• 제목/요약/키워드: Pressure Valve

검색결과 1,780건 처리시간 0.033초

비례감압밸브의 압력제어특성 (Pressure Control Characteristics of Proportional Pressure Reducing Valve)

  • 윤소남;함영복;조정대
    • 동력기계공학회지
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    • 제7권1호
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    • pp.68-73
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    • 2003
  • The purpose of this study is to develop a new proportional pressure reducing valve and to verify the validity of a new mechanism with pressure control pin. The dynamic characteristics of the object pressure reducing valve was studied by numerical analysis of the mathematical model. Also, static and dynamic characteristics of the new pressure control valve were tested with a testing system based on the test standard.

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모터링시 전류 파형과 크랭크각 센서를 이용한 기관의 압축압력 및 밸브 타이밍 분석 (Analysis of Cylinder Compression Pressure & Valve Timing by Motoring Current & Crank Signal during Cranking)

  • 김인태;박경석;심범주
    • 한국자동차공학회논문집
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    • 제19권5호
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    • pp.45-50
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    • 2011
  • Compression pressure of individual cylinder and valve timing have big influence on combustion pressure, indicated mean effective pressure (IMEP), emission, vibration, combustion noise and many other combustion parameters. Conventional method, however, to check compression pressure uniformity is done by mechanical pressure gage and valve timing is checked manually. This conventional method causes inaccuracy of cylinder pressure measurement because of different cranking speed results from battery status and temperature. Also to check valve timing, related FEAD parts should be disassembled and timing mark should be checked. This study describes and suggests new methodology to measure compression pressure by analysis of start motor current and to check valve timing by cylinder pressure with high accuracy. Results, it is found that detection of bulky as well as small leaky cylinder is possible by cranking motor current analysis and wrong valve timing can be detected by cylinder pressure analysis and cam and crank sensor signal.

피스톤 형상변화에 따른 압력평형밸브의 유동특성연구 (Flow Characteristics of Pressure Balancing Valve with Various Piston Shapes)

  • 김태안;안병재;김윤제
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2003년도 춘계학술대회
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    • pp.2168-2173
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    • 2003
  • Pressure balancing valve is one of important control devices, which is fully automatic and no manual controls, regulating or adjustments are needed. It is typically used to maintain constant temperature of working fluid in power and chemical plants and domestic water supply systems. Pressure balancing valve is composed of body, cylinder and balancing piston. Therefore, the balancing piston shapes are important design parameters for a pressure balancing valve. In this study, numerical and experimental analyses are carried out with two different balancing piston shapes. Especially, the distribution of static pressure is investigated to calculate the flow coefficient($C_v$). The governing equations are derived from making using of three-dimensional Navier-Stokes equations with standard ${\kappa}-{\varepsilon}$ turbulence model and SIMPLE algorithm. Using commercial code, PHOEIC, the pressure and flow fields in pressure balancing valve are depicted.

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뇌압 펄스하에서 션트밸브의 압력-유량제어 특성곡선의 변화 (Changes in The Pressure-Flow Control Characteristics of Shunt Valves Under Brain Pressure Pulsation)

  • 홍이송;이종선;장종윤
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2002년도 학술대회지
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    • pp.699-702
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    • 2002
  • Shunt valves implanted in the subcutaneous tissue of brain to treat patient with hydrocephalus were numerically simulated to investigate influence of pressure pulsation on their flow control characteristics. Shunt valves are subjected to pressure variation since ventricles enclosing the brain are under pressure pulsation rather than uniform pressure due to blood pressure variation. We modeled flow orifice through shunt valve and imposed pulsating pressure and valve diaphragm movement to compute flow through the valve. The results of our study indicated that flow rate increased by $40{\%}$ by introducing pressure pulsation and diaphragm movement on the shunt valve. Our results demonstrate the pressure-flow control characteristics of shunt valves unplanted above human brain may be quite different from the characteristics obtained by syringe pump test with uniform pressure and no diaphragm movement.

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현가시스템용 압력제어밸브에 관한 연구 (A Study on Hydraulic Pressure Reducing Valve for Active Suspension Systems)

  • 김동원;양승현;이석원
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2005년도 제36회 하계학술대회 논문집 D
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    • pp.2528-2530
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    • 2005
  • In this paper, a study on the analysis and design of an electro-hydraulic pressure reducing valve for active suspension system of car is fulfilled. Also, the structurally improved direct-acting electro-hydraulic pressure reducing valve is proposed to satisfy the performance that active suspension system requires. To prove the possibility whether the proposed valve can be used for active suspension system or not, the mathematical modeling and analysis for this valve is fulfilled and the experiment of response to controlled pressure is achieved. Here we conformed the response speed to controlled pressure of the structurally improved valve changed for the better by modifying the shape of spool such as the structure which make use of the power of controlled pressure derived from the area difference between two section areas of valve spool.

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ER-Valve 간극내에서 분산계 ER유체의 유동특성 (Flow Characteristics of Dispersive ER Fluid Clearance between ER-Valve)

  • 장성철;염만오;이종두;장성수
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2003년도 춘계학술대회 논문집
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    • pp.1123-1126
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    • 2003
  • In this research 4 plate type ER-Valves which have same surface but different width and length are designed and an experimental apparatus is constructed. With this experimental apparatus, flow rate and pressure drop of ER fluid flowing in ER-Valve are measured by varying electric field strength of ER-valve, and relation between valve types and pressure drop is also experimented. ER fluid is made silicon oil mixed with 40wt% starch having hydrous particles. The pressure drop according to the strength of electric field by differential pressure gauge in the present ER-Valve was used. This test reviewed experiment for the special changes of ER fluids in the steady flow condition.

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자석을 이용한 유압직동형 릴리이프 밸브에 관한 연구 (Study on a Magnet-Coupleed Hydraulic Direct Relief Valve)

  • 조규식;이정오
    • 대한기계학회논문집
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    • 제1권2호
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    • pp.65-72
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    • 1977
  • Major problems in the design and use of refief valve are (a) chattering because of instability, (b) excessive pressure differential which makes the valves crack far below maximum pressure diminishing useful flow in the system. In this study, A magnet-coupled relief valve is investigated theoretically and experimentally in order to improve the performance of a conventional direct type reliefvalve. A theory is developed to predict the performance, response, and stability of the magnet-coupled valve taking into account the delivery line response. In the experiment, a typical magnet-coupled relief valve is designed on the basis of the analytical results; the discharge rates are measured varying the supply pressure, and both the pressure-time curves and valve displacament-time curves are recorded providing the supply pressures greater than the setting pressure. The measured override characteristic curves are then compared with those of conventional pilot type and direct type releif valves. It is showm that the excessive pressure differential of a magnet-coupled relief valve becomes less than that of a conventional direct type valve. It is also shown that the most important chatacteristic of a magnet-coupled relief valve is to eliminate valve chattering due to instability regardless of the magnitude of setting pressures and discharge rates, which suggests wide applications of the idea of the use of a magnet in the design of hydraulic valves.

해양구조물용 고압 컨트롤 밸브 수치해석 (A Numerical Analysis on High Pressure Control Valve for Offshore)

  • 이중섭;장성철;정휘원;남태희
    • 대한설비공학회:학술대회논문집
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    • 대한설비공학회 2008년도 하계학술발표대회 논문집
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    • pp.1195-1200
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    • 2008
  • This study have goal with conceptual design for Offshore Structures of high pressure control valve for localization. Ball valve for development accomplished with flow analysis based on provision of ANSI B16.34, ANSI B16.10, ANSI B16.25 In order to localize the Offshore Structures high pressure control valve. Numerical simulation using CFD(Computational Fluid Dynamic) in order to predict a mass flow rate and a flow coefficient form flow dynamic point of view. The working fluid assumed the glycerin($C_3H_8O_3$). The valve inlet and outlet setup a pressure boundary condition. The outlet pressure was fixed by atmospheric pressure and calculated until increasing 1bar to 10bar. CFD analysis used STAR-CCM+ which is commercial code and Governing equations were calculated by moving mesh which is rotated 90 degrees when ball valve operated opening and closing in 1 degree interval. The result shows change of mass flow rate according to opening and closing angle of valve. Flow decrease observed open valve that equal percentage flow paten which is general inclination of ball valve. Relation with flow and flow coefficient can not be proportional according to inlet pressure when compare with mass flow rate. Because flow coefficient have influence in flow and pressure difference. Namely, flow can be change even if it has same Cv value. The structural analysis used ANSYS which is a commercial code. Stress analysis result of internal pressure in valve showed lower than yield strength. This is expect to need more detail design and verification for stem and seat structure.

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전자식 비례 압력제어밸브 내 오일 오염 입자 제거 제어 알고리즘 검증 (Verification of Control Algorithm for Removing Oil Contaminant Factor from Proportional Pressure Control Valve)

  • 천수환;박진감;장경제;심성보;장민호;이진웅
    • 드라이브 ㆍ 컨트롤
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    • 제18권4호
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    • pp.1-8
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    • 2021
  • An electro proportional pressure control valve is mainly used to control the clutch of an agricultural tractor's automatic transmission. During transmission, the operating, hydraulic oil is mix with many kinds of contaminants. The contaminants can be trapped between the valve body and spool of the proportional pressure control valve leading to abnormal operating conditions and finally critical damage to the transmission hydraulic system. The present study aimed to verify the valve control algorithm as a basic study of developing control logic that removes contaminants between the spool and the body of the proportional pressure control valve. To develop the algorithm, MATLAB/SIMULINK was used. PWM method was used to control the applied solenoid coil current. The effectiveness of the algorithm was verified by comparing the actual pressure of the normal valve with the actual pressure of the abnormal valve. Based on the present study findings, when the algorithm was applied, the response of the valve pressure according to the current became stable and oil contaminated particles were removed. In the future study, the control algorithm will be optimized for the stability of the proportional pressure reducing valve, and it will be verified in consideration with the driving of the clutch.

안전릴리프밸브의 블로우 다운 예측 및 유체-구조 연성해석 (Blowdown Prediction of Safety Relief Valve and FSI Analysis)

  • 최지원;장시환;이권희
    • 한국산학기술학회논문지
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    • 제18권12호
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    • pp.729-734
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    • 2017
  • 안전릴리프밸브는 배관라인 혹은 탱크의 과도한 압력을 완화하고 사용 적정압력 수준으로 유지해주는 장치이다. 안전릴리프밸브는 스프링 보닛에 통풍구가 대기 쪽으로 혹은 배출구 쪽으로 뚫려 있는지에 따라 배압의 변화에 직접적으로 영향을 받게 된다. 배압은 축적 배압(Built-up back pressure)과 부과 배압(superimposed back pressure)으로 나뉘게 되며 사용조건에 따라 배압의 특성이 달라진다. 본 연구에서 사용되는 안전밸브는 Conventional Safety Relief Valve로써, 배압의 특성을 가정하였다. 또한 개방력과 스프링력 사이의 힘의 평형 방정식을 세워 이론적 접근방법으로 초기 스프링 변위를 구하였다. 디스크가 받는 반력 즉 개방력과 스프링력을 비교하여 블로우 다운을 예측하였다. 블로우 다운은 설정 압력과 디스크 재닫힘 압력 간의 차이다. 본 연구는 ASME 규격 코드에 따라서 블로우 다운 시험 전에 전산 유동해석프로그램 CFX17.1을 이용하여 수치적으로 예측하였음을 밝힌다. 또한 유체-구조 연성해석(fluid-structure interaction analysis)을 통해 안전밸브 트림부의 안전성을 검토하였다. 향후, 시험과 전산수치해석 값을 서로 비교하여 블로우 다운 이론적 접근방법과 유동해석방법을 제안하고자 한다.