• Title, Summary, Keyword: Cylinder contact

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Proposition of copper-foil magnetic sensor for the two-axis remote measurement of bending vibration of a non-metallic cylinder (비금속 배관에서의 원격 2 축 굽힘 진동 측정을 위한 동박 패치형 자기 센서의 제안)

  • Kim, Jin-Ki;Han, Soon-Woo;Kim, Yoon-Young
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.322-325
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    • 2007
  • This paper suggests a non-contact sensor for measuring bending vibration of a non-metallic cylinder in two orthogonal directions simultaneously. Recent research shows that a solenoid can pick up bending vibrations of a nonmetallic cylinder based on the reversed Lorentz force mechanism if an electrical conductive patch is attached to the cylinder. In this work, pairs of specially designed patches are used to make two independent paths for the current induced by bending vibrations, which enables the measurement of bending vibrations along two orthogonal directions simultaneously. The working performance of the developed sensor was verified by using two accelerometers.

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A Study on Structural Safety of the Boom Hoisting Cylinder of a Coal Handling Machine (석탄하역기 붐 호이스팅 실린더의 구조 안전성에 관한 연구)

  • Choi, Yong Hoon;Kwak, Hyo Seo;Kim, Chul
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.39 no.12
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    • pp.1265-1273
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    • 2015
  • A coal handling machine is a type of equipment used for loading coal, the main material in a steam power plant, along a conveyer belt from a ship, and is placed after the driving chain bucket. However, studies on the boom hoisting cylinder, which is a hydraulic system used to control the angle of the boom based on loading location, indicate that domestic models are insufficient, and are thereby often substituted with a foreign product. In this study, a technique for analyzing the contact pressure in a thick-walled cylinder was established by comparing the contact pressure, which is calculated theoretically based on the results obtained from FEM simulation, and by checking whether the working oil is leaking from the boom hoisting cylinder using a v-seal. In addition, the driving motion was simulated according to the strokes of the cylinder, and the structural stability was verified under the maximum output conditions.

Deformation characteristics at the contact boundary in cylinder compression process (원기둥 압축 공정에서 접촉 경계면의 변형 특성)

  • Min, Kyung-Ho;Ko, Byung-Du;Lee, Ha-Seong
    • Journal of the Korea Society of Die & Mold Engineering
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    • v.8 no.2
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    • pp.30-36
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    • 2014
  • In this study, surface deformation patterns have been investigated by the rigid-plastic finite element method for friction factor test in solid cylinder compression process. AA1100 and AA6063 aluminum alloys, which show different work hardening characteristics respectively, have been adopted as model materials used for analysis. The main objective of this study is to provide the deformation mechanics in detail in solid cylinder compression process, especially at the die/workpiece interface that is closely related with the frictional conditions. For this reason, solid cylinder compression process has been numerically analyzed. The surface flow patterns at the contact boundary have been analyzed in terms of surface expansion, surface expansion velocity, pressure distributions exerted on the die surface along the die surface. By defining bulge factor, barreling phenomenon also have been examined with calibration curves to verify their effects on the surface flow pattern that is important for evaluating the frictional condition at the interface.

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Fundamental study of energy for jumping motion of a water strider off water (소금쟁이의 수면 위 도약을 위한 에너지에 관한 기본 연구)

  • Lee, Duck-Gyu;Kim, Ho-Young
    • Proceedings of the KSME Conference
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    • pp.399-402
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    • 2007
  • In the previous research, it has been found that water strider's legs are strongly water repellent due to hierarchical structure of hydrophobic setae on the legs. Here we propose an answer why they should be so hydrophobic by showing that the work required to remove a floating hydrophobic cylinder from an interface depends very sensitively on the contact angle of the cylinder: superhydrophobic cylinders require relatively little work to remove them from an interface. Also we experimentally study the work required to lift a leg out of water with different contact angles and compare our experimental results with a theoretical prediction.

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The Error Analysis of Leak Measurement for Pneumatic Cylinder Using Isothermal Chamber

  • Jang, Ji-Seong;Ji, Sang-Won;Kagawa, Toshiharu
    • Transactions of The Korea Fluid Power Systems Society
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    • v.5 no.1
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    • pp.6-12
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    • 2008
  • ISO pneumatic cylinder reliability test requires air leakage measurement. Air cylinder has many parts and the leakage shall be measured before, during and after endurance test, and, the leakage should smaller than the specified value. The existing measurement method needs complex operation and the calibration of leak detector, and, has to separate the testing cylinder from endurance test device, which causes the change of contact condition of seal in the cylinder. Therefore, it is hard to evaluate the air leakage during endurance test, and guarantee the reliability of the conventional measurement method. In this paper, a new method for air leakage measurement using isothermal chamber, which does not requires calibration or temperature compensation, and, can measure air leakage accurately with quite simple operations, is proposed. As a result, reliability of air leakage measurement can be improved because the proposed method does not have to separate the testing cylinder from the endurance test device for air leakage measurement. The effectiveness of the proposed method is proved by error analysis of leak measurement from experimental result.

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The influence of various factors on piston friction (피스턴마찰에 미치는 각 인자의 영향)

  • 이종태;이성열
    • Journal of the korean Society of Automotive Engineers
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    • v.5 no.1
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    • pp.45-53
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    • 1983
  • There exist many kinds of frictions in internal combustion engine such as piston ring and skirt, cam and tappet, bearing friction etc. Among them, the frictions between piston ring, skirt and cylinder are particular. These frictions for motoring test are differ from that of firing test even though the temperature of cooling water and lubricating oil keep identically. The frictions for firing test are increased due to combustion pressure and products. The precise calculation of the friction is difficult. But we can assume that the friction is governed by the viscosity of lubricating oil and gas pressure of cylinder. And the viscosity of lubricating oil is dependant on gas temperature of cylinder, so the piston friction may be governed by gas pressure and temperature of cylinder. In this treatise, we propose the method of evaluating piston friction under the condition of constant engine speed, and we analyzed the behaviours and influence of factors concerned with the piston friction for output correction when the inlet pressure and temperature were varied. The main results are as follows: 1) The behaviours on the inlet conditions for the contact force of the piston rings and the viscosity of the lubricating oil concerned with piston friction are found. 2) The essential point the these behaviours is dependant on the cyclic variation following to the inlet conditions. 3) According to our analysis, It was observed that the viscosity of lubricating oil is more effective than the contact force to the piston rings.

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Orientation Correction of a Cylinder for Surface-Profile Measurement (원통 축 방향의 표면거칠기 측정을 위한 시료의 자세 보정)

  • 조남규
    • Journal of The Korean Society of Manufacturing Technology Engineers
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    • v.5 no.4
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    • pp.108-120
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    • 1996
  • A new technique and theory are proposed which correct orientation of a cylinder to perform a reliable measurement of the surface profile. We analyze characteristics of machined surfaces, e.g., ground, lapped and turned surfaces. Based upon the results. the optimum correction technique is derived by the statistical method. To verify the techinques, measurements are carried out by using the contact stylus profilometer on a controllable table. The measurement shows that surface information of cylinders can be acquired with high accuracy.

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Friction Characteristics between the Cylinder Block and the Spherical Valve Plate in Hydraulic Axial Piston Pump (유압 액셜 피스톤 펌프에서 실린더 블록과 구면 밸브 플레이트 사이의 마찰 특성)

  • 김종기;오석형;정재연
    • Tribology and Lubricants
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    • v.14 no.4
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    • pp.23-28
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    • 1998
  • To increase the efficiency of the hydraulic axial piston pumps, it is need to know the various characteristics in the sliding contact parts of them. Especially, friction characteristics between the cylinder block and the valve plate in the hydraulic axial piston pumps plays an important role to high power density. In this paper, we tried to clarify friction characteristics between the cylinder block and the spherical valve plate in bent-axis-type axial piston pump in experimentally. Results are arranged as follow; (1) friction torque between the cylinder block and the spherical valve plate has a proportional relation to weight or rotational speed, and is strongly affected by temperature. (2) Friction torque strongly depends on force balance ratio in valve plate. (3) In this experiment, lubrication condition between the cylinder block and the spherical valve plate is under hydrodynamic lubrication.

Theoretical Analysis of the Characteristics of Heat Transfer in Cylinder Drum for Paper Dryer (제지건조기용 실린더드럼에서 열전달특성에 관한 이론적 분석)

  • Lee, Ki-Woo;Chun, Won-Pyo;Lee, Kye-Jung;Jung, Seok-Pil
    • Proceedings of the KSME Conference
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    • pp.2082-2087
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    • 2008
  • The heat transfer process from steam to web through the cylinder drum consists of the thermal resistance by condensate thickness. thickness of shell, and the contact resistance between cylinder and web. The most thermal resistance in conventional cylinder drum dryer is generated by condensate, which is increased by the increase on revolution per minute(RPM). Therefore, the increase of RPM for the production enhancement results in the more thermal resistance, and eventually RPM is restricted. In this study, the theoretical analysis on the characteristics of heat transfer in cylinder drum for paper dryer was performed in the stationary state of steam in drum. The overall heat transfer coefficient, steam quantity and heat transfer quantity were predicted by diameter and length of drum, condensate thickness, revolution per minute and steam temperature for experimental apparatus design.

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Finite Element Analysis of Contact Pressure Behavior in Compression Ring-Oil Film (압축링-유막간의 접촉압력 거동에 관한 유한요소해석)

  • 김청균;김한구;한동철
    • Tribology and Lubricants
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    • v.11 no.4
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    • pp.53-57
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    • 1995
  • The contact pressure behavior is examined by means of a finite element analysis. The oil film between the piston ring and cylinder liner is analyzed on the basis that it behaves like a polymer material. The calculated results indicate that a shape of sloping edge with a straight line, which is designated as a Model III, shows a good performance on the contact pressure behavior for the increased speed. Obviously, the ring face profiles play an important role on the contact pressure between compression ring and oil film.