• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 추계학술대회 논문집
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• pp.729-732
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• 2002

In this paper, poppet valve with cone type poppet and sharp edged seat was studied. In order to develope poppet valve which have a specification of 315(bar) and 3(lpm), effect of design parameter as valve seat diameter, poppet angle, spring stiffness and spring pre-load was evaluated. The validity of simulation was confirmed and basic data far poppet valve design was derived.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 추계학술대회
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• pp.876-881
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• 2004

In this study, A special quality analysis and experiment for low power consumption type pneumatic on-off micro valve was performed. And flow characteristics of the micro valve by stroke change was numerically investigated. As a result, it is shown that magnetic force(2.4N) is exerted enough to move poppet with 0.3mm stroke with 0.01 seconds of response time, and that there is no magnetic force emitted by yoke. Under the condition of poppet stroke smaller than about 0.8mm, dynamic pressure acts to poppet wall up to supply pressure level. But, that is decreasing to 40% when poppet stroke is 0.8mm.

• 유공압시스템학회논문집
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• 제1권2호
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• pp.15-19
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• 2004

In this study, Design and simulation for low power consumption type pneumatic on-off micro valve was performed. And flow characteristics of the micro valve by stroke change was numerically investigated. As a result, it is shown that magnetic force(6.8N) is exerted enough to move poppet with 0.438mm stroke with 0.01 seconds of response time, and that there is no magnetic force emitted by yoke. Under the condition of poppet stroke smaller than about 0.4mm, dynamic pressure acts to poppet wall up to supply pressure level. But, that is decreasing to 40% when poppet stroke is 0.8mm.

• 드라이브 ㆍ 컨트롤
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• 제17권2호
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• pp.55-62
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• 2020

There are two types of IMV for MCV, the spool type and the poppet type. The spool type is used in the existing excavator MCV and easily meets large-capacity flow conditions, but has a flow force problem which affects the spool control. The poppet type stably blocks the flow and has excellent rapid response. However, the larger the capacity, the larger the diameter of the poppet needed, requiring a strong spring to withstand the oil pressure. In this study, a bi-directional three-stage IMV for MCV that can be used in medium and large hydraulic excavators was proposed. This is a poppet type, enabling bi-directional flow control and resolves the problem of proportional solenoid suction force limitation. To investigate the validity of the proposed valve, the system was mathematically modeled and the static and dynamic characteristics were investigated through the simulation using commercial software. It has been concluded that the reverse flow is possible in a regeneration circuit and that the proposed IMV can be used to perform various excavation modes.

• 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.

• 한국수소및신에너지학회논문집
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• 제11권3호
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• pp.107-117
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• 2000

Ball poppet valve type high pressure hydrogen injection valve actuated by solenoid has been developed for the feasibility of practical use of hydrogen fueled engine with direct injection and the precise control of fuel injection ratio in hydrogen fueled engine with dual injection. The gas-tightness of ball poppet injection valve is improved by the introduction of ball-shaped valve face, valve end typed spherical pair, and valve stem with rotating blade. Ball poppet valve is mainly closed by differential pressure due to the area difference between valve fillet and pressure piston. So, it can be operated by solenoid actuator with small driving force. From the evaluation of ball poppet injection valve, it was found that the gastightness and controlment of this injection valve are better than those of injection valve had been developed before.

• 대한기계학회논문집A
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• 제20권8호
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• pp.2480-2490
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• 1996

This paper presents a new type of hydraulic servo chllinder which is characterized by its simple construction and an ubtegrated feedback mechanism. Piston position of the cylinder is controlled by eletrical input and mechamical feedback deduced from its own structure. Hydraulic pressure in each cylinder room is controlled by a poppet valve. The poppet is activated by a solenoid and is linked to the piston. Solenoid input current pulls up the poppet, which results in pressure drop and thus piston motion. The piston motion generates pull down force on the poppet by the linkage and the motion stops at equilibrium. In that way the piston position is controlled by an expernal input current. Characteristics of the servo cylinder is verified by stability analysis, tranient vehavior and steady state positing for step input. Design parameter analyses have been executed by derivation of analytical approximate solutions and by computer simulations. A prototype hydraulic servo cylinder is developed and tested. The experimental results show successful function of the servo cylinder and consistency with the theoritical results.

• 동력기계공학회지
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• 제14권3호
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• pp.77-82
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• 2010

In general, the control valves are essential components in hydraulic systems. Structural changes within the valves remain a challenge because many parameters of valve tend to interact in terms of static and dynamic performance. Therefore, the valve characteristics is applied directly to the stability of hydraulic system. Inner structure of the valve which is used mainly in the industries is made up poppet type and spool type. This paper made a description of the method for numerical analysis and modeling of the valve with a built-in moving part of four-type. Based on the physical parameters of the valves, a numerical model of objected valve is developed using the bond graph method. It is to verified the results that the moving part of four-type has an effect on pressure and flow characteristics. Also, It is analyzed the results which has an effect on response characteristic by angular of poppet valve face and inertia variation of the valve with a built-in moving part. In the results, it is confirmed that the rising and settling time vary with the shape of moving part in valve.

• 수산해양기술연구
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• 제26권2호
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• pp.213-217
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• 1990

본 연구에서는 유량제어 조직밸브의 기초특성을 집중정수계 모델을 사용하여, 해석하고, 이것을 실험적으로 확인하였다. 그 결과를 요약하면 아래와 같다. 1. 로직밸브의 주밸브 유량은, 그것보다 매우 소유량인 파일럿 유량에 의하여 제어할 수 있다. 2. 주밸브(파핏밸브)~파일럿실간의 개구면적이 주밸브 변위에 비례하도록 밸브를 설계함으로써 주밸브변위(혹은 면적)와 부하유량사이에 양호한 직선성이 얻어진다. 3. 유량제어 로직밸브에서 주밸브 유량의 제어범위의 상한은 기름홈의 개구면적의 최대치에 의하여 결정한다.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2008년도 제30회 춘계학술대회논문집
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• pp.14-17
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• 2008

비교적 단순한 개폐작동을 통해 액체추진기관 연소기로의 극저온 액체산소 공급을 조절하는 산화제 개폐밸브로써, 공압으로 작동하는 포펫 타입의 밸브가 채택되어 관련 연구개발이 진행되고 있다. 일반적인 포펫 타입의 밸브들은 포펫과 피스톤이 연결되어 일체로 움직이면서 유로 개폐를 제어하지만, 개발 중인 산화제 개폐밸브는 밸브 설계의 유연성을 확보하기 위해 포펫과 피스톤 부분이 서로 접촉되어 있을 뿐 독립적으로 분리되어 있다. 포펫과 피스톤 부분이 분리되어 있는 포펫 타입의 밸브 개폐 시, 피스톤 부분이 밸브 몸체와 충돌할 수 있기 때문에 이와 같은 충돌을 피하기 위해 밸브가 닫히는 동안의 힘평형에 대한 분석이 필수적이다. 따라서 본 연구에서는 산화제 개폐밸브가 닫히는 동안의 힘평형에 대한 분석 내용을 소개하고, 결과적으로 안전한 밸브 작동을 확보할 수 있는 힘평형 조절을 위한 주요 설계 변수를 유도하기로 한다.