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이정호,전상운,이영호 한국항공우주학회 2014 한국항공우주학회 학술발표회 논문집 Vol.2014 No.11
유공압 엄빌리칼은 유공압 라인이 있는 플레이트와 파이로 밸브에 의해 구동되는 콜렛 메카니즘으로 구성된다. 플레이트는 타원형으로 설계하였으며 두 짝으로 구성되어 있다. 비행용 플레이트를 먼저 축정렬을 한 후 기체에 고정하고, 지상용 플레이트를 콜렛 메카니즘을 통해서 두 개의 플레이트가 결합된다. 분리는 콜렛로드가 파이로밸브의 구동에 의해서 콜렛으로부터 분리가 되고, 지상용 플레이트에 있는 분리 스프링에 의해서 두 개의 플레이트를 서로 밀어낸다. 본 논문은 한국항공우주연구원에서 수행한 한국형발사체용 축소형 유공압 엄빌리칼의 개발시험에 관한 것이다. The pnemo-hydraulic umbilical consists of plate with pnemo-hydraulic hole and collet mechanism actuated by pyro-valves. We designed a pneumo-hydraulic umbilical plates that have an ellipse type and compose of flight plate and ground plate. The first, flight plate is installed, aligned and locked at launch vehicle, and then ground plate is assembled by collet mechanism. Two plates are disassembled by operating of pyro valve that pulls collet rod out collet fingers. This paper presents design and test results of sub-scale umbilical plates performed at KARI for development of the KSLV-II.
양방향 회전형 사축식 유압 피스톤 펌프의 밸브 플레이드 형상이 토크 맥동에 주는 영향
김성훈(Sung-Hun Kim),홍예선(Yeh-Sun Hong),김두만(Doo-Man Kim) 한국항공우주학회 2007 韓國航空宇宙學會誌 Vol.35 No.3
EHA용 유압 펌프의 토크 맥동은 저속 회전 영역에서 실린더 위치의 제어에 외란으로 작용할 수 있다. 원칙적으로 피스톤 펌프에 의해 발생되는 반력 토크의 주기적인 변화는 실린더 압력의 파형과 밀접한 관계를 가지고 있다. 일정 속도로 회전하는 단방향 피스톤 펌프의 경우에는 밸브 플레이트의 예압각이나 노치를 활용하여 실린더 압력의 오버슈트나 변화율을 조절할 수 있다. 따라서 본 연구에서는 밸브 플레이트의 형상이 EHA용 사축식 유압 피스톤 펌프의 토크 맥동에 미치는 영향을 분석하였다. 그 결과로서, 양방향 회전형 유압 피스톤 펌프의 토크 맥동은 회전 속도의 영역에 무관하게 밸브 플레이트의 예압각이나 노치를 이용하여 개선하는 것이 불가능한 것으로 나타났다. The torque ripple of the hydraulic pumps for the Electro-hydrostatic Actuators can disturb the cylinder position control under slewing speed operation condition. In principle, the periodic change of the reaction torque generated by a piston type pump is highly dependent on the waveform of its cylinder chamber pressure. In case of uni-directional pumps operating at constant speed, the transient overshoot and rising slope of the cylinder pressure can be adjusted by the precompression angle and notch shape of their valve plates. Therefore, the influence of the valve plate geometry on the torque ripple magnitude of a bent-axis type piston pump for EHA application was investigated in this study. The results showed that any improvement of the torque ripple of such a bi-directional pump can not be achieved by modifying the valve plate geometry, regardless of its operation speed.
SimulationX<SUP>Ⓡ</SUP>를 이용한 가변 사판식 액셜 피스톤 펌프의 밸브플레이트 노치 최적화에 관한 연구
이산성(San Seong Lee),정원지(Won Jee Chung),임동재(Dong Jae Lim),차태형(Tae Hyung Cha),김수태(Soo Tae Kim),이정실(Jeong Sil Lee),최경신(Kyung Shin Choi) 한국기계가공학회 2018 한국기계가공학회지 Vol.17 No.4
Considering the shape of a valve plate in design is important for reducing the pulsation phenomenon, which is a negative factor in pump performance. The purpose of this study is to propose an optimized method for a valve-plate V-type notch of a piston pump by modeling and simulation. The method uses SimulationX<SUP>Ⓡ</SUP>, a commercial hydraulic analysis program, and to provide data for the designing of the notch. The opening areas are determined by performing kinematic analysis of the notch part where the opening area changes rapidly. After applying the result analysis, the main effects on maximum pressure pulsation and maximum backflow according to the notch design factors are analyzed by using the full factorial method of experimental design. The optimized solutions are derived for the notch design variables, based on the analyzed data.
최웅걸(Woongkirl Choi),전광호(Kwangho Chun),이은상(Eunsang Lee),조항덕(Hyangduck Cho),신시명(Simyeong Shin) 대한기계학회 2014 대한기계학회 춘추학술대회 Vol.2014 No.11
Boiler for thermal power generation are generally supplied air and fuel with air supply systems. And these air supply systems need flow contorl orifices to control air and fuel transfer path. The orifice plate is usually used to adjust the flow rate of air and fuel in thermal power generation. However, the orifice plate is difficult to control the air and fuel flow. Therefore, the orifice valve which can control the air and fuel flow is developed. It is widespread nowadays for thermal power generation, but the coal particles leak into the valve unit and gap which lead to a flow control failure. Spherical orifice which can overcome the shortcomings of orifice plate and orifice valve is designed and developed. In this study, computational fluid dynamics (CFD) analysis was carried out to clarify the flow characteristics of different types thermal power generation orifices with different opening and flow rates . Finally, we confirmed the spherical orifices advantages and usability relative to orifice plate and orifice valve.
양방향 구동 사판식 액시얼 피스톤 펌프의 밸브 플레이트 노치 설계에 관한 연구
최세령(Sae Ryung Choi),이일영(Ill Yeong Lee),한성민(Sung Min Han),신정우(Jung Woo Shin) 유공압건설기계학회 2016 드라이브·컨트롤 Vol.13 No.3
Flow and pressure ripple in swash plate type piston pumps is largely dependent on the design of notches(silencing grooves) in the valve plate. In uni-directional pumps, the basic design concept for notches in the valve plate could be said to be established. It is easily deduced that the design concept for notches in uni-directional pumps can not be simply applied to bi-directional pumps requested for EHA(electric hydrostatic actuators). To carry out systematic research on technological issues regarding notch applications to bi-directional piston pumps, five notch designs are devised. The effects of the notch designs on the characteristics of the pump are investigated by numerical simulations and experiments. Through this study, basic concepts about notch design for bi-directional piston pumps are suggested.
사판식 유압 피스톤 펌프의 실린더블록과 밸브 플레이트의 응력해석
김지홍(J. H. Kim),조인성(I. S. Cho),백일현(I. H. Baek),정재연(Jae-Youn Jung),오석형(Suk-Hyung Oh) 한국트라이볼로지학회 2004 한국트라이볼로지학회 학술대회 Vol.39 No.-
Recently, the technologies related to the swash plate type oil hydraulic piston pump are requiring extreme technologies to overcome the limit of high efficiency in cope with high speed and pressure, and are devoted to compact the unit, to gain low noise level, and to adopt electronic technologies, and the question regarding to maximize the mechanical efficiency, that is, to minimize the torque loss by minimizing the leakage loss in the relative sliding region but these are in trade-off relation that tribological responding is very difficult. Cylinder block-valve pate in high speed relative sliding motion has the characteristics that shoud be extremely controlled for the optimization of these leakage loss and mechanical efficiency, and pressure resistance designing of them is important for high pressure performance. But, studies on the stress analysis of these parts have not been performed briskly, so in this paper the stress distribution and the region where the highest displacement appears are described through the static stress analysis using CATIA V5. Through the future studies on these theme, it has the purpose of finding the suitable materials for the other parts as well as cylinder block and valve plate, in cope with high pressure operation through the stress analysis with the most similar conditions for the practical operation.
굴삭기용 선회 모터의 가속시 소음 진동 개선을 위한 밸브 플레이트의 설계에 관한 연구
이승현(S. H. Lee),진정만(J. M. Jin),소순재(S. J. So) 유공압건설기계학회 2016 유공압건설기계학회 학술대회논문집 Vol.2016 No.11
Flow and pressure ripple in swash plate type piston motors is largely dependent on the design of notches. The basic design concept for notches in the valve plate could be said to be established for the general solution of flow and pressure ripple In this paper, it was lead theoretical formular to identify the major parameters caused the vibration and noise in the time of accelerating operation for swing motor and proposed the method of solution by return hole in notch of valve plate. also the effect for design of return hole in notch is prooved through the bench test considered inertio load according to excavator operating condition.
자동차 부품 소재 개발에 따른 캐스팅 과정의 부품 내부온도 거동에 관한 연구
차용훈(Cha Young-Hoon),성백섭(Sung Back-Sub),장훈(Jang Hoon),김미애(Mi-ai kim),김정대(jung-Dae Kim),김선진(Sun-jun Kim),김덕중(Duck-joong Kim),이연신(Youn-sin Lee) 한국정밀공학회 2005 한국정밀공학회 학술발표대회 논문집 Vol.2005 No.10월
The casting defects that are caused by molten metal were cold shut formation, entrapment of air, gas, and inclusion. But the control of casting defects has been based on the experience of the foundry engineers. In this thesis, the computer simulation analyzed the flow of molten metal. The quantitative analyses which proposed the effective mold design was executed Flow patterns of 0.15-0.16m/s molten metal in 15 mm thin plate casting were investigated in order to optimize die-casting process. As increasing ingate velocity in thin plate casting, cold shot was decreased. The parameters of runner shape that affected on the optimized conditions that was calculated with simple equation were investigated. These die casting process control techniques of automobile valve body mid-plate have achieved good agreement with the experimental data of tensile strength, hardness test, and material structure photographies satisfactory results.
임태형(T. H. Lim),오병수(B. S. Oh),이홍선(H. S. Lee),양순용(S. Y. Yang) 한국정밀공학회 2006 한국정밀공학회 학술발표대회 논문집 Vol.2006 No.5월
The purpose of this paper is pulsation-analysis of the swash plate type axial piston pump for excavator and the method of side branch hose application, which is used normally in construction equipments. In this paper, draw the mathematical modeling for pressure pulsation mechanism of the swash plate type axial piston pump for excavator, expression the flow pulsation in the pipelines by transfer matrix method, programmed simulation for pulsation by AMEsim software, and the reliability of that was verified by the comparison with the experimental results.