• 제목, 요약, 키워드: Cylinder contact

검색결과 156건 처리시간 0.048초

Power 서보 실린더의 피스톤 헤드용 AlBC의 마멸 특성 (Wear Characteristics of AlBC for Piston Head of Power Servo Cylinder)

  • 조연상;박흥식
    • Tribology and Lubricants
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    • v.27 no.2
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    • pp.65-70
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    • 2011
  • The power servo cylinder for driving accurately turbine stop valve of an atomic power plant is necessary to do turn-over owing to a leakage of oil and a structure problem, especially, it of a power plant be in demand a high quality standard depends entirely on import. There are much problem that the AlBC be to used as a material of piston head in cylinder are caused by wear. Therefore, it is necessary to examine friction characteristics of it. In this study, wear test experiments was carried out with AlBC and SCM440, using reciprocating friction tester of pin on disk. This result was shown that the wear mechanism of AlBC on working condition is adhesive wear and the maximum temperature of infra redray thermal image of frictional surface show over 2 mm from contact surface of pin and disk.

자동차 수동 변속기 클러치 시스템의 답력 이력 특성 예측 모델 (Automotive Manual Transmission Clutch System Modeling for Foot Effort Hysteresis Characteristics Prediction)

  • 이병수
    • 한국자동차공학회논문집
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    • v.16 no.5
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    • pp.164-170
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    • 2008
  • A typical clutch system for automotive manual transmissions transfers hydraulic pressure generated by driver's pedal manipulation to the clutch diaphragm spring. The foot effort history during the period of push is different than the period of the clutch pedal's return. The effort or load difference is called clutch foot effort hysteresis. It is known that the hysteresis is caused by friction. The frictional force and moment are produced between various component contact points such as between the rubber seal and the inner wall inside the hydraulic cylinder and between the diaphragm spring and the pressure plate, etc. Understanding the clutch pedal foot effort hysteresis is essential for a clutch release system design and analysis. The dynamic model for a clutch release system is developed for the foot effort hysteresis prediction and a simulation analysis is performed to propose a tool for analysing a clutch system.

마찰과 토크를 고려한 차륜/레일 접촉 해석 (Wheel/Rail Contact Analysis with Consideration of Friction and Torque)

  • 송기석;한승희;최연선
    • 한국철도학회논문집
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    • v.17 no.1
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    • pp.14-18
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    • 2014
  • 차륜/레일 접촉은 철도차량의 동특성을 결정하는 중요한 요소이다. 본 연구에서는 철도 차륜과 레일 사이에 작용하는 토크에 의한 견인력과 마찰력을 두 원통의 접촉문제로 이론해석과 전산해석을 하고 수직하중과 전단력이 작용하는 실제 차륜과 레일에 대한 전산해석을 하였다. 철도차륜과 레일 접촉문제는 구름과 미끄러짐이 있는 탄성접촉인 크리프에 의한 크리프힘을 생성하는 과정으로서 차륜과 레일의 형상 및 마찰계수에 따라 달라짐을 알 수 있었다.

원통결합부의 열특성 최적설계를 위한 예측 시뮬레이션 방법 (Simulation Method for Thermal appropriate Desing of Compound Cylinder using Bondgraph Modeling)

  • 민승환;박기환;이선규
    • 한국정밀공학회:학술대회논문집
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    • pp.635-640
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    • 1996
  • A thermo-elastic system in the production machine has highly nonlinear dynamic characteristics. In general, the finite element method is utilized for accurate analysis. However, it requires large computing time. Thus, thermo-elastic systems are usuallymodeled as electric and fluid system using lumped para,eter. In this paper. we propose the bondgraph model and transient simulation methodology of thermo-elastic system in consideration of various boundary and joint contact conditions. Consequently, the proposed method ensures a possibility of its on-line compensation about undesirable phenomena by using real time estimate process and electronic cooling device for thermal appropriate behavior. Thermo-elastic model consisting of bush and shaft including contact condition is presented.

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엔진 배기계의 배기가스 누설 메카니즘과 설계인자들의 영향에 관한 연구 (A Study on the Effects of the Design Parameters and Sealing Mechanism of the Exhaust Gas in Engine Exhaust System)

  • 최복록
    • 한국동력기계공학회지
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    • v.14 no.4
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    • pp.37-42
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    • 2010
  • This paper deals with the sealing mechanism of the gasket component and the effects of design parameters for the exhaust manifold. The finite element model includes hot-end exhaust system and a simplified gasket model supplied by ABAQUS software. The mechanical behaviors of bead and body of a gasket are measured after several times of cyclic loads by gasket supplier. From the finite element analysis due to the cyclic thermal loads, the flange of exhaust manifold shows thermal expansion and contraction in longitudinal direction as well as convex and concave deformations with respect to the engine cylinder head. And, the contact pressures of the gasket beads suddenly changes by normal deformation of inlet flanges. Therefore, the magnitudes of contact pressures could be used to determine the sealing characteristics of the exhaust gas in the exhaust system. The distributions of contact pressures in gasket bead lines shows a good agreement with the engine test results.

Evaluation of APR1400 Steam Generator Tube-to-Tubesheet Contact Area Residual Stresses

  • KIPTISIA, Wycliffe Kiprotich;NAMGUNG, Ihn
    • 한국압력기기공학회 논문집
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    • v.15 no.1
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    • pp.18-27
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    • 2019
  • The Advanced Power Reactor 1400 (APR1400) Steam Generator (SG) uses alloy 690 as a tube material and SA-508 Grade 3 Class 1 as a tubesheet material to form tube-to-tubesheet joint through hydraulic expansion process. In this paper, the residual stresses in the SG tube-to-tubesheet contact area was investigated by applying Model-Based System Engineering (MBSE) methodology and the V-model. The use of MBSE transform system description into diagrams which clearly describe the logical interaction between functions hence minimizes the risk of ambiguity. A theoretical and Finite Element Methodology (FEM) was used to assess and compare the residual stresses in the tube-to-tubesheet contact area. Additionally, the axial strength of the tube to tubesheet joint based on the pull-out force against the contact joint force was evaluated and recommended optimum autofrettage pressure to minimize residual stresses in the transition zone given. A single U-tube hole and tubesheet with ligament thickness was taken as a single cylinder and plane strain condition was assumed. An iterative method was used in FEM simulation to find the limit autofrettage pressure at which pull-out force and contact force are of the same magnitude. The joint contact force was estimated to be 20 times more than the pull-out force and the limit autofrettage pressure was estimated to be 141.85MPa.

클러치 마스터실린더 컵-시일 고무의 마찰계수 실험 연구 (An Experimental Study on The Friction Coefficient of Rubbers for Clutch Master Cylinder Cup-Seals)

  • 이재천;임문혁;이병수;장지현;정용승;허만대;최병기
    • 한국자동차공학회논문집
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    • v.11 no.5
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    • pp.112-118
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    • 2003
  • The friction coefficients of the rubber for clutch master cylinder were experimentally measured in this study. The cylindrical rubber samples for primary cup-seal and secondary cup-seal were tested against the aluminum or the steel plates of master cylinder housing under the various conditions of brake oil temperatures and normal loads. Dry sliding friction coefficients were also measured under various load conditions. The test revealed following results. First, the friction coefficient under fluid lubrication condition in general decreases, as the oil temperature or normal load increases. Second, the steel plate of low surface roughness yielded comparatively low friction coefficient on the range of 0.30∼0.67. On the other hand, the aluminum plate of high surface roughness yielded high friction coefficient on the range of 0.31∼1.15. Third, the friction coefficient of dry surface contact decreases as the normal load increases. This is contrary to the general principle of friction coefficient between metal plates.

Crevice Corrosion Study of Materials for Propulsion Applications in the Marine Environment

  • Deflorian, F.;Rossi, S.;Fedel, M.;Zanella, C.;Ambrosi, D.;Hlede, E.
    • Corrosion Science and Technology
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    • v.14 no.6
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    • pp.288-295
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    • 2015
  • The present work addresses crevice and galvanic corrosion processes occurring at the cylinder head gasket/cylinder head interface and cylinder head gasket/cylinder liner interface of four-stroke medium-speed diesel engines for marine applications. The contact between these systems and the marine environment can promote formation of demanding corrosion conditions, therefore influencing the lifetime of the engine components. The electrochemical behavior of various metals and alloys used as head gasket materials (both ferrous alloys and copper alloys) was investigated. The efficacy of corrosion inhibitors was determined by comparing electrochemical behavior with and without inhibitors. In particular, crevice corrosion has been investigated by electrochemical tests using an experimental set-up developed starting from the requirements of the ASTM G-192-08, with adaptation of the test to the conditions peculiar to this application. In addition to the crevice corrosion resistance, the possible problems of galvanic coupling, as well as corrosive reactivity, were evaluated using electrochemical tests, such as potentiodynamic measurements. It was possible to quantify, in several cases, the corrosion resistance of the various coupled materials, and in particular the resistance to crevice corrosion, providing a basis for the selection of materials for this specific application.

디젤엔진 실린더 라이너-피스톤 링 소재의 연삭 마멸 특성 (Abrasive Wear Characteristics of Materials for Diesel Engine Cylinder Liner and Piston Ring)

  • 장정환;김정훈;김창희;문영훈
    • 열처리공학회지
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    • v.20 no.2
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    • pp.72-77
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    • 2007
  • Abrasive wear between piston ring face and cylinder liner is an extremely unpredictable and hard-to-reproduce phenomenon that significantly decreases engine performance. Wear by abrasion are forms of wear caused by contact between a particle and solid material. Abrasive wear is the loss of material by the passage of hard particles over a surface. From the pin-on-disk test, particle dent test and scuffing test, abrasive wear characteristics of diesel engine cylinder liner-piston ring have been investigated. Pin-on-disk test results indicate that abrasive wear resistance is not simply related to the hardness of materials, but is influenced also by the microstructure, temperature, lubricity and micro- fracture properties. In particle dent test, dent resistance stress decreases with increasing temperature. From the scuffing test by using pin-on-disk tester, scuffing mechanisms for the soft coating and hard coating were proposed and experimentally confirmed.

유압 실린더 내 피스톤 위치측정을 위한 정전용량 센서 설계 (Design of Capacitive Sensor for Measuring the Position of the Piston in Hydraulic Cylinder)

  • 이성휘;이재건;강용주;홍익표
    • 한국정보통신학회:학술대회논문집
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    • pp.509-512
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    • 2015
  • 본 논문에서는 유압 실린더내의 피스톤 위치를 측정하기 위한 정전용량 센서(Capacitive Sensor) 구조를 연구하였다. 기존에 유압 실린더 내 피스톤 위치 측정을 위해 인덕티브(Inductive) 방식을 응용한 LVDT(Linear Variable Differential Transformer) 센서가 사용되고 있으며, 높은 정확도를 갖지만, 고가이며 구조적으로 복잡하다는 단점이 있다. 본 논문에서는 이러한 단점을 극복하기 위한 방법으로 유압실린더 내 최적화된 구조를 바탕으로 여러 가지 비접촉 정전용량 센서 구조 방식을 연구하였다. 실험을 통하여 본 논문의 제안구조를 사용하면 유압 실린더 내 피스톤 위치측정이 가능함을 확인하였다.

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