• 한국산업융합학회 논문집
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• 제26권3호
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• pp.455-462
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• 2023

In this study, an automatic spraying lubrication system was developed to maintain the cleanliness of the switchgear when detecting the movement of the track through the switchgear. To develop this system, an air tank, valve block, and spray nozzle were designed, and the safety was secured through the pressure test of the prototype after designing the air tank. Furthermore, the environmental aspect was considered by minimizing the use of lubricant by enabling the mixing of air and lubricant through the production of a valve using the Venturi principle. The performance evaluation was conducted by implementing (producing) the injection system, and the product developed in this study was deemed installable in actual switchgear. It is expected that the proposed system will enable the maintenance of the cleanliness of the track during switching and reduce faults and malfunctions caused by switchgear defects.

• 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.

• 드라이브 ㆍ 컨트롤
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• 제10권4호
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• pp.7-13
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• 2013

A tractor is a farm vehicle that is designed to provide a high tractive effort at low speed. It is used for versatile agricultural tasks such as hauling a trailer, tillage, mowing and construction work. As the intensity of work increases, tractors equipped with automatic transmission become popular due to the work convenience. Though manual and power shuttle transmissions are produced by domestic corporations, development for full-automatic power shift transmissions has never been challenged, and so related technology level is quite low. This paper gives a survey of the automatic transmissions from advanced foreign company, which includes layout of gear train, the way hydraulics controls clutches and brakes, electronic control system. The results are expected to be utilized as a basis in the development of original power train design for tractor.

• 한국지능시스템학회논문지
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• 제26권1호
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• pp.82-86
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• 2016

본 논문은 이륜차의 근원적인 도난방지를 위한 기존의 탈착방식의 기구적 열쇄방식을 개선하고 NFC(Near Field Communication) 접목하여 사용자 인증 및 개인화 서비스를 위한 이륜차 이동제한 및 정보 보안 시스템 개발 연구로서 모터사이클 운전자 편의성 및 보안성 요구 증대에 따른 근거리 무선통신 기술을 융합한 브레이크 장치의 이동제한 방법을 제시하였다. 제안 방법의 기본적인 원리 및 보안인증에 따른 이동장치의 구성 및 동작원리 등을 제시하였다. 본 연구에서는 모터사이클용 이동제한 및 정보 보안 시스템의 연동으로 원격에서 락/언락 기능을 수행하기 위한 솔레노이드 밸브 장착방법을 설계하였다. 사용자 휴대단말기의 인증으로 이동제한장치 해제를 위한 NFC 보안인증 방법을 설명하고 정지 상태에 자동 또는 수동으로 모터사이클 브레이크 유압흐름 제어하는 방법과 실험단계의 기구적 제작 결과를 제시하였다.

• 한국시뮬레이션학회논문지
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• 제24권4호
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• pp.29-34
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• 2015

순수 기계식 시스템에 의존하던 군용차량의 전자화가 진행되고 있다. 이미 소형 군용차량의 전자화는 상당부분 상용화되었으며, 점차적으로 대형군용차량으로 확대될 것이다. 군용차량의 안정적인 주행성능을 위해서는 자동변속기용 솔레노이드 밸브의 설계가 매우 중요하다. 본 연구에서는 솔레노이드 밸브에 대해 ATF온도 변화에 의한 성능변화를 정량적으로 예측할 수 있는 해석(Simulation)수법을 개발하는 것을 목적으로 한다. 연구는 자장해석소프트웨어인 Maxwell과 유압해석프로그램인 AMESim을 연동하여 진행한다. 시뮬레이션 결과 고온($120^{\circ}C$이상)과 극저온($-20^{\circ}C$이하)을 제외한 온도 영역에서 실험결과와 매우 유사함을 보인다.

• 한국주거학회논문집
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• 제13권6호
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• pp.89-99
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• 2002

The purpose of this research is to analyze the characteristics of flow rate distribution in hot-water piping networks in the apartment building. A 14-story apartment house was selected as a sample building and analyzed numerically by Hardy-Cross method. Two different piping networks, one has three vertical zones and the other of a single zone with automatic balancing valves, were compared. Some of research results are as follows; As the temperature of supply hot-water increases, the flow rate of it does by buoyancy effect, but this effect is not found in the piping network with automatic balancing valves. Non-uniformity in hot-water flow distributions to all stories in the piping system of single vertical zone can be completely reformed by the installation of either manually operated or automatic balancing valves in every story.

• 한국가스학회지
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• 제12권2호
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• pp.105-109
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• 2008

안전밸브는 정압기지 내에 정압기의 파괴 또는 관 내 수분의 응축 등으로 인한 관내 압력의 비정상적인 증가를 자동적으로 완화시켜주는 메커니즘을 가지고 있는 밸브이다. 따라서 정압기지의 안전을 위해서 안전밸브의 유동 특성과 유동 형태를 살펴보는 것은 매우 중요하다. 본 논문은 안전밸브의 분출용량과 필요분출면적에 따른 유동 특성을 수치해석을 통해서 분석하였다. 본 결과를 국내 외 안전밸브 관련 규정인 미국의 API(America Petroleum Institute), 유럽 연합의 EN(European Standard), 프랑스의 NF(Norme Francise)를 이용하여 분석, 비교하였다. 또한 안전밸브의 최대 필요 분출 면적을 이용하여 국내 및 국외 규정을 각각 적용하였을 때의 안전밸브의 필요 설치 수량에 대한 고찰을 해보았다.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2000년도 춘계학술대회논문집 - 한국공작기계학회
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• pp.561-566
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• 2000

A screw driver is essentially used in assembling machine parts and electronic products such as the printed circuit board with a housing. As the parts to be assembled becomes small and precise, the higher precision of the controling screw driver torque is required. However, because the operator controls the fastening torque by his experience, it must be inexact. Thus the screw driver which can exactly control the fastening torque by a bellows is designed and developed in the study. The bellows is expanded by the inner air pressure and contracted and by the spring operation. The bellows driver is composed of the entrance solenoid valve, the exit solenoid valve and the pressure sensor. The pressure sensor senses the bellows pressure. When the pressure sensor output reaches the setting value, it operates the exit solenoid valve not to deliver further torque by letting the air of the bellows out. Through a series of experiments, the performance is studied and verified.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.51-52
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• 2006

Gabion can be used for the purpose of preventing overflow of river and side loss of road. However the manufacturing process of the gabion is manually controlled especially to the joining process at the terminal part of gabion with small diameter wire. In this paper automatic feeding guide system was designed and fabricated to make automation. The fabricated system was tested in the factory level. Pneumatic system was considered as the main idea of the feeding system. 3/2-way and 5/2-way manual control valve, eight double-acting cylinders were used. Based on the theoretical simulation and actual test the fabricated system was well controlled. The system was applied to the patent.

• 공학교육연구
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• 제19권2호
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• pp.3-7
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• 2016

A flow control system was designed and fabricated to control the flow rate of liquid through the pipe. This control system was composed of hardwares and software, hardwares as controller, gate valve, orifice meter and data aquisition board and software as National instruments Labview program. Control of flow rate was executed by adjusting the pneumatic valve located at the center of pipe line based on the control signal generated by LabView PID control algorithm, which converts analog signal measured by pressure difference of orifice to digital signal to adjust pneumatic valve. For the controller setup Ziegler-Nichols tuning technique was applied and control performances were investigated for not only the disturbance but also the set point changes. Developed system showed good control performances in flow control enough to use as teaching tool of feedback control theory and practice in university, and also as industrial application.