통합 검색 | Korea Science

오세규;장지훈;전태언;박형동;유인종
- 대한용접접합학회:학술대회논문집
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- 대한용접접합학회 1995년도 특별강연 및 춘계학술발표 개요집
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- pp.118-122
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- 1995
The hydraulic or pneumatic valve spools become essential as the important components on the production of automatic hydraulic or pneumatic machinaries as mechanical industry is developed rapidly. The machining precision is asked for manufacturing the valve spools. They could be unstable in the quality by the conventional arc welding and they have a lot of technical problems in manufacturing because their shapes are generally small. By the Precision casting process such as lost wax process, the production cost will be increased. But by the friction welding technique, they will be able to be made without such problems. Furthermore, there is a few study on friction welding of such hydraulic valve spool steels and in-process real-time weld quality evaluation technique by acoustic emission. So that, the final purpose of this study is 1) the development of design and manufacturing technique of hydraulic or pneumatic valve spool by optimizing of friction welding, and 2) the development of in-process real-time weld quality evaluation technique by acoustic emission.
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문영대
- Design & Manufacturing
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- 제9권2호
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- pp.10-15
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- 2015
The water has been the suitable for the cooling medium until now. But the water as cooling medium seem to have the limit for high speed injection. The steam plastic molding injection use the steam as the medium when raise the mold temperature. The weld line has been the major quality problems in a plastic injection parts to be difficult to be solved. These problems in injection-molded plastic parts are difficult to find the reason because these issues are usually in tradeoff realtions with each other. The purpose of this paper is to obtain the optimum injection moulding condition for improving the quality of plastic injection parts and to inquire the productivity improvement with the measured cycle time by steam plastic moluding injection. Based on these numerical results, the guidelines of mould design and injection processing condition were established. As a result, the improvement of quality and the reduction of cycle time was achieved.
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조용준;이세헌;신현일;배경민
- Journal of Welding and Joining
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- 제17권2호
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- pp.97-103
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- 1999
The dynamic resistance monitoring in primary circuit is one of the important issues. Because in-process and real time quality assurance of resistance spot weld is needed to increase the product reliability. In this study, new dynamic resistance detecting method is proposed as a practical manner of weld quality assurance using instantaneous current and voltage measured at the primary circuit. and also, various patterns of primary dynamic resistance curve are characterized with the macro photograph and the weldability lobe curve. It is found that the primary dynamic resistance patterns are basically similar to those of the secondary, but there is evident advantage such as no extra devices are needed to obtain the quality information and eventually real time feedback control will be possible.
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곽윤상;이종호;박준홍
- 한국음향학회지
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- 제38권3호
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- pp.334-339
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- 2019
차량 점용접 부위에서 BSR(Buzz, Squeak, Rattle) 소음 발생 가능성을 국부 진동을 사용하여 비파괴적으로 추정하는 진동기반 계측법을 제시한다. 용접부에 부착된 구조물에 의한 점용점 부위의 국부적인 진동을 유발하고 진동전달 특성을 파악한다. 관측된 진동 특성으로부터 국부 구조의 굽힘강성값을 도출하였다. 강성값의 변화로부터 점용접의 상태 강건성을 파악하였다. 제시되는 방법의 검증을 위해 부분적으로 용접품질이 변화된 시편을 제작하였다. 제작된 시편에서 계측된 진동 특성을 분석하였다. 용접 강건성에 의해 변화하는 특정 주파수 대역을 파악하였다. 구조별, 위치별 계측을 통해 제시된 방법으로 분별이 가능한지 검증하였다. 국부 진동 평가방법은 구조물의 용접 강건성을 생산 현장에서 파악하게 하는 평가방법으로써 BSR발생 가능성을 저감하기위한 생산 품질 확보에 사용될 수 있다.
https://doi.org/10.7776/ASK.2019.38.3.334 인용 PDF KSCI HTML