• 소성∙가공
• /
• 제18권8호
• /
• pp.607-616
• /
• 2009

There are three sub-processes associated with the assembly of the valve seat and cylinder head; heat fitting, cold fitting, and shrink fitting. In the heat fitting stage, the cylinder head is heated to a specified temperature and then squeezed toward the outer diameter of the valve seat. The cold fitting process cools the valve seat and safely squeezes it toward the inner diameter of cylinder head. However, these methods increased the installations & running cost and curtailed productivity. To address these problems, we analyzed the shrink fitting process using the contact pressure caused by fitting interference between the outer diameter of the valve seat and the inner diameter of the cylinder head. In this study, a closed form equation for predicting the contact pressure and fitting load is proposed. For quality control of the assembly line, principal factors of the shrink fitting process influenced in contact pressure were simulated by the FEM. Actual loads measured in the field showed good agreement with the results obtained by theoretical and finite element analysis.

• Elastomers and Composites
• /
• 제54권2호
• /
• pp.123-127
• /
• 2019

Shrink film is currently being used for plastic container lavels to avoid the use of glue. Polyethylene terephthalate (PET) bottle lavels also use shrink films in the same PET materials for easy recycling of PET bottles. An air layer is generated between the shrink film and PET bottle surface due to the bent shape of the bottle surface. This air layer can insulate external heat, as air has a relatively lower thermal conductivity. In this study, the insulation property of the air layer was examined by computer simulation. Two PET bottle models were used, one with and the other without an air layer between the PET bottle surface and lavel. The two bottle models were filled with cold liquid and exposed to room temperature for 6 h, and the temperatures of the contents were then compared. The results showed that the temperature of the contents in the bottle with the air layer was lower than that without the air layer by at least $2^{\circ}C$. This study suggests an effective lavel design of PET bottles while ensuring that the temperature of the bottle contents is maintained.

• 한국시뮬레이션학회논문지
• /
• 제19권4호
• /
• pp.21-29
• /
• 2010

본 연구는 시뮬레이션 방법을 이용한 자동차용 열 수축 튜브 생산 공정을 가상의 생산 공정 모델로 구현하고, 구현된 모델을 기반으로 열 수축 튜브 생산 공정을 분석하는 연구이다. 자동차용 열 수축 튜브 생산 공정을 분석하기 위해서 공정별로 생성되는 데이터를 수집하고, 수집된 데이터 분석을 통한 자동차용 열 수축 튜브 생산 공정을 분석할 수 있는 가상의 생산 공정 모델을 구현하였다. 구현된 모델을 통해 공정 내에서 발생되는 병목현상 파악 및 원인분석, 공정별 사이클 타임, 부품 생산량 등을 산정함으로써 현 공정 분석 및 개선방안을 모색할 수 있어 기업의 생산 공정관리 효율성을 높일 수 있다.

• International Journal of Automotive Technology
• /
• 제7권7호
• /
• pp.847-852
• /
• 2006

A fitting process carried out in the automobile transmission assembly line is classified into three classes; heat fitting, press fitting, and their combined fitting. Heat fitting is a method that applies heat in the outer diameter of a gear to a suitable range under the tempering temperature and assembles the gear and the shaft made larger than the inner radius of the gear. Its stress depends on the yield strength of a gear. Press fitting is a method that generally squeezes gear toward that of a shaft at room temperature by a press. Another method heats warmly gear and safely squeezes it toward that of a shaft. A warm shrink fitting process for an automobile transmission part is now gradually increased, but the parts (shaft/gear) assembled by the process produced dimensional change in both outer diameter and profile of the gear so that it may cause noise and vibration between gears. In order to solve these problems, we need an analysis of a warm shrink fitting process in which design parameters such as contact pressure according to fitting interference between outer diameter of a shaft and inner diameter of a gear, fitting temperature, and profile tolerance of gear are involved. In this study, an closed form equation to predict the contact pressure and fitting load was proposed in order to develop an optimization technique of a warm shrink fitting process and verified its reliability through the experimental results measured in the field and FEM, thermal-structural coupled field analysis. Actual loads measured in the field have a good agreement with the results obtained from theoretical and finite element analysis and also the expanded amounts of the outer diameters of the gears have a good agreement with the results.

• 한국정보과학회논문지:시스템및이론
• /
• 제31권10호
• /
• pp.593-602
• /
• 2004

정렬되지 않은 3차원 측정점들로부터 이들을 근사하는 표면을 재구성하는 방법을 제안하였다. 제안된 방법은 경계면 축소포장 방식에 의한 표면 재구성 방법(shrink-wrapped boundary face： SWBF) 으로, 측정점으로부터 경계셀과 경계면을 구해 초기 메쉬를 생성하고 이를 연속적으로 축소하는 방식에 의해 표면을 재구성한다. 제안된 방법은 기존의 표면 축소포장 방식의 메쉬 생성 방법의 문제점인 물체의 토폴로지에 대한 제약이 없이 어떠한 형태의 표면 재구성에도 적용이 가능하며, 기존 방법이 축소 단계에서 각 메쉬 정점에 대한 최단거리 측정점을 찾는 전역 탐색을 해야 하는데 비해 지역 탐색만으로 최적의 측정점을 찾을 수 있으므로 처리 시간 측면에서도 우월하다. 실험을 통해 제안된 표면 재구성 알고리즘이 측정점들간의 관계를 알 수 없는 정렬되지 않은 3차원 점들에 대한 표면 재구성에 매우 안정적이고 효과적임을 확인할 수 있었다.

• 한국정밀공학회지
• /
• 제23권9호
• /
• pp.54-60
• /
• 2006

Fitting process carried out in automobile transmission assembly line is classified into three classes; heat fitting, press fitting, and their combined fitting. Heat fitting is a method that heats gear to a suitable range under the tempering temperature and squeezes it toward the outer diameter of shaft. Its stress depends on the yield strength of gear. Press fitting is a method that generally squeezes gear toward that of shaft at room temperature by press. Another method heats warmly gear and safely squeezes it toward that of shaft. Warm shrink fitting process for automobile transmission part is now gradually increased, but the parts (shaft/gear) assembled by this process produced dimensional changes of gear profile in both radial and circumferential directions. So that it may cause noise and vibration between gears. In order to solve these problems, we need an analysis of warm shrink fitting process, in which design parameters are involved; contact pressure according to fitting interference between outer diameter of shaft and inner diameter of gear, fitting temperature, and profile tolerance of gear. In this study, an closed form equation to predict contact pressure and fitting load was proposed in order to develop optimization technique of warm shrink fitting process and verified its reliability through the experimental results measured in the field and FEM, that is, thermal-structural coupled field analysis. Actual loads measured in the field have a good agreement with the results obtained by theoretical and finite element analysis and also the expanded amounts of the gear profile in both radial and circumferential directions are within the limit tolerances used in the field.

• 한국정밀공학회지
• /
• 제23권5호
• /
• pp.37-43
• /
• 2006

Fitting process carried out in automobile transmission assembly line is classified into three classes; heat fitting, press fitting, and their combined fitting. Heat fitting is a method that heats gear to a suitable range under the tempering temperature and squeezes it toward the outer diameter of shaft. Its stress depends on the yield strength of gear. Press fitting is a method that generally squeezes gear toward that of shaft at room temperature by press. Another method heats warmly gear and safely squeezes it toward that of shaft. Warm shrink fitting process for automobile transmission part is now gradually increased, but the parts (shaft/gear) assembled by this process produced dimensional change in both outer diameter and profile of the gear. So that it may cause noise and vibration between gears. In order to solve these problems, we need an analysis of warm shrink fitting process, in which design parameters are involved; contact pressure according to fitting interference between outer diameter of shaft and inner diameter of gear, fitting temperature, and profile tolerance of gear. In this study, an closed form equation to predict contact pressure and fitting load was proposed in order to develop optimization technique of warm shrink fitting process and verified its reliability through the experimental results measured in the field and FEM, that is, thermal-structural coupled field analysis. Actual loads measured in the field have a good agreement with the results obtained by theoretical and finite element analysis and also the expanded amounts of the outer diameters of the gears have a good agreement with results.

• 정보처리학회논문지A
• /
• 제14A권3호
• /
• pp.133-140
• /
• 2007

SWBF(shrink-wrapped boundary face) 알고리즘은 조직되지 않은 3차원 측정점으로부터 표면을 재구성하기 위해 최근에 제안된 방법이다. 본 논문에서는 SWBF 알고리즘의 표면 중복문제를 제기하고, 이를 해결하기 위한 개선된 표면 재구성 방법을 제안한다. 제안된 방법은 경계셀이 아닌 모든 셀들을 내부셀과 외부셀로 구분하고, 개선된 경계면의 정의를 이용해 초기메쉬에서 표면의 중복이 발생하지 않도록 하였다. 또한, 측정 방향에 따라 표면 샘플링의 조밀도가 차이가 나는 일반적인 3차원 스캐너로부터 추출된 데이터의 처리를 위해 셀 영상에서 2차원 연결성을 정의하여 사용하였다. 실험을 통해 제안된 방법이 SWBF 알고리즘의 표면중복문제를 극복하는데 매우 유용함을 알 수 있었다.

• 한국정밀공학회지
• /
• 제25권6호
• /
• pp.47-54
• /
• 2008

Fitting process carried out in the automobile transmission assembly line is classified into three classes; heat fitting, press fitting, and their combined fitting. Heat fitting is a method that heats gear to a suitable range under the tempering temperature and squeezes it toward the outer diameter of shaft. Its stress depends on the yield strength of gear. Press fitting is a method that generally squeezes gear toward that of shaft at room temperature by a press. Another method heats warmly gear and safely squeezes it toward that of shaft. Warm shrink fitting process for the automobile transmission part is now gradually increased, but the parts (shaft/gear) assembled by this process produced dimensional changes in both the outer diameter and profile of the gear. So that it may cause noise and vibration between gears. In order to solve these problems, we need an analysis of warm shrink fitting process, in which design parameters are involved; contact pressure according to fitting interference between outer diameter of shaft and inner diameter of gear, fitting temperature, and profile tolerance of gear. In this study, an closed form equation to predict contact pressure and fitting load was proposed in order to develop an optimization technique of the warm shrink fitting process and verified its reliability through the experimental results measured in the field and FEM, that is, thermal-structural coupled field analysis. Actual loads measured in the field was in good agreements with the results obtained by the theoretical and finite element analysis.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2003년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
• /
• pp.57-59
• /
• 2003

Shrink fitting is often used to constrain a conventional mechanical fasteners and fastening methods with temperature difference. Localized heating of the mating surface provides temporary expansion and allows slip fit assembly. The resulting interference fit exhibits exceptional strength without surface deformation at ambient temperatures. We studied an analysing method to find out a deformation of motor axis as variation of constrained method with shrink fitting.