• 유공압시스템학회논문집
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• 제7권4호
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• pp.44-49
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• 2010

This paper represents solenoid design of control valve for incline angle control in variable compressor. Some theoretical and numerical analysis were performed to analyse solenoid and compared with experimental results. Maxwell program was used for numerical analysis. Through redesigns of housing body, plunger, core, and disk in control valve, the needed force was gotten. Reduction of core groove and housing body air-gap had a large influence on magnetic force. But increasing of disk thickness had little effect on magnetic force. Control valve efficiency could be improved through solenoid redesign.

• 대한기계학회논문집A
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• 제26권4호
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• pp.683-692
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• 2002

The most important parameter for hydraulic active suspension system is to sustain desirable vehicle maneuvering stability and ride comfort without increasing power consumption. The performance of hydraulic active suspension system depends on damping force of body damping valve and piston damping valve. Hydraulic actuator design and damping valve parameter selection are essential and basic procedure to design hydraulic system. This paper is on computer simulation with use of mathematical model that was delivered from dynamic characteristic of hydraulic actuator, as know basic damping characteristics of hydraulic active suspension system. The aim of this paper is to select the system parameter that affect mainly hydraulic active suspension, and identify the validity on the system parameter selection.

• Tribology and Lubricants
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• 제40권1호
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• pp.24-27
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• 2024

A monotype valve body for a dual clutch transmission has the potential to reduce costs, weight, and manufacturing time by modularizing various parts, including those of existing solenoid packs and valve bodies, into one through the application of super-precision die casting technology. However, this approach may lead to challenges such as reduced rigidity and increased interference due to modularization and compactness, impacting both product performance due to the reduced weight as well as durability and reliability. Unlike existing products, this approach requires a high-precision thin-wall block to avoid more complicated flow line formation, interference between flow lines, and leaks, as well as a strict quality requirement standard and precise inspections including detection of internal defects. To conduct precise inspections, we built an equivalent model corresponding to a driving distance of 300,000 km. Testing involved simulating actual road loads using a real vehicle and a chassis dynamometer in the FTP-75 mode (EPA Federal Test Procedure). The aim of the study was to establish a vehicle load-based part durability model for manufacturing a mono-type valve body and to develop fundamental technology for part weight reduction through preliminary design by introducing analytical weight reduction technology based on the derived results.

• 한국가스학회지
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• 제17권3호
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• pp.14-19
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• 2013

본 연구에서는 특수가스용기용 밸브의 안전성에 관한 실험적 연구를 수행하였다. 시험용 밸브는 특수가스용기에 부착되었던 것을 무작위로 수거한 것으로 가스누출 및 작동 안전성에 대한 시험을 실시하였다. 실험결과에 의하면, 밸브의 몸체, 나사 체결부, 안전판, 방출구, 스템부, 핸들에서 가스누출 안전성에 영향을 미칠 정도의 크랙, 마모, 부식, 변형이 발생하지 않았다. 다만, 핸들의 페인트 일부가 벗겨지고, PT나사와 몸체에서 녹이 국부적으로 형성되어 있지만, 가스누출 안전성에 영향을 미칠 정도는 아니었다. 또한, 탈거한 밸브에서 가스누출은 발생되지 않았다. 다만, 밸브스템의 영구변형과 오링의 마찰표면 일부에서 손상이 관찰되었다. 따라서, 탈거된 밸브의 가스누출 안전성을 보장하기 위해서 밸브시트와 오링 교체하는 것이 바람직함을 알 수 있다. 또한, 핸들의 조임력을 주기적으로 점검하는 것이 필요함을 알 수 있었다.

• 상하수도학회지
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• 제36권5호
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• pp.261-273
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• 2022

In this study, we collect water control valves that have had accidents due to existing cracks, etc. are collected, and propose investigation items for strengthening the valve structural safety evaluation through a series of analyzes from valve specifications to physicochemical properties are proposed. The results of this study are as follows. First, there was a large variation in the thickness of the body or flange of the valves to be investigated, which is considered to be very important factor, because it may affect the safety of the valve body against internal pressure and the flange connected with the bolt nut. Second, 60% of the valves under investigation had many voids in the valve body and flange, etc. and the decrease in thickness due to corrosion was relatively large on the inner surface in contact with water rather than the outer surface. It is judged that the investigation of depth included voids is very important factor. Third, all valves to be investigated are made of gray cast iron foam, and therefore it is judged that there is no major problem in chemical composition. It is judged that the chemical composition should be investigated. Fourth, as a physical investigation item, the analysis of metal morphology structure seems to be a very important factor for nodular cast iron from rather than a gray cast iron foam water valve with a flake structure. As it was found to be 46.7~68.8% of the standard recommended by KS, it could have a direct effect on damage such as cracks, and therefore it is judged that the evaluation of tensile strength is very important in evaluating the safety of the valve.

• 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.

• 동력기계공학회지
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• 제18권2호
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• pp.31-36
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• 2014

In this paper, pneumatic valve which consists of valve body, valve controller, nozzle and a multi-bender PZT actuator was suggested and fabricated. The fabricated pneumatic valve was experimented for performance evaluation. From the experimental results, we know that the flow rate of the suggested valve is 23 lpm at the pressure difference of 1bar and the maximum flow rate is 30 lpm at the pressure difference of 4 bar. The flow rates after endurance test of 9.8 million were 22.57 lpm and 28.62 lpm at the pressure difference of 1bar and 4bar, respectably. Finally, it was verified that the B10 life of the suggested pneumatic valve is over 50 million.

• Journal of Mechanical Science and Technology
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• 제17권9호
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• pp.1316-1323
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• 2003

This paper presents a structural analysis on the rigid and deformed motion of the leaflet induced by the blood flow required in the design of a bileaflet mechanical heart valve (MHV) prosthesis. In the study on the design and the mechanical characteristics of a bileaflet mechanical heart valve, the fluid mechanics analysis on the blood flow passing through leaflets, the kinetodynamics analysis on the rigid body motion of the leaflet induced by the pulsatile blood flow, and the structural mechanics analysis on the deformed motion of the leaflet are required sequentially and simultaneously. Fluid forces computed in the previous hemodynamics analysis on the blood flow are used in the kinetodynamics analysis on the rigid body motion of the leaflet. Thereafter, the structural mechanics analysis on the deformed motion of the leaflet follows to predict the structural strength variation of the leaflet as the leaflet thickness changes. Analysis results show that structural deformations and stresses increase as the fluid pressure increases and the leaflet thickness decreases. Analysis results also show that the leaflet becomes structurally weaker and weaker as the leaflet thickness becomes smaller than 0.6 mm.

• 한국수소및신에너지학회논문집
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• 제20권3호
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• pp.179-187
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• 2009

This paper presents a static and dynamic characteristics of the relief valve which is a kind of direct operated pressure control valve for hydrogen compressor. The valve is consisted of a main poppet, a spring, an adjuster and a valve body. The purpose of this study is development of the simulation model for relief valve by using commercial AMESlM$^{(R)}$ tool. Poppet with sharp edge seat type and ball poppet with sharp edge seat type compare for P-Q characteristic. The dynamic simulation results are presented the operating pressure characteristics of relief valve. High pressure power unit of which maximum pressure control range is 100MPa was manufactured, and the pressure control valve was experimented using the above-mentioned power unit. The new model of pressure control valve from this results was suggested. It was confirmed that the suggested valve has a good control performance from experimental setup.

• 한국자동차공학회논문집
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• 제2권1호
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• pp.26-37
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• 1994

In this study, flow of a model intake port/valve system is analyzed by using low Reynolds number $k-{\varepsilon}$ model. Discharge coefficient was obtained from computational results for the various cases of valve lifts. Discharge coefficient becomes maximum when the valve lift is 20mm, and does not increase or decrease in proportional to valve lift. Most of pressure drop and production of turbulent kinetic energy occur at the edge points of the valve and the valve seat Thus, in order to improve discharge coefficient, rounding of edge points in valve and valve seat is recommended. As valve lift is increased, the velocity of the intake jet in the valve passage decreases, and the direction of the jet is more inclined toward the valve seat.