• 연구논문집
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• 통권25호
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• pp.91-98
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• 1995

Recently, improving the energy efficiency of a pneumatic system and reducing the consumption of compressed air were a concern of scholars at domestic and abroad. The using fields of a pneumatic system are widely used in factory automation of manufacturing line, chemical factories with explosiveness danger and petroleum industries etc. In particular, pneumatic cylinder is applied to feeding work of workpiece. jig tools and press mechanism, reciprocation and rotary motion with rack and pinion. In this study, the experimental apparatus consisted to pneumatic cylinder, dual supply pressure regulator and solenoid valve. The dual supply pressure regulator connected to outlet port of solenoid valve. The supply pressure($4.5kg_f/cm^2$) of compressed air goes into the rodless chamber 1 to drive the piston rod forward which is named working stage. The supply pressure ($2kg_f/cm^2$) of compressed air goes into the rod chamber 2 to drive the piston rod backward which is named no-working stage. Accordingly, the research results of this study can be obtained to Energy-Saving Effects of the compressed air about 35%.

• KSTLE International Journal
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• 제1권2호
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• pp.101-106
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• 2000

Variable displacement axial piston pumps are widely used for raising the energy level of the fluid in hydraulic systems. And the regulator is the device which regulates the discharge flow of the piston pump by controlling the swivel angle. The regulator receives the hydraulic pilot pressure and controls the pump output flow depending on the machine load and engine speed. This work deals with constant power control (horsepower control) in the design of a regulator by using a bent-axis type piston pump. In order to effectively use engine power, we must keep the horsepower from the engine to the pump constant. Therefore the regulator operates the constant power control. As a result, optimum power usage is obtained by accurately following the power hyperbola. This study focused on developing a simulation model of a regulator. First, the governing equations of the regulator are derived, and analysis is performed by computer simulation, which can identify significant parameters of regulator. As a result, the variation of the swivel angle, flow rate, hyperbolic curve, inner leakage and responsibility are simulated, and significant parameters of a regulator are identified.

• 한국가스학회지
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• 제22권1호
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• pp.60-63
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• 2018

본 연구에서는 LPG 용기용 가스밸브의 강도안전성에 대한 FEM 해석결과를 제시하고 있다. FEM 해석결과에 의하면, 가스밸브가 완전히 열린 상태에서 3.5 MPa의 공급압력을 적용하였을 때, 안전밸브와 나사의 상단부사이의 경계 지역에서 발생한 von Mises 최고응력은 99.2 MPa로 나타났다. 99.2 MPa라는 von Mises 최고응력은 황동소재의 항복강도에 비해 낮은 값으로 충분히 안전한 결과이다. 이 경우에, 압력조정기의 상측 오른쪽에서는 최대 변위량 0.002mm가 발생하였다. 최대로 변형된 이 지역은 가스밸브에 설치된 오링이나 다이어프램과 같은 밀봉 부분이 아니므로 의미를 부여할 필요는 없다. 기존의 개폐식 밸브와 압력 조정기를 일체형으로 형성하여 제시한 하이브리드형의 가스밸브 모델은 LPG 용기용으로 가스누출이 없는 메커니즘과 최소로 단순화시킨 크기의 가스모델로 추천된다.

• 한국산학기술학회논문지
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• 제22권1호
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• pp.37-44
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• 2021

수소연료전지차(FCEV)는 전기를 자체 생산하는 연료전지를 동력원으로 하고 있으며 기존 기계식 레귤레이터의 출구압은 시스템 사양에 의해 제작 시점에서 고정되며 순간적인 수소 공급량에 의한 출구압 강하가 발생하는 경우 수소의 공급유량이 부정확해지는 문제가 있다. 본 연구에서는 기존에 존재하는 1단 기계식 감압 레귤레이터를 보완하기 위한 2단 감압 레귤레이터의 형상 설계 및 재질 선정을 수행하였다. 2단계 감압을 통한 맥동과 느린 응답을 보상하고 고압 편차 문제를 해결하기 위해 감압 유닛의 접촉면 형상을 가공성을 고려하여 설계하였다. 기밀성 측면에서 TPU의 변형량은 최대 15.82% 작은 변위량을 보였으며, 재질 선정에서는 2단 감압에 보편성을 확보하고 다양한 수소 연료 공급시스템에 적용 가능한 전자식 솔레노이드를 고려하여 자성체를 선정하고 적절한 도금 종류를 검증하기 위한 수소 취성 및 내식성 평가를 실시하였다. 시편의 표면 부식은 Cr 도금의 경우에서만 발생되지 않았으며, 인장 시험을 통해 부식과정간 연신율을 비교하였을 때, 2% 이내의 차이를 확인하였다.

• 한국자동차공학회논문집
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• 제14권6호
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• pp.160-170
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• 2006

If hydraulic pump controlled by mechanical type regulator has more than one control function, the construction of regulator will be very complicated and control performance falls drastically. It is difficult to have more than one control function for hydraulic pump controlled by electronic type hydraulic valve due to the inconsistency of controllers. This paper proposes a multi-function control technique which controls continuously flow, pressure and power by using EPPR(Electronic Proportional Pressure Reducing) valve in swash plate type axial piston pump. Nonlinear mathematical model is developed from the continuity equation for the pressurized control volume and the torque balance for the swash plate motion. To simplify the model we make the linear state equation by differentiating the nonlinear model. A reaction spring is installed in servo cylinder to secure the stability of the control system. We analyze the stability and disturbance by using the state variable model. Finally, we review the control performances of flow, pressure and power by tests using PID controller.

• 대한기계학회논문집B
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• 제32권8호
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• pp.567-573
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• 2008

The conventional refrigeration system is composed of a compressor, condenser, receiver, expansion valve or capillary tube, and an evaporator. The refrigeration system used in this study has additional expansion valve and evaporator along with an evaporation pressure regulator(EPR) at the exit side of the evaporator. The two evaporators can be operated at different temperatures according to the opening of the EPR. The experimental results obtained using the refrigeration system with parallel control of evaporation pressure are presented and the performance analysis of the refrigeration system with two evaporators is conducted.

• Journal of Mechanical Science and Technology
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• 제20권9호
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• pp.1339-1345
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• 2006

The development of an accurate and energy saving electro-pneumatic regulator that may be applied to a variety of practical pressure control applications is described in this paper. A novel modified pulse width modulation (MPWM) valve pulsing algorithm allows the electro-pneumatic regulator to become energy saving system. A comparison between the system response of conventional PWM algorithm and that of the modified PWM (MPWM) algorithm shows that the control performance is almost the same, but energy saving is greatly improved by adopting this new MPWM algorithm. The effectiveness of the proposed control algorithm is demonstrated through experiments with various reference trajectories.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.1339-1342
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• 2005

The development of an accurate and energy saving pneumatic regulator that may be applied to a variety of practical pressure control applications is described in this paper. A novel modified pulse width modulation(MPWM) valve pulsing algorithm allows the pneumatic regulator to become energy saving system. A comparison between the system response of conventional PWM algorithm and that of the modified PWM(MPWM) algorithm shows that the control performance is almost the same, but energy saving is greatly improved by adopting this new MPWM algorithm. The effectiveness of the proposed control algorithm is demonstrated through experiments with various reference trajectories.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.1482-1483
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• 2008

This report describes the design, fabrication and experimental results of an implantable micro pressure regulator. It consists of three silicon substrates, a glass substrate, and a PDMS layer. Silicon and glass substrates are fabricated by using bulk micro machining and sandblasting. The PDMS layer is used as a intermediate layer for Si-Si and Si-glass bonding processes. This micro regulator is a key component of the portable drug delivery systems for low power consumption. The device has some advantages, such as a passive type device, no power consumption, and simple structure.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1994년도 추계학술대회 논문집
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• pp.635-641
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• 1994

Recently, Improving the energy efficiency of a pneumatic system and reducing the consumption of compressed air were a concern of scholars at domestic and abroad. The using fields of a pneumatic system are widely used in factory automation of manufacturing line, chemical factories with explosiveness danger and petroleum industries etc. In particular, Pneumatic cylinder is applied to feeding work of workpiece, jig tools and press mechanism, reciprocation and rotary motion with rack and pinion. In this study, The experimental apparatus consisted to pneumatic cylinder, dual supply pressure regulator and solenoid valve. The dual supply pressure regulator connected to outlet port of solenoid valve. The supply pressure (4.5kgf/cm$\^$2/) of compressed air goes into the rodless chamber 1 to drive the pistion rod forward which is named working stage. The supply pressure(2kgf/cm$\^$2/) of compressed air goes into the rod chamber 2 to drive the piston rod backward which is named no-working stage. Accordingly, The research results of this study can be obtained to Energy-Saving Effects of the compressed air about 35%.