• 제목/요약/키워드: 유압 실린더

검색결과 205건 처리시간 0.025초

가변 하중을 갖는 편로드 유압 실린더의 합성 자기동조 제어 (Hybrid Self-Tuning Control of a Single rod Hydraulic Cylinder with Varying Payload)

  • Kim, M.S.;Kim, J.T.;Han, K.B.
    • 한국정밀공학회지
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    • 제14권12호
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    • pp.174-181
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    • 1997
  • A proposed hybrid self-tuning control scheme for single rod hydraulic cylinder which has varying loads is presented here. An adaptive controller is developed for the system that use feedforward and P feedback control for simultaneous parameter identification and tracking control. Through experimental results, the performance comparison of the hybrid self-tuning controller with a constant gain P contro- ller clearly shows its superior ability in handling load changes in quiescent states.

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용접이음 된 유압 실린더용 로드/너클 조립체의 피로거동 해석 (Fatigue Behavior Analysis of Welded Rod/Knuckle Assembly for Hydraulic Cylinder)

  • 이환우
    • 한국기계가공학회지
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    • 제12권4호
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    • pp.93-99
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    • 2013
  • Parts and structures such as piston rod and knuckle joint for the use of hydraulic cylinder are often welded together in some fashion, usually due to cost and process effectiveness. Welding strongly affects the material by the process of heating and subsequent cooling as well as by the fusion process with additional filler material. Furthermore, a weld is usually far from being perfect, containing inclusions, pores, cavities, undercuts etc. As a consequence, fatigue failures appear in welded structures mostly at the welds rather than in the base metal, even if the latter contains notches. For this reason, fatigue analyses are of high practical interest for all welded structures under the action of cyclic loads. This paper describes the influence of welding parameters, material combinations and heat treatment on the fatigue behavior of welded cylinder rod. In addition, statistical characterization of stress-life response in weldment of hydraulic cylinder rod are presented.

유압실린더의 쿠션링 형상에 따른 쿠션 특성 연구 (Study of The Cushion Characteristics in accordance with Shapes of Cushion Ring of Hydraulic Cylinder)

  • 이용범;고재명;박종호
    • 유공압시스템학회논문집
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    • 제5권2호
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    • pp.14-19
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    • 2008
  • Hydraulic excavator consists of booms, arms, bucket, and cylinder. The cylinder make these structures moved and the cushion parts of cylinder in operation absorb the great impact which is stemmed from high velocity and pressure at cushion parts of cylinders. The cushion technology of cylinders has a great effect on the operator's comfortable as well as protecting equipment from damage by suppressing the inertia of the hydraulic excavator. In this study, three hydraulic cylinders have different shapes of a cushion ring, respectively. we studied optimal cushion pattern by analyzing the change of cushion pressure and time, according to supply pressure and velocity variations.

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유압측정을 위한 피스톤-실린더 간격내의 압력분포에 대한 수치해석 (Numerical Analysis of Pressure Distribution in Piston-Cylinder Unit for Accurate Pressure Measurement)

  • 우삼용;박종호
    • 대한기계학회논문집B
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    • 제20권9호
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    • pp.2909-2915
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    • 1996
  • Precise and accurate pressure measurements are obtained using deadweight piston gauges. Pressure distribution and elastic distortion in the piston-cylinder unit are the leading factors in determination of effective area. The distortion depends upon the pressure distribution in the clearance between piston and cylinder and those are coupled each other. Considering the viscosity pressure relation of oil and governing flow equation in the clearance, a new numerical iterative algorithm is developed. The disagreement between the monotonous and sharp pressure profiles is an indication that the pressure profile will be different for each piston and cylinder unit due to material variances.

수송기기 유압 실린더 블록 재료의 Fe-Cu 계면반응 특성 (A Characteristic of Fe-Cu Interfacial Reaction in the Hydraulic Cylinder Block for Vehicle Parts)

  • 김해지;김남경
    • 한국기계가공학회지
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    • 제3권1호
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    • pp.90-94
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    • 2004
  • Generally, a hydraulic cylinder block which is one of a vehicle parts that plays Important role in excavator power transmission, has copper alloy separation phenomenon by sliding motion between metals in high pressure condition. In this paper, to solve this problem, the interfacial reaction layer of Fe-Cu With SCM440 and copper alloy is studied through the melting method. As the result of this study, it is found that the interfacial reaction layer of $1{\mu}m$ created in the interface of Fe-Cu which has very strong physical bonding. It has been also confirmed that the melting method can improve life of the hydraulic cylinder block.

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편로드 유압실린더의 운동제어를 위한 자기동조 제어기설계 (Self-Tuning Controller design for the motion control of a Single Rod Hydraulic Cylinder)

  • 김정태;김문생
    • 소음진동
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    • 제8권3호
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    • pp.441-449
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    • 1998
  • A self-tuning control scheme, incorporated with the simplified 1st-order ARMAX(Auto-Regressive Moving Average eXogenous) model, for single rod hydraulic cylinder which has varying dynamic characteristics is presented here. An adaptive controller is developed for the system that uses feedforward and optimal feedback control for simultaneous parameter identification and tracking control. Through experimental results, the performance comparison of the self-tuning controller with a fixed gain proportional controller clearly shows its superior ability in handling load changes in quiescent states.

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상하운동하는 유압실린더의 제어특성 (Control Characteristics of Fluid Power Cylinder Moving Up and Down)

  • 염만오;윤일로;이석영
    • 대한기계학회논문집A
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    • 제28권8호
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    • pp.1152-1158
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    • 2004
  • In this study a MRAC(model reference adaptive control) for fluid power elevator model system was designed. The MRAC was compared with PI control in case of applying to the elevator model system with constant external load and changing external load. In this case external load was produced by a single fluid power cylinder combined with pressure control valve. In conclusion the MRAC control performance was better than PI control performance because overshoot and steady state error of the elevator model system controlled by the MRAC were not appeared for constant and changing external load.

가변하중을 받는 유압실린더의 제어특성개선 (Control Characteristics Improvement of Single Rod Hydraulic Cylinder Subjected to Varying Load)

  • 염만오
    • 한국기계가공학회지
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    • 제2권4호
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    • pp.46-52
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    • 2003
  • For position control of electro-hydraulic servo system, single rod cylinders and double rod cylinders are used. Single rod cylinders have simple structure for manufacturing but different volume ratio of two sides induce to non-linearity in process of then mathematical modeling. So only with conventional PID control method it is difficult to control single rod cylinders precisely. For mole precise position control of single rod cylinders, a controller which is inserted a velocity feedback PID controller and MRAC controller are proposed. With experiment control performances of three control methods are compared. In case of experiment, for external varying load to the system, a hydraulic cylinder and a pressure control valve are used. In conclusion a MRAC is considered a suitable control method for external varying load.

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유압실린더-토글 서보 메카니즘의 모델링 및 운동제어 (Modeling and Motion Control for Hydraulic Cylinder-Toggle Servomechanism)

  • 조승호
    • 드라이브 ㆍ 컨트롤
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    • 제10권3호
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    • pp.21-26
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    • 2013
  • This paper presents a robust motion tracking control of a cylinder-toggle servomechanism for injection molding machines. Virtual design model has been developed for a five-point type toggle mechanism. A sliding function is defined and combined with PID control to accommodate mismatches between the real plant and the linear model used. From tracking control simulations, it is shown that significant reduction in position tracking error is achieved with clamping force build-up through the use of proposed control scheme.

속도제어-유압펌프에 의하여 구동되는 사출성형 실린더의 궤적추적제어 (Trajectory Tracking Control of Injection Molding Cylinder Driven by Speed Controlled Hydraulic Pump)

  • 조승호
    • 유공압시스템학회논문집
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    • 제4권2호
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    • pp.21-27
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    • 2007
  • This paper deals with the issue of trajectory tracking control of a clamping cylinder for injection moulding machine, which is directly driven by speed controlled hydraulic pump in combination with AC servomotor. As a fundamental step prior to tracking controller design, feedback control system is developed by implementing a position control loop parallel with a system pressure control loop. A sliding mode controller combining velocity feedforward scheme is developed for enhancing the tracking performance. Consequently a significant reduction in tracking error is achieved for both position and pressure control applications.

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