• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2012년도 추계학술대회 논문집
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• pp.775-776
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• 2012

• 드라이브 ㆍ 컨트롤
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• 제15권2호
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• pp.46-51
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• 2018

Many research studies have been carried out related to saving energy and environmental pollution in the field of construction machinery. The best solution for reducing the related environmental pollution is to reduce fuel consumption by upgrading the energy efficiency of machinery used in this field. An efficiency upgrade in the field of construction machinery would mean minimizing the pressure loss in hydraulic pipe lines or achieving optimal operating conditions while responding to a load. One way to achieve this is to make an equivalent circuit, like an electrohydrostatic actuator, or to improve the spool type valve using the 4/3 way method. This study deals with an electrohydraulic proportional flow control valve. SimulationX software is used as a simulation tool for analyzing the dynamic characteristics. The analysis results, including the performance and characteristics of design parameters, are discussed and the validity of the theoretical analysis is also evaluated.

• 유공압시스템학회논문집
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• 제2권3호
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• pp.6-11
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• 2005

A household gas valve is used for flow control of LPG(Liquefied Petroleum Gas) or LNG(Liquefied Natural Gas) of which pressure is about $200mmH_2O(\fallingdotseq\;0.0196[bar])$. Currently, two kinds of valves such as rotary type and button type are widely used in many applications. But, these valves have some problems that they are not controllable and reliable. Piezo actuation combined with modem microelectronics provides a reliable, quiet, low energy, infinitely adjustable gas valve. In this paper, gas valve using piezo actuator which are bimorph and a circle type was studied. Also, Prototype for gas valve was manufactured and characteristics of the prototype gas valve were analyzed.

• Journal of Mechanical Science and Technology
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• 제17권7호
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• pp.978-985
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• 2003

In this paper, a new proportional solenoid invented for pneumatic directional control valves is introduced. The new proportional solenoid has two-dimensional structure and a pivoting armature on which the friction force is inherently negligible. Another advantageous feature of this solenoid is that its mechanical parts can be easily manufactured and assembled. The working principle and design example of the now proportional solenoid, its application to the activation of a 4/3-way directional control valve, and the evaluation of its control performance in a position control loop are reported.

• 한국정밀공학회지
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• 제15권12호
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• pp.142-147
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• 1998

Developing robot hands with multi-degree-of-freedom is one of the topics that researchers have recently begun to improve the limitation by adding flexibility and dexterity. In this study, an articulated servo-pneumatic robot hand system with direct-drive joints has been developed whose main feature is the minimization of the dimension. The servo-pneumatic system is advantageous to fabricate a dexterous robot hand system due to the high torque-to-weight and torque-to-volume ratio. This enables the design of a finger joint with an integrated rotary vane type actuator which produces high output torque without reduction gears, being very robust. In order to control the servo-pneumatic finger joints, a miniature proportional valve that can be attached to the robot hand is required. In this paper, a flapper nozzle type 4/3-way proportional directional valve has been designed and tested. The experimental results show that the developed valve can control a finger joint satisfactorily without much vibratory joint movements and acoustic noises.

• 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.

• 드라이브 ㆍ 컨트롤
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• 제15권2호
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• pp.38-45
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• 2018

In this study, the theory of fluid mechanics and dynamics is used to build a mathematical model for a three-stage flow control valve. The significance of the study is that the mathematical model can easily be used to study the effect of different design parameters on the performance of the valve. The geometry of the valve and the properties of the fluid were used in this study to determine the variation in the performance of the valve when varying the magnetic force on the pilot spool. While a linearization technique is not used to solve the developed model, the solution of the mathematical model is found in the time domain by simulation of the equations using a software package. The results indicate that if the developed mathematical model is solved for the different values of magnetic force, the valve behaves linearly; the valve is thus called the proportional flow control valve.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2004년도 학술대회지
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• pp.157-160
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• 2004

In this paper, a performance characteristic pump and motor is investigated. The hydraulic pump and motor are axial piston type with swash plate. Proportional control valve which can control that plate is an important component for its performance characteristics. We will show the control characteristics for them Experiment results show that behavior can be shown with changing the various parameters.

• 조명전기설비학회논문지
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• 제26권7호
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• pp.84-91
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• 2012

In this paper, design by magnetic analysis software and proportional control of solenoid for pressure valve for electric pressure cooker is described. The validation of design was proved by 3D finite element analysis results. Also the efficiency of an air ventilation mechanism was considered when pressure was happened by fluid analysis results. The linear proportional control system by AVR was manufactured and its validation was proved by pressure control of solenoid.

• 대한의용생체공학회:의공학회지
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• 제28권6호
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• pp.768-776
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• 2007

A new type of the fluid circulation blood pressure simulator was proposed to enhance the blood pressure simulator used for the development and evaluation of automatic sphygmomanometers. Various pressure waveform of fluid flowing in the pipe was reproduced by operating the proportional control valve after applying a pressure on the fluid in pressurized oil tank. After that, appropriate fluid was supplied by operating the proportional control valve, which enabled to reproduce various pressure wave of the fluid flowing in the tube. To accomplish this work, the mathematical model was carefully reviewed in cooperating with the proposed simulator. After modeling the driving signal as input signal and the pressure in internal tube as output signal, the simulation on system parameters such as internal volume, cross-section of orifice and supply pressure, which are sensitive to dynamic characteristic of system, was accomplished. System parameters affecting the dynamic characteristic were analyzed in the frequency bandwidth and also reflected to the design of the plant. The performance evaluator of fluid dynamic characteristic using proportional control signal was fabricated on the basis of obtained simulation result. An experimental apparatus was set-up and measurements on the dynamic characteristic, nonlinearity, and rising and falling response was carried out to verify the characteristic of the fluid dynamic model. Controller was designed and thereafter, simulation was performed to control the output signal with respect to the reference input in the fluid dynamic model using the proposed proportional control valve. Hybrid controller combined with an proportional controller and feed-forward controller was fabricated after applying a disturbance observer to the control plant. Comparison of the simulations between the conventional proportional controller and the proposed hybrid simulator indicated that even though the former showed good control performance.