• 제목/요약/키워드: Magneto-rheological Fluid

검색결과 133건 처리시간 0.024초

MR 유체를 이용한 비틀림진동 감쇠기 (Torsional Vibration Damper Using Magneto-Rheological Fluid)

  • 안영공;신동춘;양보석;김동조
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2001년도 춘계학술대회논문집
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    • pp.313-317
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    • 2001
  • Magneto-Rheological fluid (MR fluid) is known as a class of functional fluid with controllable apparent viscosity of the fluid by the applied magnetic field strength. Extensive researches with the functional fluids have been done on applications of the fluid to mechanical components such as suspension, absorber, engine mount, clutch, break, valve, etc. In this study, a new torsional damper using MR fluid is proposed, and the response property of the damper was theoretically investigated. The present damper is quit effective for reducing the driveline vibration in a wide range of the engine speed.

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항공기 엔진용 유체 마운트의 성능해석

  • 안영공
    • 유체기계공업학회:학술대회논문집
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    • 유체기계공업학회 1998년도 강연회 및 연구개발 발표회 논문집
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    • pp.220-227
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    • 1998
  • This paper evaluate the performance of a Magneto-Rheological (MR) fluid mount. The mount incorporates MR fluid in a conventional fluid mount to open and closed the inertia track between the fluid chambers of the mount. It is shown that such switching of the inertia track improves the mount's isolation effect, by eliminating the large transmissibility peak that commonly exists at frequencies higher than the notch frequency for conventional fluid mounts. The switching frequencies of the MR mount is evaluated, based on the parameters of the mount. A simple control scheme for switching the mount between the open and closed states is proposed, and the performance of the controlled mount is compared with conventional mounts. A sensitivity analysis is conducted to evaluate the effect of parameter errors in estimating the switching frequencies and mount performance. The results show that the switching frequencies can be accurately determined from mount parameters that are easily measured or estimated.

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MR 유체 작동기의 전자기적 설계 방법 (Electromagnetic Design Methodology for MR Fluid Actuator)

  • 남윤주;문영진;이육형;박명관
    • 대한기계학회논문집A
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    • 제30권10호
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    • pp.1305-1313
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    • 2006
  • This paper presents an electromagnetic design methodology for the magneto-rheological (MR) fluid actuator. In order to improve the performance of the MR fluid actuator, the magnetic circuit including the MR fluid, the ferromagnetic material for flux path and the electromagnetic coil should be well designed, thereby the magnetic field intensity can be effectively supplied to the MR fluid. First of all, in order to improve the static characteristic, the length of the flux path is decreased by removing the unnecessary bulk of the yoke. Next, in order to improve the dynamic and hysteretic characteristics, the magnetic reluctance of the ferromagnetic material is increased by minimizing the cross section through which the flux passes. The effectiveness of the proposed design methodology is verified by the magnetic analysis and a series of basic experiments.

MR 밸브 내장형 서보 액추에이터의 힘 제어에 관한 연구 (A study on the force control of a servo actuator with built-in MR Valve)

  • 안경관;송주영;김정수;안영공;박중호
    • 유공압시스템학회논문집
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    • 제3권1호
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    • pp.1-6
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    • 2006
  • A servo actuator with a valve using MR (Magneto-Rheological) fluid is proposed for fluid control systems. The MR fluid is well known as a functional fluid whose apparent viscosity is controlled by the applied magnetic field strength. The pressure in the MR cylinder can be controlled by the applied magnetic field strength. Good points of the MR cylinder are more simple, compact and reliable structure than a conventional oil hydraulic cylinder. The experimental results show that the MR cylinder could be used as a servo actuator.

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동일한 간극을 갖고 있는 ER 및 MR 클러치의 성능 비교 (Performance Comparison Between ER and MR Clutches with Same Gap Size)

  • 홍성룡;최승복
    • 대한기계학회논문집A
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    • 제23권6호
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    • pp.1055-1064
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    • 1999
  • In this wort ER(electro-rheological) clutch and MR(magneto-rheological) clutch are devised and their performance characteristics such as response time and controllability are compared. As a first step, field-dependent yield stresses of ER and MR fluids are distilled in shear mode. For reasonable comparison between two clutches, a nondimensional design model is established by choosing same design parameters of gap size and number. Following the manufacturing of two clutches, field-dependent torque level, response time to step input, mechanical Power generation to electric power consumption are experimentally measured and compared. In addition, in order to investigate torque controllability of the clutches a sliding mode controller is formulated and experimentally realized. Control bandwidths of two clutches are identified and tracking control responses for desired torque trajectories are presented.

연마공정에서 MR 유체의 트라이볼로지적 성질에 대한 연구 (A Study on Tribological Properties of Magneto-Rheological Fluid (MRF) in Polishing Process)

  • 이성오;장경인;민병권;이상조;석종원
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2006년도 춘계학술대회 논문집
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    • pp.497-498
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    • 2006
  • Tribological properties of a Magneto-Rheological(MR) fluid in a polishing process are studied. For this polishing process, abrasive wear model is proposed as a function of shear force, normal force and actual mean velocity of MR particles at workpiece surface. Experimental conditions are changed by varying the gap distance between workpiece and tool and the rotational speed of tool. From the experimental results, a modified Stribeck curve is obtained, and the friction coefficient turns out to have linear relationship with a modified Sommerfeld number. The validity of the wear model is supported by additional experiments performed for measuring material removal rates.

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소형 MR 댐퍼의 모델링 및 진동제어 (Modeling and Vibration Control of Small-sized Magneto-rheological Damper)

  • 이종우;성민상;우제관;최승복
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2012년도 추계학술대회 논문집
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    • pp.344-349
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    • 2012
  • This paper presents a new small-sized damper featuring magneto-rheological (MR) fluid which can be applied to vibration control system. The proposed MR damper consists of cylinder, piston, a couple of bearings, oil-seals and magnetic circuit which has two coils. In this damper, approximately 5cc of MR fluid is used. The damping force of the MR damper is designed to be followed by linear shear-mode Bingham-plastic model. In order to verify the performance of the MR damper, an experimental apparatus is established. In the experimental test, the damping force of the MR damper is measured with respect to time, displacement and velocity. In addition, the time response of MR damper is measured when 1A of step current is applied. Finally, The proposed small MR damper is applied to vibration control. In this process, a simple 1-DOF system is modeled and controlled using PID controller.

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소형 MR 댐퍼의 모델링 및 진동제어 (Modeling and Vibration Control of Small-sized Magneto-rheological Damper)

  • 이종우;성민상;우제관;최승복
    • 한국소음진동공학회논문집
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    • 제22권11호
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    • pp.1121-1127
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    • 2012
  • This paper presents a new small-sized damper featuring magneto-rheological(MR) fluid which can be applied to vibration control system. The proposed MR damper consists of cylinder, piston, a couple of bearings, oil-seals and magnetic circuit which has two coils. In this damper, approximately 5cc of MR fluid is used. The damping force of the MR damper is designed to be followed by linear shear-mode Bingham-plastic model. In order to verify the performance of the MR damper, an experimental apparatus is established. In the experimental test, the damping force of the MR damper is measured with respect to time, displacement and velocity. In addition, the time response of MR damper is measured when 1A of step current is applied. Finally, the proposed small MR damper is applied to vibration control. In this process, a simple 1-DOF system is modeled and controlled using PID controller.

MR 유체의 동특성 (Identification of Dynamic property of MR Fluid)

  • 안영공;하종용;안경관;양보석;백석준언;삼하신
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2005년도 춘계학술대회논문집
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    • pp.576-579
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    • 2005
  • MR (Magneto Rheological) fluids are well known as a smart fluid and their application researches to control vibration have been conducted by many researchers. However, their dynamic properties have not been identified clearly yet. Therefore, the MR effect is investigated by using a rotational viscometer and a single degree of freedom system with an MR damper. The results obtained from the experimental study show that stiffness and viscous damping coefficients of the system with an MR damper are changed according to the variation of the applied current.

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MR 밸브의 전자기적 설계와 성능 평가 (Electromagnetic Design and Performance Evaluation of an MR valve)

  • 김기한;남윤주;박명관
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2007년도 춘계학술대회A
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    • pp.968-973
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    • 2007
  • This paper presents an electromagnetic design for the magneto-rheological fluid valve. The MR valve can control high-level fluid power without moving parts, due to the apparent viscosity controllability of the MR fluid in magnetic fields. In order to improve the static characteristic of the MR valve, the length of the flux path is decreased by removing the unnecessary bulk of the yoke. Then, in order to improve the dynamic and hysteretic characteristics, the magnetic reluctance of the ferromagnetic material is increased by minimizing the cross sectional area through which the flux passes. Two MR valves, one is a conventional type valve and the other is the proposed one, were fabricated and performance evaluation is experimentally achieved through the comparison study using by-pass damper system.

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