• 한국산업융합학회 논문집
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• 제2권2호
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• pp.155-163
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• 1999

In this study, single cylinder engines with different tumble ratio were made to find out in-cylinder fluid motion and flame propagation. Tumble ratio derived from the steady state flow rig test. Flame propagation speed was obtained using cylinder head gasket ionization probe and the piston ionization probe. And the combustion pressure in cylinder was measured to analyze the combustion characteristics. In case of high tumble engine, BSFC and BSHC were decreased and BSNOx was increased at part load test. Also BMEP and combustion peak pressure was increased at full load test. Tumble flow motion had an great effects on initial burning period rather than main burning period in part load test.

• Fibers and Polymers
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• 제6권2호
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• pp.151-155
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• 2005

A twisting machine is to twist yarns for improving yam strength. After twisting yams, the twisting machine winds yams into a bobbin. The traverse mechanism is very important part of winding mechanism. Because it performs uniform winding onto the bobbin. the traverse cam is the main part of the traverse mechanism. This paper proposes design method of the traverse cam using the relative velocity method [4,5]. The relative velocity method is used to calculate the relative velocity of the follower versus the cam at the center of roller, and then to determine the contact point using the geometric relationship and kinematical constraints. Finally, we present examples verifying the accuracy of the proposed methods.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2004년도 ICEIC The International Conference on Electronics Informations and Communications
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• pp.87-91
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• 2004

This research presents distributed database and knowledge-base modeling approach for intelligent product design system. The product design information in this study is described by a collection of rules and design knowledge that are utilized according to the product development procedures. In this work, a network-based architecture has been developed to enable dispersed designers to simultaneously accomplish remote design tasks. A client/server communication diagram has also been proposed to facilitate consistent primary information modeling for multi-user access and reuse of designed results. An intelligent product design system has been studied with the concepts of distributed database and network-based architecture in order to support concurrent engineering design and automatic design part assembly. The system provides the capability of composing new designs from proper design elements stored in the database and knowledge-base. The distributed intelligent product design is applied to the design of an automobile part as an example.

• 한국안전학회지
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• 제24권6호
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• pp.150-156
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• 2009

The oil pressure switch(OPS) for automobile is very important part to prevent an overheated engine and other problems by checking the operation of an engine oil system and displaying oil signs on a dashboard. OPS is the part that receives various stress caused by temperature, vibration, and corrosion in an engine room. Regarding existing steel OPS cases, there occur field errors due to the rust, and much concern comes from the low anticorrosion caused by CR6+ Free according to the restrictions of heavy metals. Therefore, the study analyzed average life, the failure rate, and reliability through the tests of performance according to temperature changes, mechanical strength, and run-test in order to confirm if the use of the oil pressure switch with Al of anti-corrosion can improves the reliability, instead of the existing steel products.

• 한국공작기계학회논문집
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• 제14권6호
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• pp.68-73
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• 2005

Tire manufactures have dealt with noise problem by varying the pitch of the tread. The various formulas for the variations are generally determined differently, however. Often these variations are based on a combination of trial and error, intuition, and economics. Some manufactures have models and analogs to test tread patterns and their variations. These efforts, however practical, do not determine the best variation beforehand or guarantee the best results. For this reason it was felt that a general mathematical approach fur determining the best variation was needed. Moreover, the method should be completely general, easy to use, and sufficiently accurate. This paper discusses a mathematical method called Mechanical Frequency Modulation(MFM) which meets the above requirements. Thus, MFM pertains to computing an irregular time sequence of events so that the resulting excitation spectrum is shaped to a preferred form. The first part of this paper treats the theoretical basis for computing an optimum variation ; the second part discusses experimental results and simulation program which corroborate the theory.

• 한국생산제조학회지
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• 제21권1호
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• pp.21-25
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• 2012

In this study, the safest model can be selected by the simulation result of structural safety analysis according to the shape of impact bar affected at side door of automobile. The open sectional model of semicircle type has the lowest deformation and stress among 4 kinds of models. As the weight of this model has 30% in comparison with other models, it becomes most economical and stable. As the open sectional model of cap type the highest deformation and stress among 4 kinds of models, it becomes weakest. The closed models with circular and rectangular types has the stress far lower than cap type. The maximum deformation is shown at the center part of impact bar but the maximum stress occurs at the joint part between impact bar and frame.

• 산업경영시스템학회지
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• 제38권1호
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• pp.110-117
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• 2015

Spare part management is very important to products that have large number of parts and long lifecycle such as automobile and aircraft. Supply chain must support immediate procurement for repair. However, it is not easy to handle spare parts efficiently due to huge stock keeping units. Qualified forecasting is the basis for the supply chain to achieve the goal. In this paper, we propose an agent based modeling approach that can deal with various factors simultaneously without mathematical modeling. Simulation results show that the proposed method is reasonable to describe demand generation process, and consequently, to forecast demand of spare parts in long-term perspective.

• 한국생산제조학회지
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• 제21권6호
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• pp.1018-1023
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• 2012

In order to substitute and recycle the existing automobile parts for GMT-sheet, researches on the effects of GMT-sheet on the establishment of precise joining strength, joining condition that are lap length of joining part, compression ratio, and closure speed must be carried out but until now. Besides, many researches on adhesion joint had been conducted until now but no systematic research on press lap joint of GMT-sheet has been implemented until recently and the reliability of joining strength is not yet established. In press lap joining molding of GMT-sheet, tensile stress and lap joining connection efficiency was increased according to the increase of lap length L. However, as the increase of compression ratio and fiber content ratio per unit area was higher in tensile test, it has caused the deterioration of lap joining efficiency after joining molding of GMT-sheet. Clarify joining strength and lap joining efficiency during high temperature compression press lap joining molding of GMT-sheet and research data regarding to the lap length of joining part was presented. The purpose of this study is to contribute to the substitution of existing products as well as usage development in non-automobile field and also to find out precise dynamic characteristics as designing data of structures.

• 대한기계학회논문집A
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• 제37권3호
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• pp.339-344
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• 2013

보론강을 사용하는 열간성형은 경량화된 자동차 차체부품의 생산을 위해서 최근에 널리 사용되고 있으며, 열간성형 후 약 1,500 MPa 정도의 고강도 특성을 얻을 수 있다. 그러나 열간성형이 현가부품에 사용되기 위해서는 고강도 특성보다 피로특성이 더 중요해진다. 따라서, 본 연구에서는 열간성형에 의해 제작된 자동차 현가부품의 일종인 튜블러 토션빔 액슬의 피로특성에 대하여 연구하였다. 냉각방식에 따른 보론강의 저주기 피로특성에 대하여 연구하였으며, 튜블러 토션빔 액슬의 피로수명을 예측하기 위해서 구조 및 피로해석이 수행되었다. 튜블러 토션빔 액슬의 토션빔 영역에서 응력집중이 발생하였으며, 열간성형에 의한 고강도화가 튜블러 토션빔 액슬의 수명향상에 큰 영향을 미쳤다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 춘계학술대회논문집
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• pp.309-313
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• 2006

Many researchers have studied on the lightness of automobile. These researches are such as a body shell, sub frame, fuel tank, engine etc. The transmission Part is a magnitude one in the aspect of weight. A drive shaft (propeller shaft) transmits the engine power to rear differential gear assembly. It is used in the compact car that is a single drive shaft. But in the case of long body cars such as SUV (Sports Utility Vehicle), truck and large vehicle, two or three divided drive shaft are used to prevent the vibration damage from a drive shaft that has been taken high torsion and rotation. This multi-divided drive shaft structure is so heavy because it is assembled by yoke, center bearing and solid spline axis. When the rear axle move up and down, the spline shaft adjust the variation of a length between the transmission and rear axle gearbox. In this paper, it is studied in the experimental method that is a bending vibration characteristic of slip in tube shaped propeller shaft. This type propeller shaft is developed to combine the spline axis with drive shaft and can be light in weight of transmission part.