• International Journal of Fluid Machinery and Systems
• /
• v.9 no.1
• /
• pp.28-38
• /
• 2016

The flexible control system for hydraulic pile hammer using main control valve is present to the requirement of rapidly reversing with high frequency. To ensure the working reliability of hydraulic pile hammer, the reversing performance of the main control valve should commutate robustness to various interfere factors. Through simulation model built in Simulink/Stateflow and experiment, the effects of relative parameters to reverse performance of main control are analyzed and the main interfere factors for reversing performance are acquired. Treating reverse required time as design objects, some structure parameters as control factors, control pressure, input flow and gaps between spool and valve body as interfere factors, the robust design of the main control valve is done. The combination of factors with the strongest anti-jamming capability is acquired which ensured the reliability and anti-jamming capability of the main control valve. It also provides guidance on design and application of the main control valve used in large flow control with interferes.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.9 no.2
• /
• pp.6-11
• /
• 2010

For the purpose of reducing the energy consumption in the house heating, the various devices have been developed. One of these is to control the flow in the heat pipe and the flow control valve using shape memory alloy(SMA) spring is proposed in our study. The proposed house heating system is to save the gas consumption and the remote control system is designed for the convenience of using the proposed valve. The developed valve consists of SMA spring, disk, return spring, and regulation handle. The regulation handle is for supplying the additional hot water and is controlled by remote-control-motor. In order to design the remote control system, the Zigbee wireless communication protocol is used. The performance of the proposed valve structure is shown through the experimental result.

• Journal of ILASS-Korea
• /
• v.23 no.2
• /
• pp.58-65
• /
• 2018

An analytic strategy to control the variable valve actuation applied to two intake valves (flow port intake valve and swirl port intake valve) was performed in this study. we considered the variation in phasing of intake valve profiles by using the Cam-in-Cam technology. The analytic model was implemented in the GT-Power simulation program and analyzed the result of regulated emissions such as, NOx and Soot, especially with IMEP characteristics. Namely, we meticulously investigated the sources of having effect on the amount of NOx and soot formation under the test conditions with retard timing of both flow port and swirl port intake valves for decreasing the opening duration by 35CAD. Also, we analyzed the effect of incylinder pressure and temperature with NOx variations and in-cylinder pressure and temperature on NOx variations and normalized turbulent intensity. Through this analysis, some useful results on the combustion and flow characteristics of the swirl port and flow port control of the intake valve were obtained by this study.

• Journal of Drive and Control
• /
• v.13 no.4
• /
• pp.7-13
• /
• 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.

• Transactions of the Korean Society of Machine Tool Engineers
• /
• v.16 no.5
• /
• pp.41-47
• /
• 2007

The structure of ER valve is simple that its designing and manufacturing are easy. The flow rate and pressure of ER fluids flowing in the ER valve are controlled only by electric field. In this study a three port ER valve is designed and manufactured. Then, the flow rate and pressure dorp of ER fluids flowing in the ER valve are measured. The system proposed controls flow rate and pressure fast. So, this system can be easily substituted for the existing hydaulic and pneumaitc control system.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.21 no.5
• /
• pp.67-73
• /
• 2013

This experimental work described the effect of flow control valve type on the performance of wobble plate type fuel pump for the stable DME fuel supply. In order to study this, different four types of flow control valves (ITV, SCV, IMV and MPROP) were installed on the wobble plate fuel pump, and fuel flow rate, torque, and temperature variation of pump were investigated under various operating conditions by using pump performance test system. It was revealed that wobble plate type fuel pump worked well with ITV and SCV control valve, and the flow rate and torque of fuel pump was in proportion to the value of valve open duty. The maximum flow rate and torque of fuel pump were achieved around the 50% duty of control valve. Temperature variation at all pump measuring points were under $60^{\circ}C$ which is acceptable.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.8 no.1
• /
• pp.54-62
• /
• 2000

The purpose of this study is to bring out the optimal design factors which effect on dynamic characteristics in the design of flow control servo valve with high response characteristics, and to verify the validity of the design factors. In this study, force feedback type flow control valve with nozzle/flapper and with no drain is studied. And, the effect of the parameters, such as fixed orifice, nozzle diameter, and maximum displacement between nozzle and flapper are analyzed. We have done simulations using the optimal design factors and simulink(Matlab) as a simulation tool, and verified the validity of our simulations by means of comparison our simulation results with an experimental results of another similar valve.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.17 no.5
• /
• pp.515-520
• /
• 2004

We report on the development of a Piezoelectric valvc that is designed to have a high reliability for fluid control systems, such as mass flow control, transportation and chemical analysis. The valve was fabricated using a MCA(multilayer ceramic actuator), which has a low consumption power, high resolution and accurate control. The fabricated valve is composed of MCA, a valve actuator die and an seat die. The design of the actuator dic was done by FEM(finite element method) modeling, respectively. And, the valve seat die with 6 trenches was made. and the actuator die, which possible to optimize control to MCA, was fabricated. After Si-wafer direct bonding between the seat die and the actuator die, MCA was also anodic bonded to the scat/actuator die structure. PDMS(poly dimethylsiloxane) sealing pad was fabricated to minimize a leak-rate. It was also bonded to scat die and stainless steel package. The flow rate was 9.13 sccm at a supplied voltage of 100 V with a 50 % duty ratio and non-linearity was 2.24 % FS. From these results, the fabricated MCA valve is suitable for a variety of flow control equipments, a medical bio-system, semiconductor fabrication process, automobile and air transportation industry with low cost, batch recess and mass production.

• Journal of Drive and Control
• /
• v.17 no.4
• /
• pp.87-96
• /
• 2020

In this study, a variable elasticity spring was applied to improve the pressure control precision of conventional relief valves. The equilibrium equation of the forces acting on the valve poppet was derived; it is demonstrated that matching the elastic rate of the pressure-adjusting coil spring to the equivalent elastic rate of the flow force improved the pressure override. The procedures that were used to design the variable elasticity spring are presented, and some applications of the variable elasticity spring are also introduced. Computer simulations were used to analyze three cases: a poppet-closed flow force structure, a poppet-open flow force structure with a constant elasticity spring, and a structure containing a variable elasticity spring. It is confirmed that the pressure control precision of the relief valve can be significantly improved upon by applying a variable elasticity spring to the poppet-open flow force structure.

• Journal of the Korean Society of Industry Convergence
• /
• v.26 no.2_2
• /
• pp.307-313
• /
• 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.