• Title/Summary/Keyword: 공기압 쿠션 실린더

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Characteristic Comparison on Internal Cushion Devices at High-speed Pneumatic Cylinders (고속 공기압 실린더 내장용 쿠션기구의 특성 비교)

  • Kim, Dotae;Zhang, Zhong Jie
    • Transactions of the Korean Society of Automotive Engineers
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    • v.21 no.6
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    • pp.24-30
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    • 2013
  • This paper studies the comparative analysis on two different internal cushion devices (the types of needle and relief valve) used to absorb the energy which is generated when the pneumatic cylinder moves with the load at meter-out speed control system. The effect at varying the piston velocity under same driving condition is mainly investigated. The simulation results on pressure in the cushion chamber and the dynamic behavior of the relief valve type cushion device are compared with the needle valve type. Design and performance are improved with the cushion configuration of better quality at high-speed pneumatic cylinder. Based on the relation between absorbed energy and impact energy at cushion process, cushion performance at pneumatic cylinder is evaluated.

Computer Simulation and Modeling of Cushioning Pneumatic Cylinder (공기압 실린더의 쿠션특성에 관한 모델링 및 컴퓨터 시뮬레이션)

  • 이상천
    • Journal of Advanced Marine Engineering and Technology
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    • v.23 no.6
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    • pp.794-805
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    • 1999
  • Pneumatic cushioning cylinders are commonly employed for vibration and shock control. A mathematical simulation model of a double acting pneumatic cushioning cylinder designed to absorb shock loads is presented which is based on the following assumptions; ideal equation of state isentropic flow through a port conservation of mass polytropic thermodynamics single degree of freedom piston dynamics and energy equivalent linear damping. These differential equation can be solved through numerical integration using the fourth order Runge-Kutta method. An experimental study was conducted to validate the results obtained by the numerical integra-tion technique. Simulated results show good agreement with experimental data. The computer simulation model presented here has been extremely useful not only in understanding the has been extremely useful not only in understanding the basic cushioning but also in evaluating different designs.

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Experimental Study of Cushioning Pneumatic Cylinder with Meter In/Meter Out Control System (메타인 및 메타아웃 제어에 의한 공기압 실린더의 쿠션특성에 관한 실험적 연구)

  • 김동수;이상천
    • Journal of the Korean Society for Precision Engineering
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    • v.17 no.2
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    • pp.97-104
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    • 2000
  • Pneumatic cylinder is widely used for mechanical handling systems. Often, the impact occurs at the both ends points of pneumatic cylinder and generates destructive shock with in the structural operating members of the machine or equipment. To reduce the damage of system, therefore, shock absorbing devices are required. Cushioning of pneumatic cylinders at one or both ends of piston stroke is used to reduce the shock and vibration. The cylinder body have to withstand under high velocity and load. In this research, the pneumatic cushioning cylinder moving tests have been conducted for different load mass and supply pressure. The velocity of pneumatic cylinder actuation system with multiple orifice cushion sleeve which is set vertically controled with meter-in/out system. This study examines the dynamic characteristics of pneumatic cylinder with cushion devices. It turns out that the cushion pressure is mainly a function of the external load rather than the supply pressure. The cushion region characteristics was also revealed in the meter-in system.

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Analysis of Cushion Mechanism with Relief Valve for High-Speed Pneumatic Cylinders (고속 공기압 실린더용 릴리프밸브형 쿠션기구의 특성 해석)

  • Kim, Do-Tae;Zhang, Zhong Jie
    • Transactions of the Korean Society of Automotive Engineers
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    • v.18 no.3
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    • pp.95-103
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    • 2010
  • This paper presents a simulation model of a double-acting high-speed pneumatic cylinder with a relief valve type cushion mechanism. The model predicts piston motion, mass flow rate, pressure and temperature time histories of cushion chamber. Of interest here is to investigate the cushioning effect of varying the piston and piston-rod diameter, cushion ring diameter and length, and stoke in cushion mechanism. As a result, this cushion mechanism is found to be adequate under high-speed driving of pneumatic cylinders. The simulation model proposed here will be very useful to analyze the dynamic characteristics and to improve or design the better cushion mechanism in high-speed pneumatic cushion cylinders.

Driving Characteristics of Pneumatic Cylinder with Relief Valve Cushion Devices (릴리프밸브 쿠션기구 내장형 공기압 실린더의 구동 특성)

  • Kim, Do Tae
    • Journal of Drive and Control
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    • v.13 no.4
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    • pp.7-13
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    • 2016
  • This paper presents the meter-out and meter-in speed control characteristics of a pneumatic cylinder with relief valve type cushion device. The piston displacement and velocity are measured to investigate high speed driving performance with variation of the pressure setting in relief valve, air supply pressure, load mass, the supply and exhaust flow rate from the cylinder. Also, the internal pressures and temperatures driving pressure and cushion chamber are measured. The piston displacements and velocities of meter-out and meter-in control are compared experimentally determined data. A comparison experimental data meter-out and meter-in control show that a relief valve type cushion device is suitable for high speed pneumatic cylinders. The desired response characteristics of piston displacement and velocity are satisfactory adjust the pressure setting of a relief valve with varying system parameters such as air supply pressure, load mass and controlled flow rate.

A Study on the Meter-Out and Meter-In Speed Control Characteristics in Pneumatic Cushion Cylinders (공기압 쿠션 실린더의 미터아웃/미터인 속도제어 특성에 관한 연구)

  • Kim, Do-Tae
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.22 no.1
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    • pp.1-7
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    • 2013
  • Pneumatic cylinders are widely used to actuators in automatic equipments because they are relatively inexpensive, simple to install and maintain, offer robust design and operation, are available in a wide range of standard sizes and design alternatives. This paper presents a comparative study among the dynamic characteristics of meter-out and meter-in speed control of pneumatic cushion cylinders with a relief valve type cushion mechanism. Because of the nonlinear differential equations and a requirement for simultaneous iterative solution in a mathematical model of a double acting pneumatic cushion cylinder, a computer simulation is carried out to investigate pressure, temperature, mass flow rate in cushion chamber and displacement and velocity time histories of piston under various operating conditions. It is found that the piston velocity and pressure response in meter-in speed control are more oscillatory than with meter-out those when pneumatic cushion cylinders are driven at a high-speed. In meter-out speed control, the effective area of the flow control valve is larger than that of meter-in, and the supply pressure has to be much higher than the pressure required to move the load because it has also to overcome the back pressure in cushion chamber.

Comparison of Cushion Performance on Parameter Changes in High Speed Pneumatic Cylinder Driving System (공기압 실린더 고속 구동시스템에서 파라미터 변화에 따른 쿠션성능 비교)

  • Kim, Do Tae;Jang, Zhong Jie
    • Journal of Drive and Control
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    • v.12 no.4
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    • pp.54-59
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    • 2015
  • Due to the tendency to use high speed pneumatic cylinders to improve productivity, cushioning devices are adopted to decelerate the piston motion of pneumatic cylinders to reduce noise, vibration, and impact. This paper presents a comparison of the cushion characteristics of a high speed pneumatic cylinder with a relief valve type cushioning device. The system parameters selected are the damping coefficient, Coulomb friction, heat transfer coefficient, and cracking pressure of the relief valve in the air cushioning device. The integral of the time multiplied square error (ITSE) is used to quantitative measure the cushioning performance to assess the effect of varying these. The cushioning performance achieved good results when the ITSE is a minimum value. In a comparison of the piston displacement and velocity with the variations in system parameters, the heat transfer coefficients are not as significantly affected as the other. Also, the cracking pressure of the relief valve is mainly affected by the pressure and temperature in the cushion chamber.

A Study on the Design of a High-Speed Pneumatic Cushion Cylinder (고속 공기압 쿠션 실린더의 설계에 관한 연구)

  • Kim, Do-Tae;Kim, Dong-Soo;Ju, Min-Jin
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.18 no.5
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    • pp.491-497
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    • 2009
  • Of all of pneumatic components utilized in the make up of pneumatic circuits on either automatic assembly machine or industrial equipment, the pneumatic cylinder is more oriented toward being a structural as well as a pneumatic member. The structural design must be based to a large degree on the end of application of the cylinder on the equipment it is operating. In this paper, design studies of a double-acting pneumatic cushion type cylinder with low-friction and high-speed driving have been developed. Of interest here is to investigate the stress and strain analysis of cylinder tube, piston rod, end cover, and to analyze the buckling of piston rod. A finite element analysis is carried out to compute the distribution of the displacement, stress and safety factors by using ANSYS. As a result, the structural safety factors of each parts in pneumatic cushion cylinder are evaluated and confirmed at the design specifications.

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A Study on the Design of a Low-Friction, High-Speed Pneumatic Cylinder (저마찰 고속형 공기압 실린더의 설계에 관한 연구)

  • Kim, Do-Tae;Kim, Dong-Soo;Ju, Min-Jin
    • Proceedings of the KSME Conference
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    • 2008.11a
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    • pp.1230-1235
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    • 2008
  • Of all of pneumatic components utilized in the make up of pneumatic circuits on either automatic assembly machine or industrial equipment, the pneumatic cylinder is more oriented toward being a structural as well as a pneumatic member. The structural design must be based to a large degree on the end of application of the cylinder on the equipment it is operating. In this paper, design studies of a double-acting pneumatic cushion type cylinder with low-friction and high-speed driving have been developed. Of interest here is to investigate the structural analysis of cylinder tube, piston rod, end cover, and to analyze the buckling of piston rod. Also, a relief valve type cushion mechanism is considered. This cushion mechanism is found to be adequate under a high-speed driving of pneumatic cylinders.

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