety before they are put in manufacturing. This research adopts commercial softwares for modeling and mechanical simulation. The test result shows that the design with smaller mating area and deeper insertion produces higher safety in terms of structure and durability. From the conclusion, this paper proposes the assembly-typed nozzle plate to replace the welding typed.

회수용 포장용기의 설계 및 해석

정종윤 ( Jong Yun Jung ),이동포 ( Dong Po Lee ),김지관 ( Jie Kwan Kim ),박철순 ( Chul Soon Park ) 대한설비관리학회 2012 대한설비관리학회지 Vol.17 No.2

Packing containers for heavy weighted goods are mainly made with wood, which causes a lot of cost to discard them. Wooden box is not suitable for retrieval because of high recycling cost. The material for packing containers is currently being replaced with plastic for retrieval and re-use. This paper presents for design and analysis of a plastic container which is both foldable and multistage type. The container is designed with box form and its details are modeled with CATIA. Once the dimension of the container has been determined, the structural analyses are accomplished to improve the structural safety. This research revised the design for the shape of container through the prototype that is manufactured by injection molding. Through the evaluation in view of structural safety and usability, the dimensions and shapes are slightly changed and modified. After all parts are assembled together in a modeling state, the container is analyzed to prove mechanical safety.

유한요소해석을 통한 리테이너의 설계 안전성 검증

정종윤 ( Jong-yun Jung ),김준섭 ( Joon-seob Kim ) 대한설비관리학회 2020 대한설비관리학회지 Vol.25 No.4

Process driving turbines have been used for a long time in high-temperature and high-pressure environments and are placed in poor environmental conditions, so the stability of the design to prevent deformation or damage is very important. The retainer, which is a core part of the turbine, rotates under steam pressure of high temperature and high pressure, so safety against deformation and damage due to vibration must be ensured. Therefore, safety verification after design is an essential process in turbine design. The purpose of this study is to verify the stability of the process retainer design by finite element analysis. There may be several methods for verifying the stability of a machine, but as machine parts become more complex and diversified, the finite element method is increasingly used. For stability verification, after verifying the deformation and damage of the part by static analysis, the possibility of fatigue failure was checked through the fatigue safety factor and fatigue life through fatigue analysis. In order to verify the safety of the rotating retainer, the possibility of occurrence of resonance according to the natural frequency was confirmed, and total deformation was confirmed through a harmonic response. Through this series of processes, it was verified that the designed retainer, the subject of this research, is safe.

사용자 중심의 시나리오에 기반한 개인화 서비스 합성 및 제공 시스템

정종윤(Jong-yun Jung),류기열(Ki-yeol Ryu),노병희(Byeong-hee Roh) 한국정보과학회 2009 정보과학회 컴퓨팅의 실제 논문지 Vol.15 No.9

유비쿼터스 환경에서 사용자의 상황에 부합하는 서비스를 제공하기 위해 기존의 서비스를 합성 하여 새로운 서비스를 제공하는 방안에 대한 연구가 점점 증가하고 있다. 그러나 다수의 사용자들이 존재하는 서비스 공간에서 사용자에게 개인화된 서비스를 제공하는 것은 매우 어려운 일이다. 본 논문은 사용자 중심의 서비스 시나리오에 기반한 서비스 합성 모델을 제안하고 사용자의 상황에 필요한 서비스를 동적으로 발견하고 결합하여 개인화된 서비스를 제공하는 시스템을 제안한다. 이 시스템은 유비쿼터스 공간에 존재하는 이질적이고 제한된 자원을 가지는 다양한 스마트 객체들로부터 필요한 서비스를 찾기 위한 서비스 발견 프로토콜을 지원한다. 또한 제안된 시스템은 사용자로부터 파생되는 다양한 서비스 시나리오와 정보의 저장소 및 사용자에게 필요한 서비스 실행기로서의 역할을 수행한다. 본 논문에서는 제안한 시스템을 검증하기 위하여 휴대용 단말기를 위한 프로토타입 시스템을 구현한다. To deliver services suitable to user's situation in the ubiquitous environment, the researches on realizing new services by combining existing ones have been continuously increased. But, it is difficult to provide the personalized services to each user located in the ubiquitous service space where multiple users coexist. In this paper, we propose a service composition model based on user-centered service scenarios and a system for providing personalized services through finding services suitable to user's situation and combining them. The proposed system supports a simple service discovery protocol for finding services from heterogeneous smart objects with limited computing power in the ubiquitous environment. The system aggregates and stores various service scenarios and data derived from users and executes the appropriate services for users. We design and implement a prototype system for the mobile personal device.

MQL 가공에서 기계가공면의 표면 품위 향상

정종윤(Jong-Yun Jung),조형찬(Hyung-Chan Cho),이춘만(Choon-Man Lee) 한국산업경영시스템학회 2007 한국산업경영시스템학회지 Vol.30 No.3

Machining processes produce high accurate metallic parts in metal working industries. Lubrication for machining enhances quality of machined surface and it prolongs the life of cutting tools. Since lubricant is poisonous to human body and environment, it causes occupational diseases for workers and air pollution in environment. Because of these problems generated, developed countries do not permit the excessive usage of lubricant in machining shops. This research focuses on the development of MQL machining technique that consumes minimal amount of lubricant, which reduces possible outbreak of occupational diseases and air pollution. This research sets experimental equipments for MQL machining. Experiments for this study are designed with major machining parameters in MQL. Through the analysis of experiments, this paper presents the optimal machining parameters.

FEM 시뮬레이션을 이용한 임펠러의 구조 안전성 평가

정종윤(Jong Yun Jung) 한국산업경영시스템학회 2020 한국산업경영시스템학회지 Vol.43 No.4

As modern industries are highly being developed, it is required that mechanical parts have to be manufactured with a high precision. In order to have precise parts, error-free designs have to be done before manufacturing with accuracy. For this intention being fulfilled, a mechanical analysis is essential for design proof. Nowadays, FEM simulation is a popular tool for verifying a machine design. In this paper, an impeller, being utilized in a compressor or an oil mixer as an actuator, is studied for an evaluation. The purpose of this study is to present a safety of an impeller for a proof of its mechanical stability. A static analysis for stress, strain, and deformation within a regular usage is examined. This simulation test shows 357.26×106 Pa for maximum equivalent stress and 0.207mm for total deformation. A fatigue test is carried to provide durability and its result shows that minimum safety factor is 3.2889, which guarantees that it runs without a fatigue failure in 106 cycles. The natural frequencies for the impeller is ranged from 228.09Hz to 1,253.6Hz for the 1st to the 6th mode. Total deformations at these natural frequencies are shown from 6.84mm to 12.631mm. Furthermore, Campbell diagram reveals that a critical speed is not found throughout regular rotational speeds. From the test results for the analysis, this paper concludes that the suggested impeller is proved for its mechanical safety and good to utilize at industries.

곡면 Fitting을 이용한 고속가공 표면거칠기의 최소화

정종윤(Jong-Yun Jung),조혜영(Hea-Young Cho),이춘만(Choon-Man Lee),문덕희(Dug-Hee Moon) 한국산업경영시스템학회 2004 한국산업경영시스템학회지 Vol.27 No.2

High speed machining is a machining process which cuts materials with the fast movement and rotation of a spindle in a machine tool. It reduces machining time because of the high feed and the high speed of a spindle. In addition it gets rid of post processes for high precision machining. When the high speed machining is applied to especially hardened steel, operators should select the proper parameters of machining. This can produce machining surfaces which is qualified with good surface roughness. This paper presents a method for selecting machining parameters to minimize surface roughness with high speed machining in cutting the hardened steels. Experimental data for surface roughness are collected in a machining shop based on the cutting feed and the spindle rotation. The data fits in bi-cubic polynomial surface of mathematical form. From the model this research minimize the surface roughness to find the optimal values of the feed and the spindle speed. This paper presents a program which automatically generates optimal solutions from the raw data of experiments.

프로펠러 블레이드의 형상설계 및 CNC 공구경로 생성

정종윤(Jong-Yun Jung) Korean Society for Precision Engineering 1998 한국정밀공학회지 Vol.15 No.8

육안검사 시편개발에 관한 연구

정종윤(Jong-Yun Jung),황영수(Young-Su Hwang),이춘만(Choon-Man Lee),문덕희(Dug-Hee Moon) 한국산업경영시스템학회 2004 한국산업경영시스템학회지 Vol.27 No.2

High-speed machining is one of the most effective technologies to improve productivity. Because of the high speed and high feed rate, high-speed machining can give great advantages for the machining of dies and molds. High speed machine tool makers try to find best machining condition with the one that they have built. Machine builders need to develop test specimen since it helps finding characteristics of machine tools when the machining properties of the specimen are analyzed. This paper develops test specimen to identify features of the main spindle, the feeding device, and the frame of a machine tool.