http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
쇼트피닝가공한 평기어의 최적 피닝강도 탐색에 관한 연구
이동선(Dong-Sun Lee),이국진(Kook-Jin Lee),김태형(Tae-Hyung Kim),정성균(Seong-Kyun Cheong) 한국생산제조학회 2005 한국생산제조시스템학회 학술발표대회 논문집 Vol.2005 No.5
The shot peening process is often used to improve fatigue properties of metal parts. Among them, It is the most use in an auto-component. In order to achieve optimum, repeatable and reliable fatigue enhancement from the shot peening process, the important shot peening parameters must be controlled. In this paper, the optimum peening intensity (Almen intensity) condition is investigated by experiment. The Spur Gear steel was used to investigate shot peening effects. The fatigue life at σ<SUB>a</SUB>=1,050 and σ<SUB>a</SUB>=1,250㎫ first gently increases, then drops gently as peening intensity increases compared with unpeened specimen. Experimental results show that the optimum peening intensity range is 0.391-Q.434㎜A..So the fatigue strength and fatigue life have been tremendously increased by optimum-peening treatment. However, the fatigue strength and fatigue life have been decreased by over peeing.
이동선(Dong-sun Lee),이국진(Kook-jin Lee),이태근(Tae-keun Lee),정성균(Seong-kyun Cheong) 한국자동차공학회 2005 한국자동차공학회 춘 추계 학술대회 논문집 Vol.2005 No.11_3
As the industrial society develops rapidly, weight reduction and High Strength are demanded gradually. In case of the gear which receives the repeat load, it does a Carburized control generally and it improves the material Strength. But if it applies the technique which is shot peening, it will be able to improve the durability and the fatigue characteristic of material because the hardness and the residual stress of the surface are on the increase. As the condition of shot peening, there is a great difference in fatigue life. Accordingly, this study investigated material characteristic and cause which it follows in condition of peening. In this study, we detect the optimal peening condition and hardness, roughness, and evaluate reliability.
쇼트피닝에 의한 자동차용 기어소재의 마모특성에 관한 연구
이동선(Dong-Sun Lee),이국진(Kook-Jin Lee),김태형(Tae-Hyung Kim),정성균(Seong-Kyun Cheong) 한국자동차공학회 2005 한국자동차공학회 춘 추계 학술대회 논문집 Vol.2005 No.11_3
This paper investigates the characteristics of friction and wear of shot peened gear material. Material is SCM920H. Four types of specimen(0,4,8,12min) were used to get experimental result and impeller's velocity is 1400rpm. According to the wear velocity, we investigate the friction and wear volume. Relative specimen was used the same material and, TE77(PLINT) friction and wear tester was used to obtain the experimental data under 300N and 2, 3, 4, 5㎐. The experimental results show that the shot peened specimens are effective for characteristics of friction and wear.
응력 집중을 갖는 기어의 피로수명 향상을 위한 최적 피닝강도 탐색
이동선(Dong-Sun Lee),이국진(Kook-Jin Lee),김태형(Tae-Hyung Kim),황재희(Jae-Hee Hwang),이재헌(Jae-Heon Lee),정성균(Seong-Kyun Cheong) 대한기계학회 2005 대한기계학회 춘추학술대회 Vol.2005 No.11
As the industrial society develops rapidly, weight reduction and high strength are demanded gradually. In case of the gear which receives the repeat load, it does a carburized control generally and it improves the material strength. But if it applies the technique which is shot peening, it will be able to improve the durability and the fatigue characteristic of material because the hardness and the residual stress of the surface are on the increase. As the condition of shot peening, there is a great difference in fatigue life. Accordingly, this study investigated material characteristic and cause which it follows in condition of peening. In this study, we detect the optimal peening condition and hardness, roughness, and evaluate reliability.
남지헌(Ji-Hun Nam),구대림(Dae-Lim Kou),이국진(Kook-Jin Lee),이동선(Dong-Sun Lee),정성균(Seong-Kyun Cheong) 한국철도학회 2004 한국철도학회 학술발표대회논문집 Vol.- No.-
Corrosion highly affects to reduce lifetime and performance of machinery metallic components. The effects of shot peening on the fatigue life of metal material under corrosive environment are investigated in this paper. Experimental results show that the fatigue limit of shot peened specimen increases about 52%. That means the fatigue life of metallic components is highly extended by shot peening. The corrosion greatly reduces the fatigue strength depending on the corrosive condition from one week up to one year. In case of shot peened specimen, the corrosion does not reduce the fatigue strength and fatigue life up to six months. It means that shot peening has superior effectiveness to reduce the influence of corrosion to the metallic materials.
쇼트피닝 가공에 의한 자동차용 Drive Plate의 내구성 향상
이국진,이동선,이재헌,정성균 한국공작기계학회 2005 한국공작기계학회 춘계학술대회논문집 Vol.2005 No.-
The effects of shot peening on the fatigue strength of SK-5M steel is investigated by experiment. The shot peening process is investigated optimum peening condition by changing impeller speed and exposure time. Bending fatigue test is accomplished to investigate the effect of optimum peening condition on the fatigue characteristics. As exposure time is increased, fatigue life in high stress is increased in early stage, become the maximum from 60 to 100 seconds, and then is decreased. Observing fracture surface through SEM after fatigue test, we can see clear configuration of cracks and peening layer.
쇼트피닝가공한 평기어의 최적 피닝강도 탐색에 관한 연구
이동선,이국진,김태형,정성균 한국공작기계학회 2005 한국공작기계학회 춘계학술대회논문집 Vol.2005 No.-
The shot peening process is often used to improve fatigue properties of metal parts. Among them, It is the most use in an auto-component. In order to achieve optimum, repeatable and reliable fatigue enhancement from the shot peening process, the important shot peening parameters must be controlled. In this paper, the optimum peening intensity (Almen intensity) condition is investigated by experiment..The Spur Gear steel was used to investigate shot peening effects. The fatigue life at σ_(a)=1,050 and σ_(a)=1,250MPa first gently increases, then drops gently as peening intensity increases compared with unpeened specimen. Experimental results show that the optimum peening intensity range is 0.391~0.434mmA..So the fatigue strength and fatigue life have been tremendously increased by optimum-peening treatment. However, the fatigue strength and fatigue life have been decreased by over peeing.
昆蟲의 精子形成에 關한 電子 顯微鏡的觀察 : 방아개비(Acrida lata Matschulsky)에 對하여 On the Acrida lata Matschulsky
安永弼,李國震 慶北大學校 1963 論文集 Vol.7 No.2
The perparation on which the present study is based were made from Insects (Acrida lata Matschulsky) testis that were immersed in a solution of 1 percent osmium tetroxide buffered at P.H.7.4 with veronal acetate buffer for 4 hours. Dehydrated, embedded in n-butyl metha-crylate and sectioned by Hitachi UM-2 type ultramivrotome at thickness ranging between 200-300AU. And observe Hitachi HM-3 type electon microsope. 1. The nucleus is trasformed into the spermhead. The nucleus of the spermtid is spherical in the early starly of metamorphosis but later it becomes ellipsoid and then more and more elongated until it is a long slender rod, concurrently with these changed of the nucleus, remarkable changes occur in the fine structure of the karyoplasm. 2. The exact process of formation of axial filaments and their sheath had been traced, the former being derived from th centrosome, the latter from the mitochondria and lipoid droplets. 3. The axial fiber of spermatozoa under development is composed of nine filaments arranged in a ring shape around a two filaments which were placed in the middle. 4. The mitochonpria in the germ cells are variable in size and location during spermiogenesis. 5. The authors found the group motion fo spermatozoa as in the mause and guinea pig.