• International Journal of Automotive Technology
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• v.8 no.4
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• pp.429-436
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• 2007

In this study, we improved control performance of an EMV (electromechanical valve) system using a PM/EM (permanent magnet/electromagnet) hybrid EMA (electromagnetic actuator) and showed the feasibilities of both soft landing and fast transition of the EMV system using a simple PID control. The conventional EMV systems using only EM show significant nonlinear characteristics. Therefore, it is very difficult to control the valve position and several complex control schemes are used. This paper focused on the control performance improvement using a PM/EM hybrid actuator. In particular, a PM is used as a key design parameter such as a bias current of a magnetic bearing in order to improve the linear characteristic of the actuator, although most PM/EM hybrid actuators use a PM as a power saver during valve-open and -closed states. First, a FE (finite element) analysis was performed to confirm its linear static force characteristics. Then, both a test rig and a valve control system were built in order to prove experimentally the control performance improvement of the actuator. Finally, feasibilities of both soft landing and fast transition of the system were shown experimentally through gain-scheduled PID (proportional derivative integral) control.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.390-391
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• 2006

This paper describes the design, fabrication and characteristics of a micromachined piezoelectric valve utilizing a multilayer ceramic actuator (MCA). The micromachined MCA valve, which uses a buckling effect, consists of three separate structures: the MCA, the valve actuator die and the seat die. The valve seat die with 6 trenches was made, and the actuator die, which is driven by the MCA under optimized conditions, was also fabricated. After Si wafer direct bonding between the seat die and the actuator die, the MCA was also anodically bonded to the seat/actuator die structure. A polydimethylsiloxane (PDMS) sealing pad was fabricated to minimize the leak rate. Finally, the PDMS sealing pad was also bonded to the seat die and the stainless steel package. The MCA valve shows a flow rate of 9.13 sccm at an applied DC voltage of 100 V with a 50% duty cycle and a maximum non-linearity of 2.24% FS. Therefore, the fabricated MCA valve is suitable for a variety of flow control equipment, as a medical bio-system and in the automobile industry.

• Journal of Drive and Control
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• v.9 no.4
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• pp.14-18
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• 2012

Two kinds of piezoelectric actuator are applied to the valve for controlling the direction, the flow and the pressure of the fluid. One is a stack type piezoelectric actuator which has very fast response characteristics but very tiny displacement. The other is a bender type piezoelectric actuator which has also fast response characteristics but lower than the stack type one, and has longer displacement than the stack type one. So, the bender type piezoelectric actuator has advantage to apply to the valve for controlling a large amount of flow and fast on-off operating. In this study, the bender type piezoelectric pneumatic valve for color sorter is designed and fabricated. The new type high speed piezo valve with the both side supporting mechanism for high operating frequency and high reliability is discussed for separating the foreign body from the grains. Finally, the performance characteristics of a fabricated valve are analyzed and the frequency characteristics are also discussed for substituting the conventional type solenoid actuator.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.291-295
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• 2004

New valve driving system to control for the best volumetric efficiency at each load of an internal combustion engine within one engine cycle has been developed. The system needs to reduce pumping loss that cause by throttle valve during the intake valve is opened. In this system the intake valve is driven by a linear DC electromagnetic actuator which is controlled by personal computer. The result is compared both installed and uninstalled actuator into the cylinder head. By both of experimental and numerical calculation, the responsibility of the valve driving system to the engine speed was examined

• Transactions of The Korea Fluid Power Systems Society
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• v.2 no.3
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• pp.6-11
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• 2005

A household gas valve is used for flow control of LPG(Liquefied Petroleum Gas) or LNG(Liquefied Natural Gas) of which pressure is about $200mmH_2O(\fallingdotseq\;0.0196[bar])$. Currently, two kinds of valves such as rotary type and button type are widely used in many applications. But, these valves have some problems that they are not controllable and reliable. Piezo actuation combined with modem microelectronics provides a reliable, quiet, low energy, infinitely adjustable gas valve. In this paper, gas valve using piezo actuator which are bimorph and a circle type was studied. Also, Prototype for gas valve was manufactured and characteristics of the prototype gas valve were analyzed.

• Journal of Magnetics
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• v.21 no.1
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• pp.65-71
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• 2016

To increase the retaining force, a novel design for a concentric, bi-directional, electromagnetic valve actuator that contains double-layer permanent magnets is presented in this paper. To analyze the retaining-force change caused by the magnets, an equivalent magnetic circuit (EMC) model is established, while the EMC circuit of a double-layer permanent-magnet valve actuator (DLMVA) is also designed. Based on a 3D finite element method (FEM), the calculation model is built for the optimization of the key DLMVA parameters, and the valve-actuator optimization results are adopted for the improvement of the DLMVA design. A prototype actuator is manufactured, and the corresponding test results show that the actuator satisfies the requirements of a high retaining force under a volume limitation; furthermore, the design of the permanent magnets in the DLMVA allow for the attainment of both a high initial output force and a retaining force of more than 100 N.

• Journal of Power System Engineering
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• v.18 no.2
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• pp.31-36
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• 2014

In this paper, pneumatic valve which consists of valve body, valve controller, nozzle and a multi-bender PZT actuator was suggested and fabricated. The fabricated pneumatic valve was experimented for performance evaluation. From the experimental results, we know that the flow rate of the suggested valve is 23 lpm at the pressure difference of 1bar and the maximum flow rate is 30 lpm at the pressure difference of 4 bar. The flow rates after endurance test of 9.8 million were 22.57 lpm and 28.62 lpm at the pressure difference of 1bar and 4bar, respectably. Finally, it was verified that the B10 life of the suggested pneumatic valve is over 50 million.

• Journal of Power System Engineering
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• v.2 no.2
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• pp.60-66
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• 1998

Positioning performance with a normal pneumatic positioning system, is mainly affected by friction force on the actuator and nonlinear characteristics of the control valve. We proposed a positioning system which is composed of a pneumatic actuator and high speed control valve. for accurate and speedy positioning. Driving piston on the actuator is mounted with externally pressurized air bearings to clear the friction force. This paper studies a method in order that improves positioning ability of the pneumatic positioning system considering the nonlinear characteristics of the control valve and the actuator.

• Transactions of The Korea Fluid Power Systems Society
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• v.3 no.2
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• pp.1-6
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• 2006

The pressure regulator which is used for controlling the reducing pressure in the piezoelectrically driven pneumatic valve has been studied. The pneumatic valve of this study object is 2-stage type and consists of a piezoelectric actuator, a controller, a poppet valve and a pressure regulator. Nominal flow of 50 lpm, maximum operating pressure of 0.9MPa and frequency characteristic of 10Hz and over are required in this pneumatic valve, but the pressure regulator is needed because piezoelectric actuator has no ability to control the pressure of 0.9MPa directly. In this study, bimorph type PZT actuator of $25.2mm(L){\times}7.2mm(W){\times}0.5mm(H)$ with constant of $-220{\times}10-12$ CN-1 was proposed and investigated. Maximum operating force of 0.052 N and maximum displacement of $63{\mu}m$ were gotten from the fabricated PZT actuator. From the analysis results, the orifice diameter of 0.6mm for a piezoelectric actuator was derived and then the pressure regulator which can be operated under 0.15 MPa easily was designed and manufactured. Performance and effects of design parameters were simulated by the Simulink of Matlab software, and it was confirmed that the performance characteristics of manufactured pressure regulator are superior in the common use pressure range of 0.5 MPa to 0.7 MPa. The results show that the proposed pressure regulator is suitable for the pneumatic valve with a PZT actuator.

• Journal of international Conference on Electrical Machines and Systems
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• v.2 no.2
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• pp.239-245
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• 2013

Modern electric controlled valves are demanded that its solenoid actuator should be smaller size, lighter weight, lower consumption power, and higher response time. For achieving these purposes, the major design factors of solenoid actuator such as magnetic flux density, coil turn numbers, plunger size, bobbin dimension, and etc. are must be optimized. In this study, for optimal design of high speed solenoid actuator for hydraulic servo valve operation, we draw up governing equations which are composed by combination of electromagnetic theories and empirical knowledge, and deduct the values of major design factors by use of them. For more increase the operating speed, voice coil are used as main armature in manufacturing of prototype actuator. And, we have proven the propriety of the governing equations and speed increasing method by experiments using the hydraulic valve assembly adopted the prototype of solenoid actuator.