• Title/Summary/Keyword: Metering valve

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A Study on the Flow Analysis According to Impeller Speed for City Water Supply Measuring Valve (상수도용 계량 밸브 임펠러 회전수에 따른 유동해석에 관한 연구)

  • Tea-Joon Kim;Chung-Seob Yi;Chi-Woo Lee
    • Journal of the Korean Society of Industry Convergence
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    • v.26 no.2_2
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    • pp.307-313
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    • 2023
  • This study conducts the flow analysis on the basis of the impeller RPM of water metering valve. The software used for the flow analysis is STAR-CCM+. In terms of the structure of the metering valve, it has an impeller installed inside, and a metering chamber has inlet and outlet holes. The flow analysis on the water metering valve drew the following conclusions: Regarding the flow field in the valve, the impeller had the highest velocity distribution, and complex flow field was generated in the metering chamber. In particular, since the path between the inlet and outlet holes in the metering chamber and the valve body was narrow, there was a section that had flow field interference. The flow rate and flow coefficient distribution according to the impeller RPM were on the linear increase. Given that, it showed the feature of the valve used for water metering on the basis of the impeller RPM.

A Study on the Development of Fuel Metering Unit for Air Breathing Engine (공기흡입식 추진기관용 연료조절밸브시스템 개발에 관한 연구)

  • Lee, Do-Yun;Choi, Hyun-Young;Park, Jong-Seung;Koo, Ja-Yoeng
    • Journal of the Korea Institute of Military Science and Technology
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    • v.8 no.4 s.23
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    • pp.152-158
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    • 2005
  • In this paper, we have proposed a fuel metering unit of ai breathing engine. The proposed valve system consists of a constant pressure drop valve and a metering valve, which are controlled by servovalve. We carried out nonlinear and linear analysis, computer simulation and experimentation to find effects of some factors on system performance. Analysis and experimental results show a good agreement. It is also shown that the system stability is affected by pressure drop of metering valve and inlet pressure of injectors.

A Study on the Oil Inertia Effect and Frequency Response Characteristics of a Servo Valve-Metering Cylinder System (서보밸브-미터링 실린더 시스템의 오일 관성효과와 주파수 응답 특성에 관한 연구)

  • Yun, Hongsik;Kim, SungDong
    • Journal of Drive and Control
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    • v.18 no.2
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    • pp.9-19
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    • 2021
  • The spool displacement signal of a directional control valve, including the servo valve, can be considered as the standard signal to measure dynamic characteristics. When the spool displacement signal is not available, the velocity signal of a metering cylinder piston can be used. In this study, the frequency response characteristics of the metering cylinder are investigated for the spool displacement input. The transfer functions of the servo valve-metering system are derived taking into consideration the oil inertia effect in the transmission lines. The theoretical results of the transfer functions are verified through computer simulations and experiments. The oil inertia effect in the transmission lines was found to have a very significant effect on the bandwidth frequency of the servo valve-metering cylinder system. In order to more precisely measure the dynamic characteristics of a servo valve, the metering cylinder should be set up to minimize the oil inertia effect by increasing the inner diameters of the transmission lines or shortening their lengths.

A Study on the Phase Bandwidth Frequency of a Directional Control Valve based on the Metering Orifice (미터링 오리피스를 이용한 방향제어밸브 위상각 대역폭 주파수 측정에 관한 연구)

  • Kim, Sungdong;Jeon, Sehyeong;Yun, Jooseop
    • Journal of Drive and Control
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    • v.15 no.1
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    • pp.1-9
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    • 2018
  • The spool displacement of directional control valve can be considered as the standard signal to measure the bandwidth frequency of a directional control valve. When the spool displacement is not available, the metering-orifice system is implemented in this research as an alternative way of measuring the 90 degrees phase bandwidth frequency of the hydraulic directional control valve. The inertia effect on the transmission line oil induces the phase lead of the valve load pressure when compared with the phase of spool displacement. The capacitance effect of the oil induces the phase lag of the valve load pressure. The phase of the load pressure can be adjusted to be the same as that of the spool displacement by controlling the opening area of the metering orifice. A series of experiments were conducted to verify the effectiveness of the metering orifice. The 90 degrees phase bandwidth frequency measured from the valve load pressure was significantly deviated in some cases from the frequency of the spool displacement. The metering orifice was hard to be applied to measure the -90 degrees phase bandwidth frequency of the high precision.

A Study on Stability Improvement of Fuel Metering Unit for Air Breathing Engine (공기흡입식 추진기관용 연료조절밸브 시스템 안정성 향상에 관한 연구)

  • 이도윤;박종승;최현영;구자용
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.34 no.9
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    • pp.76-81
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    • 2006
  • This paper deals with a fuel metering unit (referred to as FMU) for air breathing engine. The proposed FMU consists of a constant pressure drop valve and a metering valve, both of which are controlled by servovalve. Linear analysis derived from a nonlinear mathematical model of FMU is carried out to find major parameters on the system performance. Numerical results using established model of FMU were in good agreement with the experimental results. It is also shown that the system stability is improved by reducing the constant pressure drop at metering valve and applying the triangular orifice to constant-pressure-drop valve through the simulation and experiments.

A Study on the Frequency Response Signals of a Servo Valve (서보밸브의 주파수 응답 신호에 관한 연구)

  • Yun, Hongsik;Kim, SungDong
    • Journal of Drive and Control
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    • v.18 no.1
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    • pp.17-23
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    • 2021
  • The flow signal or spool position signal is used to determine the dynamic characteristics of directional control valves. Alternatively, the signal of spool position or flow can be replaced with the velocity of a low friction, low inertia actuator. In this study, the frequency response of the servo valve equipped with a spool position transducer is measured with a metering cylinder. The input signal, spool displacement, load pressure, and velocity of the metering cylinder are measured, and the theoretical results from the transfer function analysis are verified. The superposition rule for magnitude ratio and phase angle was found to be always applicable among any signal type, and it was found that the load pressure signal is not appropriate for use as the signal for measuring the frequency response of a servo valve. It was confirmed that the frequency response of a servo valve using metering cylinder was similar to the results from a spool displacement signal. The metering cylinder used for measuring the frequency response of a servo valve should be designed to have sufficiently greater bandwidth frequency than the bandwidth frequency of the servo valve.

A Study on the Bandwidth Frequency of Directional Control Valves based on the Amplitude of the Metering-Orifice Pressure (미터링 오리피스 압력 진폭을 이용한 방향제어밸브 대역폭 주파수에 관한 연구)

  • Kim, Sungdong;Jeon, Sehyeong;Shin, Daeyoung
    • Journal of Drive and Control
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    • v.14 no.2
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    • pp.1-8
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    • 2017
  • The spool displacement of a directional control valve can be considered as the standard signal for the measurement of its bandwidth frequency. When the spool displacement is not available, the metering-orifice system is suggested in this study as an alternative way to measure the - 3 dB amplitude-ratio bandwidth frequency of the hydraulic directional-control valve. The amplitude ratio of the metering-orifice pressure can be adjusted to equal that of the spool displacement through the controlling of the metering-orifice opening area. A series of experiments were conducted to verify the effectiveness of the metering-orifice system. The metering orifice was confirmed as adequate for the measurement of the - 3 dB amplitude-ratio bandwidth frequency.

Bucket Actuator Pressure Control by Independent Metering Valve for Excavator (독립제어 밸브에 의한 굴삭기 버켓 액추에이터 압력제어)

  • Yang, Joo-Ho;Jung, Tae-Rang
    • Journal of Power System Engineering
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    • v.20 no.3
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    • pp.36-42
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    • 2016
  • A cylinder control system of the conventional construction machine has been controlled by hydraulic spool valves. This system is low-cost but system efficiency is not high. Recently, to improve this, all valves are controlled electronically and independently. Bu and Yao suggested four way electronic hydraulic control valve system. It is called IMVT(Independent Metering Valve Technology). The purpose of the study is to find proper IMV pressure control method for excavator and to validate excavator's bucket regeneration energy effect by controlling the IMV system. In this paper, we mathematically describe the bucket system of excavator first. And then, based on these results, we design the control system which is divided into two operations(none regeneration or regeneration).The results of the experiment show the desirable performance and usefulness of the designed control system.